Session 439 Corneal refractive surgery II

Transcription

ARVO 2016 Annual Meeting Abstracts
439 Corneal refractive surgery II
Wednesday, May 04, 2016 11:00 AM–12:45 PM
Exhibit/Poster Hall Poster Session
Program #/Board # Range: 4841–4893/A0057–A0109
Organizing Section: Cornea
Contributing Section(s): Visual Psychophysics/Physiological Optics
Program Number: 4841 Poster Board Number: A0057
Presentation Time: 11:00 AM–12:45 PM
Successful Treatment with Combined PRK/PTK Smoothing for
the Treatment of Severe Corneal Haze after Surface Ablation
Bongjoon Choi. Ophthalmology, Lee Eye Hospital, Busan, Korea (the
Republic of).
Purpose: The surface irregularity is known as important cause of the
corneal haze after eximer laser surface ablation. We evaluated the
clinical effects of PRK and PTK smoothing for treatment of severe
corneal haze after surface ablation
Methods: We retrospectively reviewed the medical records of 10
eyes of 6 patients who had undergone gentle removal of corneal haze,
PRK and PTK smoothing for the treatment of severe corneal haze
after surface ablation.
Corneal epithelium was removed with 20% alcohol instillation for
50 seconds. Subepithelial haze was debrided softly and half of the
refractive error was corrected with PRK mode. Then PTK smoothing
was performed with slit scanning excimer laser using masking
fluid(0.3% HA) until the rough corneal surface was smooth. At the
end of the surgery, the 0.02% mitomycin C was applied
Results: The mean corneal haze score was 3.1 grade. Mean PRK
correction was -1.6D and PTK depth was 41.4 μm(about 10 μm real
depth). Mean mitomycin C application time was 85 seconds. All
of the eyes had clear cornea and uncorrected visual acuity of more
than 20/20 1 year after surgery. The manifest refraction was within 1
diopter from emmetropia in all eyes.
Conclusions: Combined PRK and PTK smoothing was effective for
treatment of severe corneal haze after surface ablation. and we can
prevent the recurrence of corneal haze and reduce the mitomycin C
application time.
Commercial Relationships: Bongjoon Choi, None
Outcomes for Clinical Studies to Reduce Post-Operative
Induction of Spherical Aberration for Myopic LASIK Surgeries
Guang-ming G. Dai, Dimitri Chernyak, Sanjeev Kasthurirangan,
Janice Tarrant. Ophthalmology, Abbott Medical Optics, Milpitas, CA.
Purpose: To investigate the effectiveness of a new treatment
algorithm to reduce post-operative induction of spherical aberration
for myopic LASIK surgeries.
Methods: A new algorithm has been developed to reduce the
induction of spherical aberration observed in LASIK surgeries. The
process was postulated as a linear filtering operation to the cornea
after the ablation and during the healing process. An optimization
algorithm was employed to yield an optimized mathematical kernel
that can be applied to develop modified ablation shapes. A clinical
trial (STAR-114-SARA) was designed to test the effectiveness of
the new algorithm. 26 myopic patients were recruited in Bogota,
Columbia to participate in the study. The study was prospective,
paired-eye randomized, single-center, contralateral study with
the study eye treated with the new algorithm and the control eye
treated with CustomVue®. The pre-operative MRSE ranges from
-4 D to -12 D, with astigmatism up to 8 D. The patients’ ages range
from 20 to 48. Post-operative refractions, acuities, OCT, subjective
questionnaire, and high order aberration were collected in 1-day,
1-week, 1-month, and 3-month after surgery.
Results: The primary spherical aberration and secondary spherical
aberration of both the study eyes and the control eyes were
examined, together with other major HOA terms, such as coma and
secondary astigmatism, over a 6 mm diameter and a 5 mm diameter,
respectively. Over time, there is an increase of spherical aberration.
However, the amount of spherical aberration at the same time
point for the study eye is statistically significantly smaller than the
control eye, both at 6 mm diameter and 5 mm diameter, indicating
effectiveness of the new algorithm over previous treatments. At 6
mm diameter, the spherical aberration at 3-month post-op has a mean
of 0.2 um for the study eyes and 0.26 um for the control eyes. The
difference becomes more prominent at a smaller diameter. At 5 mm
diameter, the spherical aberration at 3-month post-op has a mean
of 0.02 um for the study eyes and 0.06 um for the control eyes. As
for the visual acuities, there is no statistically significant difference
between the two groups as expected, for both uncorrected and bestcorrected acuities.
Conclusions: The study shows the effectiveness of the new algorithm
to reduce the induction of spherical aberration for myopic LASIK
surgeries.
Commercial Relationships: Guang-ming G. Dai;
Dimitri Chernyak, Abbott Medical Optics;
Sanjeev Kasthurirangan, Abbott Medical Optics; Janice Tarrant,
Abbott Medical Optics
Clinical Trial: Bogota Laser, Bogota, Colombia, NCT01988415
Quality of Vision After Wavefront-Guided Laser-Assisted In Situ
Keratomileusis (LASIK) or Wavefront-Guided Photorefractive
Keratectomy (PRK): A Prospective Randomized Contralateral
Eye Evaluation
Michele D. Lee, Edward E. Manche. Ophthalmology, Stanford
University, Palo Alto, CA.
Purpose: To compare subjective quality of vision between two
modalities of refractive surgery, wavefront-guided LASIK and
wavefront-guided PRK, in the treatment of myopia up to one year
post-surgery in a prospective randomized contralateral eye study.
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/
to access the versions of record.
Methods: 64 eyes of 32 patients underwent refractive surgery,
with one eye treated with LASIK and the other with PRK with
eyes randomized for dominance. During preoperative visit and on
visits scheduled on postoperative months 1, 3, 6, and 12, patients
completed a questionnaire assessing their quality of vision and visual
symptoms. Results were quantified, and statistical comparisons
between the two modalities were made using a Student’s t-test, with a
P-value of less than 0.05 representing statistical significance.
Results: Preoperatively, there were no significant differences in
subjective visual quality or symptoms of each eye. One month
post-operation, PRK eyes were noted to have significantly worse
clarity during the day (P = 0.001) and at night (P = 0.001), worse
overall vision (P = 0.024), more fluctuations in vision (P = 0.006),
and more double vision or “ghosting” (P = 0.022) than LASIK eyes.
On postoperative months 3, 6, and 12, these symptoms were no
longer significantly different. In eyes with a higher order aberration
measured preoperatively (root-mean-square of 0.3 or greater),
which account for 44.1% of operated eyes, PRK eyes demonstrated
significant worsening in clarity during both day and night (P = 0.006
and 0.012, respectively) and more fluctuation in vision (P = 0.041)
at postoperative month 1 as compared to LASIK eyes. In eyes with
a lower order aberration, the only significant difference between
the two eyes was a decrease in daytime clarity in PRK eyes versus
LASIK eyes (P = 0.036) after 1 month. At 3, 6, and 12 months, there
were no significant differences in subjective symptoms between the
two eyes.
Conclusions: Subjective symptoms were overall better in LASIK
eyes only at postoperative month 1. Among pairs of eyes with a lower
order aberration, there were few differences in these symptoms when
contrasting the two modalities.
Commercial Relationships: Michele D. Lee, None;
Edward E. Manche
Clinical Trial: NCT01140594
Photonic Crystal Fibers for Femtosecond Laser Beam Delivery in
Medical Applications
Vladimir G. Lemberg, Saidur Rahaman, Zenon Witowski, Hong Fu.
Research & Development, Abbott Medical Optics, Milpitas, CA.
Purpose: Femtosecond lasers continue to revolutionize the field
of minimally invasive surgery. Unique properties of the ultra-short
pulses are very useful in variety of medical applications ranging from
general surgery, otolaryngology and dentistry to ophthalmology. In
some applications the use of conventional optical fiber laser beam
delivery is a common and convenient way to deliver the laser energy
to the target tissue. However, the uses of conventional fiber-based
beam delivery for ultra-short laser pulses are limited due to the
optical fiber’s dispersion. Recently hollow-core photonic crystal
fibers have been developed to address these limitations.
Methods: We evaluated the properties of Kagome hollow-core
photonic crystal fiber PMC-C-Yb-7C (GLOphotonics SAS, Limoges,
France) and its potential applications in ultra-short laser beam
delivery systems. The femtosecond laser beam was launched into
the Kagome fiber via variable NA optical system designed to focus
the laser beam to match the beam waist to fiber mode field diameter
and the numerical aperture of the fiber. We evaluated the coupling
efficiency, near and far field intensity profiles, fiber bend optical
losses as well as peak power handling capability. The Frequency
Resolved Optical Gating (FROG) was used to measure pulse duration
broadening at the fiber output.
Results: The femtosecond laser was coupled to the Kagome fiber
with 94.8% coupling efficiency. The transmission loss measured were
2.3% per 2 meter. This resulted in attenuation of -0.05 dB per meter
at the design wavelength 1030 nm. Particular emphasis was given to
the study of the beam quality and transmission losses as a function
of the bending radius down to 20 mm. The femtosecond laser
pulses were transmitted with virtually no pulse width broadening
due to close to zero dispersion (~1 fs/nm/meter) at design 1030 nm
wavelength.
Conclusions: Our study revealed that hollow core photonic crystal
fibers have the potential to be used for femtosecond laser beam
delivery. Its attributes of close to zero dispersion at the design
wavelength, absence of Fresnel reflections from the fiber-end faces,
high damage threshold and low transmission and bend losses down
to 30 mm bend radius render it a viable option to femtosecond beam
delivery to target tissue. This new technology provides the basis for
ultra-short and high power laser beam delivery.
© 2015 Abbott Medical Optics Inc.
SC2015RF0021
Commercial Relationships: Vladimir G. Lemberg,
Abbott Medical Optics; Saidur Rahaman, Abbott Medical
Optics; Zenon Witowski, Abbott Medical Optics; Hong Fu,
Abbott Medical Optics
Nomogram Based Lenticle setup in Smile
Francisco R. Sanchez-Moreno,
Oscar Fernandez, ELISA ALEGRIA GOMEZ. Cornea and refractive
surgery, Hospital de la Luz (FHNSL), Mexico city, Mexico.
Purpose: The following analysis attempts to answer and bring
information to refractive surgeons using the SMILE surgical setup
on the modifications that should be performed on the preoperative
refraction according to the final visual results.
Methods: Analytic, descriptive and ambispective study. Files from
patients that underwent SMILE based refractive surgery between
January 1st, 2015 and October 15th, 2015 were reviewed. A total of
206 eyes from 102 patients were included, rendering a mean lenticle
diameter of 7.8 mm. These were organized in 3 age groups (20-29
year old group, 30-30 year old group and 40 year old plus group) and
3 degree of myopia groups (mild from 0 to 3, moderate from 3 to 6
and severe more than 6) which compared myopia, astigmatism and
spherical equivalent with the different age groups. All calculations
were run using the Alpins method for the assesment of spherical and
cylinder power according to their correction index. Data analysis
was perferomed using Excel for the calculation of the máximum,
minumum, average, standard deviation values and comparing these
using a two way ANOVA.
Results: In the 20 to 29 year old group, the general correction
index was 1.049 diopters, for group 1 - 0.87 diopters, group 2 - 0.95
diopters, group 3 - 1.19 diopters, in the 30 to 39 year old group the
correction index was 0.82 diopters, for group one - 0.97 diopters,
group 2 - 1.1 diopters, gropu 3 - 1.5 diopters.
Conclusions: There is an important difference to be taken care
of according to age and refractive error in the final results after
corrective surgery using the SMILE setup that is independent
from the accuracy of the programmed refraction, this may be due
to the differences in the cicatrization process due to age and the
refractive error.
Commercial Relationships: Francisco R. Sanchez-Moreno, None;
Oscar Fernandez, None; ELISA ALEGRIA GOMEZ, None
Objective depth of field after laser blended vision LASIK using
MEL90 platform
Jiho Song1, Jae-hyung Kim1, Dong Yoon Kim1, Tae Hyung Lim2,
Geunyoung Yoon3. 1Ophthalmology, Chungbuk National University
College of Medicine, Cheongju-si, Korea (the Republic of); 2HanGil
Eye Hospital, Incheon, Korea (the Republic of); 3Flaum Eye Institute,
University of Rochester, Rochester, NY.
Purpose: To investigate the depth of field (DoF) of dominant (DE)
and non-dominant (NDE) eyes after Laser Blended Vision (LBV)
using MEL-90 platform (Carl Zeiss Meditec).
Methods: The ocular aberrations were measured using iTrace
(Tracey Technologies) preoperatively and 1 month postoperatively.
The modulation transfer functions (MTF) were calculated for a 5 mm
pupil and the area under the MTF curve (areaMTF) up to 60 cycles
per degree (cpd) was calculated at various defocus points ranged
from -1.0 to +3.0 with 0.05 diopter (D) steps The DoF defined as
a dioptric range for which image quality is higher than 80% of the
maximum of the calculated areaMTF was evaluated.
Results: Two male patients and eight females were included
(47.2 ± 4.60 years old). The preoperative root mean square (RMS)
of spherical aberration (SA) was 0.26 ± 0.11 and 0.13 ± 0.03 in the
DE and 0.30 ± 0.07 and 0.14 ± 0.05 in the NDE (P = 0.39 and 0.39,
respectively). The postoperative RMS of SA, horizontal coma, and
oblique trefoil in the NDE (0.12 ± 0.5, 0.12 ± 0.06, and 0.15 ± 0.08)
was higher than that in the DE (0.12 ± 0.5, 0.07 ± 0.06, and
0.05 ± 0.04, respectively). The maximum of areaMTF was 14.0 ± 3.9
in the DE and 10.6 ± 3.6 in the NDE. The DoF was 1.24 ± 0.51 D and
2.01 ± 1.07 D, respectively (P = 0.01).
Conclusions: With LBV using MEL90 platform, the NDE had larger
DoF, relatively. The induced HOAs in the NDE would increase the
postoperative DoF.
Commercial Relationships: Jiho Song; Jae-hyung Kim, None;
Dong Yoon Kim, None; Tae Hyung Lim, None; Geunyoung Yoon,
None
Efficacy, predictability, and astigmatic correction error of Small
Incision Lenticule Extraction for myopic astigmatism – a
prospective 12-month study
Iben B. Pedersen, Anders Ivarsen, Jesper Hjortdal. Department of
Ophthalmology, Aarhus University Hospital, Aarhus, Denmark.
Purpose: To evaluate refractive and visual outcome after Small
Incision Lenticule Extraction (SMILE) for myopic astigmatism with
12 months follow up.
Methods: The prospective clinical trial comprised 101 myopicastigmatic eyes (101 patients) treated with SMILE (cylinder
from -4.00D to -0.75D). Preoperative, 1-week, and 1, 3, 6,
9, and 12 month examination included manifest refraction,
uncorrected (UDVA), and corrected (CDVA) distance visual
acuity. To assess the change in postoperative astigmatism, manifest
refraction data were converted from spectacle to corneal plane in
plus cylinders. Cylinder axis from included left eyes was flipped
vertically to avoid the risk of orientation errors. By Alpins method,
Target Induced Astigmatism Vector (TIA) and Surgically Induced
Astigmatism Vector (SIA) were used to calculate Difference Vector
(DV; postoperative astigmatism when target is emmetropia), Error
of magnitude (EM; magnitude of DV), Error of angle (EA; axis of
SIA subtracted axis of TIA), Correction Index (CI; magnitude ratio
of SIA and TIA), and Index of success (IOS; magnitude ratio of DV
and TIA). Kruskal-Wallis and Wilcoxon Rank test were used for
comparison (non-Gaussian distribution).
Results: Preoperative refraction averaged -5.87D±2.13D in sphere
and -1.82±1.00D in cylinder. After 12 months, 74% and 93% of eyes
were within ±0.50D and ±1.00D of attempted refraction. LogMAR
UDVA and logMAR CDVA averaged 0.03±0.16 and -0.08±0.09 after
12 months, respectively. UDVA remained stable in the postoperative
period (p>0.19).
Mean DV was 0.47x91° at 12-month follow-up. No significant
differences were seen in residual cylinder values during the
postoperative period. Mean EM was 0.12±0.44D, while arithmetic
EA was 0.28±15°, significantly different from zero (Table 1).
In predictability regression analysis of SIA and TIA, an undercorrection of approx. 10% was observed at 12-month examination.
CI was 0.94±0.38, while IOS was 0.40±0.41 at 12-month follow-up,
with no significant changes during the postoperative period.
Conclusions: Treatment of astigmatism with SMILE seems to be
predictable, effective, and compareble to what is seen after LASIK
treatments. However, there seems to be an astigmatic undercorrection of approx. 10%, with a very small counter clockwise
position of the axis.
Commercial Relationships: Iben B. Pedersen, None;
Anders Ivarsen, None; Jesper Hjortdal, Carl Zeiss Meditec (R)
Support: Carl Zeiss Meditec, Jena, Germany
Laser vision correction in the setting of systemic collagen
vascular disorders
Julie M. Schallhorn1, Steven C. Schallhorn2. 1Ophthalmology, USC,
Los Angeles, CA; 2Optical Express, Glasgow, United Kingdom.
Purpose: To describe outcomes, complications and patient
satisfaction after LASIK in a large popuplation of patients with wellcontrolled collagen vascular disorders.
Methods: The records of Optical Express (Glasgow, UK), a large
provider of LVC, were searched to identify patients with a history of
collagen vascular disease that had undergone LASIK. Patients were
permitted to have surgery if thier disease had been well-controlled for
6 months and the patients had no ocular complications and there were
no clinical signs of keratoconjunctivitis sicca. Included diseases were
as follows: rheumatoid arthritis (RA), systemic lupus erythematosis
(SLE), psoriatitc arthritis (PsA), ankylosing spondylitis (AS),
scleroderma (Scl), Sjogren’s syndrome (SS), mixed connective tissue
disorder (MCT), and polymyalgia rheumatica (PMR). Information
was collected on duration of rheumatologic condition, current
medications, preoperative and postoperative best-corrected vision
(BCVA), manifest spherical equivalent (MSE), dry eye symptoms
using a standardized questionnaire, and overall satisfaction with the
procedure.
Results: A total of 290 patients (594 eyes) were identified. The
average age was 45.9 ± 11.5 years (range 19 to 69 years), and the
population was 70% female. The majority of patients (59%) had RA,
followed by 21.4% with SLE, 14.5% with PsA, 1.4% with Scl, 1%
with AS, and 0.3% each with SS, MCT, and PMR. The majority of
patients (23%) were controlled on methotrexate, followed by 9% on
hydroxychloroquine, 4% on sulfsalazine, 3% on diclofenac, 2% on
acetaminophen, 1.7% on prednisone, and 1% each on qunine and
etanercept. A total of 43% of patients were on no systemic therapy
at time of treatment. Treatments were for myopia (average MSE
-2.91 ± 1.85D) in 70% and hyperopia (average MSE +1.99 ± 0.89D)
in 30%. Postoperatively, 78% of patients had a monocular BCVA
of 20/20 or better, and 90% of patients had a binocular BCVA of
20/20 or better. 82% of patients had none to mild dry eye symptoms
preoperative, and 75% of patients reported none to mild dry eye
symptoms postoperative. Overall, 81% of patients reported they
were satisfied or very satisfied with the outcome, and 89% would
recommend treatment to a friend. No patient experienced a corneal
melt.
Conclusions: LASIK can be safely performed on patients with wellcontrolled collagen vascular disorders. Both clinical outcomes and
patient satisfaction are favorable.
Commercial Relationships: Julie M. Schallhorn, None;
Steven C. Schallhorn, Optical Express, Abbot Medical Optics (C)
Myopic LASIK Visual Rehabilitation: Multicenter Analysis of
Longitudinal Outcomes up to 1 year
Tarika Thareja2, George Asimellis1, Laurence T. Sperber2, A.
John Kanellopoulous1, 2. 1LaserVision.gr Clinical & Research Eye
Institute, Athens, Greece; 2Department of Ophthalmology, New York
University School of Medicine, New York, NY.
Purpose: Laser in situ keratomileusis (LASIK) is a safe, effective,
and predictable surgical procedure for myopia correction. Recent
advances in refractive laser platforms have been introduced. The
purpose of this study is to report one-year visual rehabilitation results
of myopic LASIK employing the Alcon/WaveLight Refractive Suite
(FS200-femtosecond and EX500-Excimer lasers, Alcon Surgical,
Ft.Worth, Tx).
Methods: Fifty-nine myopic eyes were subjected to femtosecondlaser assisted LASIK at two independent centers: one US-based (US
n1 = 24 eyes) and one Europe-based (EU n2 = 35 eyes). Eleven eyes
had myopia and 48 had myopia + astigmatism. Mean patient age
was 33.3 +/- 9.22 years (19 to 60). The following assessments were
performed pre-operatively (baseline) and post-operatively (PO):
visual acuity (uncorrected – UDVA, best corrected – CDVA, both
performed with EDTRS charts) and manifest refraction.
Results: Mean baseline refraction was -4.25 +/- 2.33D sphere (-12.00
to -0.25) and -0.95 +/- 0.85D cylinder (-4.0 to 0.0). For OD, mean
baseline CDVA was -0.046 +/- 0.086 LogMAR. Post-operative
UDVA was 0.043 +/- 0.147, -0.021 +/- 0.127, -0.024 +/- 0.112,
-0.041 +/- 0.098, and -0.059 +/- 0.127 LogMAR at day 1, 1 month,
3 months, 6 months, and 12 months PO, respectively. For OS, mean
baseline CDVA was -0.042 LogMAR. Post-operative UDVA was
0.038 +/- 0.118, -0.029 +/- 0.113, -0.027 +/- 0.113, -0.045 +/- 0.112,
and -0.067 +/- 0.099 LogMAR, respectively. At 1 month, 59.3% of
eyes had no change in CDVA, 22.0% of eyes gained 1 line, and 5.1%
gained 2 lines. At 12 months, 35.6% of eyes had no change in CDVA,
50.0% of eyes gained 1 line, and 7.6% gained 2 lines. There was no
statistically significant difference between the US and EU centers in
any metric evaluated.
Conclusions: This study documents and confirms extensive myopic
LASIK longitudinal outcome analysis indicating safety and efficacy
from two independent centers.
Commercial Relationships: Tarika Thareja, None;
George Asimellis, None; Laurence T. Sperber;
A. John Kanellopoulous, Alcon/WaveLight (C), Avedro (C),
Allergan (C), Keramed (C), i-Optics (C), ISP Surgical (C)
Phase-contrast X-ray CT observation of porcine cornea after
VisMax femtosecond laser photo-disruption of ReLEx pattern
irradiation
Takeshi Miyamoto1, Masato Hoshino2, Reiko Takatsuki1,
Hisako Fujimura3, Yukihisa Takada1, Shizuya Saika1.
1
Ophthalmology, Wakayama Medical University, WAKAYAMA,
Japan; 2JASRI, Sayo-cho, Japan; 3Physics, Wakayama Medical
University, Wakayama, Japan.
Purpose: To observe a porcine cornea after photo-dusruption of the
refractive lenticel extraction (ReLEx) pattern irradiation by VisuMax
femtosecond laser (FS) by using phase-contrast X-ray CT imaging.
Methods: Enucleated porcine eyes (n = 4) underwent FS laser
irradiation of ReLEx (FLEx or Smile with/without lenticel extraction)
pattern. After fixation in 4% paraformaldehyde, cornea was removed,
embeded in the agar and observed by phase-contrast X ray CT in a
synchrotron radiation facility SPring-8, Hyogo, Japan. Images were
processed for three-dimensional reconstruction.
Results: Double-layered many vacuoles were detected in the corneal
strom without lenticel extraction. Flap seemed to be precisely cut in
the uniform thickness in the ReLEx FLEx corneal stroma following
lenticel extraction. In the stromal bed, bump of the lenticle sidecut
was observed. In the cornea after ReLEx Smile procedure, the
stromal cap and bed were closely attached and vacuole-like spaces
were observed between the stromal wound.
Conclusions: Phase contrast X-ray CT was well applicable to
non-destructive observation of the porcine corneal stroma after
experimental FS irradiation. Vacuoles in the stroma seemed to contain
gas produced by plasma explosion.
Commercial Relationships: Takeshi Miyamoto; Masato Hoshino,
None; Reiko Takatsuki, None; Hisako Fujimura, None;
Yukihisa Takada, None; Shizuya Saika, None
Changes in anatomical parameters, visual performances and
quality of vision after a LASIK refractive surgery
Imene SALAH1, 2, Damien Gatinel2, 3, Richard Legras1. 1Laboratoire
Aimé Cotton, CNRS, Université Paris-Sud, Univ. Paris-Saclay,
Paris, France; 2Anterior segment and refractive surgery, Fondation
ophtalmologique Adolphe de Rothschild, Paris, France;
3
CEROC: Center of Expertise and Research in Optics for
Clinicians, Paris, France.
Purpose: To evaluate changes in anatomical parameters of the eye,
visual performances and quality of vision after a LASIK refractive
surgery performed with the WaveLight® Refractive Suite-ALCON®
(Alcon Laboratories, Inc., Fort Worth, TX).
Methods: We examined 30 eyes of 15 myopic (average Spherical
Equivalent of – 4.5D ranging from -8.5 to -0.75D) patients aged
from 24 to 39 years. Anatomical parameters (pachymetry, corneal
hysteresis (CH), resistance factor (CRF), Intra-Ocular Pressure (IOP),
central keratometry, Q-factor, corneal and total aberrations on a 4.5
mm pupil), visual performances (high and low contrast visual acuity
(VA), contrast sensitivity at 12 cycles per degree and tolerance to
blur defined as the range of defocus for which high contrast letters
of 20/50 was still perceived acceptable), dry eye assessment (Break
Up Time (BUT), OSDI questionnaire) and quality of vision (QoV
and Scale Ophthalmology questionnaire) were measured prior to the
surgery and 1 day (D1), 1 month (M1) and 3 months (M3) after.
Results: Three months after surgery, keratometry became flatter
and the Q-factor more positive (more oblate from-0.19±0.08
to+0.45±0.46). Both were significantly correlated (r2=0.7). CH, CRF
and BUT significantly decreased respectively from 11.6±1.4mmHg
(mean±SD) to 9.3±1.1mmHg, from 10.7±1.4mmHg to 7.5±1.4mmHg
and from 9±1.6sec to 6.7±3.4sec at M3. Pachymetry decreased by
124±62.2µm at D1 and increased by 44±32.6µm between D1 and M3
probably due to epithelial remodelling. Refraction became hyperopic
at D1 (+0.40±0.51D). At M3, refraction shifted to a less hyperopic
value (+0.13±0.41D) whereas keratometry continued to decrease
(from 40.77±1.94 to 40.5±2.02). Corneal refractive index and/or
internal changes may explain this difference. The only significant
high-order aberration change postoperatively was an increase of 3rd
order coma. While corneal astigmatism significantly decreased from
0.85 to 0.55D, total astigmatism remained unchanged (from 0.41 to
0.33). Three months after surgery, high and low contrast VA were
slightly (<0.05 logMAR) but significantly improved, whereas contrast
sensitivity and tolerance to blur remained unchanged. Quality of
vision was not affected by surgery.
Conclusions: Some corneal and/or internal changes arising between
D1 and M3 may limit the amount of residual refractive error to finally
provide a good vision 3 months after this refractive surgery.
Commercial Relationships: Imene SALAH, None;
Damien Gatinel, None; Richard Legras, None
Changes in Densitometry and Aberrations following Small
Incision Lenticule Extraction (SMILE) in patients treated for
myopic astigmatism
Sashia Bak-Nielsen, Iben Bach B. Pedersen, Anders Ivarsen,
Jesper Hjortdal. Department of Ophthalmology, Aarhus University
Hospital, Aarhus, Denmark.
Purpose: Small Incision Lenticule Extraction (SMILE) is a
corneal refractive procedure designed to treat refractive errors. A
femtosecond laser is used to create a corneal lenticule, which is
extracted through a small incision. SMILE has been shown to be
safe, reliable and precise. However as with any corneal refractive
procedure visual disturbances may be present postoperatively.
Corneal light scatter may be estimated with densitometry
measurement whereas Zernike polynomials can be used to describe
aberrations. The purpose of this study was to evaluate the degree
of light scatter and aberrations following SMILE in patients with
myopic astigmatism.
Methods: Prospective controlled study including 101 randomised
eyes. Examinations were performed pre- and 3, 6, 9, and 12 months
after surgery.
Corrected distance visual acuity (CDVA) and Pentacam HR based
densitometry and aberrations measurements were preformed.
Densitometry measurements of 0.0-2.0mm and 2.0-6.0mm annular
zones were performed in the anterior 120 my of the cornea.
Aberration measurements were calculated as root mean square
(RMS).
Results: Densitometry measurements increased significantly from
before surgery to 3 months after SMILE (zone 2.0-6.0), but then
gradually decreased to a significantly lower level compared. RMS
Astigmatism improved significantly at 3 months and remained steady
throughout the follow-up period. Coma and higher order aberrations
(HOA) increased significantly after surgery and remained steady. No
significant change was seen in RMS spherical aberration.
Conclusions: The improvement in light scatter objectified by
densitometry at 12 months post-SMILE compared to pre-SMILE
indicates that potential visual disturbances reported by patients are
not due to an increase in corneal light scatter, but may be caused by
an increase in coma-like higher-order corneal aberrations as seen
after other corneal refractive procedures. It is important to note that
spherical aberrations did not increase after SMILE, which stands in
contrast to most reports on excimer laser based treatments.
Table 1
Commercial Relationships: Sashia Bak-Nielsen, None; Iben
Bach B. Pedersen, None; Anders Ivarsen, None; Jesper Hjortdal
Cross-linking and photoablative keratectomy
Jean-Louis Bourges1, 3, Chadi Mehana1, Laurent Jonet3,
Michèle Savoldelli3, Christophe Panthier1,
Francine F. Behar-Cohen2, 3. 1Department of Ophthalmology,
Hopitaux Universitaires Paris Centre, Hôtel-Dieu, Assistance
Publique-Hôpitaux de Paris, Paris, France; 2department of
ophthalmology, Université de Lausanne, Jules Gonin Hospital
FAA, Lausanne, Switzerland; 3Paris Descartes Faculty of medicine,
INSERM UMR 1138, team 17, Sorbonne Paris Cité university, Paris,
France.
Purpose: Refractive or therapeutic photoablations have been
proposed in association with collagen cross-linking (CXL) protocols,
despite riboflavin masks part of ultraviolet (UV) at excimer’s
wavelengths. We aimed therefore at investigating photoablation
depths resulting from excimer laser treatment on human corneas
exposed to Riboflavin and UV.
Methods: Human experimental corneas were obtained from the
Banque Francaise des Yeux. Experiments were conducted in the
department of ophthalmology at Hotel-Dieu hospital, Paris.
We separated experimental corneas in 3 groups of treatment:
Group BSS (n=3) exposed to BSS only, group B2 (n=3) exposed
to Riboflavin and group B2-UV (n=4) exposed to Riboflavin then
irradiated with UV 10 mW/mm2-9 min. All cornea were then
subjected to a myopic 4 D PRK (intended 61 µm depth). Corneas
were photoablated on half of a 6.5mm central area, by separating the
optic zone (OZ) with a PMMA plate. The central corneal thickness
(CCT) was measured by US pachymetry before BSS/Riboflavin
exposure, and after PRK. Corneas were then fixed and processed for
optical microscopy. The maximal depth of ablation was quantified on
semithin section in each group at the ablation transition line within a
1 mm central area.
Results: Mean (±SD) CCTs of Group BSS, B2 and B2-UV
were initially 628±3 µm, 729±2 µm and 665±1 µm. All CCTs
decreased after exposure and before PRK from 12%, 20%
and 37% respectively. Mean photoablation depths (±SD) were
BSS=113±30 µm, B2=103±46 µm and B2+UV=105±13 µm.
Conclusions: Corneal edema interferes with excimer laser by
enhancing depth of photoablation. The full collagen cross-linking
procedure seems to limit PRK mean photoablation depths compared
to BSS or Riboflavin alone.
Commercial Relationships: Jean-Louis Bourges, None;
Chadi Mehana, None; Laurent Jonet, None; Michèle Savoldelli,
None; Christophe Panthier, None; Francine F. Behar-Cohen,
None
Support: Support provided: Banque Francaise des Yeux graciously
provided experimental corneas and Abbott Medical Optics-Laser
division graciously provided laser procedures
A prospective comparison of wavefront-guided LASIK and
wavefront-guided PRK following previous keratorefractive
surgery
Lisa Chen, Edward E. Manche. Byers Eye Institute at Stanford, Palo
Alto, CA.
Purpose: There is limited prospective information comparing
retreatment with LASIK to retreatment with PRK following
previous keratorefractive surgery. This study prospectively
evaluates whether LASIK or PRK retreatment yields superior
results over a long follow-up period.
Methods: In this prospective study, 28 eyes of 23 patients status post
prior LASIK or PRK surgery underwent retreatment with wavefrontguided LASIK (n=10) or wavefront-guided PRK (n=18) for residual
refractive error using the AMO VISX S4 CustomVue IR excimer
laser. Safety, efficacy, predictability, and wavefront outcomes were
evaluated.
Results: At last follow-up, both LASIK and PRK retreatment
resulted in similar improvement in visual acuity with mean ±
standard deviation (SD) uncorrected distance visual acuity (UDVA)
of -0.08 ± 0.10 logMAR and -0.04 ± 0.17 logMAR in the LASIK
and PRK groups respectively (p=0.44). 20% (n=2) of LASIK eyes
and 27.8% (n=5) of PRK eyes gained one or more lines of bestcorrected distance visual acuity (CDVA), while 10% (n=1) and
16.7% (n=3) of eyes lost lines of CDVA, respectively. 100% (n=10)
of LASIK eyes and 88.9% (n=16) of PRK eyes were within ± 0.50
diopter of emmetropia with a corresponding mean ± SD spherical
equivalent of -0.075 ± 0.25 and -0.090 ± 0.44 in the two groups
(p=0.91). Wavefront analyses revealed a similar reduction in total
higher-order aberrations in the LASIK and PRK groups from a
mean ± SD preoperative RMS error of 0.50 ± 0.17 and 0.54 ± 0.19
to postoperative values of 0.465 ± 0.17 and 0.45 ± 0.22 respectively
(p=0.56). Furthermore there was no significant difference in coma
(p=0.42), trefoil (p=0.53), or spherical aberration (p=0.51) between
the LASIK and PRK groups.
Conclusions: Wavefront-guided LASIK and wavefront-guided PRK
following prior keratorefractive surgery demonstrate similar safety,
efficacy, and predictability. Furthermore postoperative higher-order
aberrations appear to be comparable between the two treatment
groups.
Commercial Relationships: Lisa Chen, None; Edward E. Manche,
Presbia (C), Calhoun Vision (I), Oculeve (C), Abbott Medical Optics
(C), Veralas (I), Seros Medical (I)
White Light Interferometer Characterization for Femtosecond
Laser Dissected Tissue Surface Roughness
Alireza Malek Tabrizi, James E. Hill, Hong Fu, Saeed Taheri. Abbott
Medical Optics, Milpitas, CA.
Purpose: The purpose of this study is to characterize the tissue
surface roughness of femtosecond laser flap and deep lamella
dissection using white light interferometer.
Methods: Two femtosecond laser setups with wavelengths
near ~1 um were used in this study. Setup#1 had a pulse energy
smaller than 0.2 μJ, and a focus spot diameter smaller than
1.3μm; Setup#2 had a pulse energy smaller than 0.7 μJ, and
a spot diameter greater than 1.6 um. Porcine eye globes were
used for this study. Flap cut and deep lamellar dissections were
programmed and executed on the porcine corneas. A ContourGT Interferometer (manufactured by Bruker Inc.) was used to
characterize the dissected tissue surface roughness. White light
interferometer technique doesn’t require sample fixation and
conductive coating, and can be conveniently used to measure the
tissue surface roughness.
Results: Different types of dissections were evaluated using
the Bruker interferometer in order to have a quantitative surface
roughness comparison for the two setups and for different laser
parameter settings. Mean Roughness and Root Mean Square
(RMS) Roughness were evaluated over the complete 3D surface,
respectively. In general we obtained smoother surface for dissections
done with lower pulse energy and smaller spot separation. For
example, for a 400 um deep lamellar dissection, the Mean Roughness
of the surface dissected by Setup#1 is 5.992μm, and RMS Roughness
of 1.918μm; while the Mean Roughness for the surface dissected by
Setup#2 is 2.930 μm, and RMS Roughness of 0.175μm.
Conclusions: The white light interferometer is proven to be a convenient
tool for characterizing the tissue surface roughness. Using this approach,
we found that the femtosecond laser setup with smaller pulse energy and
tighter focus spot produce relatively smoother tissue surface.
© 2015 Abbott Medical Optics Inc. sc2015rf0024
Commercial Relationships: Alireza Malek Tabrizi; James E. Hill,
None; Hong Fu, None; Saeed Taheri, None
Effect of LASIK on mental health-related quality of life
Junichiro Yajima1, Kenya Yuki1, Kaoru Tounaka-Fujii1,
Kazuno Negishi1, Ikuko Toda2, Takeshi Ide2, Teruki Fukumoto2,
Emiko Miki2, Kazuo Tsubota1. 1Keio University, Tokyo, Japan;
2
Minami Aoyama Eye Clinic, Tokyo, Japan.
Purpose: Laser in situ keratomileusis (LASIK) is one of the most
established corneal refractive surgeries in the world. While there is
strong evidence for visual function improvement following LASIK, it
remains unclear whether LASIK also improves quality of life (QOL).
We performed a prospective, cohort study to investigate whether
LASIK improves health-related quality of life (HRQoL), and to
identify factors that affect postoperative HRQoL.
Methods: A total of 213 Japanese patients who underwent primary
LASIK were analysed in this study. The average age was 35.0 ± 9.4
years old. Subjects were asked to answer questions regarding QOL
(using the Japanese SF-36v2), at 3 time points: before LASIK, 1
month after LASIK, and 6 months after LASIK. Longitudinal change
over 6 month in the mental component summary (MCS) score and
the physical component summary (PCS) score outputs from the
SF-36v2 questionnaire were compared between time points using
a linear mixed-effects model. Delta MCS and PCS were calculated
by subtracting the postoperative score (1 month after LASIK) from
the preoperative score. We evaluated preoperative and postoperative
factors associated with a change in MCS score or PCS score via
linear regression model.
Results: Of the 213 subjects who responded to the preoperative
SF-36 questionnaire, 212 subjects (99.5%) responded to the SF-36
at 1 month after surgery, and 114 subjects (53.5%) responded at 6
months. Preoperative MCS score was 51.0 ± 9.4, and increased to
52.0 ± 9.8 and 51.5 ± 9.6 at 1 and 6 months after LASIK, and a trend
for the change from baseline in MCS through 6 month was significant
(p=0.03). PCS score did not change following LASIK. Delta MCS
was significantly negatively associated with preoperative spherical
equivalent, axial length, postoperative severity of halo, glare, double
vision, and dry eye sensation after adjusting for age, gender, axial
length, presence of systemic disease, BUT, pupil diameter, and
fluorescein score. No preoperative or postoperative factors were
associated with delta PCS.
Conclusions: LASIK significantly improves mental HRQoL.
Preoperative axial length may predict postoperative mental HRQoL.
Commercial Relationships: Junichiro Yajima, None; Kenya Yuki,
None; Kaoru Tounaka-Fujii, None; Kazuno Negishi, None;
Ikuko Toda, None; Takeshi Ide, None; Teruki Fukumoto, None;
Emiko Miki, None; Kazuo Tsubota, None
Precise Laser Pulse Characterization for Ophthalmology
Applications
Saidur Rahaman, Zenon Witowski, Hong Fu. R&D, Abbott Medical
Optics, Milpitas, CA.
Purpose: The laser pulse duration is a key factor for femtosecond
laser corneal incisions. For a given spot-size, shorter pulses generally
ablate at lower energy levels and generally present lower collateral
damage than longer pulses. Recent state of the art advancements in
fiber laser technology allow for a compact laser system design for
ophthalmology applications. However, laser pulse artifacts such as
satellite pulses, are a common occurrence with this technology and
are undesirable. In this study Frequency Resolved Optical Gating
(FROG) method was used to temporally characterize the beam and
identify the levels of energy contained within the satellite pulses.
Methods: For number of years, before the advancement of FROG
technology, pulse duration was estimated using an autocorrelator
(AC). However, AC measurements do not fully reveal the presence
of satellite pulses in ultrafast pulse regime. Thus, FROG pulse
measurement method was introduced to address this issue. In FROG
measurements, the fundamental pulse is split into two and one is
variably delayed with respect to other. The two pulses are then
combined in a nonlinear second-harmonic-generation (SHG) crystal.
The SHG crystal produces “signal light” at twice the frequency of
the input light when both pulses are overlapped in time and space.
Intensity and spectrum of the resulting light signal is then recorded
at each delay point using a spectrometer and a 2D spectrogram is
plotted as a function of wavelength and delay. Spectrogram includes
essential information to characterize the laser pulse. Effectively, it
also reveals the levels of the satellite pulses.
Results: The pulse duration and the amount of the satellite pulses
have been measured using FROG. An integral value was computed
over the main pulse and the satellite pulses. The ratio of the satellite
pulses to the main pulse was approximately 10%. The data was taken
at the focus of the system and the laser was optimized to minimize
pulse duration, satellite pulses, and to pre-compensate the dispersion
of the delivery optics. Ultimately the FROG measurements and
system optimization lead to a better pulse quality at the focus.
Conclusions: Ophthalmology applications are demanding optimum
ultrafast fiber laser based solutions. FROG is an essential tool for a
full laser pulse characterization and system optimization to achieve
these demanding results.
Commercial Relationships: Saidur Rahaman, Abbott Medical
Optics; Zenon Witowski, Abbott Medical Optics; Hong Fu, Abbott
Medical Optics
Short-term results of presbyLASIK for presbyopia correction in
hyperopic patients
San Seong, Se Kyung Kim, Tae Hoon Choi, Chul Myung Choe. The
Cornea & Refractive surgery, Nune Eye Hospital, Seoul, Korea (the
Republic of).
Purpose: To evaluate the efficacy of presbyLASIK and the
satisfaction of hyperopic patients who underwent such procedure
for presbyopia correction using the biaspheric micro-monovision
protocol
Methods: presbyLASIK for presbyopia correction using the
biaspheric micro-monovision protocol was performed on 44 eyes
of 22 consecutive patients with hyperopia and presbyopia between
August 2014 and July 2015. The distance, intermediate, and near
visual acuity, and the patient’s satisfaction, were evaluated before the
surgery and six months after the surgery.
Results: The binocular uncorrected distance visual acuity was
0.7 (logMAR 0.15) or better in all the patients, and the binocular
uncorrected near visual acuity was 0.6 (logMAR 0.22) or better
in 87% of the patients. Six months after the surgery, the binocular
uncorrected near visual acuity was degraded more significantly than
the binocular corrected near visual acuity in 27% of the patients, as
was the binocular distance visual acuity in 47.1% of the patients,
without significant regression. After the surgery, the patients’ overall
satisfaction scores were good (3.23 out of 5), and the scores for the
distance, intermediate, and near visual acuity were 3.45, 3.36, and
3.17, respectively. The overall satisfaction of the group of patients
without glasses was the highest (3.42 out of 5). The level of the
patients’ dependence on post-operative glasses was 33%.
Conclusions: The presbyLASIK using the biaspheric micromonovision protocol showed good all-distance visual outcomes, and
was well-tolerated and effective for treating patients with hyperopic
presbyopia.
Commercial Relationships: San Seong, None; Se Kyung Kim,
None; Tae Hoon Choi, None; Chul Myung Choe, None
The association between posterior surface irregularity and
degradation of visual acuity after same eye Descemet’s Stripping
Automated Endothelial Keratoplasty
HIROYUKI YAZU1, 2, Takefumi Yamaguchi1, 2, Murat Dogru1, 2,
Yoshiyuki Satake1, Jun Shimazaki1, 2. 1Ophthalmology, Tokyo Dental
College, Chiba, Japan; 2Ophthalmology, Keio University, Tokyo, Japan.
Purpose: To investigate the contribution of posterior corneal surface
irregularity to higher-order aberrations (HOAs) and visual acuity
after DSAEK in the same eyes.
Methods: 31 patients who underwent DSAEK twice in the same eyes
in Tokyo Dental College Department of Ophthalmology from 2008 to
2014 were studied(62 DSAEK in total). We investigated the HOAs of
the anterior and posterior surfaces, and total cornea using the Fourier
analysis from the data of the anterior segment optical coherence
tomography (AS-OCT) in 46 DSAEK procedures of 23 patients
(8 patients were excluded due to primary graft failure in the initial
DSAEK). 23 Eyes were divided into one of the following groups in
this study; Group A : Eyes with an improvement of best corrected
visual acuity (BCVA) ≧ 2 lines of the repeat DSAEK. Group B
: Eyes with a decline of BCVA % 2 lines of the repeat DSAEK.
GroupC : Eyes with no change or change in BCVA within 1 line after
DSAEK. Same examination parameters were also compared between
initial and repeat DSAEK in eyes of groupC.
Results: There were no significant differences in the anterior
surface and total cornea HOAs between groupA and B (P=0.12 and
0.08), whereas the HOAs of the posterior surface in group B were
significantly greater than those of group A (P=0.028). There were no
significant differences in the anterior and posterior surface as well
as total cornea HOAs between initial DSAEK and repeat DSAEK
in groupC (P=0.87, 0.65 and 0.42). The BCVA had a significant
correlation with the anterior and posterior surface as well as the total
cornea HOAs (R=0.40, 0.46 and 0.53; P=0.01, 0.002 and 0.001).
Conclusions: Posterior corneal higher-order aberrations can have a
negative influence on the visual acuity in the same eyes, suggesting
the presence of heterogeneous graft thickness or folds in the graft as
the cause of visual impairment.
Commercial Relationships: HIROYUKI YAZU, None;
Takefumi Yamaguchi; Murat Dogru, None; Yoshiyuki Satake,
None; Jun Shimazaki, None
Target detection in infrared images after wavefront-guided and
wavefront-optimized PRK and LASIK
Rose K. Sia1, 5, Denise S. Ryan1, 5, Lamarr Peppers1, 5, Lorie Logan1,
Joseph Pasternak2, Richard D. Stutzman4, Tana Maurer3,
Christopher L. Howell3, Bruce Rivers1, Kraig S. Bower6. 1Warfighter
Refractive Eye Surgery Program and Research Center, Fort Belvoir
Community Hospital, Fort Belvoir, VA; 2Ophthalmology, Walter Reed
National Military Medical Center, Bethesda, MD; 3Night Vision and
Electronic Sensors Directorate, Fort Belvoir, VA; 4Ophthalmology,
George Washington University, Washington, DC; 5WRESP, Henry M.
Jackson Foundation, Bethesda, MD; 6Ophthalmology, Johns Hopkins
University, Baltimore, MD.
Purpose: To assess the ability of U.S. military servicemembers
to detect targets in infrared images before and after undergoing
wavefront-guided (WFG) and wavefront-optimized (WFO)
photorefractive keratectomy (PRK) and LASIK.
Methods: A total of 53 U.S. military servicemembers (mean age 29.9
±5.5 years) electing to undergo either PRK or LASIK for myopia
with or without astigmatism (mean manifest refractive spherical
equivalent -3.78 ±1.44 diopters) were randomized to undergo WFG
or WFO treatment. WFG treatment was performed using the VISX
CustomVue STAR S4 IR and WFO with Wavelight Allegretto
Wave EyeQ. In addition to clinical tests, the participants underwent
computer-based experiments preoperatively (with optical correction)
and at 6 weeks and 6 months postoperatively (6M PO) (without
correction) assessing their ability to detect targets of military interests
during wide field of view, long range search process: 1) mid-wave
(MW) infrared images of human targets; and 2) MW and long-wave
(LW1 and LW2) infrared images of combat vehicle targets. The
probability of detection (Pd) for each experiment was calculated
and the treatment groups were compared. Associations between
postop target detection performance and clinical outcomes were also
determined.
Results: The participants underwent either WFG PRK (n=14), WFG
LASIK (12), WFO PRK (13) or WFO LASIK (14). All treated eyes
except for one WFO PRK-treated eye achieved uncorrected distance
visual acuity of 20/20 or better at 6M PO. In detecting human
targets, there was no significant difference in Pd over a period up
to 6M PO among the treatment groups (p=0.55). There was also no
significant difference in Pd over time for detecting combat vehicle
targets whether the targets were MW infrared images (p=0.91) or LW
infrared images (LW1, p=0.52; LW2, p=0.71). At 6M PO, UDVA,
MSE and the type of surgery were significantly associated with the
Pd for human targets (R2=0.61, p=0.035) but not with the Pd for
vehicle targets (p>0.126).
Conclusions: U.S. military servicemembers undergoing PRK or
LASIK with either WFG or WFO technology for myopia or myopic
astigmatism appear to benefit from their treatment, eliminating the
need for corrective lenses while maintaining their ability to perform
visual discrimination tasks. The outcomes of surgery appear to be
strongly associated with their ability to detect human targets.
Commercial Relationships: Rose K. Sia, None; Denise S. Ryan,
None; Lamarr Peppers, None; Lorie Logan, None;
Joseph Pasternak, None; Richard D. Stutzman, None;
Tana Maurer, None; Christopher L. Howell, None; Bruce Rivers,
None; Kraig S. Bower, None
Support: Dept of Defense W81XWH-09-2-0018
Visual performance of U.S military servicemembers (USM) in
identification of infrared targets after wavefront-guided (WFG)
and wavefront-optimized (WFO) photorefractive keratectomy
(PRK) and LASIK
Denise S. Ryan2, 1, Rose K. Sia2, 1, Lamarr Peppers2, 1,
Jennifer B. Eaddy2, 1, Richard D. Stutzman3, Joseph Pasternak4,
Tana Maurer5, Christopher L. Howell5, Bruce Rivers2,
Kraig S. Bower6. 1WRESP, Henry M. Jackson Foundation,
Bethesda, MD; 2Warfighter Refractive Eye Surgery Program and
Research Center, Fort Belvoir Community Hospital, Fort Belvoir,
VA; 3Ophthalmology, George Washington University, District of
Columbia, DC; 4Ophthalmology, Walter Reed National Military
Medical Center, Bethesda, MD; 5Human Perception Lab, Night
Vision and Electronic Sensors Directorate, Fort Belvoir, VA; 6Wilmer
Eye Institute, Baltimore, MD.
Purpose: To assess the probability of identification (PID) of combat
vehicles in infrared images by USM before and after undergoing
WFG and WFO PRK and LASIK.
Methods: In this prospective study, USM (mean age 29.9 ±5.5 years)
with myopia or myopic astigmatism electing to undergo PRK or
LASIK (mean manifest refractive spherical equivalent -3.78 ±1.44
diopters) were randomized to receive either WFG (VISX CustomVue
STAR S4 IR, Abbott Medical Optics) or WFO surgery (Wavelight
Allegretto Wave EyeQ, Alcon Surgical). Pre- and postop clinical
exams included visual acuity tests, refraction, and slit lamp exam.
USM also underwent computer based experiments, preop with
optical correction and at 6 weeks (W) and 6 months (M) postop
without correction, to assess PID: 1) with infrared imagery captured
in multiple wavebands and digitally fused using an image-averaging
algorithm; and 2) with varying target contrasts. The PID for each
experiment and among the treatment groups were compared using
a repeated measures analysis of variance. Association of PID
with the postop visual acuity, residual refractive error and surgery
was analyzed using linear regression. A p-value <0.05 considered
statistically significant.
Results: Of the 53 participants, 14 underwent WFG PRK, 12 WFG
LASIK, 13 WFO PRK and 14 WFO LASIK. At 6M postop, all
eyes achieved uncorrected distance visual acuity (UDVA) of 20/20
or better except for one eye treated with WFO PRK. There was no
loss of more than one line of corrected distance visual acuity. In
identifying combat vehicles, there was no significant difference
among the treatment groups in PID over time whether the targets
in different wavebands were fused (p=0.92) or the target mean,
background mean, and standard deviation of the target signatures
were altered (p=0.59). There were no significant associations between
the 6M UDVA, MSE as well as the type of surgery and the PID for
combat vehicles in fused wavebands (p=0.72) or in varying contrasts
(p=0.72).
Conclusions: The application of WFG and WFO technologies for
PRK and LASIK results in excellent refractive outcomes. In the
context of military operations, these techniques are effective in
reducing soldiers’ dependence on corrective lenses while maintaining
their ability to perform military relevant tasks, such as infrared target
identification.
Commercial Relationships: Denise S. Ryan; Rose K. Sia,
None; Lamarr Peppers, None; Jennifer B. Eaddy, None;
Richard D. Stutzman, None; Joseph Pasternak, None;
Tana Maurer, None; Christopher L. Howell, None; Bruce Rivers,
None; Kraig S. Bower, None
Support: Funded by USAMRAA Award W81XWH-09-2-0018
Inflammatory markers in the SMILE lenticule and its impact on
corneal healing
CAROLINA E. MOLINA RÍOS, ELISA ALEGRIA GOMEZ,
Oscar Fernandez. CORNEA AND REFRACTIVE SURGERY,
HOSPITAL NUESTRA SEÑORA DE LA LUZ, DF, Mexico.
Purpose: To describe the inflammatory markers in the lenticule of
corneal SMILE related inflammatory process in patients undergoing
refractive surgery.
Methods: Prospective, transversal, observational and descriptive
study in patients undergoing refractive surgery (SMILE) who
meet the inclusion criteria. All the extracted lenticules underwent
determination of inflammatory cytokines and these results were
correlated with visual acuity and spherical equivalent pre and
postoperative data with flap and residual stromal lenticule.
Results: 36 patients (43 eyes) were analyzed. The average age for
men of 28 ± 6 years and women 29 ± 7 years. IL8 cytokines obtained
were 1.1 ± 1.3pg / ml and 1.3 ± TNF alfa 1.3pg / ml, 0.5 ± 0.5pg
IL12 / ml and 0.3 ± IL1b 1.3pg / ml. The suction flap and lenticule
do not have significant correlation with cytokine levels, however the
minimum thickness 16.0 ± 4.0μm correlated negatively with TNF
alfa (p = 0.034) and IL-12 (p = 0.017).
Conclusions: IL8 interleukins, TNF alfa, IL12 and IL1b are released
in response to stromal and epithelial injury, even without being given
their impact on refractive outcomes, establishing the need for future
studies.
Commercial Relationships: CAROLINA E. MOLINA RÍOS,
None; ELISA ALEGRIA GOMEZ, None; Oscar Fernandez, None
Comparison of higher-order aberrations following small incision
lenticule extraction (SMILE) and wavefront-guided FemtoLASIK
Xiaoqin Chen1, 2, Yan Wang2, Jiamei Zhang1, Shunnan Yang3,
Xiaojing Li4. 1Tianjin Medical University, Tianjin, China; 2Tianjin
Eye Hospital, Tianjin, China; 3Visual Performance Institue,
Pacific University, Forest Grove, OR; 4Qinghuangdao Hospital,
Qinghuangdao, China.
Purpose: To evaluate changes in high-order aberrations
(HOAs) following SMILE and wavefront guided Femto-LASIK
(WF-LASIK), and to investigate the relation between these changes
and preoperative spherical equivalence (SE).
Methods: Fifty-one eyes of 28 patients were included in the
study. The mean preoperative SE refraction was -5.50 diopters
(D)±1.32 (SD) and -4.91 diopters (D)±2.34 (SD) in the SMILE and
WF-LASIK group, respectively (t=1.045, p =0.305). Uncorrected
distance visual acuity (UDVA), corrected distance visual acuity
(CDVA), refractive error were measured before and 3 months after
surgery to evaluate resultant visual comes. Also, Zernike coefficients
of second- to sixth-order HOAs were measured and analyzed.
Results: Similar UDVA and CDVA were found after WF-LASIK
(Mean ± SD: -0.02±0.05 and -0.05±0.04 logMAR respectively)
and SMILE surgeries (-0.02±0.06 and -0.04±0.04 logMAR). There
was significant difference in vertical coma (Z = -2.257, p = 0.024)
between two groups after surgery although there were no difference
in vertical or horizontal trefoil, horizontal coma, spherical aberration
and total HOA. The preoperative SE was correlated to horizontal
coma (r = -0.670, p = 0.001) in WF-LASIK and vertical coma (r=0.520, p=0.003) in SMILE group after surgery.
Conclusions: Both SMILE and WF-LASIK in correcting myopia
can achieved similar visual outcomes. For optical quality, however,
specific changes were demonstrated since the principal and design is
different which might cause the different wounding healing.
Commercial Relationships: Xiaoqin Chen; Yan Wang, None;
Jiamei Zhang, None; Shunnan Yang, None; Xiaojing Li, None
Support: National Science Foundation (No. 81470658) in China
Analysis topographical Orbscan and Pentacam in refractive
surgery technique Small incision lenticule extraction
Karla Alejandra Ramirez Collazo. Clinical, Hospital de la Luz,
Mexico DF, Mexico.
Purpose: Correlate the changes that occur in the corneal topography
after refractive surgery SMILE by Orbscan and Pentacam.
Methods: This is a prospective, observational, longitudinal and
comparative study. The data were obtained from patients with
refractive surgery technique SMILE selected at the fundación
Hospital Nuestra Señora de la Luz, IAP. The procedure was
performed using VisuMax® Platform, Carl Zeiss, consisting
of femtosecond laser. All patients underwent preoperative
ophthalmologic evaluation. They underwent Orbscan and Pentacam
before surgery, the first day, a week and a month of post-operative,
numerical results and image were analyzed. For statistical analysis,
Mann Whitney test was used to compare pre- and post-operative and
Pearson test values to correlate the differences between devices. The
results were considered statistically significant if a value of p <0.05
was obtained.
Results: They were 72 eyes of patients with refractive surgery
technique SMILE. Variables best fit sphere (BFS), front and rear and
central and peripheral keratometries were compared. The averages of
the BFS above preoperatively with Orbscan and were Pentacam was
respectively(7.63-8.49 mm)and 7.9 mm(7.5 - 8.45mm) (p =0.0856).
On the first day postoperative, average of 8.309mm(7.89- 8.8 mm)
and 8.36mm(8.88mm 7.51)(p=0.3342). At 7 days the postoperative,
an average of 8,297mm (8.1- 8.79 mm) and 8.47mm (9.03- 8.13mm)
(p = 0.2394) was obtained. At 30 days the postoperative, was
obtained from 8.33 mm (8.32- 8.34 mm) and 8.35mm (8.32 8.38mm) (p = 0.5000). The averages preoperative back BFS was
6.49mm (6.01 - 7.15mm) and 6.42 mm (5.95 - 7.01mm)
(P = 0.0208) and 6.47 mm (5.99 - 7.51mm) (P = 0 0219). On the
first day posto- averaged 6.33mm (6.82mm 5.83) and 6.47 mm
(5.99 – 7.51mm) (P=0 .0219. At 7 days after surgery, 6.36mm (6.23 6.57mm) and 6.62 mm (6.37 - 7.08mm) (P = 0.0254). At 30 days
after surgery of 6.38mm (6.35 - 6.41mm) and 6.44 mm
(6.43 - 6.45mm) (P = 0.0001). The central pachymetry were
preoperatively 554.74 μ (495- 632 μ) and μ 535.8 (459-614 μ)
(p = 0.2578).
Conclusions: The findings indicate that changes in the posterior
corneal surface after refractive surgery may be underestimated in the
Orbscan. The Pentacam may be a better tool for the investigation of
rear elevation of the cornea after refractive surgery.
Commercial Relationships: Karla Alejandra Ramirez Collazo,
None
A Retrospective Clinical Validation Study on the Modelling of
Regression, Refractive Change and Morphological Results After
Refractive Surgery
Riccardo Vinciguerra1, Harald Studer3, Paolo Vinciguerra2.
1
Ophthalmology, Department of Morphological and Surgical
Sciences, Insubria University, Varese, Italy; 2Eye Center, Humanitas
Clinical and Research Center, Rozzano, Italy; 3Optimo Medical AG,
Biel, Switzerland.
Purpose: Refractive surgery induces modifications in the corneal
shape aimed to persist over time. Nevertheless, corneal remodeling
can induce regression of the intended correction and limit the optimal
outcome of the procedure. The aim of this study was to validate a
numerical model of regression, refractive change and morphological
results (VRM), with long-term follow-up clinical data of refractive
surgery
Methods: Forty-eight eyes of 30 patients who underwent to
refractive surgery were included in this retrospective study.Group
1 comprised 20 eyes of 11 patients with unstable topography and
refraction, post-operative known regression and high curvature
gradient(CG) due to primitive ablation, done several years ago.Group
2 included 20 eyes of 19 patients with stable topography, refraction
and low CG, obtained with new ablation profiles
The first available follow-up topography measurement(25±29 in
group 1 and 44±14 days in group 2), was imported in the prediction
model and subsequently the program was run to create the predicted
map at the selected follow-up. Predicted changes of group 1 and 2
were compared to clinical follow-up data
Results: Clinical data of group 1 at 201±21 days of follow-up
showed respectively a central and paracentral curvature values
of 37.41±2.02D and 42.45±1.61D while the VRM anticipated for
the same follow up respectively 37.68±1.95D and 42.31±2.17D.
Prediction accuracy was 0.27±0.79D and -0.14±1.50D
Similarly, clinical data of group 2 at 471±130 days of follow-up
displayed individually a central and paracentral curvature values of
38.38±2.17D and 40.83±2.42D while the VRM displayed for the
selected follow-up respectively 38.81±1.94D and 40.45±2.30D.
Prediction accuracy was 0.42±0.43D and -0.38±0.43D
Comparative results showed no significant differences between
the real follow up measurements and the VRM predictions in all
parameters evaluated (p>0.05)
Conclusions: The statistical analysis showed no significant
differences between VRM predictions and clinical data,
demonstrating that VRM is able to anticipate remodeling, refractive
change and morphological after refractive surgery either in ablation
profiles tending regress or the more advanced and stable ones.
The proposed mathematical model, if implemented in the laser
software, could permit to avoid regression after refractive surgery by
planning an ablation profile that minimizes remodeling
Commercial Relationships: Riccardo Vinciguerra, Optimo
Medical AG (F); Harald Studer, Optimo Medical AG;
paolo vinciguerra
Optimum laser beam characteristics for achieving smoother
ablations in laser based vision correction
Samuel Arba Mosquera, Shwetabh Verma. Research and
Development, SCHWIND eye-tech-solutions, Kleinostheim,
Germany.
Purpose: Controversial opinions exist regarding optimum laser beam
characteristics for achieving smoother ablations in laser based vision
correction. We tested the impact of laser beam characteristics like
super Gaussian order, truncation radius, spot geometry, spot overlap
and lattice geometry on ablation smoothness, from both theoretically
optimized super Gaussian beam profiles and physical intensity beam
profiles acquired using a beam profiler camera.
Methods: Given the super Gaussian order, the theoretical beam
profile was calculated and optimum truncation size was determined
following Beer-Lambert model and using the metric ablation volume
per laser pulse optimized for minimum pulse energy incident on
a single spot (Biomed Opt Express. 2013 Jul 24;4(8):1422-33),.
The physical intensity beam profile was acquired from an excimer
laser using a beam profiler camera. For both the beam profiles, two
geometries (round and square spots) were considered, and two types
of lattices (reticular and triangular) were simulated with varying
spot overlap distances and ablated material (cornea or PMMA). Real
ablations on PMMA completed the study setup. Optimum global
configurations were analyzed based on the minimum roughness in
ablation estimated from the root mean square error in ablation.
Results: Open based on the test cases. In general, there is an
optimum peak radiant exposure for a given supergaussian order. The
optimum truncation size corresponds to cutting off the flanks not
contributing to the ablation process. Round spot geometries produce
lower simulated roughness values than square ones. Triangular
lattices produce lower simulated roughness values than reticular
ones. Roughness on PMMA tend to be lower than on the cornea
(but also ablation volume). Theoretical modelled beams produced
lower simulated roughness values than the ones obtained with the
beam profiler camera. Simulated roughness tends to be lower than
measured roughness. Repetition rate affects the beam profile of the
excimer laser. Simulated and measured results showed a good degree
of correlation.
Conclusions: The proposed model can be used for optimization of
laser systems used for ablation processes at relatively low cost and
would directly improve the quality of results.
Commercial Relationships: Samuel Arba Mosquera, SCHWIND;
Shwetabh Verma, SCHWIND
Refractive results comparison between Myopic Small-incision
Lenticule Extraction and LASIK
George Chatzilaou1, George Asimellis1, 2, A. J. Kanellopoulos1, 3.
1
LaserVision.gr Eye Institute, Athens, Greece; 2Kentucky College of
Optometry, Pikeville, KY; 3Ophthalmology, NYU Medical School,
NY, NY.
Purpose: The purpose of this study was to comparative investigate
two myopic correction femtosecond laser techniques: femtosecondassisted LASIK was compared to an all femto-second laser Small
Incision refractive Lenticule Extraction (SMILE). Six-month
refractive outcomes were comparatively evaluated.
Methods: This is a single-center, retrospective analysis of 100
consecutive myopic patients. Group-A was treated with the SMILE
(n=48 eyes), while the other eye (group-B) with LASIK (n=52
eyes). The LASIK procedure employed the Alcon Refractive surgery
platform (Alcon Surgical, Ft. Worth, TX) comprised of the FS200
femtosecond and the EX500 excimer laser. The SMILE procedure
employed the 500 kHz VisuMax® femtosecond laser (Carl Zeiss
Meditec AG, Jena, Germany). All operations were performed by the
same surgeon (AJK).
Results: LASIK SEQ corrected: -5.12±2.74 D(range -1.50 to -12.00).
6-month results: 82% within ± 0.25D, 87% within ± 0.50D; 91% had
20/20 UDVA or better; 54% no change in Snellen lines, 46% gained 1
or more; predictability r^2 = 0.999.
SMILE SEQ corrected: -4.63±1.90 D (range -2.50 to -9.50). 6-month
results:
84 % within ± 0.25D, 95% within ± 0.50D; 88% had 20/20 UDVA
or better; 45% no change in Snellen lines, 55% gained 1 or more;
predictability r^2 = 0.972.
Conclusions: FS-assisted LASIK and SMILE appear to have similar
refractive results up to 6 months.
Commercial Relationships: George Chatzilaou, None;
George Asimellis, None; A. J. Kanellopoulos, i-Optics (C), ISP
Surgical (C), Avedro (C), Keramed (C), Allergan (C)
Effect of geometrical parameters on the change of corneal
functionality with femtosecond laser-assisted INTACS-SK
implantation in patients with corneal ectasias
Themistoklis Tsintarakis1, Timo Eppig2, Achim Langenbucher2,
Berthold Seitz1, Moatasem El-Husseiny1. 1Ophthalmology, Saarland
University Medical Center, Homburg, Germany; 2Experimental
Ophthalmology, Saarland University, Homburg, Germany.
Purpose: To evaluate the effect of geometry of corneal ring implants
(INTACS SK) and their intrastromal position on the change of
functional outcome with treatment of keratoconus, pellucid marginal
degeneration and post-LASIK keratectasia.
Methods: The CASIA SS-1000 swept-source OCT was used to
image the implanted INTACS SK of size 210, 300, 350, 400, 450 and
500 µm 3 months postoperatively in 60 eyes of 51 patients (mean age
35.8 ± 10.6 years) who underwent femtosecond laser-assisted corneal
ring segment implantation between August 2011 and June 2015.
Mean and maximum corneal power (Kmean and Kmax) derived
from Pentacam HR, spherical equivalent and refractive cylinder from
subjective refraction as well as spectacle-corrected visual acuity
were assessed preoperatively as well as 3 months postoperatively and
the change from pre- to postoperative follow-up was derived. From
HighRes cornea mode OCT measurements we extracted geometric
parameters on meridional sections perpendicular to the implantation
axis as follows: thickness and width of the corneal ring implants, the
distance of the ring to the anterior and posterior corneal surface, the
thickness of the surrounding cornea 350 µm central and peripheral to
the implanted ring segment. Moreover the lateral positioning of the
ring implants relative to the pupil centre was assessed.
Results: Spherical equivalent / refractive cylinder from
subjective refraction changed from -9.95±5.99 dpt / -6.25±2.04
dpt preoperatively to -2.88±3.14 / -2.52±1.74 dpt 3 months after
surgery (p<0.001 both). Kmean / Kmax from Pentacam decreased
from 48.89±4.45 / 57.51±6.12 dpt preoperatively to 45.99±3.94
/ 55.44±6.02 dpt 3 months postoperatively (p<0.001 / p=0.017).
Spectacle corrected VA increased from 0.41±0.10 preoperatively to
0.69±0.20 3 months postoperatively (p<0.001).
In a generalized linear model (GLM) the change in spherical
equivalent and in Kmean (dependent variables), described with the
effect sizes of measured geometric parameters (covariates), was
significantly affected only by the thickness of the ring segment
(R=26.393, p=0.006 / R=-10.33, p=0.022).
Conclusions: Our results imply that mostly the thickness of the ring
segments shows an effect on the reduction of maximum corneal
power and increase of spherical equivalent of subjective refraction
after INTACS-SK implantation.
Commercial Relationships: Themistoklis Tsintarakis, None;
Timo Eppig, None; Achim Langenbucher, None; Berthold Seitz,
None; Moatasem El-Husseiny, None
Efficiency, predictability and security of the trans-epithelial
photorefractive keratectomy (trans-PRK) for low and medium
myopia and astigmatism: retrospective study about 118 eyes
Julie Colne, Cedric Ghetemme, Jean-Marc Perone. Metz, CHR
Mercy, Rambervillers, France.
Purpose: The photorefractive keratectomy was the first correction
mode refractive laser. It’s a photo-ablation of a predetermined
thickness of anterior corneal stroma. Debridement of epithelium
can be done either mechanically (m-PRK) or by laser (trans-PRK).
Trans-PRK has a lot of interests: facility and speed of procedure as
well as suppression of human variable. Very good results are obtained
by m-PRK. The aim of this study is to show equivalence or non
inferiority of trans-PRK over conventional m-PRK in terms of safety
and refractive efficiency.
Methods: This is a retrospective, observational and monocentric
study including 62 patients and 118 eyes. Were included myopia up
to -4D (dioptries) and cylinders up to -3D. The ametropia was stable
for 2 years. Careful refraction was made. All trans-PKR were made
on the schwind amaris 500E platform. Epithelium ablation profile
was 55µm in the center against 65 µm in the periphery. The optical
central zone was equal to 6,5 mm. Young patients (under 35 years)
had a + 0,25 D target refraction, for the older, the not leader eye was
left intentionally myopic (between -0,50 and -2D) and the others had
for refractive target 0D. The visual target acuity in log MAR was 0.
The postoperative treatment consisted of rimexolone eye drops and
final refractive control was made at two months.
Results: Of the 118 eyes operated, 51 presented myopia, 9
astigmatism and 58 myopia and astigmatism. Postoperatively, 5 eyes
had uncorrected VA less effective than the preoperative best corrected
visual acuity (BCVA). 113 eyes had their target visual acuity (0
log MAR or visual acuity equivalent of their BVCA). The residual
average refractive disorder was calculated in spherical equivalent:
it was equivalent to 0,318 +/-0,028 D (myopia: 0,27 +/- 0,180D,
astigmatism : 0,498 +/- 0,337D, myopia-astigmatism :0,333+/0,234D). No eye had a refractive disorder superior to 1D.
Conclusions: In any confused ametropia, the residual average
refractive disorder was equal to 0, 31 D. Result was lower when only
myopia was corrected (0,27D) and more important when considering
cylinder correction (0,498D). The trans-PKR procedure appears as
a simple, fast, uniform, secure and reproducible procedure, with
excellent refractive final results, comparable and not lower than those
obtained after m-PRK.
Commercial Relationships: Julie Colne, None; Cedric Ghetemme,
None; Jean-Marc Perone, None
Visual Performance with Night Vision Goggles following
Wavefront-guided and wavefront-optimized refractive surgery
Bruce Rivers1, Rose K. Sia1, 2, Denise S. Ryan1, 2, Lamarr Peppers1, 2,
Jennifer B. Eaddy1, 2, Lorie Logan1, Richard D. Stutzman3,
Joseph Pasternak4. 1Warfighter Refractive Eye Surgery Program and
Research Center, Fort Belvoir Community Hospital, Fort Belvoir,
VA; 2WRESP, Henry M. Jackson Foundation, Bethesda, MD;
3
Ophthalmology, George Washington University, Washington, DC;
4
Ophthalmology, Walter Reed National Military Medical Center,
Bethesda, MD.
Purpose: To assess visual performance with night vision goggles
(NVG) among U.S. military servicemembers before and after
wavefront-guided (WFG) and wavefront-optimized (WFO)
photorefractive keratectomy (PRK) and LASIK.
Methods: A total of 52 active duty U.S. military servicemembers
with myopia or myopic astigmatism electing to undergo PRK
or LASIK were randomized to undergo either WFG (VISX
CustomVue STAR S4 IR) or WFO treatment (Wavelight Allegretto
Wave EyeQ excimer laser system). Best-corrected low contrast
visual acuity (LCVA) of the aiming eye was assessed pre- and
postoperatively using a 25% contrast chart viewed through a
NVG filter. Firing performance with a NVG and aiming light was
evaluated preoperatively with optical correction and postoperatively
without correction. A M16-A4 rifle was fired on a modified range
with a 25-meter distance standardized target. Visual performance
was compared among groups using a repeated measures analysis
of variance. Associations between postoperative firing scores and
LCVA with NVG, residual refractive error and type of surgery were
determined using a regression analysis.
Results: The study participants (mean age 30.0 ±6.7 years and
refractive error -3.77 ±1.40 diopters) underwent one of the following
procedures: WFG PRK (n=12), WFG LASIK (n=13), WFO PRK
(n=13) or WFO LASIK (n=14). At 6 months postoperatively, there
were no significant differences in the LCVA with NVG or in firing
scores among the groups (Table 1). Postoperative firing scores were
not significantly associated with postoperative LCVA, residual
refractive error or the type of surgery received (R2=0.09, p=0.63).
Conclusions: Myopic correction with PRK or LASIK using either
WFG or WFO treatment was safe and effective in terms of visual
performance with NVG under low light conditions. Independent of
the type of surgery, there was no significant loss of visual acuity or
firing performance under a visually degraded condition.
Commercial Relationships: Bruce Rivers, None;
Rose K. Sia, None; Denise S. Ryan, None; Lamarr Peppers,
None; Jennifer B. Eaddy, None; Lorie Logan, None;
Richard D. Stutzman, None; Joseph Pasternak, None
Support: Funded by USAMRAA Award W81XWH-09-2-0018
Visual, Refractive, Clinical Outcomes and Quality of Life
Assessment After Small-Incision Lenticule Extraction (SMILE)
vs. Implantable Collamer Lens for High Myopia
Arturo J. Ramirez-Miranda1, Jesus Cabral1, Juan
Carlos Serna-Ojeda1, Alejandro Navas1, Aida Jimenez-Corona2,
Enrique O. Graue-Hernandez1. 1Cornea and Refractive Surgery,
Instituto de Oftalmologia Conde de Valenciana, Mexico City,
Mexico; 2Biostatistics Department, Instituto de Oftalmologia Conde
de Valenciana, Mexico City, Mexico.
Purpose: To compare visual acuity, refraction measurements and the
quality of life in high myopic patients before and after SMILE and
Implantable Collamer Lens (ICL).
Methods: Retrospective case series. Patients who underwent bilateral
high myopic treatments (-6.00 D to -10.00 D). UCVA and refraction
follow-up was performed at day 1, 7, 30, 90 days. The Quality of life
Impact of Refractive Correction (QIRC) questionnaire was applied;
the outcome was the comparison of the overall QIRC score.
Results: 34 eyes for each group were analyzed. Preoperative mean
spherical equivalent was -7.43 D (range -6.00D to -9.75D) in the
SMILE group and -8.55 (range -6.00 to -10.00D) in ICL group
(P>0.50). There was a statistical significant difference in spherical
equivalent and visual acuity at day one towards the ICL group.
At 3 months spherical equivalent and visual acuity values were
similar in both groups. The QIRC median score of the patients with
SMILE (51.58, 95%CI from 47.49 to 55.68) was not different from
the median score of the ICLV4 group (52.59, 95%CI from 44.85
to 60.33) (p=0.053) after adjustment by spherical equivalent and
baseline logMAR.
Conclusions: ICL group showed better visual acuity at day one than
the SMILE group, after 1 week the values were similar for both
groups and continued during follow-up. SMILE patients had similar
QIRC scores than ICL patients
Commercial Relationships: Arturo J. Ramirez-Miranda, Thea
Laboratoires (R), Carl Zeiss Meditec (R); Jesus Cabral; Juan
Carlos Serna-Ojeda, None; Alejandro Navas, carl zeiss Meditec
(C), staar (C); Aida Jimenez-Corona, None; Enrique O. GraueHernandez, None
Effect of pupil size on visual performance of presbyopes with
small-aperture corneal inlay
Srividhya Vilupuru, Ling Lin. Clinical and Regulatory, AcuFocus Inc,
Irvine, CA.
Purpose: The effects of photopic pupil size on visual acuity and
mesopic pupil size on visual symptoms were evaluated in naturally
emmetropic presbyopes with a small-aperture corneal inlay implanted
in the non-dominant eye for the treatment of presbyopia.
Methods: This was a prospective, non-randomized study of 154
subjects (age 45-60 years) at 12 months postoperative. Eligible
subjects had a preoperative spherical equivalent refractions of
+0.50 to -0.75 D; best-corrected distance acuity of 20/20 and
uncorrected near acuity of 20/40 to 20/100. Corneal inlays were
implanted into stromal pockets created with femtosecond laser using
spot/line settings of 6x6 microns or less. Photopic and mesopic
pupil sizes were measured using a pupilometer to the nearest halfmillimeter. Uncorrected visual acuities at distance (UDVA) and near
(UNVA) were measured in ETDRS letters. Visual symptoms of glare,
halos and night vision problems were rated by subjects from 0 (none)
to 7 (very severe). For analyses, photopic and mesopic data sets were
each divided into two groups: greater than average (group 1) and less
than or equal to average (group 2). Further, a large pupil size group
was defined as being two or more standard deviations (SDs) above
average.
Results: Mean photopic pupil size was 4.4 ± 0.88 mm; UDVA for
photopic pupil size groups 1 and 2 were 49.8 ± 4.8 and 50.9 ± 4.3
letters, respectively and UNVA were 41.0 ± 7.1 and 42.2 ± 8.1 letters,
respectively. The between-group differences were not statistically
significant (p=0.14 for distance and 0.34 for near). Mean mesopic
pupil size was 5.9 ± 0.93 mm; for mesopic pupil groups 1 and 2,
the mean ± SD severity of halos was 1.1 ± 1.4 and 0.83 ± 1.5, glare
0.92 ± 1.3 and 0.64 ± 1.3 and night vision 0.87 ± 1.3 and 0.99 ± 1.6,
and the between-group differences were not statistically significant
(p=0.32, 0.18 and 0.61, respectively). In subjects with the largest
pupils (about 5%), acuity was 2-3 letters and symptoms were 1 rating
level worse.
Conclusions: Pupil size has none to minimal impact on visual acuity
and visual symptoms in the eye implanted with the small-aperture
corneal inlay. Subjects with the largest pupils tended to show slightly
worse outcomes, however, these trends were not statistically or
clinically significant.
Commercial Relationships: Srividhya Vilupuru; Ling Lin,
AcuFocus Inc
Corneal biomechanical changes after Small Incision Lenticule
Extraction (SMILE) and Femtosecond Laser Assisted In Situ
Keratomileusis (Femto LASIK) using a non contact tonometer
with visualization and measurement of corneal deformation
Ibrahim O. Sayed-Ahmed2, 1. 1Cornea, Bascom Palmer Eye Institute,
Miami, FL; 2Cornea, Roaya Vision Correction Centers, Alexandria,
Egypt.
Purpose: To evaluate and compare corneal deformation amplitude
in patients prior to and following small incision lenticule extraction
(SMILE) and Femtosecond laser in situ keratomileusis (Femto
LASIK) using a non contact tonometer with visualization and
measurement of the corneal deformation response to an air pulse with
an Ultra-High-Speed Scheimpflug camera (Corvis®ST)
Methods: In this comparative study, 20 patients 40 eyes divided
into 2 groups, the first group being those that underwent SMILE
and the second being those who had Femto-LASIK. Corneal
Deformation amplitude was recorded prior to and 3 months after
corneal laser refractive surgery for myopia. Preoperative corneal
hysteresis was correlated with age and preoperative central corneal
thickness (CCT). Postoperative corneal hysteresis was correlated
with postoperative CCT in both treatment groups. The correlations
between postoperative change in hysteresis and stromal ablation/
removal depth, percentage of tissue ablated/removed, optical zone
and patient age were also examined. The femtosecond laser platform
used for SMILE and for flap creation was theVisumax 500 (Carl
Zeiss meditec) and the eximer laser platform was ALLEGRETTO
excimer laser (WaveLight Laser Technologie AG).
Results: The IOP difference was significantly lower postoperatively
in both groups. In both groups the Corvis showed a significant
postoperative reduction in the cord length of corneal applanation
(A1 and A2), A2 time (time from starting until second corneal
outward applanation), HC time (time until highest corneal concavity
is reached), and highest concavity (HC) radius of curvature. A1
time decreased in group II only. The deformation amplitude and
HC peak distances (distance between corneal peaks at point of
highest concavity) increased significantly in both groups. The mean
percentage of change in HC radius of curvature was significantly
higher in group I while the mean percentage of change of HC peak
distance and deformation amplitude were significantly higher in
group II. It was also noted that the mean percentage of change of the
deformation amplitude was higher in group II than group I.
Conclusions: Both Femto LASIK and SMILE substantially
decreased the corneal biomechanical properties with less reduction in
the SMILE group.
Commercial Relationships: Ibrahim O. Sayed-Ahmed, None
The relationship between subjective happiness and LASIK
surgery
Shinichiro Matsuguma1, Motoko Kawashima2, Kazuno Negishi2,
Tomoo Oobayashi3, Ikuko Toda3, Kazuo Tsubota2. 1Ophthalmology,
Keio University Graduate School of Medicine, Nakano-ku, Japan;
2
Ophthalmology, Keio University School of Medicine, Shinjuku-ku,
Japan; 3Minamiaoyama Eye Clinic, Minato-ku, Japan.
Purpose: Although LASIK (laser in situ keratomileusis) surgery
has become widely known in Japan, there are few studies regarding
the psychological effects on the LASIK patients. Thus it is of
crucial importance to observe the subjective happiness among the
patients over the course of the surgery. In this retrospective study, we
analyzed the data to understand whether LASIK surgery would affect
the patients’ subjective state of happiness.
Methods: The analysis was conducted on 342 patients (mean age
was 33.95 years old; range was 17 to 64), who underwent LASIK
surgery and completed Lymbomirsky’s Subjective Happiness Scale
(SHS) at preoperatively and one-month postoperatively. SHS consists
of four items rated on a 7-point Likert scale requiring individuals
to indicate whether they agree or disagree with the statements. The
first three items are related to the state of happiness, and the last one
related to unhappiness, which is reverse coded. We also analyzed
the correlation between the patients’ subjective happiness and their
uncorrected visual acuity (logarithmic minimum angle of resolution,
logMAR) as well as their subjective refraction (spherical equivalent.)
of the right eye.
Results: The pre- and post-operative mean scores of the first
three items (± standard deviation: SD) were as follows: (the item
1) 5.48 (± 1.07) and 5.65 (± 1.07), (the item 2) 5.26 (± 1.08) and
5.44 (± 1.09), and (the item 3) 4.90 (± 1.30) and 5.11 (± 1.24),
respectively. The pre- and post-operative score of the last item was
5.21 (± 1.31) and 5.22 (± 1.46), respectively. We found the significant
increase in the scores of the first three items: the item 1 (p = 0.04),
the item 2 (p = 0.03), and the item 3 (p = 0.03), respectively, and
non-significant change in the score of the last item (p = 0.97) after
the LASIK surgery. We could not observe any correlation between
the patients’ subjective happiness and the improvement of their
uncorrected visual acuity (r = 0.0013), nor their subjective refraction
(r = 0.0001).
Conclusions: LASIK surgery can somehow positively affect the
patients’ psychological state of happiness. Further studies are
required to underpin what factor is directly related to the increase in
patients’ subjective happiness.
Commercial Relationships: Shinichiro Matsuguma,
None; Motoko Kawashima, None; Kazuno Negishi, None;
Tomoo Oobayashi, None; Ikuko Toda, None; Kazuo Tsubota,
None
Post-surgical immune keratitis after laser vision correction
Peter Lipscomb1, Andrew E. Holzman1, 2. 1Ophthalmology, University
of Virginia, Charlottesville, VA; 2TLC Laser Eye Center, McClean,
VA.
Purpose: Peripheral keratitis after laser vision correction, distinct
from diffuse lamellar keratitis, is a rare entity that has been described
in the literature. With our case series we seek to further describe this
rare but significant complication and provide insight into risk factors,
treatment options and preventive measures for these patients. We
believe our series to be the largest of such reported cases.
Methods: In our busy refractive surgery practice we reviewed charts
and identified 13 patients (23 eyes) in our last 30,000 cases, between
2007 and 2015, who developed peripheral corneal infiltrates after
undergoing laser vision correction.
Results: Laser in-situ keratomileusis (LASIK) was performed in 18
eyes and photorefractive keratectomy (PRK) in 5 eyes. Ten patients
had bilateral disease and 3 had unilateral. Eleven patients (83%) had
a systemic pro-inflammatory condition and 5 patients (42%) had an
ocular pre-disposition.
In all cases the infiltrates were peripheral, circumferential along the
wound edge, and separated from the limbus with an area of clear
cornea. There was overlying loose epithelium and corneal thinning.
All patients were treated with low dose topical steroid until the
corneal thinning resolved and the surface improved. Topical
antibiotics were given for coverage. Patients were treated oral
prednisone on a tapered dose, which led to regression of the
infiltrates. No patients suffered loss of best-corrected distance visual
acuity and 83% of eyes achieved 20/20 snellen uncorrected distance
acuity.
Conclusions: The bilateral tendency, worsening with antibiotics,
location along the wound edge, and improvement with oral steroids
yielded low suspicion for bacterial infection. While the etiology is
unknown, in our series there was a strong association with systemic
pro-inflammatory conditions such as atopy, hypothyroidism, and
psoriasis suggesting a possible immunologic nature. We suspect
these factors are even more important if underlying meibomian gland
dysfunction, blepharitis, or rosacea is also present. We recommend
these at-risk patients be pre-treated with oral steroid in an attempt to
prevent disease occurrence. A high degree of suspicion for infectious
etiology must be maintained. When treated appropriately with oral
steroid visual outcomes are excellent. There is, however, significant
risk of complication if not recognized early.
Figure 1: Infiltrates along the wound edge on day 3 following LASIK
Commercial Relationships: Peter Lipscomb, None;
Andrew E. Holzman
Anterior Segment OCT to Assess Predictability of Femtosecond
Laser-Assisted Intrastromal Corneal Ring Segment Depth
Michele A. Pacheco1, Arturo J. Ramirez-Miranda1, Alejandro Navas1,
Leticia E. Pacheco2, Enrique O. Graue-Hernandez1. 1Ophthalmology,
Instituto de Oftalmología Conde de Valenciana, Mexico City,
Mexico; 2Ophthalmology, Centro Médico Nacional Siglo XXI,
México City, Mexico.
Purpose: To evaluate the predictability of ISRS depth using anterior
segment optical coherence tomography (AS-OCT)
Methods: Transversal study of 33 eyes, which underwent
intrastromal femtosecond, assisted ICRS with the Visumax.
Postoperatively, AS-OCT distances from the anterior corneal surface
to the anterior surface of the ring, ring depth and incision depth was
evaluated, and compared with the attempted depth
Results: Distance from the ring apex to the anterior corneal surface
was shorter (283 um) than the target femtosecond depth (471 um),
probably due to stromal compaction (P<0.05)
Conclusions: In order to assess segment depth, incision depth may be
considered since AS-OCT provides evidence of stromal compaction
after femto-assisted ISRS implant.
Commercial Relationships: Michele A. Pacheco, None;
Arturo J. Ramirez-Miranda, Carl Zeiss Meditec (C);
Alejandro Navas, STAAR Surgical (C), Alcon Laboratories (C), Carl
Zeiss Meditec (C); Leticia E. Pacheco, None; Enrique O. GraueHernandez, None
SMILE for hyperopia: refractive outcomes, optical zone
centration, diameter, and aberration induction
Dan Z. Reinstein1, 2, Kishore R. Pradhan3, Purushottam Dhungana3,
Glenn Carp1, Timothy J. Archer1, Marine Gobbe1, Raynan Khan1.
1
London Vision Clinic, London, United Kingdom; 2Columbia
University Medical Center, New York, United Kingdom; 3Tilganga
Institute of Ophthalmology, Kathmandu, Nepal.
Purpose: To evaluate visual and refractive outcomes, optical quality
and centration of small incision lenticule extraction (SMILE) for
hyperopia.
Methods: Prospective study of vertex-centered hyperopic SMILE
using the VisuMax femtosecond laser (Carl Zeiss Meditec). Inclusion
criteria were intended sphere ≤+7.00 D, astigmatism ≤6.00 D, and
age ≥21 years. Lenticule parameters were 6.3-6.5 mm diameter,
2 mm transition zone, 30 μm minimum thickness, and 120 μm
cap thickness. The study was divided into phases based on CDVA,
starting with densely amblyopic eyes and progressing to sighted eyes.
Manifest refraction and Atlas topography were obtained before and
3 months after surgery for 57 eyes. Optical zone centration, optical
zone diameter (based on Atlas tangential curvature difference maps),
and change in corneal spherical aberration were analyzed for all eyes
and compared to MEL80 LASIK matched control groups for 6.5
mm and 7 mm optical zones (transition 2 mm). Visual and refractive
outcomes were analyzed for eyes with CDVA 20/40 or better (sighted
eyes, n=31). Refractive predictability was compared to a MEL80
LASIK matched control group.
Results: Mean attempted SEQ was +5.63±0.90 D (+3.20 to +6.87
D). Mean astigmatism was 1.22±1.00 D (0.00 to 4.00 D). Mean
optical zone offset was not different between SMILE and LASIK
(p>0.77); 0.30±0.21 mm in SMILE and 0.32±0.20 mm in LASIK.
Mean achieved optical zone diameter was 5.02±0.30 mm for 6.3 mm
SMILE; larger than 6.5 mm LASIK (4.58±0.24 mm, p<0.001) and
7 mm LASIK (4.90±0.25 mm, p<0.05). Mean spherical aberration
change was -0.53 μm in 6.3 mm SMILE, equivalent to 7 mm LASIK
(-0.47 μm, p=0.916), but less than 6.5 mm LASIK (-0.76 μm,
p<0.01). For the 31 sighted eyes (CDVA 20/40 or better), UDVA was
20/40 or better in 84% and 20/63 or better in 100% of eyes. Mean
postop SEQ relative to the intended target was -0.04±0.79 D (-2.20
to +1.88 D), with 65% within ±0.50 D and 87% within ±1.00 D. No
eyes lost 2 or more lines CDVA. Predictability was 53% within ±0.50
D for the LASIK control group.
Conclusions: Optical zone centration was equivalent between
vertex-centered hyperopic SMILE and LASIK. Less spherical
aberration was induced by 6.3 mm SMILE than 6.5 mm LASIK and
was equivalent to 7 mm LASIK. Achieved topographic optical zone
diameter was larger for 6.3 mm SMILE than 6.5 and 7 mm LASIK.
Refractive predictability of SMILE was similar or better than for
LASIK.
Commercial Relationships: Dan Z. Reinstein, Carl Zeiss Meditec
(C), ArcScan Inc (I), ArcScan Inc (P), Carl Zeiss Meditec (P);
Kishore R. Pradhan; Purushottam Dhungana, None; Glenn Carp,
Carl Zeiss Meditec (R); Timothy J. Archer, None; Marine Gobbe,
None; Raynan Khan, None
Topography-Guided Custom Ablation for Optical Zone
Enlargement and Recentration after Previous Myopic LASIK
Timothy J. Archer1, Dan Z. Reinstein1, 2, Marine Gobbe1,
Alastair J. Stuart3, Eleanor A. Miller1, Glenn Carp1. 1London Vision
Clinic, London, United Kingdom; 2Columbia University Medical
Center, New York, NY; 3King’s College Hospital, London, United
Kingdom.
Purpose: Report the results of optical zone enlargement and
recentration using topography-guided ablation after previous myopic
LASIK.
Methods: Retrospective analysis of 73 eyes that underwent a
topography-guided retreatment for optical zone enlargement or
recentration after primary myopic LASIK with the MEL80. Atlas
corneal topography, corneal wavefront and manifest refraction were
used to generate the ablation profile using the CRS-Master and
MEL80 excimer laser. Refractive and visual outcomes were analysed.
Optical zone centration and diameter were assessed by electronically
overlaying a set of paracentral rings and central grid onto tangential
curvature difference maps, with the edge of the optical zone identified
as the mid-peripheral power inflection point. The change in corneal
spherical aberration was also calculated. Follow-up was 3 to 12
months.
Results: SEQ was -0.54±0.99 D (-3.75 to +1.00 D) after the primary
LASIK and -0.21±0.63 D (-1.88 to +2.25 D) after the topographyguided retreatment, with 71% within ±0.50 D and 92% within ±1.00
D of the intended target SEQ. UDVA after the retreatment (vs CDVA
before retreatment) was 20/20 or better in 82% (91%) and 20/25 or
better in 93% (92%) of eyes. No eyes lost 2 lines CDVA, and contrast
sensitivity was normal and unchanged. Optical zone decentration
from the corneal vertex was reduced by 63% from 0.58±0.26 mm
(0.05 to 1.28 mm) to 0.21±0.14 mm (0.00 to 0.54 mm). Optical zone
diameter was increased by 11% from 5.65±0.52 mm (4.8 to 7.0 mm)
to 6.33±0.52 mm (5.0 to 7.6 mm). Corneal spherical aberration was
reduced by 46%, coma was reduced by 49%, and higher order RMS
was reduced by 39%.
Conclusions: Topography-guided custom ablation is an effective
treatment for decentrations and optical zone enlargement. Refractive
accuracy was similar to standard LASIK retreatments.
Commercial Relationships: Timothy J. Archer, None;
Dan Z. Reinstein, ArcScan Inc (I), Carl Zeiss Meditec (C),
Carl Zeiss Meditec (P), ArcScan Inc (P); Marine Gobbe, None;
Alastair J. Stuart, None; Eleanor A. Miller, None; Glenn Carp,
Carl Zeiss Meditec (R)
Corneal Wound Healing after Small Incision Lenticule
Extraction (SMILE)
Yuan Sun1, Ting Zhang1, Manli Liu1, Yugui Zhou1, Shengbei Weng1,
Xiaonan Yang1, Chi-ho To2, 1, Quan Liu1, 2. 1State Key Laboratory
of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen
University, Guangzhou, China; 2School of Optometry, The Hong
Kong Polytechnic University, Hong Kong, Hong Kong.
Purpose: To evaluate the wound healing response after SMILE
procedure in rabbit model.
Methods: SMILE was performed in both eyes of 12 New Zealand
White rabbits. The cap diameter and thickness were 7.5 mm and
100 μm, respectively. The refractive spherical correction was set at
-6.00 D. These animals were divided into 6 groups and the followup examinations were performed 1 hour, 4 hour and 1 day, 3 days,
7 days and 28 days after surgery. Corneas were evaluated using
slit lamp and in vivo confocal microscopy. The enucleated eyes
were used for light microscopy, terminal deoxyribonucleotidyl
transferasemediated dUTP-digoxigenin nick-end labelling (TUNEL)
assay and immunofluorescence staining (Fibronectin, Tenascin C,
CD11b, alpha-SMA).
Results: The central corneas did not show any noticeable opacity
at any time point of follow-up. In the contrast, there were obvious
scar tissues at the incision position. Scattering hyper reflective spots
were observed through in vivo confocal microscopy at 4 hours
postoperatively. Large sums of TUNEL-positive keratocytes were
detected near the laser ablation zone at 1 hour after surgery and
decreased afterwards. Inflammation cells were found to enter from
the incision into the central cornea. The inflammatory reaction was
observed from 1 hour after surgery. The deposition of extracellular
matrix (ECM; Fibronectin & Tenascin) was detected at 1 day
postoperatively. The distribution pattern of ECM between the central
cornea and the incision was different. Alpha-SMA-positive fibroblasts
were detected at the incision position, but it was not observed at
central cornea.
Conclusions: It is necessary to implement anti-inflammation
intervention at early stage after surgery. The non-scar wound healing
response was resulted in the different reaction patterns between the
central cornea and the incision.
Commercial Relationships: Yuan Sun, None; Ting Zhang;
Manli Liu, None; Yugui Zhou, None; Shengbei Weng, None;
Xiaonan Yang, None; Chi-ho To, None; Quan Liu, None
Support: Supported by grants from the Natural Science Foundation
of China (81261130021), the Science and Technology Program of
Guangzhou (2013B 021800126) and the Natural Science Foundation
of Guangdong (2015A 030310098).
Aspheric Micro-monovisionLASIK in Correction of Presbyopia
and Myopic astigmatism: Early Clinical Outcomes in Chinese
Population
Ting Zhang, Yuan Sun, Manli Liu, Quan Liu. zhongshan ophthalmic
center, Guangzhou, China.
Purpose: The sheer number of presbyopic candidates who might
seek permanent freedom from spectacle has stimulated development
of various methods for surgical correction. Purpose of this study is to
analyze early clinical outcomes of aspheric micro-monovisionLASIK
for correction of presbyopia and myopia with or without astigmatism.
Methods: This study was a prospective, noncomparative case series
of 50 eyes of 25 patients with a mean age 44±4 years (range 38
to 62 years) treated bilaterally using aspheric micro-monovision
protocol. The target refraction was plano for distance vision eye and
between -0.75 to -2.00 diopters (D) for near vision eye. Meanwhile
the depth of field (DOF)increasedvia induced greater amounts of
spherical aberration to provide a blend zone, which enable continuous
distance to intermediate to near vision between the two eyes. Clinical
outcomes and satisfaction-score questionnaires were evaluatedafter
surgery.
Results: Three months after surgery, the mean spherical equivalent
(SE) refraction in distance eye was 0.03±0.20 D, while the attempted
and achieved SE in near eye were -1.34±0.26 D and -1.18±0.34
D respectively. Ninety-four percent of eyes were within 0.50 D of
target defocus. The uncorrected distance visual acuity (UDVA) after
surgery was -0.126±0.05logMAR (20/14.3), 0.174±0.11logMAR
(20/31), and -0.141±0.05logMAR (20/13.8), for distance eyes,
near eyes and binocularly, respectively. Ninety percent of patients
achieved simultaneously uncorrected distance visual acuity 0.0
logMAR(20/20) or better and uncorrected near visual acuity J2 or
better. Minus-Lens–Stimulated accommodative amplitude changed
from 4.48D to 5.02 D (P<0.05). Satisfaction questionnaire scores was
93.00±5.3.
Conclusions: This aspheric micro-monovision protocol provided a
well-tolerated and effective means for treating myopic astigmatism
and alleviating presbyopic symptoms simultaneously.
Commercial Relationships: Ting Zhang, None; Yuan Sun, None;
Manli Liu, None; Quan Liu, None
Clinical Trial: ChiCTR-IPC-15005842
A laboratory study on the rainbow glare effect after femtosecond
laser corneal surgery
Valeria Nuzzo1, Fatima Alahyane2, Karsten Plamann2. 1ECE Paris
School of engineering, Paris, France; 2Laboratoire d’optique
appliquée, ENSTA ParisTech – École polytechnique – CNRS,
Université Paris-Saclay, Palaiseau, France.
Purpose: The rainbow glare effect is reported increasingly often as
a side effect of femtosecond (fs) laser corneal surgery. It consists in
the appearance of faint coloured images superposed on normal vision.
It is likely linked to light diffraction due to regular patterns at the
interface of the incision. Our goal was to reproduce the effect in a
laboratory setting and identify strategies of its suppression.
Methods: Lamellar incisions were performed in pig cornea and
glass slides with a fs laser. The transmitted light from three red,
bleu and green lasers was viewed on a screen. Corneas were excised
from fresh enucleated pig globes, stored in 10% Dextran in Hank’s
solution before laser cutting and mounted between two coverslips.
Experimental conditions for lamellar incisions were: surface 5mm2,
depth 200µm, energy density slightly higher than the threshold
(1-2J/cm2), focussing numerical aperture (NA) 0.3 and 0.45; Laser:
1.03µm wavelength, 730fs pulse duration, 10kHz repetition rate;
Raster scan: 3µm and 5µm spot separation. Parameters of our
experiments were similar to those of clinical practice. After cutting,
the sample was irradiated by three collimated superposed continuous
lasers of wavelengths 457nm, 532nm, 633nm. Images of the
transmitted light viewed on a screen were captured by a camera and
post-processed using ImageJ and MATLAB.
Results: When irradiated by the red-green-blue lasers at the positions
of the lamellar incisions, corneas (n=3 per set of parameters) showed
the formation of a diffraction pattern within the transmitted light. This
was observed for raster scans performed at a energy density slightly
higher than the threshold and at all combinations of spot separations
(3µm or 5µm) and NAs (0.3 or 0.45). The angular separation between
the orders of diffraction at the three wavelengths corresponds to the
theoretical diffraction values. The diffracted light patterns of corneas
and glass slides, incised with the same parameters, were superposed.
No diffraction was obtained from non treated regions of the corneas.
This phenomenon resembles the clinical rainbow glare effect
previously reported.
Conclusions: Our laboratory study shows that the fs laser raster
scanning of corneas created a diffraction grating in the tissue,
regardless of the combination of spot separations and numerical
apertures used. Different cutting strategies should be further
investigated to prevent the rainbow glare formation.
Commercial Relationships: Valeria Nuzzo, None;
Fatima Alahyane, None; Karsten Plamann, None
Assessment of Next Generation Femtosecond Laser Using
Scanning Electron Microscopy and Optical Coherence
Tomography
James E. Hill1, Alireza M. Tabrizi2, Hong Fu2, Ling C. Huang1,
Ronika S. Leang1. 1Bilogical Sciences, R&D, Abbott Medical Optics,
Santa Ana, CA; 2R&D, Abbott Medical Optics, Inc., Milpitas, CA.
Purpose: We present preliminary results for a novel femtosecond
(FS) laser for creating corneal flaps on porcine globes.
Methods: The novel next generation FS Laser was used to create
LASIK flaps in porcine eyes (N=28) with a smaller laser spot size,
faster rep rate and lower energy than current state of the art FS laser
systems. Gross assessment of the laser pattern and placement were
viewed with a surgical grade microscope. The lift of the flap was
assessed using a scale of 1-4 (1= no lift, 2= moderate, 3= minimal,
4= no adhesion). Optical Coherence Tomography (OCT) was used
to evaluate wound architecture for uniform pattern fidelity. The flaps
were removed and the cornea resected was sent for Scanning Electron
Microscopy (SEM) analysis to evaluate the bed quality.
Results: Following laser treatment, the globes were examined under
a surgical grade microscope. A complete pattern was discernible with
lighter and darker bubble patterns dependent upon the laser energy
used. Uniformity of the bubble patterns can lead to a better lift of
the flap as well as a smoother bed as noted by Aristeidou et al (2015
Eye and Vision). The novel next generation laser had uniform bubble
patterns with no adhesions of the bed or entry side cut lift using a
single uniform swipe with spatula from superior hinge to inferior
edge of the flap. With 15 eyes = 4, 5 eyes = 4-, and 8 eyes = 3+. The bed
quality after the lift appeared even and smooth as viewed through the
microscope at 100X. The OCT images presented even spacing for flap
location and depth. The SEM images of the bed tissue were smooth with
no noticeable unevenness even at high magnification (250X).
Conclusions: Evaluation of the bubble pattern showed consistent
pattern fidelity which was verified by uniform OCT images showing
well demarcated lines of uniform depth. The SEM images compared
to current state of the art FS laser system demonstrated very similar
quality with smooth beds at high magnification. The flap lifts created
by this novel next generation FS laser are equivalent or better for
performing LASIK surgery.
Commercial Relationships: James E. Hill, Abbott Medical Optics,
Inc; Alireza M. Tabrizi, Abbott Medical Optics, Inc; Hong Fu,
Abbott Medical Optics, Inc; Ling C. Huang, Abbott Medical Optics,
Inc; Ronika S. Leang, Abbott Medical Optics, Inc
Refractive Surgery in the Elderly Population
Paloma Lopez, Julio C. Hernandez, Jorge E. Valdez. Ophthalmology,
Centro Medico Zambrano Hellion, Monterrey, Mexico.
Purpose: Report on the safety, efficiency and results of refractive
surgery in patients aged 65 or older.
Methods: Retrospective analysis of the records of elderly patients
that underwent corneal refractive surgery during the period June
2010 to June 2015 at Hospital Zambrano Helion; Monterrey, Mexico.
Refractive surgery was performed by one experienced surgeon using
the Technolas 217z Excimer Laser (Bausch&Lomb, Rochester, NY,
US). Inclusion criteria were patients ≥65 years old with preoperative
manifest refraction spherical equivalent (MRSE) up to -8.5D,
cylinder up to 6.0D, corrected distance visual acuity of 20/25 of
better and central corneal thickness >500μm with no other ocular
pathology.
Results: A total of 44 eyes (24 patients) were included. Mean age
was 67.2±3.1 (range 65 to 80), with a mean follow up of 6.2±1.3
months. Conventional LASIK was performed in 20 patients (Group
1, 36 eyes) to improve uncorrected distance visual acuity (10 eyes
myopic LASIK, 26 eyes hyperopic LASIK) and presbyopic LASIK
(monovision) in 4 patients (Group 2, 8 eyes) to restore near vision
performance. Preoperative MRSE for the myopic eyes in group
1 was -2.79±1.88D and +2.19±1.88D for hyperopic eyes, MRSE
for group 2 was +2.10±0.87D. Preoperative UDVA in group
1 was 0.67±0.30 LogMAR (20/100 Snellen) and 0.46±0.18
LogMAR (20/50 Snellen) and Jaeger ≥4 in 90% of the patients.
Postoperative MRSE was -0.29±0.86D (myopic LASIK)(p<.001),
-0.34±0.62D (hyperopic LASIK)(p<.001) and -1.25±0.59D
(non-dominant eye) in presbyopic LASIK. Postoperative UDVA
in myopic LASIK was 0.15±0.30 (20/25 Snellen)(p=.001)
and 0.11±0.11 (20/25 Snellen)(p<.001) for hyperopic LASIK,
with binocular UDVA 0.16±0.17 (20/25 Snellen)(p=0.12) and
UNVA ≥J2 in 100% of the patients.
Conclusions: Even though elder patients may present greater
LASIK restrictions due to lens evolution and other eye conditions
related to older age, patients ≥ 65 years that were candidates showed
satisfactory and safe results on both groups. 84% of the patients
underwent conventional LASIK to correct myopia and hypermetropia
to obtain better visual distance. The other 16% of the patients
underwent monovision LASIK surgery to correct both near and far
distances.
Commercial Relationships: Paloma Lopez, None;
Julio C. Hernandez, None; Jorge E. Valdez, None
Changes in visual acuity and high-order aberrations after SMILE
Jesus N. Jaurrieta-Hinojos, Oscar Fernandez. Cornea, Fundación
Hospital “Nuestra Señora de la Luz” IAP, Distrito Federal, Mexico.
Purpose: To analize high-order aberrations (HOA) before and
1 week, 1 month and 3 months after Small Incision Lenticule
Extraction (SMILE) refractive surgery.
To quantify the change in uncorrected visual acuity (UCVA) after
SMILE.
Methods: Prospective, analytic, observational study design done
from January 1st until September 1st 2015. We analyzed logMAR
UCVA, and the root mean square (RMS) of several HOA including:
comma, trefoil, spherical aberration, defocus and astigmatism using
a Hartmann-Shack aberrometer (WaveScan, VisX®). All these
measurements were done before SMILE and 1 week, 1 month and 3
months afterwards. SMILE surgery was realized using an Visumax
500 kHz (Carl Zeiss Meditec®) femtosecond laser. All data was
emptied to an Excel data sheet and statistical analysis was done using
SPSS 21 (IBM®). Student’s t was used to compare HOA before and
after surgery and Pearson’s test was used to assess the correlation
between the study’s variables.
Results: 71 eyes of 37 patients were included. Mean age at first visit
was 28 years. An increase in HOA RMS was found after surgery at
all time points evaluated (p<0.05). There was a decrease in defocus,
astigmatism and UCVA logMAR (p<0.05). Both trefoil and spherical
aberration were not statistically significant modified. We found a
positive correlation between the degree in astigmatism with the flap
diameter (r=0.661, p<0.0001) and with the optical zone (r=0.661,
p=0.000007). A negative correlation was found between UCVA
logMAR and HOA RMS and spherical aberration (p=0.044 and
p=0.004, respectively).
Conclusions: SMILE surgery entailed an statistically significant
increase in HOA RMS, coma and a decrease in defocus and
astigmatism at a week, 1 month and 3 months postoperatively. All
included patients in this study achieved an UCVA logMAR of 0.09 or
better at 3 months. We believe that SMILE is an efficient refractive
technique with a mild induction of HOA RMS and comma after
surgery that mantains stable at least after 3 months.
Figure 2 - Individual HOA before surgery, 1 week, 1 month and 3
months postoperatively
Commercial Relationships: Jesus N. Jaurrieta-Hinojos, None;
Oscar Fernandez, None
Visual outcomes and change in aberration profile following
wavefront-optimized photorefractive keratectomy (PRK)
Roy D. Swanson, Ronald R. Krueger. Cole Eye Institute, Cleveland
Clinic, Cleveland, OH.
Purpose: To report the visual outcomes and change in aberration
profile following wavefront-optimized photorefractive keratectomy
(PRK) in low, moderate and high myopic corrections.
Methods: A retrospective chart review was performed on 60 eyes
targetted for emmetropia with wavefront-optimized PRK using the
ALLEGRETTO WAVE Eye-Q excimer laser (Alcon Laboratories
Inc). Patients were subdivided into low (< -3.00 D, n=9), moderate
(-3.00 to -6.00 D, n=30), and high myopia (> -6.00 D, n=21). Preand 3 to 12-month postoperative uncorrected distance visual acuity
(UDVA) and wavefront aberrometry (at 5.5 mm pupil diameter) were
compared.
Results: A moderate increase in spherical aberration of 0.07
± 0.04 μm (P=.19) and 0.11 ± 0.02 μm (P<.01) was noted for
low and moderate myopic corrections, respectively, while high
myopes showed a proportionally greater increase of 0.27 ± 0.05
μm (P<0.001) A decrease and mild increase was found in coma
of -0.04 ± 0.05 μm (P=.67) and 0.07 ± 0.03 μm (P=.04) for mild
and moderate myopia, respectively, while, high myopia achieved a
greater induction of coma of 0.22 ± 0.06 μm (P<0.001) Likewise, an
increase in overall higher order aberrations of 0.11 ± 05 μm (P<.001),
and 0.12 ± 0.02 μm (P<0.001) were noted for mild and moderate
myopia respectively, with a greater change among higher myopes at
0.33 ± 0.06 μm (P<0.001). Uncorrected visual outcomes, however
were not statistically different with the level of myopia, revealing
percentages of 20/15 and 20/20 to be 38% and 88% among low
myopes, 69% and 90% among moderate myopes, and 48% and 71%
among high myopes, respectively.
Conclusions: Wavefront-optimized PRK with the WaveLight
Allegretto Wave Eye-Q achieves excellent postoperative UDVA
results, with the greatest increase in higher order aberrations
(spherical aberration, coma and total higher order aberrations)
among eyes with high myopia. Despite this trend of inducing a
proportionately greater range of HOAs with high myopia, the visual
acuities show this to not be visually significant.
Commercial Relationships: Roy D. Swanson, None;
Ronald R. Krueger, Alcon Laboratories Inc (C), Alcon Laboratories Inc (F)
Contrast Sensitivity after Wavefront Guided LASIK for Myopia
Ying Wang, Sanjeev Kasthurirangan, Stan Bentow. Clinical Research,
Abbott, Santa Ana, CA.
Purpose: It is known that refractive surgery for myopia yields
reliably predictable outcomes for sphere and cylindrical refractive
errors. With wavefront guided LASIK (Laser Assisted in situ
Keratomileusis), it is of interest to evaluate contrast sensitivity of
subjects before and after surgery. One hypothesis for any contrast
sensitivity improvement is the effect of spectacle magnification i.e.
minification preoperatively for larger refractive errors that would not
be present postoperatively and the aim of the current study was test
this hypothesis.
Methods: This was a prospective, non-randomized, clinical study
conducted at 12 investigative sites in the USA that included 334
eyes of 170 subjects treated with wavefront-guided myopic LASIK
with the iDesign Advanced WaveScan Studio System and Star S4 IR®
Excimer Laser System. Treatment plans derived based on iDesign®
System spherical equivalent (IDSE) refractive error ranged from
-1.04 D to -11.98 D. Uncorrected visual acuity (UCVA), contrast
sensitivity and refractive outcomes were assessed at 6-months.
Monocular, best corrected contrast sensitivity was tested using
sine-wave grating charts (spatial frequencies of 3, 6, 12, and 18
cycles per degree [cpd]) at 2.5 meters (8 feet) under three lighting
conditions: photopic (85 cd/m2) without glare, mesopic (3 cd/m2)
without glare and mesopic with glare.
Results: At 6 months, 98.2% of eyes had UCVA of 20/40 or better,
UCVA of 20/20 or better was 82.6%, manifest refraction spherical
equivalent within 0.50 D was 68.9% and within 1.00 D was 93.4%.
Statistically significant improvements of approximately 0.15 log units
or more in mean contrast sensitivity under mesopic conditions with
and without glare was seen. Most eyes (≥89%) experienced either
no change or an improvement in contrast sensitivity postoperatively;
under mesopic conditions with or without glare, there was a four-fold
increase in the proportions of eyes with clinically significant (i.e.
0.30 log units at 2 or more spatial frequencies) increases (41%-47%)
compared to decreases (≤11%). Contrast sensitivity improvement
versus preoperative refractive error showed no relationship for 12 cpd
(r = -0.063; p = 0.25) or 18 cpd (r = -0.065; p = 0.24).
Conclusions: Wavefront guided LASIK for myopia led to improved
contrast sensitivity postoperatively. Spectacle magnification does not
lead to this improvement in contrast sensitivity.
Commercial Relationships: ying wang; Sanjeev Kasthurirangan,
Abbott; Stan Bentow, Abbott
To know the number of complications in the surgical technique
“SMILE”
ELIZALDE F. GERMAN, Oscar Fernandez. CORNEA, HOSPITAL
FUNDACION NUESTRA SEÑORA DE LA LUZ, DF, Mexico.
Purpose: The use of femtosecond laser in refractive surgery has
taken importance in Mexico.
The learning curve of the SMILE surgical technique is not known
with accuracy to be a relatively new technique.
Determine the number of complications in this technique helps us to
prevent and have a better manage post-surgical.
Methods: Prospective, descriptive and observational study.
We studied the complications intraoperative and postoperative,
uncorrected visual acuity pre and post-surgery, equivalent sphere
and keratometry of patients undergoing refractive surgery with the
surgical technique SMILE by femtosecond during January to October
2015, at the Foundation Hospital Nuestra Señora de la Luz. The
platform for the surgery is VisuMax of Zeiss. The statistical analysis
in Excel platform.
Results: Were studied 180 eyes of 90 patients undergoing refractive
surgery with surgical technique “SMILE”. Visual acuity corrected
average pre surgical was not of 1.14 LogMAR (Snellen 20/276).
The equivalent spherel pre surgical average - 4.2 diopters. The
keratometry more flat and curved average was 42.9 and 44.6
diopters respectively. The average pachymetry was 559. 5±32
microns. Intra-operative complications were observed in 45/180
eyes. The main complication was difficult to extract the lenticule
19 (10.5%) cases, tear of incision 8 (4.4%) cases, epithelial abrasion
7 (3.8%) cases, loss of suction 5 (2.7%) cases, incomplete lenticule
3 (1.6%) cases, blackspot 2 (1.1%) cases and hemorrhage interface
one (0.5%) case. All complications were resolved intraoperative.
Two patients with loss of suction the incision was performed
manually, the 3 remaining rescheduled its refractive surgery 3
months later.
Postsurgical findings by biomicroscopy were 31 cases with detritus
(17.22%) cases, superficial punctate keratopathy 25 (13.88%) cases,
epithelial defect 8 (4.44%) cases, haze 8 (4.44%), edema in interface
2 (1.11%), folds in incision 2 (1.11%), epithelial growth, interface
with lenticule and diffuse lamellar keratitis one (. 55%)case for each
of them.
The postsurgical spherical equivalent average per month was - 0.18
±.31 diopters. The average final visual acuity was 0.02 LogMAR.
Conclusions: Intra-operative complications can be resolved at the
time without affecting the fina lvisual acuity.
The SMILE surgical technique is secure with excellent results in the
final visual acuity.
Commercial Relationships: ELIZALDE F. GERMAN, None;
Vector Analysis in Refractive Surgery with Femto-LASIK
Azyadeh Camacho Ordoñez, Oscar Fernandez, ELISA ALEGRIA
GOMEZ. Hospital de la luz, Mexico, Mexico.
Purpose: To determinate the induced and residual astigmatism after
Femto-LASIK surgery
Methods: A total of 66 eyes from 33 subjects were included,
mean age was 27.7±5.7 years, with a spherical refractive error range
-10.50 to +4.50D and cylindrical power -0.50 to -6.50D. Subjects
were divided in three groups according to preoperative cylinder:
group I <1 diopter (D), group II 1-2D and group III >2D. The flap
was made with VisuMax Femtosecond laser and underwent LASIK
correction on STAR S4 IR laser platform. The calculation of induced
and residual astigmatism was made with a vector analysis performed
by a mathematical formula described by Holladay and Hersh with
double angle graphic at first week, one and three months.
Results: The average preoperative astigmatism was -2.66x173,
after surgery the induced astigmatism was -0.17x117 at week one,
-0.23x105 at first month and -0.16x13 at third month; the residual
astigmatism was -0.26x50 at first week, -0.31x173 at first month and
-0.27x170 at third month. The induced sphere was -0.97 at first week,
-0.69 at first month and -0.68 at third month. The residual sphere was
-0.50, -0.65 and -0.56 respectively.
Induced and residual astigmatism were -0.04x124 and -0.01x160 in
group I, -0.04x181 and 0.04x177 in group II, -0.10x156 and 0.11x160
in group III at third month respectively.
Conclusions: The induced and residual astigmatism at third month
with Femto-LASIK was minimum. The residual astigmatism was
higher in patients with >2D preoperative cylinder. The induced and
residual sphere at third month was 0.56 and 0.68 respectively.
Commercial Relationships: Azyadeh Camacho Ordoñez;
Oscar Fernandez, None; ELISA ALEGRIA GOMEZ, None
Differential impact of LIRIC and femto-LASIK on keratocyte
viability in cat cornea
Kaitlin Wozniak1, Noah Elkins2, Daniel Brooks1, Daniel E. Savage1, 3,
Margaret DeMagistris4, Scott MacRae3, 4, Holly B. Hindman3, 4,
Jonathan D. Ellis1, 5, Wayne H. Knox1, 3, Krystel R. Huxlin3, 4. 1Institute
of Optics, University of Rochester, Rochester, NY; 2Department of
Biomedical Engineering, University of Rochester, Rochester, NY;
3
Center for Visual Science, University of Rochester, Rochester,
NY; 4Flaum Eye Institute, University of Rochester, Rochester, NY;
5
Department of Mechanical Engineering, University of Rochester,
Rochester, NY.
Purpose: Laser refractive surgeries cause unwanted post-operative
side effects. We recently developed an alternative refractive
procedure, LIRIC, which changes the refractive index of cornea
using a femtosecond (fs) laser. We assessed the extent to which
LIRIC damages corneal cells, contrasting it with fs laser in-situ
keratomileusis (LASIK).
Methods: LIRIC was performed on five, excised feline eyes using a
400nm Ti:Sapphire laser. A water-immersion objective (NA=1.0) was
raster-scanned across the applanated cornea, creating a 2.5mm-wide
refractive pattern. Three layers were written either 10μm or 30μm
apart, inducing -1 to -1.5D cylinder. Two eyes underwent LASIK:
a 9mm flap was cut in applanated corneas using a fs laser. With the
flap retracted, a Technolas 217 excimer laser was used to produce a
-1.5D cylinder across a 4mm ablation zone. All eyes were immersed
in Optisol-GS at 4°C for 6 hours and processed for histology. Corneal
sections were stained using the TUNEL assay or immunostained for
γ-H2AX before counter-staining with DAPI. 109 photomicrographs
of 26 sections were analyzed with a custom MATLAB cell counting
program to assess the distribution of TUNEL and γ-H2AX-positive
cells.
Results: In LIRIC-treated eyes, no TUNEL or γ-H2AX-positive
epithelial or endothelial cells were seen. TUNEL-positive keratocytes
were only within LIRIC layers, and γ-H2AX-positive cells were seen
directly adjacent to these layers. Layer separation was important.
Tight patterns caused 86±10% of cells in the LIRIC region to become
TUNEL-positive, relative to only 53±8% if the spacing was 30µm. In
contrast, in LASIK, all cells along the flap cut were TUNEL-positive,
in addition to 72±14% of cells in the sub-ablation zone. No γ-H2AX
reaction was seen with LASIK, but ~20% of stromal cells within
±50μm of all LIRIC patterns stained for γ-H2AX.
Conclusions: LIRIC causes stromal cell death in highly localized
regions. LASIK causes cell death along the flap, within and deep
beneath the ablation zone. The differential expression of γ-H2AX in
LASIK and LIRIC suggests that LIRIC may induce a DNA repair
response adjacent to the laser focal zone that is absent following
LASIK. Finally, since structural disruption of the cornea, together
with cell death usually precede a stronger wound-healing response,
LIRIC, which involves no ablation and exhibits only minimal cell
death, may cause fewer side effects than traditional laser vison
correction.
Commercial Relationships: Kaitlin Wozniak, None;
Noah Elkins, None; Daniel Brooks, None; Daniel E. Savage,
None; Margaret DeMagistris, None; Scott MacRae, None;
Holly B. Hindman, None; Jonathan D. Ellis, Clerio Vision Inc. (C),
Clerio Vision Inc. (F); Wayne H. Knox, Clerio Vision Inc. (F), Clerio
Vision Inc. (C), Clerio Vision Inc. (S); Krystel R. Huxlin, Clerio
Vision Inc. (F), Clerio Vision Inc. (C)
Support: This project was supported by an unrestricted grant to the
University of Rochester’s Department of Ophthalmology from the
Research to Prevent Blindness (RPB) Foundation, by the National
Institutes of Health (R01 grant EY015836 to KRH; Core grant P30
EY01319F to the Center for Visual Science; a Center for Visual
Science training grant fellowship T32 EY007125 to DES), by a grant
from Clerio Vision LLC, with matching funds from the University of
Rochester's Center for Emerging & Innovative Sciences, a NYSTARdesignated Center for Advanced Technology, and by an Incubator
Grant from the University of Rochester’s CTSI Scientific Advisory
Committee (SAC).
Higher Order Aberrations After Femtosecond LASIK Flap
Creation
Jason Croskrey, Matthew Caldwell, James Townley. Ophthalmology,
SAUSHEC, San Antonio, TX.
Purpose: Higher order aberrations (HOA) can decrease visual
quality and can exist naturally or are induced by procedures such as
refractive surgery. Studies have compared HOA in microkeratome vs.
femtosecond (FS) corneal flap creation, but no studies have compared
two FS lasers. The purpose of this study is to compare HOA induced
by two femtosecond lasers, the ZD4 and iFS, used to create corneal
flaps for LASIK.
Methods: 14 eyes with corneal flaps created by the ZD4 laser for
LASIK were compared to 14 eyes with corneal flaps created by
the iFS laser. The two groups of eyes were similar in age, gender,
spherical equivalent (SE), and treatment laser. The difference
between the pre-operative and three month post-operative root
mean squared (RMS) of HOA was used to compare the higher order
aberrations. The paired t-test was used to test difference between
the RMS in the iFS and ZD4 eyes. The P-value was Bonferroni
corrected.
Results: There is not a statistically significant difference in means of
RMS values between eyes that had corneal flap creation with the ZD4
and iFS lasers (p>0.05). The improvement of SE was also similar
between the two groups.
Conclusions: Based on our results both ZD4 and iFS lasers do not
induce significant changes in HOA after corneal flap creation for
LASIK surgery.
Commercial Relationships: Jason Croskrey; Matthew Caldwell,
None; James Townley, None
Toric Intraocular lens implantation in patients with irregular
astigmatism
Nizar Din, Simon S. Fung, Francesco Sabatino, Ailsa Ritchie,
Vincenzo Maurino. Moorfields Eye Hospital, Wimbledon Park,
United Kingdom.
Purpose: Irregular astigmatism presents a significant challenge in
cataract surgery. Currently, there are only a handful of case reports
and small case series on the use of toric intraocular lens (IOL) in
cataract patients with irregular astigmatism. We report a retrospective
cohort study on visual and refractive outcomes in patients with
irregular astigmatisms who underwent cataract surgery at Moorfields
Eye Hospital, England.
Methods: All patients who underwent cataract surgery along with
toric IOL implantation at Moorfields Eye Hospital, England from
over the last 5 years were recruited. Those with irregular corneal
astigmatism were identified from pre-operative Pentacam (Oculus,
Wetzlar, Germany) and Orbscan (Bausch & Lomb, Rochester, US)
corneal topography. Patients with significant visual co-morbidity
and history of ocular surgery other than corneal transplantation were
excluded. Data on pre- and post-operative uncorrected (UCVA)
and corrected distance visual acuities (CDVA), refractive errors,
intra-operative and post-operative complications were collected.
Two-tailed paired t-test was used for statistical analysis, with P value
<0.05 considered as statistically significant.
Results: In this on-going study, 12 eyes from 12 patients with
irregular corneal astigmatism treated with toric IOL have been
identified so far. Mean (± standard deviation) age was 60 ± 7.4
years, with 5 males and 7 females. Mean follow up was 40.6±24.7
months. Pre-operatively, Mean UCVA and CDVA were 1.11±0.35
and 0.48±0.25 LogMAR respectively. These improved postoperatively to 0.50±0.32and 0.22±0.20(p<0.05). Mean pre-operative
refractive spherical equivalent (RSE) was -5.77±4.80D, while
manifest astigmatism was -6.60±2.64D. Mean post-operative RSE
and astigmatism were -0.90±1.79 D and -2.40±1.24 D (p<0.05). No
intra- or post-operative complications were encountered. None of the
patient required IOL exchange or removal during the study period.
Conclusions: Though off-label, implantation of toric IOL is an
effective treatment modality for patients with irregular corneal
astigmatism. Careful patient selection is recommended and further
work on standardised selection criteria is needed.
Commercial Relationships: Nizar Din, None; Simon S. Fung,
None; Francesco Sabatino, None; Ailsa Ritchie, None;
vincenzo maurino, None
CELL BEHAVIOR OF CORNEAL TISSUE AFTER
REFRACTIVE SURGERY WITH TECHNIQUE SMILE, BY
CONFOCAL MICROSCOPY
Martha P. Gonzalez1, Oscar Fernandez2. 1STUDENT, Hospital de la
Luz (FHNSL), Distrito Federal, Mexico; 2CORNEA, Hospital de la
Luz (FHNSL), MEXICO, Mexico.
Purpose: Analyze cell behavior of corneal tissue after refractive
surgery with SMILE, in the period of January to May 2015, by
confocal microscopy.
Methods: Prospective, observational, descriptive and longitudinal
study of fifty two eyes. Corneal tissue was analyzed during 6°
months, taking an area 0.0192mm2 with NAVIS3 program evaluating
basal cell active keratocytes in the anterior and posterior to the
surgical area interface and endothelial cell count with the Kruskal
Wallis test. Subbasal presence and degree of reflectivity surgical
interface (severe, moderate and mild) nerve plexus was sought.
Results: The average basal cells in the basal state was
4783 cells / mm2, in the first days post-surgery was 5214 cells / mm2,
as of 5040 cells/mm2, the third month of 5173 cells/mm2, and the 6th
month 5243 cells/mm2, no significant changes (p =0.4060) were;no
change in morphology was observed during follow-up. The subbasal
nerve plexus observed in some eyes to the first analyzed month, but
after the third month and is displayed on the 72.5% of the population.
In anterior stroma an overall average of 21 keratinocytes by area,
of which 13 assets were observed in the first fifteen days, by month
12 keratinocytes, the third month 7 keratinocytes and keratinocytes
4 active sixth month, showing in this way was obtained progressive
decrease in metabolic activity thereof. In posterior stroma, a total
average of 15 keratinocytes was obtained by area; of which 4
active keratinocytes in the first 15 days, a month 5, the third month
3 keratinocytes, and the sixth month 2 active keratinocytes. Surgical
interface presents intense reflectivity early postoperative (57.6%) and
during their evolution tends to reduce reflectivity showing a mild to
moderate from the third month to the sixth month.
Conclusions: The evaluated corneal tissue cells suffered no
permanent morphological changes, tending to return to its ground
state. The subbasal nerve tissue is attacked not fully allowing the
progressive regeneration of the same after the third month. Surgical
interface reflectivity occurs most in the first few months, but with the
course of analysis persistence of scar tissue, but the reflectivity tends
to decline slowly appreciated. In endothelial cell movement does not
exist during the study period.
Commercial Relationships: Martha P. Gonzalez, None;
Clinical Trial: AT0FDDCDD8AD
TITLE: Stromal expression of corneal epithelial basement
membrane (EBM) components analyzed by Laser Capture
Microdissection (LCM)
Abirami Santhanam. Cleveland Clinic, Shaker heights, OH.
Purpose: To investigate the production of the corneal epithelial
basement membrane (BM) components at time points prior to lamina
lucida and lamina densa regeneration in anterior stromal cells after
-4.5D and -9.0D PRK.
Methods: Rabbits were euthanized and the corneoscleral rims
of treated and untreated contralateral eyes were removed without
manipulation of the cornea at 4 or 7 days after -4.5D or -9D PRK
with the VISX S4 IR laser. Four corneas of each group at each
time point were immediately embedded in OCT compound and
flash frozen. Cryosections were cut from the central cornea with
tissue thickness ~15µm. Cryosections were stained with Histogene
staining solution and LCM sections of thickness 35-40µm (area
~40-50000µm2) were cut from anterior stroma (AS) beneath the
epithelial basement membrane (EBM) of each cornea. Total RNA was
isolated from LCM corneal specimens and cDNAs for the genes of
interest was measured using quantitative real time PCR (QPCR).
Results: Key EBM component mRNAs nidogen-1, nidogen-2,
perlecan and laminin alpha3 (LAMA3) were analyzed by QPCR at
4 and 7 days after -4.5D and -9.0D PRK. These time points were
selected based on the results of preliminary transmission electron
microscopy (TEM) studies in which the lamina lucida and lamina
densa layers of EBM were found to regenerate fully in -4.5D PRK
corneas but not -9D PRK corneas at 7 to 9 days after surgery.
Nidogen-2 and LAMA3 were synthesized at higher levels in AS at
4 days after -4.5D PRK compared to -9.0D PRK corneas. At 7 days
after PRK, nidogen-2 mRNA levels increased in the AS of -9.0D
PRK but LAMA3 mRNA levels remained significantly lower in the
AS of -9.0D PRK corneas compared to the AS of -4.5D PRK corneas.
Conclusions: Key EBM component nidogen-1,2, perlecan
and LAMA3 mRNAs are synthesized in AS cells during EBM
regeneration after PRK. LAMA3 and nidogen-2 mRNAs are
expressed at higher levels during EBM regeneration in -4.5D PRK
corneas where EBM fully regenerates and no haze will develop
compared to -9.0D PRK corneas where EBM does not fully
regenerate and myofibroblast-related stromal haze will develop.
Figure 1. A) LCM to isolate anterior stroma (AS). After staining, the
epithelium and stroma are visualized and the laser is used to precisely
cut the AS. B) QPCR analysis of EBM components nidogen-1, 2,
perlecan and LAMA3 at four days post PRK (N= 4; ***, P < 0.001;
**, P<0.01).
Commercial Relationships: Abirami Santhanam, None
Support: EY10056

Session 439 Corneal refractive surgery II

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