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

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

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

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

Atypical retinitis pigmentosa Quadrantic Sectorial Pericentric Paravenous

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

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

Cone dystrophy Inheritance Presents - first to third decade 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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