Hereditary Dystrophies

Question 1

Retinitis pigmentosa

Answer 1

Arteriolar narrowing 
Waxy pallor of the disc
Bone spicules
Strophic pr
Atrophy of peripheral retina
CME
PSC cats

Question 2

Chiroideremia

Answer 2

Rod-cone dystrophy
CHM (Xlinked)
Night blindness in second decade

Question 3

RP ERG and genetics

Answer 3

Decreased a and b waves
Prolonged b wave and decreased amplitude

20% AR
20% AD.
Rest sporadic

Question 4

Lebers congenital amaurosis

Answer 4

Infantile RP

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Question 5

Cone dystrophies

Answer 5

Dyschromatopia
Hemerolopia
Progressive decreased VA

Question 6

Stargardt dystrophy

Answer 6

Most common 7% of macular dystrophies
Defect in ATP binding cassette in rods
AR mostly
Expanding central scotoma with foveal atrophy

Question 7

Best’s dystrophy

Answer 7

Central maculopathy childhood onset
Defect in bestrophin protein (CL channel)
AD
VMD2 on chrom 11
Abnormal EOG severe loss of light response
20% can get CMV

Question 8

Fungus flavimaculatum

Answer 8

Predominantly peripheral retina

Lipofuscin round flecks in RPE

Question 9

Stargardts disease

Answer 9

FA with dark choroid
Foveal atrophy
Lipofuscin yellow flecks in macula

Question 10

Adult onset vitelliform dystrophy

Adult ‘bests disease’

Answer 10

Pattern dystrophy
Bilateral round us foveal lesions 
 40-60 yrs old 
Normal EOG
1/3 disc diameter in size 
Drusenoid RPE detachment

Question 11

Familial dominant Drusen

Answer 11

Drusen in young people
Outside arcades nasal to disc
AD

Question 12

Pattern dystrophy

Answer 12

Midlife onset
Blurring
Mild metamorphosis

Question 13

Sorsby macular dystrophy

Answer 13

Bilateral sub foveal CNV
Defect in metalloproteinase 
AD
TIMP3 chrom 22
Onset around 40
Confluence plaque of Drusen

Question 14

Gyrate atrophy

Answer 14

Ornithine transferase gene defect
Night blindness
Scalloped peripheral atrophy

Question 15

Central areolar choroidal dystrophy

Answer 15

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Question 16

North Carolina macular dystrophy

Answer 16

Central RPE atrophy with sub retinal fibrosis

Question 17

X-linked retinoschisis

Answer 17

Splitting in NFL
Congenital and X-linked 
Spoke like intraretinal cysts 
RS1 
ERG with normal a wave. Attenuated b wave

Question 18

Goldmann Favre syndrome

Answer 18

Enhanced s-cone or blue come syndrome
AR
Two times the number of cones. Only see blue
No rods!
Night blindness. And sensitively to blue light

Question 19

Goldmann Favre syndrome findings on exam

Answer 19

Abnormal ERG. With greater response to blue light

Question 20

Arden ratio

Answer 20

For EOG. Ratio of light to dark peak. 2:1 normal.

1.65 or less abnormal

Question 21

Diseases with normal ERG and abnormal EOG

Answer 21

Beats disease 
Pattern dystrophies
Chloroquine toxicity
CSNB
X-linked retinoschesis

Question 22

AREDS clinical severity scale.

Answer 22

1 pt - at least 1 large Drusen
1 pt - pigment changes. (Hypo, hyper, non central GA)
2 pt- advanced AMD in 1 eye.
Total both eyes.
Risk if developing advanced disease in 5 yrs: 1 - 3%, 2 - 12%, 3 - 25%, 4 - 50%

Question 23

Risk of CNV in fellow eye if

• hard Drusen present
• soft Drusen present
• pigmented Drusen present
• soft and pigmented Drusen present

Answer 23

Hard 10% risk
Soft 30% risk
Pigmented 30% risk
Soft and pigmented 60% risk

Question 24

Gyrate atrophy

Answer 24

AR 
Mutation in OAT gene
High myopia with high astigmatism 
PSC cats 
Elevated ornithine levels treated with dietary restriction of Arginine