IN THIS ISSUE: • Aberration Correction: Part One • All About

Transcription

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JAN/FEB 2009
IN THIS ISSUE:
• Aberration Correction: Part One
• All About Acanthamoeba
• Keeping Solutions Safe
• Lids & Lenses
and Effective
• No-Fee CE: Develop Your
Specialty Contact Lens Practice
SUPPLEMENT TO
JANUARY 2009
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Editorial
By Joseph P. Shovlin, O.D., F.A.A.O.
Keratoconus: Navigating the Maze
Practitioners must understand the entire disease process—its natural history, clinical
signs, corrective techniques and the emotional aspects involved.
he treatment of keratoconus and other noninflammatory thinning disorders presents many
robust challenges. Contact lens wearers with keratoconus need functional vision with adequate wearing
time and reasonable comfort. Each of these items has
the potential to greatly influence quality of life, but
when such a condition starts during adolescence, it
results in the ultimate challenge in contact lens practice.
The quality of life for people with keratoconus is
almost as dismal as it is for those afflicted with macular
degeneration.1 So, you should do all you can to understand the disease process and help improve the patient’s
quality of life.
T
aberrations.2 Also, patients may not be able to wear
them for adequate periods of time.
When standard lens therapies fail, a surgical
approach provides practitioners with additional alternatives for treatment. Over the years, Intacs (Addition
Technology) corneal ring segments and collagen crosslinking with UV light and riboflavin (C3R) have
received much attention. When all else fails, deep anterior lamellar keratoplasty (DALK) is an alternative to
penetrating keratoplasty. DALK allows for faster recovery, greater tectonic support, less risk for rejection, and
generally a better visual outcome with minimal refractive change.2
Natural History
Current and Future Research
The Collaborative Longitudinal Evaluation in Keratoconus (CLEK) study has shed a vast amount of light
on this condition. Perhaps the study’s most valuable
contributions are its general description of the course of
keratoconus and discussion of factors related to vision
and disease progression. Please visit the CLEK study
Web site (https://vrcc.wustl.edu/clekarchive) to become
familiar with the many publications generated from this
NIH-funded study. Progression is generally over a
decade or slightly longer in the majority of cases.1
Individuals with an early onset generally have more
advanced disease forms. In addition, they found more
males than females affected (55% male vs. 45%
female). The study also showed that more males than
females are affected.
We do know that there are molecular differences
between patients who have this disease and those who
don’t. For example, an Aquaporin 6 deficiency has been
discovered in keratoconus. These important water
channels play a major role in collagen matrix stability.
Interleukin-6, TNF-alpha, and matrix metalloproteinase-9 are over-expressed in the tears of patients with
keratoconus, indicating that its pathogenesis may
involve chronic inflammatory events.3 Hopefully, the
information gleaned from research will help us treat
and manage patients with ectasia and thinning disorders in the future.
Eye-care practitioners who navigate the maze of
treating keratoconus are not likely to make a significant
profit; it takes endless amounts of time to manage these
patients, and the cost of materials is high. Nonetheless,
caring for these patients will keep your practice interesting, and the pay-off is huge: an improved quality of
life for a group of patients who desperately need it, and
a tremendous sense of fulfillment for you.
New Treatment Options
Quality of life surveys showed that 18% of these
patients could not wear lenses to read at night, 10%
were unable to wear lenses for leisure, and 35% had to
undergo a “refit” within the past year.1 The disease can
be morbid; approximately 5,000 corneal transplants
are performed annually for keratoconus.1 Fortunately,
there are a host of new contact lens options, such as
large-diameter GP lenses like the Rose K 2 and several
quadrant-specific designs and new hybrid designs like
SynergEyes. Rigid lenses are the mainstay of corrective
lens therapy and the alternative to surgery for most,
but they may not provide the improvement in vision
that you expect due to uncorrected posterior corneal
RCCL
1. Zadnik K, Barr, JT, Edrington TB, et al. Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus Study. Invest Ophthalmol Vis Sci 1998 Dec;39(13):2537-46
2. Augenchirurgie. Available at: www.augenoperation.de/index.php/keraengl.html.(Accessed Dec
2008).
3. Lerna I, Duran JA. Inflammatory molecules in the tears of patients with keratoconus. Ophthalmology 2005 Apr;112(4):654-659.
Joseph P. Shovlin, O.D., F.A.A.O., Clinical Editor
REVIEW OF CORNEA & CONTACT LENSES | JAN/FEB 2009
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News Review
VOL. 146, NO. 1
IN THE NEWS
• In an approval review process
for new drug applications, the
U.S. Food and Drug Administration (FDA) Dermatologic and
Ophthalmic Drugs Advisory
Committee recommends approval
of Bausch & Lomb’s broad-spectrum, anti-infective drop, besifloxacin ophthalmic suspension
0.6%, for the treatment of bacterial conjunctivitis.
• CooperVision has revamped its
corporate website www.
CooperVision.com, updating
technology, content, design, navigation and other helpful features,
such as new search function and
new modules that allow practitioners to customize and manage
their online experience. From
account information to news feeds
from eye care-related websites,
practitioners will have the information they choose to be most
relevant right at their fingertips.
• SynergEyes, Inc., will launch
the SynergEyes Enrichment
Program, a new marketing initiative designed to help practitioners
grow their specialty contact lens
practices.The SynergEyes
Enrichment Program will include a
series of live lectures, interactive
Web trainings, and peer-to-peer
roundtable discussions, covering
practice management topics such
as increasing contact lens profitability, making a difference with
new technology, and implementing effective patient marketing
campaigns.
2
Soft Lenses and Myopia
Management
S
oft contact lens wear does not
result in clinically significant
acceleration in the development of nearsightedness in children
and does not cause relevant increases in axial length or corneal curvature, a new study shows. This part
of the Adolescent and Child Health
Initiative to Encourage Vision
Empowerment (ACHIEVE) Study
set out to compare the rate of
myopic progression of eight to 11year-old children randomly assigned
to wear single vision glasses or 1Day Acuvue soft contact lenses
(Vistakon) for three years.
According to the results, there is
no clinically meaningful difference
between the two forms of vision
correction for the treatment of
nearsightedness, a vision problem
experienced by approximately onethird of the population. The new
research further dispels a long held
notion that soft contact lenses
Ocular Nutrition
For the first time, EyeScience
Macular Health Formula and EyeScience Dry Eye Formula from EyeScience Labs will be available at
CVS Pharmacy stores nationwide.
EyeScience Macular Health Formula contains 14 nutrients to support a healthy retina, including
omega-3, lutein, zeaxanthin, bilberry, grape seed extract, selenium,
L-glutathione and alpha lipoic
acid. EyeScience Dry Eye Formula
is a nutritional supplement that
addresses the underlying causes of
increase myopia progression
(“Myopic Creep”) in children more
than other vision correction
options.
“Recent clinical studies have
demonstrated that contact lenses
provide a number of quality of life
benefits to children beyond simply
correcting their myopia,” says Jeffrey J. Walline, O.D., Ph.D., Ohio
State University College of Optometry and leader of the ACHIEVE
Study. “The combined body of
research should give both doctors
and parents greater confidence in
presenting children with the option
of contact lens wear when vision
correction is required.”
Findings from the multi-site
wearing trial study, appear in the
November issue of Investigative
Ophthalmology & Visual Science.
Walline JJ, Jones LA, Sinnott L, et al. A randomized trial of the
effect of soft contact lenses on myopia progression in children.
Invest Ophthalmol Vis Sci. 2008 Nov;49(11):4702-6.
dry eye syndrome. It contains a
proprietary blend of an omega-3
essential fatty acid, flaxseed oil,
lactoferrin, magnesium, and Vitamins B6, C and E.
For more information, go to
www.EyeScience.com.
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Jobson Medical Information LLC
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Telephone (610) 492-1000
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EDITORIAL STAFF
EDITOR-IN-CHIEF Amy Hellem
[email protected]
CLINICAL EDITOR Joseph P. Shovlin, O.D., F.A.A.O.
[email protected]
EXECUTIVE EDITOR Arthur B. Epstein, O.D., F.A.A.O.
[email protected]
ASSOCIATE CLINICAL EDITOR Ernie Bowling, O.D.,
F.A.A.O.
[email protected]
ASSOCIATE CLINICAL EDITOR Alan G. Kabat, O.D., F.A.A.O.
[email protected]
ASSOCIATE CLINICAL EDITOR Christine W. Sindt, O.D.,
F.A.A.O.
[email protected]
ASSOCIATE EDITOR Izabella Alpert
[email protected]
ASSOCIATE EDITOR Leah Addis
Ten Years of Top Performance
Polyquad and Aldox, the dual disinfectants in both the Opti-Free
RepleniSH and Opti-Free Express Multi-Purpose Disinfecting Solutions from Alcon, were first introduced as the disinfecting system in
the Opti-Free franchise in 1998. Over the past decade, Opti-Free
brands containing Polyquad/Aldox have performed extremely well in
the market. In fact, since launch, approximately 147 million soft contact lens wearers have used these solutions to care for their lenses.
Polyquad, like many single entity PHMB products, provides generally good coverage against bacteria, fungi, yeasts and molds.
ALDOX was added to increase coverage against fungi and provide
additional activity against Acanthamoeba cysts and trophs. the company says.
“Dual disinfection optimizes disinfection efficacy while minimizing
corneal staining,” explains David Meadows, Alcon’s vice president,
R&D, Consumer Products.
[email protected]
CONSULTING EDITOR Milton M. Hom, O.D., F.A.A.O.
[email protected]
CONSULTING EDITOR Stephen M. Cohen, O.D., F.A.A.O.
[email protected]
ART/PRODUCTION DIRECTOR Joe Morris
[email protected]
ART/PRODUCTION Alicia Cairns
[email protected]
AD PRODUCTION MANAGER Pete McMenamin
[email protected]
BUSINESS STAFF
PRESIDENT/PUBLISHER Richard D. Bay
[email protected]
SALES MANAGER, NORTHEAST,
MID ATLANTIC, OHIO James Henne
[email protected]
SALES MANAGER, SOUTHEAST,
WEST Michele Barrett
[email protected]
REGIONAL SALES MANAGER Kimberly McCarthy
[email protected]
EDITORIAL BOARD
Mark B. Abelson, M.D.
James V. Aquavella, M.D.
Edward S. Bennett, O.D.
Brian Chou, O.D.
S. Barry Eiden, O.D.
Gary Gerber, O.D.
Susan Gromacki, O.D.
Brien Holden, Ph.D.
Bruce Koffler, M.D.
Jeffrey Charles Krohn, O.D.
Kenneth A. Lebow, O.D.
Kelly Nichols, O.D.
Robert Ryan, O.D.
Jack Scheffer, O.D.
Kirk Smick, O.D.
Barry Weisman, O.D.
REVIEW BOARD
Kenneth Daniels, O.D.
Michael DePaolis, O.D.
Desmond Fonn, Dip. Optom. M. Optom.
Robert M. Grohe, O.D.
Patricia Keech, O.D.
Jerry Legerton, O.D.
Charles B. Slonim, M.D.
Mary Jo Stiegemeier, O.D.
Loretta B. Szczotka, O.D.
Michael A. Ward, F.C.L.S.A.
Barry M. Weiner, O.D.
Relief for Patients with Keratoconus
According to a survey by Addition Technology, Inc., 93% of the
time, Intacs help delay corneal transplantation for contact lens intolerant keratoconus patients. Of the 2,136 Intacs surgeries performed
between August 2004 and April 2008, 584 patients were specifically
identified as having keratoconus. Forty-one later received transplants, which amounted to 1.9% of all procedures performed.
The survey also asked surgeons the reason for performing a transplant following the removal of Intacs. In less than 1% of all cases
performed, the patients didn’t receive a satisfactory visual effect after
Intacs. Surgeons also indicated that they didn’t envision any difficulties with performing a corneal transplant post Intacs removal.
“We are very satisfied with the survey results, which support our
view that Intacs are a standard of care for keratoconic patients who
are contact lens intolerant,” said William M. Flynn, president and
chief executive officer of Addition Technology. “We are also grateful
to the surgeons who responded to this survey; their feedback helps
us assess the benefits Intacs offer’s patients and provides valuable
insights on where to extend our technology.”
According to recent Eye Bank Association of America data, there
are approximately 4,700 to 4,800 corneal transplants performed in
the U.S. annually for keratoconus. Intacs are approved for the reduction of myopia and astigmatism in patients who suffer from keratoconus, who are contact lens intolerant, have clear corneas, and
where a corneal transplant is imminent and may be potentially
deferred. Prior to Intacs, a corneal transplant was the only option
for contact lens intolerant keratoconus patients.
Advertiser Index
Art Optical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cover 4
Benz Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cover 2
3
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contents
Review of Cornea & Contact Lenses Jan/Feb 2009
ON THE COVER
18 Keeping Solutions Safe and Effective
A look at current test procedures, what the FDA-commissioned
Ophthalmic Devices Panel has recommended and what is
planned for the future.
Susan J. Gromacki, O.D., M.S., F.A.A.O.
15 All About
Acanthamoeba
In this virtual roundtable, clinicians
discuss how to detect, treat and help
patients avoid this vision-threatening
keratitis.
H. Dwight Cavanagh, M.D., Ph.D.,
Joseph P. Shovlin, O.D., F.A.A.O.,
and Christine W. Sindt, O.D., F.A.A.O.
Depar t ments
1
Keratoconus: Navigating the Maze
Joseph P. Shovlin, O.D., F.A.A.O.
2
5
Part One
27 No-Fee CE: Develop
Your Specialty Contact
Lens Practice
By utilizing newer lens technologies and
understanding the benefits they can offer,
the practitioner will keep patients happy
and realize significant practice benefits.
Mile Brujic, O.D.
35 Lids and Lenses
Here is what you need to look for to
ensure proper eyelid analysis,
diagnosis and appropriate therapy.
Katherine M. Mastrota, M.S., O.D.,
F.A.A.O.
News Review
Guest Editorial
Interferometry and Dysfunctional
Tear Syndrome
Ashley Behrens, M.D.
23 Aberration Correction:
By applying today’s technology to an old
science, we can offer patients a chance
at acuity previously unattainable.
Pete S. Kollbaum, O.D., Ph.D.,
F.A.A.O.
Editorial
7
Down on the Pharm
A New Anti-Infective
Ernie Bowling, O.D., M.S., F.A.A.O., Dipl.
8
Out of the Box
Out with the Old
Gary Gerber, O.D.
10
Derail Dropouts
Compliance in the New Year
Mile Brujic, O.D., and Jason Miller,
O.D., M.B.A.
12
Lens Care Update
A New Dry Eye Therapy?
Christine W. Sindt, O.D., F.A.A.O.
13
Gas-Permeable Strategies
Mystery Solved!
John M. Rinehart, O.D., F.A.A.O.
14
Naked Eye
Sjögren’s Syndrome and Dry Eye
Mark B. Abelson, M.D., C.M.,
F.R.C.S.C., and Dan Dewey-Mattia
4
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Guest Editorial
By Ashley Behrens, M.D.
Interferometry and Dysfunctional
Tear Syndrome
This technology accurately measures tear film parameters, which may answer
questions about the various disorders of the ocular surface.
D
ysfunctional Tear Syndrome (DTS) is a common
ailment of the ocular surface. It affects 14% of
the adult population in the U.S.1 Although several etiologic classifications for this disease have been
proposed, recent research has been directed toward a
“tear quality” problem as the major player in the
pathophysiology of the syndrome.
One of the problems that clinicians and researchers
confront in DTS is the lack of uniform criteria to determine what are “normal” parameters of the tear film. In
all published categorizations of DTS, there is a certain
subjectivity present when assessing these parameters
and staging the disease. The lack of standardized,
objective methods to confidently assign a particular
severity level of DTS has been a major barrier in performing comparisons in systematic reviews of randomized controlled clinical trials. In previous panels of
experts, specialists tend to rely more on the symptoms
of the disease, while others tend to rely on clinical signs,
and still others stress the importance of “tests,” such as
Schirmer and tear break-up time (TBUT).2,3 Unfortunately, it is difficult to find a reliable range of parameters due to the low correlation between tests,
symptoms, and signs.
interferometry. CM has an excellent resolution in a contact mode, but the objective’s power should be considerably reduced to be used in a non-contact fashion,
affecting the final resolution (>1µm).4 OCT has similar
limitations, with resolutions close to 10µm and ultrahigh resolution capabilities in the vicinity of 3µm.5,6
Interferometry seems to be the ideal method to evaluate
tear film thickness with sub-micron resolutions (0.3µm
to 0.5µm). In addition, interferometry may scan a wide
field of the corneal surface.7
Composition and Thickness
The Interferometry Difference
The tear film is possibly one of the most important
components of the ocular surface and a major determinant of problems related to DTS. Tear film composition
and thickness are objective values that may reveal crucial information regarding the health of the eye’s surface. The lack of methods that consistently image and
measure the tear film thickness has guided researchers
to evaluate more sophisticated technologies. An ideal
approach to measuring tear film thickness should be
non-contact and non-invasive, in order to avoid disturbances that may trigger reflex responses, which could
change the basal properties of the unperturbed tear
film. Thickness and composition all over the corneal
surface are parameters that may correlate with signs
and symptoms of DTS. Potential candidates in the list
of available technologies are confocal microscopy
(CM), optical coherence tomography (OCT) and
Published studies have shown high variability in the
mean values of normal tear film thickness.7,9 These discrepancies are related in great part to the methods used
and the difficulties in achieving an accurate measurement of such a thin layer. Due to the higher resolution
of this instrument, an interferometric analysis is more
appropriate in detecting minor changes. Interference
patterns may also detect changes in the composition of
the different layers of the tear film, especially the lipid
layer, in various topographical areas of the ocular surface to determine regional defects of the tear film. In
addition, there is the possibility of analyzing the
changes associated with blinking in real time, which
is extremely difficult to assess with other available
technologies.
One of the most important benefits that interferometry may provide to clinicians is the possibility of
Technology at Work
The optical principle of interferometry relies on the
reflection of the general hue of light through interference patterns. Hue and saturation are functions of the
transparent layer causing the interference—in this case,
the tear film. A single ray emerging from the light
source of the instrument is reflected on two different
surfaces, creating two rays. The interference phenomena should be observed by specular reflection that comes
from the tear film. The generation of thin film interference derives from each incident light that is reflected by
the film—one from the surface of the tears and another
from the layer in contact with the cornea.8
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imaging the effects of different environmental conditions in tear film quality. One study used tear lipid
interferometry to analyze the effects of smoking in tear
film lipid layer spread times, and the researcher found a
highly significant difference between chronic smokers
and non-smokers.10 They found that smokers had a significantly reduced spread time and multiple premature
breaks in the lipid layer.10
Clinical Trials
Other important use of tear film interferometry is
the detection of immediate, mid- and long-term
response to various therapeutic alternatives. Most of
the available prototypes include video capabilities to
allow real-time assessment of the data. Goto and associates reported the results of a study on the use of an
antibiotic ointment for two weeks to improve the lipid
layer in the tear film of thirty patients with lipid deficiency.11 They were able to demonstrate a significant
increase of the tear lipid layer, from 39nm ± 4nm to
161nm ± 91nm, after two weeks of treatment, which
correlated well to a significant improvement in symptoms (decrease from 91.4 ± 11.9 to 33.6 ± 21.0 in
symptoms score questionnaire) and signs/tests (fluorescein staining and tear break-up time).11 In a study
comparing the effects of two lubricants in the lipid
layer thickness, researchers were able to show significant differences using a metastable oil-in-water emulsion vs. hydroxypropyl guar.12 In this report, the
effects of the instilled drops in short-term tear film
lipid layer thickness were analyzed at different time
points using interferometry. Forty patients were selected for the study, and eyes were randomized for the use
of one different eye drop in each eye. The oil-in-water
emulsion was able to double the lipid layer thickness
when compared to hydroxypropyl guar in their series
at all time points recorded.12
In patients who had undergone keratorefractive procedures, tear film lipid layer thickness assessed by interferometry is an important parameter to measure. An
example of this is a study that evaluated a group of 46
patients, of which 22 underwent laser in situ keratomileusis (LASIK). At 14 weeks postoperatively, the
mean tear film lipid layer thickness was significantly
thinner in the LASIK group (p=0.032), which may be
associated with the DTS symptoms frequently reported
6
REVIEW OF CORNEA AND CONTACT LENSES JAN/FEB 2009
after this type of surgery.13
A New Horizon
As demonstrated by presented evidence, tear film
thickness assessed by interferometry appears to be a
sensitive factor in detecting ocular surface changes associated with DTS. One of the major challenges of this
recently “reborn” technology is the standardization of
the different instruments available worldwide. Since
most of the published studies have used prototypes or
modified devices to detect interference, the standards
used may vary between apparatuses. On the other
hand, most of the reports in the literature are based on
small sample sizes, which may not be representative of
the general population and may induce bias in the
analysis of the data. For this reason, the lack of consistent interferometry results to correlate with signs and
symptoms of DTS in large population studies is hindering the popularization of this approach in clinical trials.
But, with the renewed interest in research and development of this technology in the last decade, we might
witness the beginning of the first objective method to
stage DTS for further therapeutic guidance.
RCCL
Dr. Behrens is Assistant Professor of Ophthalmology at the
Wilmer Eye Institute and Johns Hopkins University School of
Medicine, Baltimore, Md. Contact him at [email protected].
1. Schein OD, Muñoz B, Tielsch JM, et al. Prevalence of dry eye among the elderly. Am J Ophthalmol
1997;124:723-8.
2. DEWS International Panel. Methodologies to diagnose and monitor dry eye disease: report of the
Diagnostic Methodology Subcommittee of the International Dry Eye WorkShop (2007). Ocul Surf 2007
Apr;5(2):108-52.
3. Behrens A, Doyle JJ, Stern L, et al. Dysfunctional tear syndrome study group. Dysfunctional tear
syndrome: a Delphi approach to treatment recommendations. Cornea 2006 Sep;25:900-7.
4. Böhnke M, Masters BR. Confocal microscopy of the cornea. Prog Retin Eye Res 1999
Sep;18(5):553-628.
5. Wang J, Fonn D, Simpson TL, Jones L. Precorneal and pre- and postlens tear film thickness measured indirectly with optical coherence tomography. Invest Ophthalmol Vis Sci 2003 Jun;44:2524-8.
6. Hermann B, Fernández EJ, Unterhuber A, et al. Adaptive-optics ultrahigh-resolution optical coherence tomography. Opt Lett 2004 Sep;15;29(18):2142-4.
7. King-Smith PE, Fink BA, Nichols JJ, et al. Interferometric imaging of the full thickness of the precorneal tear film. J Opt Soc Am A Opt Image Sci Vi. 2006 Sep;23(9):2097-104.
8. Doane MG, Lee ME. Tear film interferometry as a diagnostic tool for evaluating normal and dry-eye
tear film. Adv Exp Med Biol 1998;438:297-303.
9. Prydal JI, Campbell FW. Study of precorneal tear film thickness and structure by interferometry and
confocal microscopy. Invest Ophthalmol Vis Sci 1992 May;33(6):1996-2005.
10. Matsumoto Y, Dogru M, Goto E, et al. Alterations of the tear film and ocular surface health in
chronic smokers. Eye 2008 Jul;22(7):961-8.
11. Goto E, Dogru M, Fukagawa K, et al. Successful tear lipid layer treatment for refractory dry eye in
office workers by low-dose lipid application on the full-length eyelid margin. Am J Ophthalmol 2006
Aug;142(2):264-70.
12. Korb DR, Scaffidi RC, Greiner JV, et al. The effect of two novel lubricant eye drops on tear film lipid
layer thickness in subjects with dry eye symptoms. Optom Vis Sci 2005 Jul;82(7):594-601.
13. Patel S, Pérez-Santonja JJ, Alió JL, Murphy PJ. Corneal sensitivity and some properties of the
tear film after laser in situ keratomileusis. J Refract Surg 2001 Jan-Feb;17(1):17-24.
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Down on the Pharm
By Ernie Bowling, O.D., M.S., F.A.A.O. Dipl.
A New Anti-Infective
This antibiotic helps treat bacterial infections and lid disease with as little as nine
drops, over a five-day period.
E
very eye-care practitioner has
encountered bacterial conjunctivitis. The condition is
quite common, but fortunately the
infections are usually self-limiting.
Most cases of bacterial conjunctivitis in both adults and children can
benefit from topical anti-infective
therapy, which shortens the course
of the disease, prevents reinfection
and reduces the risk of complications. New ocular antibiotics are
constantly needed to keep pace with
the increasing incidence of bacterial
resistance and to provide options
that allow a decrease in dosing regimens, with the ultimate goal of
improving patient compliance.
Azithromycin
Azithromycin is a macrolideclass anti-infective that is synthesized from erythromycin and
possesses a well-known safety and
tolerability profile in both its oral
and intravenous forms.1,2 The medication is widely used to treat soft
tissue infections. In eye care,
azithromycin is used in its oral
form to treat chlamydia infections.3
Azithromycin has the unique quality of achieving extremely high concentrations in tissues, and it has a
long elimination half-life—both of
these properties have been found to
translate to the eye.4,5
Clinical Use
AzaSite (azithromycin ophthalmic solution 1%, Inspire) was
approved by the U.S. Food and
Drug Administration (FDA) for the
treatment of bacterial conjunctivitis. The azithromycin is compounded in a vehicle called DuraSite, a
gel-forming polymer of polyacrylic
acid. DuraSite allows azithromycin
to be formulated in liquid form
and also increases the drug's contact time, which could potentially
increase drug tissue concentrations
in the eye.6 Because the tissue concentration is so high, dosing is
reduced. The entire treatment regimen for bacterial conjunctivitis
consists of two drops the first day,
two drops the second day, and one
drop the following five days, which
adds up to nine drops. Reports by
the manufacturer cite a clinical
improvement in 94% of bacterial
conjunctivitis patients by day three
and a favorable safety profile in
patients at least a year old.7
A growing number of eye-care
practitioners are finding a role for
AzaSite in treating lid margin disease. Erythromycin ointment is
widely used in the treatment of
anterior or posterior blepharitis;
and azithromycin, belonging to the
same macrolide class of drugs, has
a similar spectrum of activity. The
anti-inflammatory properties of
macrolide antibiotics have been
recognized for over 20 years.8
Macrolides have been shown to
affect several inflammatory pathways, including neutrophil migration and the production of
proinflammatory cytokines.9
Recent studies indicate that
azithromycin suppresses matrix
metalloproteinases, with effects
similar to doxycycline in human
and animal ocular tissue.10 Because
of the anti-inflammatory effects of
azithromycin, many doctors recommend AzaSite to patients with
meibomian gland dysfunction,
blepharitis and rosacea.11 A recent
randomized study found that combining AzaSite with warm compresses may help treat patients with
posterior blepharitis significantly
better than using warm compresses
alone. Patients using AzaSite in
conjunction with warm compresses
had significantly more improvement in meibomian gland plugging,
meibomian gland secretions and
eyelid redness than patients who
used warm compresses alone.12
A Welcome Addition
For patients who suffer from
bacterial conjunctivitis or lid margin disease, we have a new therapeutic ally. With its broad spectrum
of antimicrobial activity and
reduced dosing profile, AzaSite
plays an important role in our antiinfective arsenal. RCCL
1. Pfizer. Zithromax. Package Insert. (Oct 2008).
2. Pfizer. Zithromax for IV infusion only. Package insert. (Oct
2008).
3. Solomon AW, Holland MJ, Alexander ND, et al. Mass treatment with single dose azithromycin for trachoma. N Engl J Med
2004 Nov 4;351(19):1962-71.
4. Piscitelli SC, Danzinger LH, Rodvold KA. Clarithromycin and
azithromycin: new macrolide antibiotics. Clin Pharm 1992
Feb;11(2):137-52.
5. Kuehne JJ, Yu AL, Holland GN, et al. Corneal pharmacokinetics of topically applied azithromycin and clarithromycin. Am J
Ophthalmol 2004 Oct;138(4):547-53.
6. Expert explains latest advances in ophthalmic antibiotics. Ocular Surgery News 10/25/2008.
7. Manufacturer Web site. Inspire Pharmaceuticals. Available at:
www.AzaSite.com. (Accessed Oct 2008).
8. Scaglione F, Rossoni G. Comparative anti-inflammatory effects
of roxithromycin, azithromycin, and clarithromycin. J Antimicrob
Chemo 1998 Mar;41 Suppl B:47-50.
9. Ianaro A, Ialenti A, Maffia P, et al. Anti-inflammatory activity of
macrolide antibiotics. J Pharmacol Exp Therapeutics 2003
Jul;64(1):85-93.
10. Jacot JL, Jacot TA, Sheppard JD, et al. Evaluation of MMP
2/9 modulation by AzaSite and durasite in human corneal epithelial cells and bovine corneal endothelial cells in vitro. Poster presented at ARVO, 2008.
11. Caceres V. A new possibility for lid margin treatment. EyeWorld 2008 Oct;6(10):42.
12. Luchs J. Efficacy of topical azithromycin ophthalmic solution
1% in the treatment of posterior blepharitis. AdvTher 2008;25(9):
858-870.
7
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Out of the Box
By Gary Gerber, O.D.
Out with the Old
Learn how to present new-generation lenses to your patients, regardless of the
price tag.
O
ver the last few years, I've
done a lot of speaking and
consulting in Europe, and
in discussions with practitioners,
I've learned that their training is
less extensive than our training
here in the U.S., particularly in
the medical area. Unlike the United States, while a smaller percentage of European patients needing
vision correction wear contact
lenses, the majority of those
patients who DO wear lenses are
wearing daily disposable and silicone hydrogel lenses. So, while
the uptake of lenses overall has
been slow, the usage of newer
lenses is not. As it turns out, this
phenomenon is common in many
other countries, as well. This
observation begs the question,
“Why do we fit so many more
patients in contact lenses, yet use
older technology lenses?”
comment. But, it’s accurate. Perhaps
due to less intensive pathology
detection and treatment training,
these practitioners may take the
path of least resistance in an
attempt to avoid problems.
The Issue of Price
So, is our higher level of training
getting in the way of moving forward and embracing newer materials and modalities? Surely, we can’t
be fitting older modalities because
we have the skill to deal with the
extra problems they might cause!
That would be like a highly skilled
heart surgeon saying, “I’m so good
at what I do that I’ll use an archaic
pacemaker with a higher chance of
failure, because if it does fail, I
know I can fix it!”
where the average sale of a pair of
glasses is higher than it is here in
the U.S. and more often includes
premium products like anti-reflective technology and newer progressive lens designs.
Foreign practitioners do not
stumble and fumble over price discussions with their patients like U.S.
practitioners do. In fact, many of
them charge little or no professional
fees—only product fees. That’s a
discussion for another column, but
the point is, the higher price of
newer lenses is readily discussed
with patients. In fact, lesser quality,
older technology lenses are typically
not even mentioned during patient
encounters. There is rarely a choice
given to the patient. Instead, as I
believe things should be here,
patients are guided by the practitioner’s clinical judgment regarding
what is best for the patient.
The Path of Least Resistance
Take a Chance
Some have suggested our higher
level of training might be the root
cause of this phenomenon. During
my recent trip to Italy, this topic
came up with several Italian contact
lens company reps. Considering all
our education, you would think
that we would lean toward fitting
newer lenses, which are generally
regarded as healthier and safer.
My discussions with European
contact lens practitioners points to
health and safety as the key reasons
for choosing newer types of lenses.
Comments like, “Gary, daily disposable lenses are essentially problem-free and so easy to fit. So, why
fit anything else?” are common.
Admittedly, that’s a simplistic
Perhaps the conditioning that
comes with selling higher-end eyeglasses is at the core of their ease
with contact lens pricing discussions. And, maybe this conditioning, when coupled with the desire
to avoid corneal complications, is
the reason for their success in using
a higher percentage of newer technology lenses. Regardless of the
reason for their comfort with fee
discussions, there are two important lessons for us to learn from the
success of our foreign colleagues.
First, when given a chance to try
new technology lenses, patients will
indeed choose them. Second, the
price of lenses should not serve as
an impediment.
8
No, I don’t think we would risk
our patients’ ocular health by
deploying that sort of convoluted
logic. So, while lesser training may
be the reason for more high-tech
lens dispensing in Europe, I hope
more training won’t account for less
usage here.
Rather, our reluctance hinges on
the economics of the equation,
which apparently isn’t an impediment for our colleagues abroad.
This is certainly true with eyeglasses,
RCCL
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Derail Dropouts
By Mile Brujic, O.D., and Jason Miller, O.D., M.B.A.
Compliance in the New Year
Comfortable, healthy contact lens wear is based on many factors, including the lens
material, the care solutions and our patients’ compliance habits.
C
ontact lenses have guidelines for optimal wear, and
lack of compliance with
these guidelines can have detrimental effects on the ocular health
of the patient, threatening comfortable contact lens wear. We will
look at compliance as it relates to
the modality of wear and prescribed care regimens and learn
how to mitigate the effects of noncompliance on successful contact
lens wear.
Modality
Modality is an important topic
to address, because patients who
do not comply with their wear
schedule often have comfort issues
that affect their lens wearing experience. The key here is to listen to
your patients and understand what
they are looking for in a contact
lens. For example, patients who
wear glasses most of the time but
prefer to wear contact lenses when
they play hockey three times a
week would be poorly served by
being fit with a pair of two-week
or monthly-replacement lenses—
try daily disposable lenses instead.
The irregularity of such patients’
wearing schedules would make it
difficult to keep track of the age of
the lenses and would unintentionally force non-compliance.
Try to avoid fitting the same
type or modality of contact lens on
every patient. Individualize your
contact lens prescribing habits to
best meet each patient’s lifestyle
and to maximize compliance. We
all have our favorite lens, but it’s
best to make specific recommendations based on patient preferences,
which will ultimately lead to
improved compliance.
Contact Lens Care Systems
Just as important as the replacement schedule is the cleaning and
care of contact lenses. The unfortunate reality is that there is significant room for increasing our
patients’ compliance levels. Ralph
Stone, Ph.D., presented a paper at
the British Contact Lens Association meeting in 2007 that looked
at compliance rates over a number
of steps. Dr. Stone reported that
more than 44% of patients always
or occasionally top off or re-use
their contact lens solution, that
35% of patients do not wash their
hands before handling their lenses, and that only 25% of patients
report rinsing their contact lenses
before lens storage.1
Even if they do rinse the contact lens, odds are, they are not
performing the step as recommended by the manufacturer.
There are currently five care systems that currently have “no rub”
approval: AQuify (CIBA Vision),
Complete Easy Rub (AMO),
Renu MultiPlus (Bausch &
Lomb), Opti-Free Express (Alcon)
and Opti-Free RepleniSH (Alcon).
Under the “no rub” instructions
on each of the package inserts for
all of the products described, the
rinse cycle is five seconds per side
(except for Complete Easy Rub,
which is packaged and marketed
as requiring a 10-second rub
before rinsing the lens). It is very
rare that this level of compliance
occurs when patients do utilize
these solutions and do not rub
their contact lenses. It is important for those who utilize care
systems to be constantly re-educated on the specifics of their care
regimen. We recommend rubbing
and rinsing as important steps for
comfortable contact lens wear.
Compliance and Your
Practice
The inside of a contact lens case utilized by a patient who routinely “topped off” his
solution (left). The photo on the right shows lens deposits in the eye of a patient who
wore two-week replacement contact lenses for two months.
10
REVIEW OF CORNEA AND CONTACT LENSES | JAN/FEB 2009
Complying with prescribed contact lens replacement schedules is
important for health reasons, but
also to maximize comfort. We
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Derail Dropouts
Table 1.
Patient #1
Patient #2
Patient #3
Cost Per Box
$20.00
$20.00
$20.00
Selling Price Per Box
$30.00
$30.00
$30.00
Boxes Per Year
8 (6) Packs
4 (6) Packs
2 (6) Packs
Profit Per Year
$80.00
$40.00
$20.00
have all seen patients who have a
significant number of deposits on
their contact lenses; this presentation is directly related to “stretching out” the wearing schedule. If
we can eliminate these habits, we
will increase the patient’s chance
of comfortable, healthy contact
lens wear.
Additionally, non-compliance
with prescribed wearing regimens
will directly affect the profitability
of your practice. Let’s take three
patients, all of whom wear twoweek disposable contact lenses,
and analyze the effect that various
levels of compliance bear on practice profitability. Consider patient
number one, who replaces his contact lenses twice a month as prescribed; patient number two, who
replaces his lenses every month;
and patient number three, who
replaces his lenses every two
months. The profitability will be
directly related to the level of compliance. Table 1 summarizes the
three patient scenarios discussed:
This is a clear example of how
prescribing and reinforcing a
replacement schedule that is in the
patient’s best interest will ultimately lead to what’s in the best
interest of the practice. Increase
patient compliance with replacement schedules by encouraging
the purchase of a one-year supply
of contact lenses. Usually this type
of purchase will be accompanied
with some form of mail-in rebate
that will also financially benefit
the patient.
A New Year’s Resolution
Practitioners must take time
during every visit to constantly reeducate lens wearers on the
specifics of their care regimen.
What we typically do with all of
our contact lens wearers is ask
them to describe the way they care
for their contact lens in a step by
step manner, and then re-educate
them as needed, spending extra
time on those steps that are being
performed incorrectly. Patients are
usually very receptive and willing
to modify those steps that are not
being carried out properly.
A Case in Point
“Samantha,” a 38-year-old
patient new to our practice, has
been wearing contact lenses for
many years, but she recently
noticed a decrease in near focusing. She attributes this to many
hours spent on the computer. She
typically changes her contact lenses once monthly, even though she
admitted they were prescribed as
two-week lenses. She stated that
she can “usually tell when to
change them, based on how they
feel.” Samantha also stated that
she never rubs her lenses, and that
she uses the store brand multipurpose solution for cleaning and
storage. After her new prescription was determined, we discussed
the many types of contact lenses
available and determined that
based on her habits, monthly disposable contact lenses matched
her lifestyle best. She was refit in
a contact lens in the monthly
modality category. Her care system was changed to improve compatibility, and dry eye treatment
was initiated due to her high computer use. Samantha realized relatively quickly how comfortable
her wearing experience could be.
She currently wears her contact
lenses more successfully due to the
simple steps that were taken to
increase her level of compliance
with her contact lens wear and
care regimen.
RCCL
1. Stone R. The importance of compliance: Focusing on the
key steps. Poster. Presented at BCLA, May 2007, Manchester, UK.
11
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Lens Care Update
By Christine W. Sindt, O.D., F.A.A.O.
A New Dry Eye Therapy?
Could hyaluronic acid be instrumental in the treatment of dry eye?
F
or decades, ophthalmologists
have used sodium hyaluronate extensively in
cataract surgery, glaucoma filtration surgery, corneal transplantation, vitreous substitution and
retinal attachment surgery. Orthopedists regularly utilize it in intraarticular treatment for
osteoarthritis of the knee.
Sodium hyaluronate is also
becoming increasingly popular for
the treatment of dry eye.
Where It’s Found and How
It’s Used
Clinical Data
Sodium hyaluronate has been
shown to protect the corneal epithelium from dryness and promote
epithelial healing.1-5 It holds water
like a sponge and slowly releases it
to the epithelium. It has been studied as a dry eye tear therapy since
the mid 1980s, but in recent years,
a number of randomized, doubleblind, multi-centered, crossover
clinical trials involving 0.1% to
0.4% sodium hyaluronate have
found statistically significant
improvement in subjective symptoms, slit lamp examination findings and bulbar impression cytology
in patients with moderate to severe
dry eyes.1-5 In all cases, the study
medication was well tolerated and
no adverse events were reported.1-5
The molecular structure of sodium hyaluronate provides a unique
ability to change viscosity with the
blink. When the eye is open, the
molecule is highly coiled and viscous; it resists drainage and reduces
tear film break-up time. By remaining on the eye and contact lens, it
protects and hydrates the epithelium. When the lid is closed, lid friction and pressure uncoil the
molecule. This lowers the viscosity,
making the solution more spreadable, promoting a smooth blink.
After the blink is complete, the molecule recoils and viscosity again
increases, mimicking the behavior
of the body’s natural tears.
On the Horizon
Current sodium hyaluronate
lubrication drops, such as AQuify
Drops (CIBA Vision) and Blink
(Advanced Medical Optics), are
marketed as contact lens lubrication
drops. Blink Tears (AMO) also
combines sodium hyaluronate with
polyethylene glycol 400, an FDAapproved dry eye ingredient, to
market as a dry eye lubricant for
non-contact lens wearers. Current
research studies are looking into
combining sodium hyaluronate in
other solutions, such as hypotonic
formulations, for combined beneficial effects. With good results and
minimal blur on insertion, we will
be seeing more of this drop
in years to come.
Since hyaluronic acid is unstable as an acid, it is typically used
with sodium as a salt. Hyaluronic
acid is a naturally occurring polysaccharide found in large quantities in rooster combs, sharkskin,
whale cartilage, umbilical cords
and serum. It is widely distributed
in bodily tissues and intracellular
fluids—specifically the aqueous
and vitreous humor, synovial
fluid, and the ground substance
surrounding cells. Hyaluronic
acid plays an important
role in the maintenance of
structure, moisture and
lubrication, and it aids in
protection against invasion of bacteria. The
excellent water-holding
capacity of hyaluronic
acid makes it retain moisture better in the eyes,
joints and skin tissues. It
is used in a number of
commercial over-thecounter products, including premium lip balms
Sodium hyaluronate improves both signs and symptoms of
and ocular wetting drops. dry eye.
12
RCCL
1. Johnson ME, Murphy PJ, Boulton M. Carbomer
and sodium hyaluronate eyedrops for moderate dry
eye treatment. Optom Vis Sci 2008 Aug;85(8):750-7.
2. Prabhasawat P, Tesavibul N, Kasetsuwan N. Links
Performance profile of sodium hyaluronate in
patients with lipid tear deficiency: randomised, double-blind, controlled, exploratory study. Br J Ophthalmol 2007 Jan;91(1):47-50.
3. Troiano P, Monaco G. Effect of hypotonic 0.4%
hyaluronic acid drops in dry eye patients: a crossover study. Cornea 2008 Dec;27(10):1126-30.
4. Johnson ME, Murphy PJ, Boulton M. Effectiveness of sodium hyaluronate eyedrops in the treatment of dry eye. Graefes Arch Clin Exp Ophthalmol
2006 Jan;244(1):109-12.
5. Brignole F, Pisella PJ, Dupas B, et al. Efficacy
and safety of 0.18% sodium hyaluronate in patients
with moderate dry eye syndrome and superficial
keratitis. Graefes Arch Clin Exp Ophthalmol 2005
Jun;243(6):531-8.
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Gas-Permeable Strategies
By John M. Rinehart, O.D., F.A.A.O.
Mystery Solved!
Similar parameters, but different fit... What went wrong?
M
ost contact lens fitters
have at one time or
another come upon one
of the following situations:
1. You replace a lost lens for a
satisfied GP patient, but the new
lens does not provide the same
level of comfort as the lost lens.
2. You see a GP lens wearer,
new to your practice, and even
though the lenses have similar
base curves, the fits are grossly
dissimilar.
What happened? To put it
bluntly, the lab most likely was
not provided with all the information necessary to duplicate the
lens. This can happen in a number of ways—it could be a simple
clerical error (which should be
caught when the lenses are verified), or, more likely and most
commonly, the lab was given the
base curve, lens diameter and
power and instructed to finish the
lens with their “standard periphery,” or the lab was given K values and a refraction, but a
consultant designed the lenses.
Regardless of the situation, be
sure to record all lens parameters
and insist that your lab send you
all lens parameters with the finished lenses. This is especially
important when you change labs.
The new lab may have a different
fitting philosophy, and their
“standard periphery” may be significantly different from that of
your previous lab.
The Not-So-Standard
Periphery
As a test, I supplied the base
curve, power and diameter and
requested lens parameters for the
“standard periphery” from seven
different labs. I found that a lab’s
“standard periphery” can have
varying intermediate and peripheral curve radii and widths. I did
this not to test my impression of
the quality of the lab designs, but
rather, to determine if there is a
significant difference in standard
lens design from lab to lab. The
facilities I selected ranged from
very large, nationally known labs
to small local labs. Most designed
similar lenses, but the range varied significantly—the most significant variable was the optical
zone diameter (The lab was supplied with the following information: base curve= 8.13D; power
= -2.00D; diameter = 9.6mm. The
radii of the intermediate and
peripheral curves were very similar, but the widths did vary,
which resulted in the different
optical zone diameters (OZD).
The range of OZD was from
7.6mm to 8.4mm, which creates
a significant difference in the
sagittal depth of the lens, and as
a result, a significant difference in
fit. The lower sagittal depth of
the 7.6mm OZD would be a
much looser fit than the lens with
the 8.4mm OZD, on a normally
shaped cornea. This difference is
demonstrated in figures 1 and 2.
Ensure a Successful Fit
To avoid these problems,
record all lens information, and
when duplicating lenses, provide
all of it to the lab. This will
assure that your patient will continue to wear the well-fit lens you
prescribed. Otherwise, when you
change labs, their “standard
periphery” may be significantly
different from that of the lab you
are currently using. RCCL
1,2. This fluorescein pattern shows a lens with a 7.6mm OZD that centers superiorly—a
loosely fitting lens on this patient. Note the excessive fluorescein in the intermediate
and peripheral zones of the lens (left). The lens with an 8.4mm OZD lens provides a snug
fit for this patient (right). It centers well, but may be slightly tight in the area of the
peripheral curve.
13
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All About
Acanthamoeba
In this virtual roundtable, clinicians discuss how to detect, treat and help patients
avoid this vision-threatening keratitis.
By H. Dwight Cavanagh, M.D., Ph.D., F.A.C.S.; Joseph P. Shovlin, O.D., F.A.A.O.;
and Christine W. Sindt, O.D., F.A.A.O.
Rate of Infection
What is the current estimate of
infection rate? Do you think the
numbers are increasing or decreasing since the recall of Complete
Moisture Plus (Advanced Medical
Optics)?
DC: If I were to take a guess, I
would say that the pre-recall rate
was one to two cases per million
lens wearers. The “epidemic” is
now over. Some major centers
think that the numbers are increasing, but there really are no compelling data published. Beyond any
dispute, however, the number of
cases in Chicago are up due to a
decrease in Illinois’s water purification standards.1
JS: A recent CDC investigation
had determined that the number of
confirmed cases of Acanthamoeba
keratitis has increased since 2004.
There apparently are some significant geographic variations by U.S.
region, just as there are worldwide
differences in rates of infection.
During the peak year, the estimates
ranged from one in 30,000 to one
in 100,000 wearers per year.2 There
really is no way to know for sure
whether the rates have stabilized or
have actually decreased since the
initial outbreak and recall of the
product.
CS: Unlike with fungal keratitis
and the recall of ReNu with MoistureLoc (Bausch & Lomb), we are
still seeing Acanthamoeba infections after the recall of Complete
Moisture Plus (Advanced Medical
Optics). The true incidence of
Acanthamoeba keratitis may be
regional, but here in Iowa, we have
seen a three-fold increase in corneal
transplants secondary to Acanthamoeba infections since 2001.3
Diagnosis
What key features or signal data
help make a timely diagnosis in a
non-specific keratitis?
Dr.
Cavanagh is
the Dr. W
Maxwell
Thomas
Chair Professor at the
University of Texas
Southwestern Medical
Center in Dallas, Tex.
Dr. Shovlin
is a clinical
editor for
RCCL and a
senior
optometrist at the Northeastern Eye Institute in
Scranton, Pa.
Dr. Sindt is
director of
Contact Lens
Service at the
University of
Iowa Hospitals and Clinics, Iowa City, Iowa.
15
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DC: The confocal microscope is
the best way to make the most
rapid and accurate diagnosis.4 We
cannot make the diagnosis of AK
based only on how the eye looks
at the slit lamp. And cultures, a
method of certain diagnosis, are
hard to do for most primary care
physicians—not to mention timeconsuming.
JS: Making a diagnosis can be
menacing, and confirmation can
be challenging. In the ideal world,
confocal microscopy is the most
accurate and timely method to
diagnose the disease and avoids a
large or painful scraping (biopsy)
of the cornea. However, a trained
observer is needed; the trophozoite form of Acanthamoeba is
more difficult to recognize and is
approximately the same size as
keratocyte nuclei.
Scrapings can be plated onto
non-nutrient agar with an overlay
of heat-killed Escherichia coli or
Klebsiella, and direct and indirect
immunoflurescence can be
obtained when necessary by looking for capsid or nuclear staining.
But, not many labs are equipped
to provide this service.
So, assorted stains may aid in
your diagnosis, including calcofluor
white, hemotoxylin/eosin and
Wright’s stain. Slit lamp appearance in an otherwise non-specific
keratitis is not particularly diagnostic, with the exception of radial nerve infiltrates or lightning
flash depictions. Even radial nerve
infiltrates are not pathognomonic,
since they can be found in nonulcerative Pseudomonas keratitis
and leprosy. Ring infiltrates are
generally late to appear and are
also not pathognomonic. Keep in
mind that pain disproportionate
to the clinical picture can accompany this disease.
CS: More than 50% of patients
are going to present with punctate
epithelial erosions, while only 4%
present with a ring infiltrate.
Other features may include perilimbal neuritis and dendrite-like
lesions. As Dr. Shovlin said,
though, one feature that is
extremely common is severe
pain—these patients will typically
present with pain that seems
much greater than the corneal
findings.
Treatment
What first-line agents do you use
in treating this disease? Are you
willing or likely to treat without
This photo shows the eye of a patient with Acanthamoeba keratitis with a significant
epithelitis and radial neuritis.
16
laboratory confirmation, and if
so, when?
DC: There is currently no FDAapproved drug for AK, despite the
fact that in 1991, Brolene (propamidine isethionate, Bausch &
Lomb, Inc., was shown to be effective in an FDA Orphan Drug Study.
I use a combination of Brolene
isethionate, chlorhexidine 0.02%,
polyhexamethylene biguanide
(PHMB) 0.1% and neomycin 1%.
But, before I prescribe, I confirm
my diagnosis via confocal
microscopy—it’s so easy that no
patient should be treated without
confirmatory diagnosis. A drug
regimen to combat AK is toxic,
painful and goes on for months,
so a confirmed diagnosis is essential to begin a patient on such a
course of medication.
JS: When there is compelling or
heightened awareness and a
strong clinical picture, we generally initiate treatment immediately,
even before the diagnosis is confirmed. The cystic form of Acanthamoeba is highly resistant to
many forms of systemic and topical therapy. Biocides, cationic
antiseptics and anti-parasitic therapy are generally employed.
Treatment with either PHMB or
chlorhexidine is often combined
with a diamidine, such as Brolene
or Desomedine (hexamidine,
Chauvin). Brolene is readily available outside of the U.S. It is a presulfa era drug that is available
over-the-counter in many countries. The dosing of the biocide (or
cationic antiseptic) is every hour
around the clock for the first few
days. Treatment is then tapered
based on clinical response over
several months.
Possible new therapies include
anti-neoplastic and anti-malarial
drugs.5
The timing of topical steroid
use to control inflammation
015_rccl0109Round
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Page 17
during the course of treatment
remains controversial and should
generally be avoided in the initial
stages of treatment.5
Surgical intervention includes
the use of amniotic membrane
transplants for progressive stromal loss and persistent epithelial
defects and may delay the need
for penetrating keratoplasty. Penetrating keratoplasty should be
performed only after the infection
is under control unless there is
emergent need. But, a minimum of
three months between discontinuation of treatment and subsequent
keratoplasty is recommended to
avoid toxicity and resultant
potential graft failure.5
CS: Typically, these patients are
started on a broad-coverage
antibiotic and 0.02% chlorhexidine every hour while awake, in
combination with 200mg to 600
mg of oral itraconazole or ketoconazole per day (divided b.i.d.)
Cycloplegia is recommended.
Steroids are not advised early on,
but may be used later in the
course of treatment to control
inflammation and scarring.
When looking for cysts, the
fastest diagnosis is made with
confocal microscopy. If the cyst is
located anterior to Bowman’s
membrane—not in the stroma—
this is a fairly good predictor of
likely resolution with topical
drops, as opposed to corneal
transplantation. A deeper cyst, on
the other hand, could necessitate
transplantation.
After confocal microscopy,
corneal scrapings should be evaluated by a pathologist. Culturing
on the E. coli bed with non-nutrient agar was the standard of care
in the past, but results take some
time to develop. So, treatment
can and should typically be started with confocal microscopy
results alone.
A late presenting ring infiltrate and contiguous scleritis in a patient with AK.
Avoidance
What can you tell patients who
want to reduce their risk of Acanthamoeba infection?
DC: I warn patients against
swimming in lenses and recommend that they use peroxide disinfection systems. I believe that
there is not yet enough data on
the risk of showering with lenses
to discuss that with patients.
Also, animal and human study
data suggest that we may in the
future be able to immunize
against AK in patients with low
tear IgA levels.6
JS: Contact lens wear remains
the key risk factor for acquiring
this disease. Additional risk factors include swimming in contact
lenses, irregular or inadequate
disinfection, exposure to contaminated water (e.g., well water or
hot tubs) and corneal trauma.
Additional surveillance of every
contact lens wearer is paramount
and should help to minimize the
risk of acquiring this dreaded
disease.
CS: Contact lens wear and
exposure to water seem to be the
greatest risk factors. Peroxide
shows excellent rates of cyst
reduction when used at 3%
strength for four hours before
neutralization.7
The currently marketed peroxide
disinfectants begin the neutralization process immediately and
therefore do not provide 3%
hydrogen peroxide for a long
enough period of time to kill
cysts, and therefore, have about
the same kill rate for cysts as the
chemically-based disinfecting
solutions.7
Acanthamoeba cysts can live in
the biofilm of contact lens cases,
which is why I recommend that
patients scrub the contact lens
case weekly and “sterilize” the
case periodically—not to mention,
it’s just good hygiene. And,
patients should replace their lens
cases every three months.
RCCL
1. Joslin CE, Tu EY, Shoff ME, et al. The association of contact lens solution use and Acanthamoeba keratitis. Am J
Ophthalmol 2007 Aug;144(2):169-180.
2. Schein O. Shaepero Award Lecture, American Academy of
Optometry. Tampa. October 2007.
3. Auran JD, Dubord PJ, Glasser DB. A retrospective review
of outcomes of penetrating keratoplasty for Acanthamoeba
keratitis. Paper presented at the American academy of ophthalmology. November 10, 2008.
4. Parmar DN, Awwad ST, Petroll WM, et al. Tandem scanning confocal corneal microscopy in the diagnosis of suspected Acanthamoeba keratitis. Ophthalmology 2006
Apr;113(4):538-47.
5. Hammersmith KM. Diagnosis and management of Acanthamoeba keratitis. Curr Opin Ophthalmol 2006
Aug;17(4):327-31.
6. Alizadeh H, Neelam S, Niederkorn JY. Effect of immunization with the mannose-induced Acanthamoeba protein and
Acanthamoeba plasminogen activator in mitigating Acanthamoeba keratitis. Invest Ophthalmol Vis Sci 2007
Dec;48(12):5597-604.
7. Hughes R, Kilvington S.Comparison of hydrogen peroxide
contact lens disinfection systems and solutions against
Acanthamoeba polyphaga. Antimicrob Agents Chemother
2001 July;45(7):2038–43.
17
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Keeping Solutions
Safe and Effective
A look at current test procedures, what the FDA-commissioned Ophthalmic Devices
Panel has recommended and what is planned for the future.
By Susan J. Gromacki, O.D., M.S., F.A.A.O.
Dr. Gromacki
is a Diplomate in the
Section on
Cornea and
Contact Lenses of the
American Academy of
Optometry. She lives in
West Point, New York.
W
e are all familiar with the
Fusarium and Acanthamoeba keratitis outbreaks. Our patients are likely to be
as well, as the lay media was quick to
report the recalls of the two contact
lens multipurpose solutions associated with the respective outbreaks.
ReNu with MoistureLoc (Bausch &
Lomb) was permanently recalled in
2006, followed by Complete Moisture Plus (Advanced Medical Optics)
in 2007.
Having passed the FDA’s recommended testing guidance with flying
colors, both solutions were, of
course, approved by the United States
Food and Drug Administration
(FDA). So, it’s no surprise that the
FDA has taken this seriously. The
organization has begun steps to
review its testing methods for evaluating the activity of contact lens care
products. Let’s review the current
testing methods, the outbreaks, what
the FDA has already done, and what
it is planning to do in the future.
Current FDA Testing Methods
A contact lens solution is a Class
II device and must demonstrate disinfection efficacy before it can be
cleared for marketing in the U.S.
For example, a disinfection solution
must undergo stand-alone and regimen testing.
18
The FDA and the International
Organization for Standards (ISO)
have a protocol to evaluate the
microbial activity of a disinfecting
solution. As outlined in the 2001
document listed on the FDA Web
site, the FDA specifies the test
organisms, media, equipment, samples and procedure.1
Stand-alone testing evaluates a single solution and determines whether
it can effectively kill certain microorganisms that are inoculated into it.
The microorganisms include three
bacteria (Staphylococcus aureus,
Pseudomonas aeruginosa and Serratia
marcescens) and two fungi (Candida
albicans and Fusarium solani). For
the stand-alone test, the solution is
required to reduce each bacterium by
at least 3.0 log units of 1.0 x 105 to
1.0 x 106 colony-forming units
(cfu)/ml inoculum and each fungus by
at least 1.0 log unit. Additionally, the
fungi must not demonstrate an
increase in numbers following a period four times greater than the minimum recommended soak time.
The selected microbial strains
represent a variety of microorganisms encountered in the environment,
including two gram-negative bacteria
(Pseudomonas aeruginosa and Serratia marcescens), one gram-positive
bacterium (Staphylococcus aureus), a
mold (Fusarium solani) and a yeast
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Page 19
ISO/FDA Disinfection Efficacy Criteria
Test Organism
Reduction of Inoculum of Organisms
in Stand-Alone Criteria
Reduction of Inoculum of Organisms
in Regimen Criteria
Pseudomonas aeruginosa
Staphylococcus aureous
Serratia marcescens
Candida albicans
Fusarium solani
Reduces the bacterial level by an average at least
3.0 log units within the recommended disinfection
time.
Reduces the fungi level by an average at least 1.0
log unit within the recommended disinfection time.
For each microbe species, the average count for all
lots tested be no more than 10cfu for each
lens-solution combination following cleaning/
soaking regimen.
(Candida albicans). The strains are
obtained from the standardized
American Type Culture Collection
(ATCC). The advantage of always
utilizing the same five strains is, of
course, consistency in testing.
However, this method does omit
several “real world” microorganisms relevant to microbial keratitis,
such as Acanthamoeba. For example, there were at least 19 different
Fusarium genotypes responsible for
the recent outbreak.2 The FDA is
certainly considering how to augment the current list with additional clinical isolates (those microorganisms collected from clinically
worn contact lenses or used lens
cases) and/or more relevant strains.
The secondary criteria of the
stand-alone test states that if the
solution fails the stand-alone test, it
may be evaluated by the regimen
test described below, given that it
first passes the “regimen qualification.” That is, it reduces the
amount of the test bacteria by no
less than 1.0 log unit per single test
bacterium and 5.0 log units combined. Yeast and mold must demonstrate stasis (no additional growth).
The regimen test evaluates the
disinfection solution and, if present, all of the additional components of a care system’s cleaning
and disinfection procedure. Selected contact lenses of various materials, for which the manufacturer
seeks approval for use with the
solution regimen being tested, are
inoculated with the same organisms
used in the stand-alone procedure.
Lenses are then cleaned, rinsed and
soaked in the manufacturer’s recommended manner. After soaking,
the lenses are analyzed to determine microbial growth. The
requirements are less than 10cfu
recovered from each lens, following
the cleaning/soaking regimen for
each test organism.
It is important to note that the
regimen test is performed according
to package instructions, which
include a lengthy rinse for all currently approved no-rub solutions.
Currently, the FDA reviews a care
system based on its labeled directions for use as if it were used with
complete compliance. But, as we
know, such practices are not always
reflected in real-world settings.
In addition to disinfection efficacy, the FDA also evaluates cleaning
efficacy. And, the FDA uses the
tests, whether for a single bottle of
solution or for a system that uses a
combination of separate bottles of
solution with specific purposes,
such as for cleaning, rinsing and
disinfecting, to ensure that all products meet its requirements. Obviously, a multipurpose solution
(MPS) must be as effective with one
solution as would a care system of
separate solutions.
As with other Class II medical
devices, a contact lens solution
must show a “substantial equivalency” to comparable products
previously approved. In other
words, it must be as safe and effective as other solutions for the same
intended use or function. Assuming
the solution undergoing testing has
similar chemical components and
percentages as the approved solutions, any recommended clinical
testing may need only 30 subjects
for 30 days.
Additional testing is recommended for new ingredients without
prior history of ophthalmic use. If
the chemical components are new
or are present in different percentages, the same or additional in vitro
testing is recommended. In these
cases, clinical testing is more extensive and may include about 60 subjects for 90 days.1,3
The Fusarium and
Acanthamoeba Keratitis
Outbreaks
The United States Centers for
Disease Control and Prevention
(CDC) and the Fusarium Keratitis
Investigation Team found 164 confirmed cases of Fusarium keratitis in
the U.S. between June 1, 2005, and
June 30, 2006. There are approximately 30 million lens wearers,
0.04% (daily wear) to 0.21%
(extended wear) of whom develop
microbial keratitis annually.2,4-6 Less
than 5% of contact lens-related keratitis is caused by a fungus of any
kind.2 Even during the outbreak, the
percentage of those with Fusarium
was relatively small.
Of the 164 patients affected, 154
were soft contact lens wearers.
Approximately one-third of the 154
wore their lenses overnight. One
hundred and forty-six could identify
their contact lens care systems.
19
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Page 20
Courtesy: Eduardo C. Alfonso, M.D.
018_rccl0109_FDA
1. Fusarium keratitis. ReNu with
MoistureLoc was recalled after being
linked with this condition.
Courtesy: Christine Sindt, O.D., F.A.A.O.
Ninety-four (57%) used ReNu with
MoistureLoc (Bausch & Lomb)
exclusively; 21 (13%) used ReNu
with MoistureLoc in addition to
another product; nine (5%) used an
unspecified ReNu solution; and 22
(18%) used products other than
MoistureLoc.2
The 75% MoistureLoc association was disproportionate to its
market share, 10.7%. After much
investigation by Bausch & Lomb,
the FDA and the CDC, Bausch &
Lomb voluntarily removed the solution from the U.S. market on April
13, 2006 and from the world market on May 15 of that year.
After the investigation, there was
no evidence of contamination. People initially assumed the culprit to
be MoistureLoc’s preservative,
alexidine. However, during noncompliant conditions, “the concentration of the polymers included in
the formula to enhance comfort
may make the solution more likely
to be contaminated with Fusarium
2. Acanthamoeba Keratitis. An outbreak
of this condition led to the recall of
Complete Moisture Plus.
20
in the environment,” said former
Bausch & Lomb CEO Ron Zarella
in an American Academy of
Opthalmology member alert.7 Noncompliant conditions were defined
as allowing the solution to evaporate or not regularly replacing it in
the lens case; leaving the bottle
open between uses; not cleaning the
case properly or replacing regularly.
MoistureLoc contains a higher concentration of polymers than any
major lens care product.8 In other
words, it is likely that during noncompliant conditions, the wetting
agent (poly-quaternium 10, a polysaccharide) encapsulated the Fusarium spores, allowing them to
survive and germinate. Additional
studies have demonstrated other
care products’ reduced efficacy
against Fusarium under sustained
high temperature conditions.9
Current testing standards do not
include solution testing during
adverse environments or noncompliant care. In addition, the current FDA guidance and the
international standards do not
require testing for a solution’s efficacy against amoebae.10-12
Acanthamoeba keratitis (AK) is
a rare condition, affecting just one
to two lens wearers per million
annually.13 Of these patients, 40%
are typically noncompliant with
lens care, and 32% wear their
lenses while swimming.14 In the
most recent outbreak (138 cases
were documented by the CDC in
May 2007), 58% of culture-confirmed soft contact lens-wearing
patients had been using Complete
MoisturePlus Multipurpose Solution, which is again disproportionate to its approximate 9%
market share.14-17 As a result,
AMO voluntarily recalled the
product on May 29, 2007.
Beginning in March 2007, the
CDC began a multi-state outbreak
investigation, using the same
controls as in the Fusarium study.
On multivariate analysis, only three
variables were statistically significant. First, affected patients were
2.8 times more likely to report
“topping off” of solution and 2.8
times more likely to have worn lenses for less than five years. In addition, Complete MoisturePlus users
were 16.8 times more likely to
develop AK than patients who used
all other solutions. The CDC attributed this to insufficient anti-Acanthamoeba activity of the solution.
This may be, in part, due to the
addition of propylene glycol, a
sugar-based polymer that aids in
moisture retention.13
However, after several months
of the recall, AK rates have neither increased nor decreased. This
raises the question: What role do
environmental risk factors, such
as water contamination, have in
the outbreak?13
The FDA’s Actions
After the outbreaks, the FDA
took action, investigating their
etiologies and alerting health care
professionals and their patients.
Education regarding healthy contact lens wear included recommendations, such as removing
contact lenses prior to contact
with water, washing hands before
handling lenses, never topping off
solution, and scheduling regular
eye examinations.
On June 10, 2008, the FDA convened the Ophthalmic Devices
Panel of the Medical Devices Advisory Committee to discuss “general
issues concerning post-market experience with various contact lens care
products.” The session began with
an Open Public Hearing, in which
the public was given an opportunity
to provide testimony. Eighteen presenters, including academic
researchers, practicing clinicians,
professional society representatives
018_rccl0109_FDA
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Page 21
and industry personnel, spoke.18-21
The FDA sought advice from its
Ophthalmic Devices Panel, a neutral group of experts, regarding
modifications to preclinical and
clinical testing for contact lens care
products and to product labeling.
The panel’s recommendations on
the six topics requested by the FDA
were as follows:13,18-21
• Neither the panel’s nor the
FDA’s recommended changes in
testing or labeling should be swayed
by patient compliance. And, a product label should include a warning
against “topping off” or reusing
solution. Lenses should not be
stored in water or non-sterile solutions of any kind. Frequent case
replacement should be specified, but
additional research is needed to
determine the exact interval of time.
A solution label should include a
warning against wearing lenses during water activities, although there
was difficulty finding consensus on
what to recommend. A lens care
product’s discard date after opening
(as in Europe) would be welcomed,
although it may be difficult for
patients to follow.
• Instructions should include rub
and rinse steps for existing care
products. Both rubbing and rinsing
should be part of product instructions, but there is not enough data
at this time to specify the exact rinsing times. “Rinsing works somewhat; rubbing works even better.
The combination of the two is best
of all, and not doing either is worst
of all,” said Timothy McMahon,
O.D., Ph.D., to those attending during the panel meeting. The panel
recommended that the FDA not ban
no-rub regimens, in order to
encourage industry to create more
effective products in the future.
• An additional two-hour followup visit in manufacturers’ clinical
studies to perform a fluorescein
staining evaluation would not be
beneficial, because there is no
demonstrated correlation between
staining and keratitis. In addition,
the panel recommended including
silicone hydrogel lenses in the clinical investigations of contact lens
care products.
• Testing for solution approval
should include a contact lens and
case and utilize a more diverse and
representative set of infectious organisms, including Acanthamoeba.
Testing should be made more rigorous to include “real world” scenarios, such as solution evaporation.
• Silicone hydrogel contact lenses
should be separated from the current FDA lens material classification
system, and further subdivided into
three or four groups of their own.
• Unlike the current stand-alone
test, FDA cytotoxicity testing used
to evaluate multipurpose solutions
should include a contact lens and
contact lens case. And, it should
incorporate both conventional and
silicone hydrogel lenses.
What’s Next for the FDA
Based on the results of the June
meeting, the FDA has scheduled a
Contact Lens Microbiology Workshop for January 22 to 23, 2009, to
help develop new methods to evaluate the disinfection efficacy of contact lens care products against
Acanthamoeba, as well as “real
world” and ”worst case” scenarios.
They have invited experts in the
area of Acanthamoeba with an
emphasis on care systems and
microbiology. Among the sponsors
of the meeting are the American
Academy of Optometry, the American Optometric Association, the
American Academy of Ophthalmology and the Contact Lens Association of Ophthalmologists.
This is an important next step, as
it is in everyone’s best interest to
expedite the development of new
testing standards for contact lens
care products to ensure, once and
for all, that keratitis outbreaks
among contact lens wearers are a
thing of the past.
RCCL
1.International Standards Organization ISO 14729. Ophthalmic
Optics – Contact Lens Care products. Microbiological requirements and test methods for products and regimens for hygienic
management of contact lenses, 2001.
2. Chang DC, Grant GB, O’Donnell K, et al. Multistate outbreak of
Fusarium keratitis associated with use of a contact lens solution.
JAMA 2006 Aug 23;296(8):953-63.
3. Gromacki SJ. Hydrogel and silicone hydrogel lens care. Cont
Lens Spect 2008 Feb;23(2): 26-32.
4. Poggio EC, Glynn RJ, Schein OD, et al. The incidence of
ulcerative keratitis among users of daily wear and extended wear
soft contact lenses. N Engl J Med 1989 Sep 21;321(12):779-8.
5. Poggio EC, Abelson M. Complications and symptoms in disposable extended wear lenses compared with conventional soft
daily wear and soft extended wear lenses. CLAO 1993
Jan;19(1):31-9.
6. Schein OD, Glynn RJ, Poggio EC, et al. The relative risk of
ulcerative keratitis among users of daily-wear and extended-wear
soft contact lenses. N Engl J Med 1989 Sep;321(12): 773-778.
7. American Academy of Ophthalmology Member Alert, May 16,
2006.
8. Bausch & Lomb. Fusarium keratitis. Special report. Cont Lens
Spect. 2006 Sept;21(9):Suppl:1-8.
9. Rosenthal RA, Henry CL, Buck SL, et al. Extreme testing of
contact lens disinfecting products. Cont Lens Spect 2002
Jun;17(7):40-45.
10. Borazjani RN, Kilvington S. Efficacy of multipurpose solutions against Acanthamoeba species. Cont Lens Anterior Eye
2005 Dec;28(4):169-75.
11. Borazjani RN, Kilvington S. Effect of a multipurpose contact
lens solution on the survival and binding of Acanthamoeba
species on contact lenses examined with a no-rub regimen. Eye
Contact Lens 2005 Jan;31(1):39-45.
12. Shoff M, Rogerson A, Schatz S, Seal D. Variable responses
of Acanthamoeba strains to three multipurpose lens cleaning
solutions. Optom Vis Sci 2007 Mar;84(3):202-7.
13. FDA. Summary minutes. Medical devices advisory committee. Ophthalmic devices panel, the United States Food and Drug
Administration, June 10, 2008, Gaithersburg, Maryland. Available at: www.fda.gov/ohrms/dockets/ac/08/minutes/20084363m1.pdf. (Accessed November 2008).
14. Guttman C. Acanthamoeba keratitis increasing at alarming
rate. Ophthalmol Times 2006 Jan 1;31:1-2.
15. Bennett ES. Acanthamoeba keratitis in 2007: Stay informed
but calm. Cont Lens Spect 2007 Jun;22(7):50-2.
16. FDA. Advanced Medical Optics voluntarily recalls Complete
MoisturePlus contact lens solution. FDA News May 26, 2007.
Available at: www.fda.gov/bbs/topics/NEWS/2007/
NEW01641.html. (Accessed Nov 2008).
17. AC Nielsen. Solution use in 2006, percentage by brand. 12
week period ending 5/13/06.
18. FDA. Transcript. Medical devices advisory committee. Ophthalmic devices panel, the United States Food and Drug Administration. June 10, 2008. Gaithersburg, Maryland. Available at:
www.fda.gov/ohrms/dockets/ac/08/transcripts/2008-4363t101.pdf. (Accessed Nov 2008).
19. FDA. Transcript. Medical devices advisory committee. Ophthalmic devices panel, the United States Food and Drug Administration, June 10, 2008, Gaithersburg, Maryland. Available at:
21
CO
10:32 AM
Page 27
RNEA & CON
TA
C
LE
NSE
REVI
OF
1/8/09
T
EW
027_rccl0109_CE_F
S
Develop Your Specialty
Contact Lens Practice
By utilizing newer lens technologies and understanding the benefits they can offer,
you can keep patients happy and realize significant practice benefits.
By Mile Brujic, O.D.
C
ontact lens wearers are a
challenging—yet rewarding—part of many of our
practices. The ultimate goal for
our contact lens wearers is comfort, good vision and healthy eyes.
The unfortunate reality, however,
is that many of our contact lens
wearers become complacent about
their lens wearing experience, and
they accept a certain level of compromised comfort and vision as
something that accompanies contact lens wear. As a result, many
patients discontinue contact lens
wear. The good news is that many
of these same patients may be able
to successfully wear contact lenses
again. This will lead to more satisfied patients and significant practice benefits.1
By embracing contemporary
contact lens options you can
improve patient outcomes and differentiate the services that you offer
to your patients.
The Value of the Examination
The examination process is
composed of three elements: the
patient history, the actual examination and medical decisionmaking. Don’t undervalue the history; it helps you to understand
what contact lens may be best
suited for the patient’s hobbies,
lifestyle and occupation.
During the exam, a number of
tools aid the process considerably. Two, in particular, should
be employed in every patient
encounter: fluorescein dye and
lissamine green.
Fluorescein is a hydrophilic
molecule that hyperfluoresces
upon accumulation and when
Release Date: January 2009
Expiration Date: January 31, 2010
Goal Statement: By utilizing newer lens technologies and understanding
the benefits they can offer, the practitioner will keep patients happy and
realize significant practice benefits.
Faculty/Editorial Board: Mile Brujic, O.D.
Credit Statement: This course is pending approval for 2 hours of CE
credit. Check with your local state licensing board to see if this counts
toward your CE requirement for relicensure.
Joint-Sponsorship Statement: This continuing education course is
joint-sponsored by the University of Alabama.
Disclosure Statement: Dr. Brujic has no relationships to disclose.
viewed with a cobalt blue light
and Wratten filter (figure 1).
Lissamine green stains cells
that are devitalized. Conjunctival staining with this dye is
often the initial sign of ocular
dryness (figure 2). Guillon and
Maissa examined contact lens
wearers and showed a greater
specificity of bulbar conjunctival
lissamine green staining in those
patients who demonstrated dry
eye symptoms.2
Numerous studies establish a
correlation between patients with
corneal staining, decreased tear
film break-up times, reduced tear
prism, lid wiper epitheliopathy or
meibomian gland disease with a
tear film that could potentially
undermine comfortable contact
lens wear (figure 3).3-8 Also, neovascularization of the cornea and
This course is supported by
an unrestricted educational
grant from
27
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1. Remember to use sodium flourescein during every patient encounter. This patient
has a cornea that looks healthy and normal when viewed with a regular slit lamp
beam (left), vs. viewing the same cornea after instillation of flourescein and
utilizing a cobalt blue light and Wratten filter (right).
limbal hyperemia are typically signs
associated with corneal hypoxia.9,10
Utilizing the vital dyes and
understanding the importance of
the findings will help us deliver
better care to our patients and
guide our contact lens prescribing
habits. This testing regimen will
also begin the process of differentiating your practice as one with a
contact lens specialty.
Understanding the Materials
Traditionally, hydroxyethyl
methacrylate (HEMA) was the
mainstay material in soft contact
lenses. HEMA-based contact lenses, often referred to as hydrogels,
worked well because of their easily wettable surfaces and the
ability to provide an initially comfortable contact lens wearing
experience.11 The Dk, or oxygen
permeability of a hydrogel lens, is
directly related to the water content of the lens. Thus, a contact
lens that is higher in water content is also more oxygen permeable than a contact lens with a
lower water content. Recent
research has shown that there is
an association between contact
lens-related dry eye and high
water content contact lenses. This
is potentially due to protein deposition and spoilage of these lenses
(figure 4).12,13
Silicone hydrogel contact lenses
were manufactured as an attempt
to balance water content and oxygen permeability. The original con-
28
tact lenses in the category were
PureVision (Bausch & Lomb) and
Focus Night & Day (CIBA
Vision).14,15 These contact lenses
delivered high amounts of oxygen
to the cornea in a low water content material. The intricacies in the
combination of silicone, which
allows significant oxygen diffusion, and hydrogel, which attracts
water, allows this delicate relationship to be manipulated to optimize
both oxygen delivery and water
content. In addition to those
already listed, other contact lenses
in this category include the Acuvue
Advance and Acuvue Oasys (Vistakon), the Biofinity and Avaira
(CooperVision) and the O2Optix
and Air Optix (CIBA Vision).15-17
(See “Silicone Hydrogel Options,”
pg. 29.)
Silicone hydrogel lenses retain
significantly less protein deposits on
their surfaces than their hydrogel
predecessors.18,19 But, they are more
likely to retain lipid-rich deposits on
their surfaces.20 So, minimizing the
comfort limitations that result from
these deposits requires selecting the
solutions that are superior at protein and lipid removal. And, in
addition to selecting solutions that
inherently remove these components, it is also important to prescribe a lens-cleaning regimen that
will involve a digital rub and rinse
step prior to soaking contact lenses
in the evening.
Each silicone hydrogel lens is
designed differently to maximize
surface wettablility in an effort to
create a comfortable contact lens
wearing experience. The Acuvue
Advance (galyfilcon A) and Acuvue
Oasys (senofilcon A) contact lenses
utilize a wetting agent that contains
polyvinyl pyrrolidone (PVP), which
allows for comfortable contact lens
wear. In a study by Riley and associates that looked at several markers for healthy, comfortable contact
lens wear, 88% of contact lens wearers refit into senofilcon A contact
lenses reported better comfort.21
The Biofinity (comfilcon A) and
Avaira (enfilcon A) contact lenses
are unique, in that the silicone
hydrogel polymer used in these
lenses is hydrophilic, resulting in a
lens with a relatively low modulus.16 The Focus Night & Day
(lotrafilcon A), O2Optix (lotrafilcon
B) and Air Optix (lotrafilcon B)
lenses each undergo a surface plasma treatment, which results in a
hydrophilic surface. One study
showed that, out of several silicone
hydrogel lenses challenged in vitro,
various lipids deposited less on
both lotrafilcon A and B lenses
than on any of the other lenses tested.22 The PureVision line of contact
lenses (balafilcon A) utilizes Nvinyl pyrrolidone, which becomes
an inherent part of the lens matrix
and allows for enhanced wettability
and deposit resistance.14
The increased ability of silicone
hydrogel lenses to deliver larger
amounts of oxygen to the cornea
significantly decreases risk of
hypoxia and conjunctival hyperemia, two effects of lower Dk lenses. Limbal and bulbar hyperemia is
also often associated with low Dk
lenses and will typically decrease
when fit with a silicone hydrogel.23
Research has shown that comfort increases when patients who
wear hydrogel contact lenses are
refit with silicone hydrogel contacts.24,25
There are many health benefits
realized by embracing this category
of lenses; yet, there still seems to be
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a lack of consensus on how much
oxygen is sufficient to maintain
healthy corneal physiology. One
study suggested that a minimum
Dk/t of 125 is required to maintain normal corneal function on an
extended wear basis. It also suggested a minimum Dk/t of 35 is
needed to maintain normal corneal
physiology during daily wear.26
Researchers in another study proposed a minimum Dk/t of 90 for
daily wear.27
But, although oxygen permeability is important to maintain
normal corneal physiology, it
will not prevent microbial infections. Recent research has examined rates of microbial keratitis
in those who wear silicone
hydrogel contact lenses and has
found that infection rates are
equal to those who wear hydrogel contact lenses.28 But, regardless of the material, daily wear
seems to result in the lowest rate
of microbial keratitis.29
I hope all practitioners embrace
these contact lenses for their
potential to minimize oxygen
demand to the cornea and offer
patients superior comfort. Many
lens wear dropouts, who ceased
lens wear due to comfort issues,
may once again be able to wear
contact lenses successfully.
Toric Contact Lenses
Many patients with astigmatism are often not properly educated about their contact lens
options and associate their lens
wearing experience with a lens
that they were fit with many
years ago. These patients may
benefit significantly from
newer materials and designs
that offer both comfort and
stable vision. These patients
may be corrected with their
spherical equivalent, and
although there have been major
advancements in aspheric
optics, this correction is not
enough to result in adequate
visual improvement for such
astigmatic patients.30,31
Additionally, many practitioners
may hesitate to fit patients with
higher amounts of astigmatism
with soft toric contact lenses
because of concern about the rotational stability of the design. Fortunately, the numerous contact
lens options available allow us to
accurately and comfortably fit
those astigmats who may not have
been satisfied in the past.
The successful implementation
of comfort and visual stability will
ultimately determine the success of
a patient’s contact lens wearing
experience. There are many different designs incorporated into a
toric contact lens to add stability,
and the practitioner should be
comfortable utilizing them in
order to maximize the chance of
success when fitting these patients.
CooperVision offers an extensive line of toric contact lens
options. The two-week disposable lenses include the Biomedics
Toric and Vertex Toric, and
monthly replacement contact
lenses, such as the Frequency 55
Toric and the Proclear Toric, are
also available. Additionally, the
Proclear toric lens is available in
a daily disposable modality.
These designs offer stability and
the ability to “customize” the
amount of astigmatic correction
in the lens (see “Toric Contact
Lenses” pg. 30).
2. Lissamine green staining of the nasal conjunctiva, which can be the first sign of underlying dry eye.
Bausch & Lomb manufactures
both the SofLens 66 Toric and the
PureVision Toric contact lens.
These are available in a prismballasted design and a wide variety of powers. Many of the
features of the SofLens 66 Toric
have been incorporated into the
PureVision Toric, offering the
benefits of a proven design in a
silicone hydrogel material. This is
especially important for the inferior portion of the contact lens,
where a prism ballast typically
progresses to a slightly thicker
profile. The high oxygen permeability provided by a high Dk lens
diminishes this concern.
Vistakon’s Acuvue Advance for
Astigmatism (AAFA) and Acuvue
Oasys for Astigmatism (AOFA)
are made with a unique accelerated stabilization design. The
AAFA is composed of galyfilcon
A. The AOFA (senofilcon A) is
the most recent generation of
Table 1. Silicone Hydrogel Options
Manufacturer
Contact Lens
Bausch & Lomb PureVision
CIBA Vision
Air Optix Aqua
CooperVision
Vistakon
Focus Night & Day
02Optix
02Optix Custom
Avaira
Biofinity
Acuvue Advance
Acuvue Oasys
Material
balafilcon A
lotrafilcon B
lotrafilcon A
lotrafilcon B
sifilcon A
enafilcon A
comfilcon A
galyfilcon A
senofilcon A
Water
Dk/t
Content (at -3.00D)
36%
33%
24%
33%
32%
46%
48%
47%
38%
112
138
175
138
117
125
160
86
147
29
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lens. This lens has markings
at three, six and nine o’clock,
allowing for easy observation.
The stability of the design
allows practitioners to confidently fit this contact lens
with a high level of success.
Understanding the many
available designs will certainly benefit your patients by
allowing you to individualize
3. Lid wiper epitheliopathy results in staining on their contact lens prescripthe area posterior to the meibomian gland
tion. And, utilizing the
orifices on the superior lid. Staining of this area newest toric options improves
is highly correlated with dry eye symptoms in
the practitioner’s chances of
contact and non-contact lens wearers.
successfully fitting patients
with challenging astigmatic
visual demands.
toric lenses from Vistakon. Small
design modifications have been
made to the AOFA in order to
Multifocal Contact Lenses
create a lens that is easier to hanPatient demographics are changdle than it’s predecessor. The
ing at an alarming rate, and by the
Acuvue family of toric contact
year 2010, more than one-third
lenses has been studied extensive- of the U.S. population will be bely and has been shown to have
tween the ages of 40 and 59.34
These patients have different needs
less rotation when patients were
than presbyopes did ten years ago,
positioned on their side, on infethanks to the changing role of
rior-nasal version and during
large versional eye movements vs. technology in our society. With
prism-ballasted contact lenses.32,33 increasing utilization of cell
CIBA Vision’s Air Optix for
phones and computers, today’s
Astigmatism is a silicone hydropresbyopes will require greater
gel prism-ballast design and is a
visual functionality. Today’s dismonthly replacement contact
posable contact lens options will
give these patients the ability to
lead more versatile lives by minimizing their dependency on supplemental eyewear.
The technology behind multifocal contact lenses has progressed significantly since they
were first introduced. Now, practitioners can offer their presbyopic patients the opportunity to
function similarly to the way they
did before presbyopia set in. The
key to successfully fitting these
contact lenses is understanding
the designs of the currently available multifocal contact lens
options and the many benefits
they offer (see “Multifocal Contact Lenses,” pg. 31).
CooperVision has a number of
contact lenses available for presbyopic patients. The Proclear
multifocal and the Frequency 55
multifocal contact lenses have
very similar designs but vary in
their material. The Frequency 55
multifocal is made of methafilcon
A, while the Proclear multifocal
is made from omafilcon A, which
has been shown to help patients
with contact lens related
dryness.35-37 Such lenses may be
an ideal choice for this patient
population, as the prevalence of
Table 2. Toric Contact Lenses
30
Manufacturer
Contact Lens
Material
Bausch & Lomb
PureVision Toric
SofLens Toric
balafilcon A
alphafilcon A
2.25
2.75
CIBA Vision
Air Optix for Astigmatism
Focus Dailies Toric with AquaRelease
Focus Toric
lotrafilcon B
nefilcon A
vifilcon A
2.25
1.50
2.50
CooperVision
Biomedic Toric
Clearsight 1 Day Toric
Frequency 55 Toric (XR)
Proclear Toric (XR)
Vertex Toric (XR)
ocufilcon D
ocufilcon D
methafilcon B
omafilcon A
methafilcon A
2.25
1.25
2.25 (5.75)
2.25 (5.75)
2.25
Vistakon
Acuvue Advance for Astigmatism
Acuvue Oasys for Astigmatism
galyfilcon A
senofilcon A
2.25
2.25
Cylinder up to:
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Table 3. Multifocal Contact Lenses
Manufacturer
Bausch & Lomb
CIBA Vision
CooperVision
Vistakon
Contact Lens
Material
Description
PureVision Multifocal
SofLens Multifocal
Focus Progressives
Focus Dailies Progressives
Frequency 55 multifocal
Proclear multifocal
Proclear Toric multifocal
Acuvue Bifocal
balafilcon A
polymacon
nefilcon A
nefilcon A
methafilcon A
omafilcon A
omafilcon A
etafilcon A
Low and high add options
Low and high add options
Power is distance Rx + 1/2 add
Power is distance Rx + 1/2 add
Dominant and non-dominant design
Concentric zone design
ocular surface disease increases
with age.38 These contact lenses
have an aspheric design and are
based on the principal of simultaneous vision. The Proclear multifocal lens is produced with two
designs: a distance center, near
peripheral design (D lens), and
near center, distance peripheral
design (N lens). It is recommended to fit the D lens on the dominant eye and the N lens on the
non-dominant eye.16 Practitioners
ultimately determine how the
lenses are fit and can utilize two
D or two N lenses the way they
deem appropriate. The Biomedics
EP, also made of omafilcon A, is
a multifocal contact lens made
for the emerging presbyope,
whose add is less than +1.50D.
Patients’ powers are selected
based on their distance prescription as the add power is fixed.16
The Focus Progressives line of
multifocal contact lenses (CIBA
Vision) also utilizes aspheric
optics to meet patients’ distance,
intermediate and near vision
needs. This line of contact lenses
is unique—there is a daily disposable multifocal contact lens
option available. These contact
lens powers are determined and
ordered by adding half of the
spectacle add to the distance correction, resulting in one power
that is listed on the package.15
Bausch & Lomb is the only
company that currently offers a
multifocal in a silicone hydrogel
material. This design offers the
benefits of aspheric optics, allowing multiple focal distances. This
lens comes in a monthly replacement modality and is FDAapproved for extended-wear of
up to 30 days. These lenses are
available in low add and high
add options. This provides the
practitioner with some flexibility
when fitting presbyopes with a
variety of add powers and various lifestyle requirements.
Vistakon’s Acuvue Bifocal,
which uses a concentric ring
design that alternates between the
distance and near optical zones
throughout the lens, is available in
add powers from +1.00D to
+2.50D, in 0.50D steps. These
lenses are made of etafilcon A
material, the same HEMA-based
material that is used in the Acuvue
2 contact lens. They come in a
large range of powers and often
satisfy most patients’ visual needs.
Interestingly, Vistakon will be
releasing a new silicone hydrogel
multifocal lens, which will be composed of senofilcon A. This lens
will offer the proven comfort benefits that senofilcon A has demonstrated and will be available in
multiple add powers to satisfy a
wide variety of patient needs.
There are two factors to
remember when fitting multifocal
contact lenses: setting proper
patient expectations; and possessing a thorough knowledge of the
different options, designs and
modalities and how they meet
your patients’ varying demands.
The goal of multifocal contact
lenses is to increase patients’ functionality with minimal use of supplemental eyewear. If the patient
cannot read the 20/20 line on the
near-point card, this does not necessarily mean that the fit was
unsuccessful. Rather, some people
will need supplemental eyewear in
addition to their multifocal contact lenses for certain viewing
tasks, such as reading the small
print on a medication bottle.
Colored Contact Lenses
The numerous colored contact
lenses available offer patients the
opportunity to change the appearance of their eyes with either a
tinted or an opaque contact lens.
Tinted contact lenses work well
for those patients who have a
lighter colored iris, but those with
a darker colored iris will not see a
significant change in the appearance of their eyes with tints. For
these patients, opaque contact
lenses work best.
4. This is a patient with significant
protein deposition.
31
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In certain patients, combining
opaques and tints in unique ways
can change the appearance of a
disfigured iris or a corneal opacity.
CIBA Vision, CooperVision and
Vistakon all offer such lenses.
Tinted and opaque contact lenses offer patients the chance to
alter their appearance while providing good vision and ocular
health. Consider this option for
your patients as a means of customizing their contact lens wearing experience.
Specializing Your Practice
Understanding the intricacies of
silicone hydrogel, toric, multifocal
and tinted contact lens options is
the first step to developing a specialty contact lens practice. The
next step is cultivating loyalty
among your patients by creating
advocates for your contact lens
services. Start by creating an experience for your contact lens
patients, and begin with the new
wearer. Training first-time contact
lens wearers how to insert contact
lenses into their eyes and care for
their contact lenses is something
that happens at most offices, but
communication with the patient
before their follow-up visit is rare.
Change that protocol slightly by
asking staff members to follow-up
with a phone call a day or two
after they have gone through the
training. This will keep the communication line open between the
practice and the patient, enhancing the relationship.
When you feel that you have
exceeded the expectations of a
particular patient, use the opportunity to tell him or her about
your passion to help others with
similar conditions. Encourage such
happy patients to refer friends and
family members whom they may
know have a similar problem. For
example, an emerging presbyope
who sees you for the first time
expects glasses. These patients are
usually thrilled when they are suc-
32
cessfully fit with contact lenses.
With patients such as these,
conclude the final fitting visit by
saying, “I am so glad that we were
able to correct your vision and
make you more functional without
the need for supplemental eyewear.
If you know anyone whom you
feel would benefit from the services that you received, feel free to let
them know about our office.”
This creates a patient-centered
monologue that shows how you
genuinely want to help people who
may be limited by the same visual
problems. Incorporate such a message, and watch your specialty lens
practice soar.
Create an Experience
Embrace new contact lens
options as an opportunity to
help your patients exceed their
comfort and visual expectations.
Create an experience by cultivating loyalty and advocates for
your practice. Share your passion—and your willingness to
help others with the same concerns—with your patients. When
you implement these concepts,
you will be well on your way to
creating a successful specialty
contact lens practice.
1. Ritson M. Which patients are more profitable? Contact
Lens Spect 2006 Mar;21(3):38-42.
2. Guillon M, Maissa C. Bulbar conjunctival staining in contact lens wearers and non lens wearers and its association
with symptomatology. Cont Lens Anterior Eye 2005
Jun;28(2):67-73.
3. Nichols KK, Nichols JJ, Lynn Mitchell G. The relation
between tear film tests in patients with dry eye disease. Ophthalmic Physiol Opt 2003 Nov;23(6):553-60.
4. Pult H, Purslow C, Berry M, Murphy PJ. Clinical tests for
successful contact lens wear: relationship and predictive
potential. Optom Vis Sci 2008 Oct;85(10):E924-9.
5. Korb DR, Greiner JV, Herman JP, et al. Lid-wiper epitheliopathy and dry-eye symptoms in contact lens wearers.
CLAO J 2002 Oct;28(4):211-6.
6. Korb DR, Herman JP, Greiner JV, et al. Lid wiper epitheliopathy and dry eye symptoms. Eye Contact Lens 2005
Jan;31(1):2-8.
7. Henriquez AS, Korb DR. Meibomian glands and contact
lens wear. Br J Ophthalmol 1981 Feb;65(2):108-11.
8. Gilbard JP, Rossi SR, Heyda KG. Tear film and ocular surface changes after closure of the meibomian gland orifices in
the rabbit. Ophthalmology 1989 Aug;96(8):1180-6.
9. DeDonato LM. Corneal vascularization in hydrogel contact
lens wearers. J Am Optom Assoc 1981 Mar;52(3):235-6.
10. Papas EB. The role of hypoxia in the limbal vascular
response to soft contact lens wear. Eye Contact Lens 2003
Jan;29(1 Suppl):S72-4.
11. Nixon G. Contact lens materials update 2008. Contact
Lens Spect 2008 Nov;23(10):33-40.
12. Ramamoorthy P, Sinnott LT, Nichols JJ. Treatment, material, care, and patient-related factors in contact lens-related
dry eye. Optom Vis Sci 2008 Aug;85(8):764-72.
13. Nichols JJ, Sinnott LT. Tear film, contact lens, and
patient-related factors associated with contact lens-related
dry eye. Invest Ophthalmol Vis Sci 2006 Apr;47(4):1319-28.
14. Manufacturer Web site. Bausch & Lomb. Available at:
www.bausch.com. (Accessed Nov 2008).
15 Manufacturer Web site. CIBA Vision. Available at:
www.cibavision.com. (Accessed November 2008).
16. Manufacturer Web site. CooperVision. Available at:
www.coopervision.com. (Accessed Nov 2008).
17. Manufacturer Web site. Vistakon. Available at: www.vistakon.com. (Accessed Nov 2008).
18. Santos L, Rodrigues D, Lira M, et al. The influence of
surface treatment on hydrophobicity, protein adsorption and
microbial colonisation of silicone hydrogel contact lenses.
Cont Lens Anterior Eye 2007 Jul;30(3):183-8.
19. Suwala M, Glasier MA, Subbaraman LN, Jones L. Quantity and conformation of lysozyme deposited on conventional
and silicone hydrogel contact lens materials using an in vitro
model. Eye Contact Lens 2007 May;33(3):138-43.
20. Cheung SW, Cho P, Chan B, et al. A comparative study of
biweekly disposable contact lenses: silicone hydrogel versus
hydrogel. Clin Exp Optom 2007 Mar;90(2):124-31.
21. Riley C, Young G, Chalmers R. Prevalence of ocular surface symptoms, signs, and uncomfortable hours of wear in
contact lens wearers: the effect of refitting with daily-wear silicone hydrogel lenses (senofilcon a). Eye Contact Lens 2006
Dec;32(6):281-6.
22. Carney FP, Nash WL, Sentell KB. The adsorption of major
tear film lipids in vitro to various silicone hydrogels over
time. Invest Ophthalmol Vis Sci 2008 Jan;49(1):120-4.
23. Dumbleton K, Keir N, Moezzi A, et al. Objective and subjective responses in patients refitted to daily-wear silicone
hydrogel contact lenses. Optom Vis Sci 2006
Oct;83(10):758-68.
24. Dillehay SM. Does the level of available oxygen impact
comfort in contact lens wear? A review of the literature. Eye
Contact Lens 2007 May;33(3):148-55.
25. Chalmers R, Long B, Dillehay S, Begley C. Improving
contact-lens related dryness symptoms with silicone hydrogel lenses. Optom Vis Sci 2008 Aug;85(8):778-84.
26. Harvitt D, Bonanno J. Re-evaluation of the oxygen diffusion
model for predicting minimum contact lens Dk/t values needed
to avoid corneal anoxia. Optom Vis Sci 1999;76:712-719.
27. Ostrem E, Fink B, Hill R. A hypoxic response line model
for the human cornea. Br J Optom Disp 1996;4:53-55.
28. Dart JK, Radford CF, Minassian D, et al. Risk factors for
microbial keratitis with contemporary contact lenses: a casecontrol study. Ophthalmology 2008 Oct;115(10):1647-54.
29. Stapleton F, Keay L, Edwards K, et al. The incidence of
contact lens-related microbial keratitis in Australia. Ophthalmology 2008 Oct;115(10):1655-62.
30. Richdale K, Berntsen DA, Mack CJ, et al. Visual acuity
with spherical and toric soft contact lenses in low- to moderate-astigmatic eyes. Optom Vis Sci 2007 Oct;84(10):969-75.
31. Morgan PB, Efron SE, Efron N, Hill EA. Inefficacy of
aspheric soft contact lenses for the correction of low levels of
astigmatism. Optom Vis Sci 2005 Sep;82(9):823-8.
32. Young G, McIlraith R. Toric soft contact lens visual acuity
with abnormal gaze and posture. AAO October 2008.
33. Zikos GA, Kang SS, Ciuffreda KJ, et al. Rotational stability of toric soft contact lenses during natural viewing conditions. Optom Vis Sci 2007 Nov;84(11):1039-45.
34. Census Bureau. U.S. Interim Projections by Age, Sex,
Race, and Hispanic Origin: 2000-2050. Available at:
www.census.gov/population/www/projections/usinterimproj
(Accessed November 2008).
35. Lemp MA, Caffery B, Lebow K, et al. Omafilcon A (Proclear) soft contact lenses in a dry eye population. CLAO J
1999 Jan;25(1):40-7.
36. Young G, Bowers R, Hall B, Port M. Clinical comparison
of Omafilcon A with four control materials. CLAO J 1997
Oct;23(4):249-58.
37. Riley C, Chalmers RL, Pence N. The impact of lens
choice in the relief of contact lens related symptoms and
ocular surface findings. Cont Lens Anterior Eye 2005
Mar;28(1):13-9.
38. The epidemiology of dry eye disease: report of the Epidemiology Subcommittee of the International Dry Eye
WorkShop (2007). Ocul Surf 2007 Apr;5(2):93-107.
027_rccl0109_CE_F
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Self-Assessment Examination:
Develop Your Specialty Contact Lens Practice
DIRECTIONS: To obtain 2 hours of continuing education credit, complete the exam by recording the best answer to each self-assessment question on the Examination
Answer Sheet on Page 34. Mail the answer sheet to Optometric CE, P.O. Box 488, Canal Street Station, New York, NY 10013. A minimum score of 70 is required to
obtain a certificate of completion. There is no fee for this course.
1. Flourescein works well in examining the integrity of the cornea
because of its ____________ properties.
a. Hydrophilic.
b. Hydrophobic.
c. Bipolar.
d. None of the above.
2. All of the following are examination findings that may undermine
comfortable contact lens wear EXCEPT:
a. Corneal staining.
b. Increased tear film break-up time.
c. Presence of lid wiper epitheliopathy.
d. Meibomian gland disease.
3. Guillon and Maissa examined contact lens wearers and found a
greater specificity of ____________________ staining for those
who showed symptoms of dry eye.
a. Corneal lissamine green.
b. Conjunctival lissamine green.
c. Corneal flourescein.
d. Conjunctival flourescein.
4. Oxygen permeability in a hydrogel contact lens is:
a. Directly related to its water content.
b. Inversely related to its water content.
c. Directly related to its modality.
d. Directly related to its parameters.
5. The examination process is comprised of:
a. Lens selection, fitting, and asking the patient for a referral.
b. Conversations about new lens technologies and ocular examination.
c. A visual acuity test.
d. Gathering patient history, the actual exam and medical decision-making.
6. A silicone hydrogel contact lens will typically deposit ________
proteins and _________ lipids than their hydrogel predecessors.
a. More, more.
b. More, less.
c. Less, less.
d. Less, more.
7. Neovascularization of the cornea and limbal hyperemia are usually
signs of:
a. Dry eye.
b. MGD.
c. Corneal hypoxia.
d. Infection.
8. A hydrogel contact lens that is higher in water content:
a. Is ideal for pediatric patients.
b. Is more oxygen permeable.
c. Is rotationally stable.
d. Is less oxygen permeable.
9. In a recent study by Riley and associates, what percent of contact
lens wearers refit into the senofilcon A material reported better
comfort?
a. 35%.
b. 70%.
c. 88%.
d. 90%.
10. Which of the following signs will typically decrease when a patient
is fit with silicone hydrogel lenses?
a. Limbal and bulbar redness.
b. Palpebral papillary response and bulbar redness.
c. Hyperopic refractive error and limbal redness.
d. Corneal neovascularization.
11. Ostrem, Fink and Hill have proposed a minimum Dk/t of ____ to
maintain normal corneal physiology during daily wear of contact
lenses.
a. 35.
b. 70.
c. 90.
d. 125.
12. What seems to result in the lowest rate of microbial keratitis?
a. Utilizing lenses made of silicone hydrogel.
b. Utilizing lenses that are HEMA based.
c. Utilizing daily disposable contact lenses.
d. Wearing contacts on a daily wear schedule.
13. How can practitioners maximize the comfort of lenses known to
deposit protein and lipids on their surfaces?
a. Prescribe a solution that effectively removes lipids and protein.
b. Advise patients to include a rub-and-rise step in their care regimen
before soaking their lenses
c. Both a and b.
d. Advise patients to choose another lens.
14. What design does the Acuvue Oasys for Astigmatism utilize to stabilize the contact lens?
a. Double thin zone.
b. Prism ballast design.
c. Accelerated stabilization design.
d. Distance-center design.
15. Research has shown that comfort ________when patients who
wore hydrogel lenses are refit with silicone hydrogel lenses.
a. Decreases significantly.
b. Remains the same.
c. Increases.
d. Decreases slightly.
33
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Examination Answer Sheet
Valid for credit through January 31, 2010
Develop Your Specialty Contact Lens Practice
Directions: Select one answer for each question in the exam and completely darken the appropriate circle. A minimum score of 70% is required to earn credit.
Mail to: Optometric CE, PO Box 488, Canal Street Station, New York, NY 10013
COPE approval for 2 hours of CE credit is pending.
16. Although they have similar designs, the Frequency
55 multifocal is made of________, whereas the
Proclear Multifocal is made of __________.
a. Methafilcon A, omafilcon A.
b. Omafilcon A, methafilcon A.
c. Lotrafilcon A, omafilcon A.
d. Methafilcon A, lotrafilcon A.
17. Knowledge and utilization of the latest _________
contact lenses helps the practitioner successfully
fit astigmats with challenging visual demands.
a. Silicone hydrogel.
b. Toric.
c. Multifocal.
d. Colored.
18. _______ of the American population will be
between the ages of 40 and 59 by the year 2010.
a. One-half.
b. One-eighth.
c. One-fourth.
d. One-third.
19. The Acuvue bifocal:
a. Is a silicone hydrogel multifocal contact lens.
b. Is based on a concentric ring platform.
c. Has different contact lens designs designated as
dominant and non-dominant.
d. Is made of lotrafilcon A.
20. What type of contact lens is ideal for changing the
color of the iris in a patient with a dark colored iris?
a. Opaque.
b. Tinted.
c. Daily disposable.
d. Hydrogel.
This course is joint-sponsored by the University of Alabama School of Optometry and supported by an unrestricted educational grant from The Vision Care InstituteTM, LLC.
There is an eight-to-ten week processing time for this exam.
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21. The goal statement was achieved:
Very Well
Adequately
Poorly
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25. The quality of the course was:
Excellent
Fair
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How long did it take to complete this course?
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22. The information presented was:
Very Useful
Useful
Not Very Useful
23. The difficulty of the course was:
Complex
Appropriate
Basic
24. Your knowledge of the subject was increased:
Greatly
Somewhat
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Lesson 106026
34 REVIEW OF CORNEA & CONTACT LENSES | JAN/FEB 2009
Date
RCCL-UAB-0109
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Here is what you need to look for to ensure proper eyelid analysis, diagnosis and
appropriate therapy. By Katherine M. Mastrota, M.S., O.D., F.A.A.O.
C
lear, comfortable vision can
only be achieved with optimum interaction of the lids
with the eye and the balance maintained by a normal tear film. Any
violation of the lid architecture
and/or disruption of the tear film
will inevitably lead to compromised
visual clarity and a constellation of
pathologic symptoms that include
contact lens intolerance.
Let’s take a closer look at the
close connection between the lids,
the eye and the contact lens.
Lid Health is Skin Deep
The practitioner is encouraged
to carefully evaluate the visage
of every patient. This is best
accomplished in the examination
chair under a bright light with
the examiner scanning the face
and neck of the patient for scarring, change in facial or eyelid
tonus or dermatologic disease.
Eye-care practitioners must
assess the skin of the patient’s
face and adnexa. Any change in
normal appearance should be
noted; the skin’s texture, color,
pigmentation and overall condition all require attention. Often,
skin disease is reflected in the
eyelids and lid margins and will
ultimately have an impact on
ocular surface function.
Dr. Mastrota
is Center
Director at
the New
York Office
of Omni Eye Services.
She has lectured locally
and nationally on her special areas of interest,
which include ocular surface disease and pseudoexfoliation syndrome.
35
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1, 2. Lash misdirection and lid notching. Note lid debris (left). Pearly keratinization
along the lid margin obstructing meibomain gland orifices (right). Note scaly debris at
the eyelash base.
If you see scarring, query the
patient as to the origin and circumstances of its presence. Of
particular concern are scars on the
lids, face and neck that result
from cosmetic surgery or treatments, neck or carotid surgery,
trauma, chalazion removal, scars
incurred from past thyroid surgery, acoustic neuroma surgery or
dermatologic concerns.
Cosmetic surgery (e.g., blepharoplasty) or therapy with
Botox injection (Botulinum toxin
type A, Allergan), can alter the
position and function of the eyelids and surrounding tissues.
Exposure of the ocular surface
after blepharoplasty is not uncommon. Similarly, over-injection or
missed injections of Botulium
toxin could result in ptosis or
incomplete lid closure.1,2
Possible complications of neck
or carotid surgery include
Horner’s syndrome with anisocoria and ptosis on the ipsilateral
side.3 Trauma or excision of lid
lesions can result in lid notching
that alters the tear-spreading
capabilities of the blink. Prior
history of chalazia removal can
attest to the chronicity of a patient’s disease.
A neck scar could indicate surgical management of thyroid disease (surgical removal of the
36
thyroid gland). Such presentations
warrant further testing in order to
rule out ocular manifestations of
the disease, such as immune-mediated dry eye. Signs of hyperthyroidism include proptosis or lid
lag, both of which allow for
increased tear evaporation. Eyebrow and eyelash loss is also seen
in dysthyroidism.
Ectropion or entropion, commonly associated with age, can
also develop from pathologic
states; intuitively, these lid malpositions will create a compromised
lid-surface system and ultimately
lead to patient symptoms. The
weight of sagging jowls of a
patient with age-related mid-facial
descent can draw down the lower
eyelids, allowing for scleral show
and increased tear film evaporation. Similarly, patients with shallow cheekbones can lack adequate
bony support of the lower lids,
again allowing for incomplete
inferior ocular surface coverage.
Seborrhea, a hyperkeratinization of the skin rich in sebaceous
glands, is thought to be caused by
the yeast Pithyosporin ovale and
can lead to a scaly anterior blepharitis and cause keratinization
of the eyelid margin, contributing
to obstruction of the meibomian
gland orifices.4 More common in
men, this condition will present
as flaking in the eyebrow area,
scalp and facial skin. Antifungal
dandruff shampoos can be effective in controlling symptoms in
these patients.
Ocular rosacea may exist alone,
but often accompanies other subtypes of rosacea, which include
erythematotelangiectatic, papulopustular, and phymatous rosacea.
Rosacea is an inflammatory disease of unknown etiology. There
are many trigger factors—including sun exposure, Demodex mite
infestation, stress, hot weather
and certain foods—that exacerbate the dermatologic symptoms
of rosacea. Characteristic changes
of the skin include facial redness
or flushing, at times accompanied
by skin stinging and burning, visible blood vessels and skin roughness. Papules and pustules can
occur in rosacea, and/or phymatous (thickening) changes of the
skin (nose, chin, forehead, ears)
with large, irregular pores and
bumps. Pathology in ocular
rosacea includes mild to significant telangiectatic vessel development on the eyelid margin,
meibomian gland sebborhea and
dysfunction, keratitis and, if
aggressive, corneal ulceration with
possible perforation.
Rosacea and, to a lesser extent,
rosacea-associated MGD are
responsive to oral administration
of low-dose tetracyclines, which
have been shown to reduce bacterial lipases and inhibit collegenase, thereby tempering
inflammation.5 Two convenience
kits available by prescription are
the Alodox Kit (Cynacon OCuSOFT) and the Nutridox kit
(Advanced Vision Research). Each
includes doxycycline tablets, lid
cleaning products, and an eyelidwarming device. Of course,
adverse effects to oral tetracyclines exist, and effective local
035_rccl0109_Lids
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Page 37
application would be preferable.
Pharmacy-compounded topical
tetracyclines are being studied for
their effect in MGD, and topical
administration of the highlyabsorbed macrolide azithromycin
(AzaSite, Inspire Pharmaceuticals)
has shown significant promise in
improving MGD in this off-label
use of the product.6 Additionally,
the meibomian gland is a hormone target, therefore sparking
interest in the potential for treating MGD with topical administration of hormone compounds.
Finally, the practitioner must
question patients regarding their
history of atopic disease. Patches
of eczema or psoriasis may be evident in elbow or wrist skin creases; dermal changes in appearance
and function of the eyelid may
alert the practitioner to the allergic status of the patient. In the
young patient, look for a Morgan
Dennie fold or atopic pleat, a fold
(or multiple folds) of eyelid skin
created by lid edema in the allergic patient. Likewise, infraorbital
congestion creates dark circles
under the eyes (allergic shiner).
Ocular allergy is a major contributor to ocular surface dysfunction
and long-term changes in its
anatomy and function.
A Look Beyond
Acoustic neuromas affect approximately 2,500 people in the United
States annually.7 As schwannomas
that surround the acoustic nerve,
these brain tumors cause tinnitus.
Patients who undergo surgical
removal of the tumor are at significant risk for postoperative complications associated with inadvertent
damage to the VII nerve. These
include corneal hypoesthesia, poor
eyelid tonus and lagophthalmos.8
Similarly, any cause of VII nerve
palsy may leave lid function compromised in affected patients.
Eyelid tonus is an often-overlooked cause of ocular surface disease and contact lens-wear failure.
Laxity of either the upper or lower
eyelid allows for faulty blink
mechanics and inadequate tear
resurfacing. Lagophthalmos and
nocturnal lagophthalmos, which
at times may be challenging to
detect, are important conditions to
consider during the external evaluation.9 Every patient’s blink should
be examined for rate, excursion
and completeness; any gap or drift
in eyelid closure will set the stage
for evaporative surface problems.
The classic triad of Floppy Eyelid Syndrome (FES), first
described by Culbertoson in 1981,
is over-weight, middle-aged males
with lax, rubbery eyelids associated with papillary conjunctivitis.10
We have come to learn, however,
that FES is not exclusive to overweight individuals or men, and
that it can present in patients
young and old, svelte or obese,
male or female and in any age
group, including infants. Unless
purposely evaluated, the presence
of FES can be easily overlooked
during routine examination.11
Clinical signs of FES include
ptosis, eyelash ptosis, dermatochalasis, eyelid hyperpigmentation and lacrimal gland prolapse.
FES is associated with rosacea,
meibomian gland dysfunction
(MGD) and the presence of the
follicular and sebaceous gland
mite Demodex. Patients should
be evaluated for sleep apnea,
because there is a strong association with FES.12
Contact lens fitters are particularly interested in the association
of keratoconus with FES.13 Mechanical trauma, a proposed mechanism both of flaccid lids and of
the conjunctival pathology of FES,
has also been implicated in the
development of keratoectasia.14-17
3. Normal, regular appearance of the
Marx line stained with lissamine green.
Chronic eye-rubbing, triggered by
a variety of factors (most notably
rubbing in response to itch precipitated by allergic disease), has
been considered as an inciting factor for corneal ectasia.
Life on the Edge
Critical evaluation of the eyelid
margin is essential in routine eye
evaluations and especially important for characterizing ocular surface disease states in contact lens
wearers pre- and post-fitting.
Starting anteriorly, careful
examination of the eyelashes is
necessary; the lashes should be
examined for number, placement,
misdirection, color, integrity and
ease of epilation from the follicle.
Easily epilated lashes suggest lash
follicle edema, prompting concern
for inflammatory conditions of the
lash follicle. Causes of madarosis
must be explored and taken under
4. Undulating lissamine green-stained
Marx line in a patient with MGD. A watery
tear film is obvious.
37
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consideration. There are many
causes of madarosis, such as thyroid disease and diabetes, which
will also impact the normal functioning of the ocular surface. Cosmetic treatments of lids and
lashes, such as eyelid tattooing or
eyelash extensions (natural or synthetic “lashes” individually bonded to the natural lashes) may be
associated with meibomain gland
dysfunction and blepharitis as
well.11 Blepharitis, however, is the
primary cause of eyelash loss or
abnormal growth (figure 1).18
Blepharitis
Blepharitis, or lid margin disease,
is generally divided into two classes,
anterior and posterior blepharitis—
although the two forms impact each
other and are seldom found independent of one another. Both forms
can be inflammatory or infectious,
is usually chronic with periods of
exacerbation, and it is typically
bilateral. Long-standing lid margin
disease leads to keratinization of the
lid margin and rounding and undulation of the formerly-sharp lid
margin edge (figure 2).
5. Excessive meibomian gland capping in
a patient with both anterior and posterior
blepharitis.
Anterior blepharitis describes
pathologic lid changes surrounding
the eyelash margin. Most commonly caused by staphylococcal or sebborheic skin inflammation, it is
identified by flaky, scaly changes of
38
the eyelid skin and accumulation
of debris at the eyelash base.
Ulceration may be present under
the flaky debris. Lipolytic
enzymes produced by the resident
bacteria hydrolyze tear film lipid,
releasing highly irritating free
fatty acids (saponification), which
disrupt the tear film and its properties and causes the characteristic
foamy appearance commonly seen
in lid disease.
Similarly, in angular blepharitis,
bacterial overpopulation causes
excoriation of the skin at the canthi. Both are managed with
cleansing of the area, preferably
with a commercially developed
product such as OCuSOFT lid
scrubs (Cynacon-OCuSOFT).
OCuSOFT lid scrub products
recently have been demonstrated
to kill Demodex folliculorum,
which is associated with blepharitis.19 Home made shampoo-type
solutions expose the patient to
unnecessary fragrances and colorings and may contribute to the
disease process or precipitate an
allergic reaction. Application of
antimicrobial ointment or, for
example, the DuraSite (InSite
Vision) based macrolide AzaSite
(azithromycin, Inspire, off-label
use) to the cleaned lid margin is
appropriate therapy to reduce the
bacterial load on the skin.
Posterior blepharitis, or MGD,
commonly refers to inflammation
or changes in function of the meibomian glands. Critical examination of the lid margin behind the
eyelash line is necessary to evaluate patients with MGD. Moving
posteriorly from the eyelash line,
the examiner should identify
eyelid margin landmarks, including the mucocutaneous junction,
the gray line, and the meibomian
gland orifices. The gray line delineates the lid into anterior and posterior lamella and represents
Riolan’s muscle, the most anterior
segment of the obicularis oculi.
The mucocutaneous border of the
lid margin, a line of squamous
cells also known as Marx’s line,
runs a course parallel to the eyelid
margin. Marx’s line stains clearly
with lissamine green and in
advanced lid disease, will become
scalloped and irregular. Characterization of changes in Marx’s
line has been suggested as a simple tool in grading MGD and is
easily performed in any clinical
setting (figures 3 and 4).20
The meibomian gland orifices
open to the margin surface behind
the gray line. The production of
meibum and proper function of
the glands and the lipid they produce is essential for reducing
evaporation of the tear film. The
anatomy of the meibomian glands
should be appreciated as well as
the quality and quantity of the
lipid they produce.
Examination of the meibomian
glands begins with a look at the
quantity of gland orifices, their
position and regularity. The gland
orifice, which is surrounded by a
small translucent cuff, should be
checked for patency vs. stenosis.
Normal orifices will most often be
situated at regular intervals—in
MGD, the orifices may be pouted,
plugged, capped or positioned
irregularly due to traction or scarring (figure 5). The orifices can
become keratinized, which leads
to gland obstruction and its
sequelae that includes inflammation and in advanced disease,
atrophy. Loss of adequate
amounts of meibomian gland
lipid, or abnormal lipid, allows for
increased tear evaporation. The
compromised tear film in MGD
can make contact lens wear challenging by reducing wearing time,
causing lens awareness, and taxing
the corneal surface. The tear film
035_rccl0109_Lids
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Page 39
can become watery, as it is the
lipid layer that holds the tears film
“tight to the eye.” Frequent chalazia are not uncommon in these
patients; however, a history that
suggests a focal, recurrent lesion
should prompt an investigation in
order to rule out meibomian gland
carcinoma or perhaps, a discoid
lupus lesion of the lid margin.
Changes in lid margin vascularity also accompany MGD. The
normal small capillary loops
under the lid epithelium and the
superficial vessels derived from
the conjunctiva become engorged,
and fine filigree telangiectatic vessels develop, especially in ocular
rosacea (figure 6). Advanced cases
of ocular rosacea can manifest
with punctate epithelial keratopathy, marginal corneal infiltrates,
corneal neovascularization,
corneal thinning, ulceration and
perforation.
Treatment and Management
Mechanical expression of the
meibomian gland and examination of its contents is a useful
diagnostic practice and may be of
therapeutic value in patients with
MGD.21 There are a variety of
methods used to express meibum
from the meibomian glands; the
goal of expression is characterization of the produced lipid and an
estimation of functioning glands.
Korb has recently described a
technique that quantifies the force
of expression.22
Knowing that not all glands are
producing lipid at the same time, it
is helpful to perform meibography
(meibomian gland transillumination, easily accomplished at the
slit lamp with a muscle light) for
evaluation of gland morphology
and density corresponding to the
identified orifice. “Dimpling” or
“divoting” of the lid margin suggests focal gland contraction,
6. Lid margin telangetasia in a patient
with ocular rosacea. Notice the rounding
and irregularity of the lid margin edge
and lid debris.
dropout or atrophy (figure 7).
Every exam should include inspection of the meibomian gland on
the palpebral side of the eyelid,
looking for cystic changes or compaction of the gland.
Normal meibum egresses with
minimal pressure to the meibomian
gland and is clear; any opacification, “granulation” or thickening
of meibum indicates gland dysfunction. Lipid may be copious
(meibomian gland seborrhea) and
easily evacuated or scant and pastelike, suggesting obstruction. Recent
recommendations for grading
expressible meibum have been
introduced and can prove useful in
gauging gland disease and the
impact of applied therapies.
Expressable lipid can be graded
from clear and free-flowing, to
opaque and stagnant on a fourpoint scale.
Therapy for posterior blepharitis
is guided by the severity of its presentation. Early disease is best managed by routine warming of the lids
to soften congested meibum within
the gland, followed by mechanical
massage to aid in thickened oil
egress. Cool compresses following
massage can reduce swelling and
vasodilatation and may prove comforting to your patients.
Omega-3 fatty acids have been
demonstrated to play a positive
role in the normalization of the
meibum. Best choices for supplementation would include pharmaceutical grade, cold-pressed
commercially-prepared products
that ensure the purity and quality
of the product, avoiding solvents
and heat which can damage oils.
Also, topical ester-based steroids,
such as Lotemax and Alrex
(Bausch & Lomb) alone or in
antibiotic combination with Zylet
(loteprednol etabonate 0.5% and
tobramycin 0.3%, Bausch &
Lomb) are a good choice for managing lid disease and inflammatory
keratitis. It should be noted that
Restasis (cyclosporine A, Allergan)
has been identified to reduce signs
of posterior blepharitis and can be
an effective long-term management strategy.23
Under the Lid
7. Focal lid margin “divot” secondary to
focal meibomian gland dropout (pale
area).
Thorough lid examination
requires a look at the palpebral
conjunctival surface of the eyelid.
39
035_rccl0109_Lids
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Page 40
Without exception, every patient’s
palpebral conjuctiva (everted superior and inferior) should be
inspected under white light, followed by re-examination with vital
dye staining. Findings such as
hyperemia, papillary or follicular
reactions, lesions, granulomas or
concretions, scarring and fibrosis,
abnormal pigmentation or deposits
are all possible and require diagnosis and management.
The tarsal conjunctiva of the
upper lid features a stratified
columnar epithelium with stratified squamous epithelia on the
distal lid margins (the lid wiper).
It has been suggested that trauma
to the cuboidal lid epithelium,
sensitive and reactive to rubbing,
results in secretion of mucous and
activation of the inflammatory
cascade, ultimately leading to the
development of giant papillae on
the upper tarsal conjunctiva.24
Giant papillary conjunctivitis
(GPC), is generally grouped into
allergy-type responses. It is thought
to be precipitated by a combination of mechanical and autoimmune components.25 Although
most often associated with soft
contact lens wear (contact lens
papillary conjunctivitis, or CLPC),
GPC can develop in response to
any mechanical irritation, such as
exposed sutures, or any other antigenic material , especially those
that can accumulate on the contact
lens. Besides large tarsal papillae,
patients with GPC or CLPC may
experience itching, excessive lens
movement and a mucoid discharge.
If the papillae are excessive, there
can be a resultant ptosis.
The portion of the marginal
conjunctiva of the upper eyelid
that “wipes” the ocular surface
during blinking has been referred
to as “the lid wiper.” Changes in
the lid wiper can be highlighted
with vital dyes. Termed “lid wiper
40
epitheliopathy,” identification of
an altered lid wiper region correlates well with dry eye symptoms
in both contact lens wearers and
non-lens wearers , even in the
absence of other signs of ocular
surface disease.26,27 Thus, we must
pay particular attention to the lid
wiper region in patients who
report symptoms consistent with
ocular surface dysfunction, yet
present with minimal signs of
corneal surface staining and tear
break-up time abnormalities.
Evaluation of the palpebral
conjunctiva will, every now and
again, disclose the presence of
conjunctival concretions, otherwise known as conjunctival lithiasis. Occasionally, concretions will
erode through the conjunctiva and
abrade the corneal surface. Once
thought to be of calcific nature,
concretions have been demonstrated to be composed of mucinous secretions and degenerated
epithelial cells. It may be, as proposed by Duke-Elder in 1965,
that concretions arise from chronic conjunctival inflammation.28
Knowing this, clinicians should be
clued into those mechanisms of
chronic, low-grade inflammation,
such as allergy and perhaps
chronic staphylococcal infection
and/or hypersensitivity.
All Things Considered
The many facets of lid disease
require thoughtful evaluation and a
step-wise plan for ameliorating
symptoms related to its pathologic
effects. Therapy may be mechanical,
nutritional or can employ a variety
of therapeutic agents. Patience and patient education are key
to management of this frustrating
ubiquitous disease. Finally, attention must be given to characterization of the position and the tone of
the eyelid itself and how it interplays with the ocular surface.
RCCL
1. Carruthers A, Carruthers J. Clinical indications and injection
technique for the cosmetic use of botulinum A exotoxin. Dermatol Surg 1998 Nov;24(11):1189-94.
2. Northington ME, Huang CC. Dry eyes and superficial punctate
keratitis: a complication of treatment of glabelar dynamic
rhytides with botulinum exotoxin A. Dermatol Surg 2004
Dec;30(12 Pt 2):1515-7.
3. Perry C, James D, Wixon C, et al. Horner’s syndrome after
carotid endarterectomy—a case report. Vasc Surg 2001 JulAug;35(4):325-7.
4. Bergbrant IM. Seborrhoeic dermatitis and Pityrosporum
yeasts. Curr Top Med Mycol. 1995;6:95-112.
5. Dougherty JM, McCulley JP, Silvany RE, Meyer DR. The role
of tetracycline in chronic blepharitis: Inhibition of lipase production in Staphylococci. Invest Ophthalmol Vis Sci 1991:
32:2970-5.
6. Luchs J. Efficacy of topical azithromycin ophthalmic solution
1% in the treatment of posterior blepharitis. Adv Ther 2008
Sep;25(9):858-70.
7. Acoustic Neuroma (1991) NIH Conseus Dev Conf Consens
Statement 9:1–24,
8. Mulhern MG, Adruriz-Lorenzo PM, Rawluk D, et al. Ocular
complications of acoustic neroma surgery. Br J Ophthalmol
1999 Dec;83(12):1389-92.
9. Latkany RL, Lock B, Speaker M. Nocturnal lagophthalmos: an
overview and classification. Ocul Surf 2006 Jan;4(1):44-53 .
10. Culbertson WW, Ostler HB. The floppy eyelid syndrome. Am
J Ophthalmol 1981 Oct;92(4):568-75.
11. Mastrota KM. Impact of floppy eyelid syndrome in ocular
surface and dry eye disease. Optom Vis Sci 2008
Sep;85(9):814-6.
12. Van Nouhuys HM, van den Bosch WA, Lemij HG, Mooy CM.
Floppy eyelid syndrome associated with Demodex Brevis. Orbit
1994 Sep;13(3):125-9.
13. Negris R. Floppy eyelid syndrome associated with keratoconus. J Am Optom Assoc 1992 May;63(5):316-9.
14. Mc Monnies CW. The evidentiary significance of case
reports: eye rubbing and keratoconus. Optom Vis Sci 2008
Apr;85(4):262-9.
15. Korb DR, Greiner JV, Leahy CD. Forceful eye rubbing as a
causative factor in keratoconus. Ophthalmol
1995;102(suppl):152.
16. Mc Monnies CW, Boneham GD. Keratoconus, allergy, itch,
eye rubbing and hand dominance. Clin Exp Optom 2003
Nov;86(6):376-84.
17. Mc Monnies CW. Abnormal rubbing and keratectasia. Eye
Contact Lens 2007 Nov;33(6 Pt 1):265-71.
18. Khong JJ, Casson RJ, Huilgol SC, Selva D. Madarosis. Surv
Ophthalmol 2006 Nov-Dec;51(6):550-60. Review.
19. Yee R. Efficacy of OCuSOFT lid scrub plus on eradication of
ocular demodex. July 2008. Study on file, Cynacon OCuSOFT.
20. Yamaguchi M, Kutsuna M, Uno T, et al. Marx Line: fluorescein staining line on the inner lid as indicator of meibomian
gland function. Am J Ophthalmol 2006 Apr;141(4):669-75.
21. Paranjpe DR, Foulks GN. Therapy of meibomian gland disease. Ophthalmol Clin North Am. 2003 Mar;16(1):37-42.
Review.
22. Korb DR, Blackie CA. Meibomian gland diagnostic expressibility: correlation with dry eye symptoms and gland location.
Cornea 2008 Dec;27(10):1142-7.
23. Perry HD, Doshi-Carnevale S, Donnenfeld ED, et al. Efficacy
of commercially available topical cyclosporine A 0.05% in the
treatment of meibomian gland dysfunction. Cornea 2006
Feb;25(2):171-5.
24. Personal communication. Donald Korb. (September 02,
2008)
25. Elhers WH, Donshik PC. Giant papillary conjunctivitis. Curr
Opin Allergy Clin Immunol 2008 Oct;8(5):445-9
26. Korb DR, Greiner JV, Herman JP, Hebert E, Finnemore VM,
Exford JM, Glonek T, Olson MC. Lid-wiper epitheliopathy and
dry-eye symptoms in contact lens wearers. CLAO J 2002
Oct;28(4):211-6.
27. Korb DR, Herman JP, Greiner JV, et al. Lid wiper epitheliopathy and dry eye symptoms. Eye Contact Lens 2005
Jan;31(1):2-8.
28. Duke-Elder S. Diseases of the outer eye. Conjunctiva. In:
System of Ophthalmology. Vol 8. St. Louis. CV Mosby.1965.

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