LECTURE 9 Posterior Pole retina pathology_HTN_DM retinopathy

Ocular Examination
FRONT TO BACK
Posterior Pole
Hypertensive Retinopathy
Diabetic Retinopathy
Lecture 9
Examination Tools
• Best corrected distant • Fundus autofluorescence (FAF)
monocular VA
• Fluorescein angiography
– Macula/fovea
• Indocyanine Green
• Amsler grid
angiography (IGA)
– Macula test
• Visual field
• Slit Lamp
– Dilated
– Stereo view
• 78D, 90D,
– Use of red free filter
• BIO
• Direct ophthalmoscope
– Used in the detection of
choroidal abnormalities
• Occult choroidal
neovascularization
• OCT
• Ultrasound
Visual Fields
OCT
OCT
Fundus Autofluorescence
• Confocal scanning laser
ophthalmoscope
• By-products in the RPE
(incomplete degraded
photoreceptor cells) light up…..
Fluorescein Angiogram
Choroidal flush
Late
Early
Normal Retina
Posterior Pole Ocular Anatomy 101
Least organized
Most organized
Retinal nerve fiber layer
Vascular = respects horizontal midline
Neurological = respects vertical midline
Must Know “Healthy”
Looking at the posterior pole in a
systemic approach
• Physical signs of retinal disease
– Specific “thing” seen
•
•
•
•
•
•
Cotton wool spots
Hemorrhage (type important)
Exudates (Where/pattern)
Edema (where/what type)
RPE disturbances
Neovascularization (where/type)
• Vascular disease
–
–
–
–
Occlusions
Ischemic
Trauma
Cancers
What could go wrong?
• Photoreceptor death
– R-C/C-R dystrophies
– RP
• Familiar drusen
• Vascular changes
–
–
–
–
–
Tortuosity
AV attenuation
AV nicking
Varied ALR
Venous beading
• Ocular ischemia
• Neovascularization
– Choroidal
– Retinal
• Disc
• Elsewhere
• Hemorrhages
• Plaques
• Staphyloma
• Inflammation
– Vitreous
– Retinal
– Choroidal
• Cotton wool spots
• Disruption in RPE
•
•
•
•
•
– Angioid streaks
– Lacquer cracks
– Choroidal rupture
Nerve fiber layer dropout
Retinal folds
Chorioretinal scars
Tumors
Nevi
• Photoreceptor cell death
– Pre-ganglionic cells
– Visual field defect does not
respect the horizontal or
vertical meridian
– Functional vision usually less
than structure damage
• Familial drusen
• Choroidal pigmentation variation
Total absence of pigmentation
Tigroid fundus
• Tortuosity
Congenital VS Acquired
Normal
• Vessel attenuation
– Note the engorged venules and constricted
arterioles
• AV nicking
• Varied Arteriole Light Reflex (ALR)
– Silver-wiring
• Venous Beading
• Observations
Athersclerotic arteriole changes “pinch off” the venules. Engorgement
distally – impending branch retinal vein occlusion (BRVO)
• Staphyloma
bulge
Bulging temporal side
• Choroidal Nevi
caliper measuring 1.8 mm (1800 μm)
Infrared
image
Caliper measurement between curves
1 and 2 as 872 μm
• Choroidal melanoma
lipofuscin (orange pigment)
FA
• Angioid streaks
– Compromised Bruch’s
membrane
– Tend to radiate from ONH
– Prominent in systemic disease
processes
• Lacquer cracks
– Degenerative myopia
• Choroidal rupture
– Traumatic
Any Break in Bruch’s Membrane
• Choroidal
neovascularization
• Commotio Retinae
– Bruising of the retina
– Trauma
• Chorioretinal scar
• Nerve Fiber layer drop out Compare superior to inferior
– Slit defects
– Wedge defects
BIO and red free filter
Retinal Hemorrhages
• Superficial capillary layer in the retina
– Considered post-arteriolar
– Affected most by artery-based diseases
• Superficial hemorrhages considered artery-based
– Pre-retinal
– Flame shape
• Deeper capillary layer in the retina
– Considered pre-venular
– Affected by vein-based or congestive diseases
• Deep hemorrhages considered vein-based
– Dot-blot
Pre-retinal Hemorrhages
• Lie just under the
internal limiting lamina
& in front of the nerve
fiber layer
• Superficial capillary
system or the radial
peripapillary system
• Typically occur in the posterior pole
• Create a scotoma
Gravity causing blood down
White area is resolution (at arrow)
Creates a scotoma
Flame-shaped Hemorrhage
• From post-arteriolar superficial
capillary bed or the radial
peripapillary system
• Blood seeks lines of less
resistance in the contour of the
nerve fiber layer
• Roth Spot
• Hemorrhage surrounding a white center
• White center represents
– Focal accumulations of white blood cells in inflammatory vascular
disease
– Cotton wool spot (CWS) surrounded by heme
– Leukemia cells surrounded by heme
– Fibrin surrounded by heme
Dot-Blot Hemorrhages
• Deep retinal
hemorrhages
• Occur in the inner
nuclear layer, outer
plexiform layer and at
times outer nuclear layer
• Results from
compression deep in the
retina
– Follow vertical cleavage
lines
– Retinal structure is
displaced, however no
tissue necrosis
• Indicator of intra-retinal
compromise
1
2
Observations…..
Hint: 1 is bilateral presentation
2 is unilateral presentation
Subretinal Hemorrhages
If subretinal = red
If sub-RPE = gray-green
Visually devastating
Choroidal Neovascularization: CNV
• Mechanism poorly
understood
– Virtually any pathologic
process that involves the RPE
and damages Bruch’s
membrane
– Involves angiogenic growth
factors
Late stage hyperfluorescence
Grayish-green color
• Macroaneurysm
– Isolated dilated area of a major retinal arterial branch
– Typically occur in older patients 50 to 80 yo
• 50% have HTN
• 25% demonstrate a high 5-year post-discovery mortality rate associated
with systemic cardiovasculopathy
– Necessitate a cardiovascular-physical work-up
• Microaneurysms
– First clinically visible sign of Diabetic Retinopathy
– One visible = 20-30 others that are not visible
When one microaneurysm is visible,
20-30 more exist that are not
clinically visible
• Exudates
– Waxy, yellowish lesion in outer plexiform layer
– Circinate around microaneurysms
Exudates
• Cotton Wool Spots (CWS)
– Micro-infarct
• Implies an ischemic microvascular disease
– Swelling of local nerve fiber axons and loss of transparency
– Often at vessel bifurcations
Fluid
FA
Diffuse CWS secondary to
trauma (car accident)
• IntraRetinal Microvascular Abnormalities
(IRMA)
– Represent intraretinal re-vascularization
• No breach of the internal limiting membrane
• Remodeled capillary beds without proliferative changes
– Collateral vessels that do not leak on fluorescein angiography
– Do not cross over major blood vessels
– Usually can be found on the borders of the non-perfused retina (near
CWS)
IRMA
Note: the capillary bed dropout
Healthy
choroidal flush
• Retinal Neovascularization
–
–
–
–
•
Grow beyond the supporting structures of the retina
Usually arise from retinal veins
Begin as a collection of fine vessels
DO leak on FA
Once stimulus for growth (of new vessels) released, path is along route of
least resistance
– OHN (no “real” internal limiting membrane)
• NVD
– Defined: new vessel growth within 1DD
of the ONH
– Shallowly detached posterior vitreous face
• NVE
Retinal Emboli
• Clinical picture varies depending on type and extent
of retinal emboli
– Glowing intravascular plug to total occlusion of the
vasculature
• Strong association with cardiovascular disease
• Types of emboli
– Cholesterol
– Calcium
– Platelets
– Fibrin
– Talc or cornstarch
Artery Occlusion
Branch
Central
Vein Occlusions
Branch
Central
Putting together a few Patterns of
posterior pole disease
• HTN retinopathy
• Diabetic retinopathy
Symptoms of HTN Retinopathy
GRADE DESCRIPTION
• None
• HA
I
• Reduced visual
acuity
II
MINIMAL NARROWING OF THE
ARTERIES
A:V
RATIO
N
50%
OBVIOUS ARTERIOLE NARROWING 33%
WITH FOCAL IRREGULARITIES
(NICKING)
III
GRADE II PLUS RETINAL HEMES
(FLAMED SHAPED) AND/OR
EXUDATES AND/OR COTTON
WOOL SPOTS
25%
IV
GRADE III PLUS DISC SWELLING
AND/OR MACULAR STAR
<20
%
Hypertensive Retinopathy
Hypertensive Crisis
Hypertensive retinopathy
• 41 year old Black male
• CC: headaches associated with blurry vision OS x
2 days
• Denies systemic pathologies (DM, HTN, etc)
Observation
BP: 238/115 mm Hg
3 week history of taking Hydroxycut
Diabetic Retinopathy Symptoms
•
•
•
•
Varies widely
None
Decreased night vision
Fluctuating vision:
“Blurry”
– Sugar control issues
• Double vision
• Painless, loss of vision
– Gradual
– Sudden
• Flashes and floaters
• Unilateral or bilateral
• MUST HAVE HISTORY
QUESTIONS
– Onset (when diagnosed)
– Control?
• Self monitor glucose
levels
• HbA1c (%)
– Medications
• Ever been on insulin
– PCP
• Name (communication)
• Time line for visits
Stages: As Defined
• Nonproliferative
– It’s ALL inner retinal
– Ma, D-B hemes, Exudates
– Stages
Normal, Mild, Moderate, Severe, Very
Severe
(Defined states with photos on Blackboard)
Posterior pole disease
Typically bilateral (although can
be asymmetrical
Pathophysiology
• From the first visible microaneurysm to
exudates, the underlying pathophysiology
has been weak vessel walls and increased
vascular permeability
• Pre-proliferative NPDR
– Venous beading, CWS, IRMA,
• Cotton Wool Spots
Venous
Beading
IRMAs
Pathophysiology
• Cotton wool spots through IRMA referred
to as pre-proliferative disease
• Mechanism involves
– Capillary wall collapse
– Capillary dropout
• Progressive inner retina ischemia
CWS vs. Exudates
Stages: As Defined
• Proliferative
– Pathologies seen secondary to capillary
non-perfusion, ischemic retina and
release of vasoproliferative agents
– Neovascularization
Stages
Non-High Risk, High Risk
Pathophysiology
• Ischemia
– Widespread capillary non-perfusion
Release of
vasoactive factors and growth factors
NVD is defined as new vessel growth within
1DD of the ONH
25% of patients with PDR
NVD
NVE
Tractional retinal detachment
Summary
Ischemia
Nonproliferative
•
•
•
•
•
•
Microaneurysms
Hemorrhages
Exudates
Cotton wool spots
Venous beading
IRMA
Proliferative
•
Neovascularization
Capillary
leakage
Pathology due to weak, leaky
vessel walls
Capillary nonperfusion/drop
out
Pathology due to the
release of vasoactive
factors and growth factors
and others?
Pan Retinal Photocoagulation (PRP)
Diabetic Retinopathy
• MOST prevalent diabetic microvascular
complication
• Main vision threat
– Diabetics 25X more likely to go blind than nondiabetics
• Strong predictor of renal disease
• Following current treatments, legal blindness is
reduced to less than 5 percent in 5 years for
patients with proliferative retinopathy. Severe
vision loss is reduced to 1 percent
Stages of DR Defined
• http://eyephoto.ophth.wisc.edu/ResearchAre
as/Diabetes/DiabStds.htm
• American Optometric Association by
requesting item SDC1, General Guidelines for
the Management of Diabetic Retinopathy
Chart