E POSTER A case of Best Vitelliform macular dystrophy

AUTHORS Dr. Akshay Jawahirlal Bhandari (Assistant Professor) Dr. Surekha Bangal (Professor) Dr. Dipti Dilip Padghan (Post Graduate student)

Introduction German ophthalmologist Friedrich Best-published this disease in 1905 (Best, 1905). Rare bilateral autosomal dominant disease. Classically presents in childhood Affects the central retina Typical egg-yolk macular lesions caused by accumulations of lipofuscin within and beneath the retinal pigment epithelium (RPE).

Introduction Mutations in the VMD2-gene located on the long arm of chromosome 11. Extremely rare – the actual incidence is unknown. Atrophy of RPE in the fovea usually affects the overlying photoreceptors and leads to the impairment of central visual function. To date there is no treatment for this disorder. In case of visual acuity loss, magnifying low vision aids are helpful.

Case Report 26 year old male Six year old history of gradual, painless, progressive diminution of vision in both eyes. Not a known diabetic, hypertensive and never suffered any chronic disorder. History of tobacco addiction since 7 years. Patient’s grandmother had a history of similar complaints. General & systemic examination of the patient was normal.

Case Report Snellen’s vision of finger counting 5 meter that improved to 6/60 in both eyes with refraction. Anterior segment examination in both eyes was normal. Indirect ophthalmoscopy of right eye Clear media with normal well defined optic disc. The macula showed a large (2-2.5 disc diameter), well-circumscribed, single, yellow, subretinal lesion of a uniform density of egg yolk like appearance, over which normal retinal blood-vessels traversed.

Right eye FFA showing hyperflourescent patches at the macula Egg yolk (previtelliform) stage

Case Report Left eye- normal anterior segment. Fundus showed a normal optic disc with a large (2-2.5 disc diameter) well-defined, elevated, yellow-orange central macular lesion. The overlying retina was normal, as was the peripheral retina. FFA showed hyperflourescent patches at the macula. Electrooculography of the left eye- subnormal.

Atrophic stage of Best’s disease Hyperflourescent patches Left eye Atrophic stage of Best’s disease Hyperflourescent patches at the macula Patient was advised to use low visual aids

Discussion It is an autosomal dominant macular dystrophy. Caused by mutations in the VMD2 gene, located on the long arm of chromosome 11 , which encodes the protein bestrophin which is a transmembrane protein that acts a putative ion exchanger with lipofuscin-like deposits at the posterior pole of the eye. Onset may occur in childhood or decades later. The disease is slowly progressive and eventually results in the atrophy of the RPE and photoreceptors, severely impairing central vision.

Discussion Stages Previtelliform stage with RPE defects Egg-yolk stage with yellow material in a cyst Scrambled egg stage, pseudohypopyon appearance Atrophic or cicatricial stage, sometimes complicated by subretinal neovascularisation. Histopathological studies- deposits of lipofuscin on Bruch's membrane, the innermost layer of which is the basal membrane of the retinal pigment epithelium

Conclusion GENETIC COUNSELING AND MAGNIFYING LOW VISION AIDS ARE HELPFUL IN MANAGING THE BEST VITELLIFORM MACULAR DYSTROPHY