HEREDITARY RETINAL DYSTROPHIES

1. HEREDITARY RETINAL DYSTROPHIES 1. Photoreceptor dystrophies • Retinitis pigmentosa • Retinitis punctata albescens • Fundus albipunctatus • Cone dystrophy • Leber congenital amaurosis 2. Retinal pigment epithelial dystrophies • Best vitelliform macular dystrophy • Adult best vitelliform macular dystrophy • Stargardt macular dystrophy • Fundus flavimaculatus • Familial dominant drusen • Sorsby pseudo-inflammatory macular dystrophy • North Carolina macular dystrophy • Butterfly macular dystrophy

2. Retinitis Pigmentosa 1. Inheritance • Sporadic (23%) • Dominant (43%) • Recessive (20%) • X-linked recessive (8%) • Uncertain (6%) 2. Presents- usually prior to 30 years 3. Prognosis- dominant worst, x-linked best 4. ERG- reduced

3. Progression of retinitis pigmentosa • Perivascular ‘bone-spicule’ • pigmentation • Fine dust-like pigmentation • Arteriolar attenuation • Initially mid-peripheral • Anterior and peripheral • spread • Optic disc pallor • Maculopathy • Unmasking of large • choroidal vessels

4. Ocular associations of retinitis pigmentosa Keratoconus (uncommon) Cataract (very common) Vitreous degeneration (common) Optic disc drusen (uncommon) Myopia (common) Open-angle glaucoma (uncommon

5. Atypical retinitis pigmentosa Quadrantic Sectorial Pericentric Paravenous

6. Retinitis punctata albescens Probably variant of retinitis pigmentosa Presents - usually under age 30years Prognosis - poor ERG - reduced • Scattered white dots extending • from posterior pole • to periphery • Subsequent development of • ‘bone-spicule’ pigmentation

7. Fundus albipunctatus Inheritance - recessive Congenital stationary night blindness Prognosis - excellent ERG - reduced • Multitude of tiny yellow-white spots • Extend from posterior pole to mid-periphery • Fovea spared

8. Cone dystrophy Inheritance • Usually sporadic • Occasionally autosomal dominant or x-linked recessive Presents - first to third decade Prognosis - guarded ERG - reduced photopic, normal scotopic • ‘Bull’s eye’ macular lesion • May be associated with golden tapetal reflex • Later mild ‘bone-spicule’ pigmentation • Very late geographic macular atrophy

9. Leber congenital amaurosis Inheritance - usually autosomal recessive Presentation - frequently perinatal Prognosis - very poor ERG - non-recordable • Initially fundus may be normal • Oculodigital syndrome • Peripheral chorioretinal atrophy • and granularity • Afferent pupillary defect

10. Best vitelliform macular dystrophy Inheritance - autosomal dominant Presents - first decade Signs - very variable • Unilateral or bilateral • Single or multiple • Macular or eccentric Prognosis - guarded EOG - severely subnormal Mulifocal Best disease

11. Stage 2 Best vitelliform macular dystrophy • During first to second decade • ‘Egg-yolk’ or ‘sunny-side-up’ macular lesion • VA - normal or slight decrease

12. FA of stage 2 Best vitelliform macular dystrophy Blockage of background choroidal fluorescence corresponding to lesion

13. Stage 3 Best vitelliform macular dystrophy • Partial absorption and pseudohypopyon • VA - slight decrease

14. Stage 4 Best vitelliform macular dystrophy • ‘Scrambled egg’ appearance • VA - moderate decrease FA shows hyperfluorescence due to staining

15. Stage 5 Best vitelliform macular dystrophy • Macular scar or atrophy • VA - moderate to severe decrease

16. Adult Best vitelliform macular dystrophy Inheritance - dominant Presents - fourth to fifth decades, but may be asymptomatic Prognosis - usually good EOG - normal or slightly abnormal • Round or oval, slightly elevated, yellow, subfoveal lesion • 1/3 to 1/2 disc diameter in size

17. Stargardt macular dystrophy Inheritance - usually recessive Presents - first to second decade Prognosis - poor ERG - reduced in advanced cases • Oval macular ‘snail-slime’ or ‘ beaten-bronze’ • Occasionally surrounded by yellow-white flecks • Eventual atrophic maculopathy • VA severe decrease

18. Fundus flavimaculatus Inheritance - usually recessive Presents - fourth to fifth decades Prognosis - good in most cases ERG - reduced in advanced cases • Ill-defined, yellow-white flecks • Extending from posterior pole to mid-periphery • Vermilion colour fundus in about 50% • Eventual atrophic maculopathy in some cases

19. FA of fundus flavimaculatus • Flecks are hyperfluorescent due to RPE atrophy • Absence of normal background fluorescence (dark choroid)

20. Familial dominant drusen Presents - second to third decade, no symptoms Prognosis - usually good ERG - normal • Large, discrete, round, slightly raised, yellow lesions • Usually symmetrical distribution • Mainly at macula and peripapillary

21. Sorsby pseudo-inflammatory macular dystrophy Inheritance - dominant Presents - second to fourth decade Prognosis - very poor ERG - normal Progression • Yellow-white confluent spots • Along arcades and nasal to disc • Eventual CNV and exudative • maculopathy

22. North Carolina macular dystrophy Inheritance - dominant Presents - second decade Prognosis - variable ERG - normal Early stage Progression Yellow-white spots at periphery and macula Exudative or atrophic maculopathy Confluence of macular lesions

23. Butterfly macular dystrophy Inheritance - usually dominant Presents - fourth to fifth decades Prognosis - usually good ERG - normal Yellow pigment at fovea arranged in triradiate pattern