Abstract
Abstract: :
Purpose: To describe clinical findings and course in two first degree relatives with what appears to be a new familial annular outer retinopathy. Methods: Investigations included ophthalmoscopic examination, visual field testing, fundus photography, intravenous fluorescein angiography (IVF), electroretinography (ERG), electro–oculography (EOG) and multifocal electroretinography (mfERG). Results: Both patients were Caucasian. One was a 59 year old female who presented with good vision and dense bilateral scotomas superiorly corresponding to circumscribed areas of chorioretinal atrophy along the inferotemporal arcades. ERG showed mildly reduced rod and cone function. EOG showed marked reduction of Arden’s ratio (1.26). mfERG reproduced the visual field deficits. The second patient was her 44 year old son. His clinical findings were similar, but less advanced than those of his mother. ERG showed cone responses at the lower limit of normal. EOG showed a reduced Arden’s ratio (1.50). Conclusions: Our cases clinically resemble the ten previously reported cases of acute annular outer retinopathy. However, none of those were familial, and only three occurred bilaterally. Our cases invoke a genetic etiology. We believe it is likely that they represent a new familial annular outer retinopathy which shares similar features with its acquired counterpart, acute annular outer retinopathy. The significantly abnormal EOG finding also raises speculation that RPE involvement precedes photoreceptor dysfunction in the disease course.
Keywords: retinal degenerations: hereditary • retina: distal (photoreceptors, horizontal cells, bipolar cells) • electrophysiology: clinical