Macular and retinal dysfunction in adults of unknown origin in adults with normal fundi

Abstract

Abstract: : Purpose: Phenotypic characterization using clinical, electrophysiological and psychophysical techniques of newly recognized retinal dysfunction of unknown origin in adults. Methods: Fifteen patients were identified with bilateral visual loss over a period of months, normal ocular examination and retinal dysfunction on electrophysiological testing. Known causes such as carcinoma associated retinopathy, acute zonal occult outer retinopathy and hereditary cone dystrophy were excluded. Investigations included detailed electrophysiology, fundus autofluorescence imaging and psychophysical tests. Results: Ten were male, 5 female, and the average age was 53.5 years .Their history was characterized by bilateral visual loss and photophobia of subacute to gradual onset with progression over an average of 34 months and subsequent stabilization at a visual level of 6/36. Normal fundus appearance was found biomicroscopically, angiographically and on SLO autofluorescence imaging. Electrodiagnostic testing revealed retinal dysfunction predominantly of the cone–system, either macular or generalized. Signs of post–phototransduction involvement were frequent (67%). Photopic and scotopic (red and blue stimulus) visual fields confirmed the predominant involvement of the cone system and specified its distribution. Dark adaptation kinetics corresponded with the findings from the visual fields. Conclusions: We describe a retinal disorder of adults with unexplained cone dysfunction, normal fundus examination, and normal autofluorescence imaging. The etiology of the disorder may be mediated through an autoimmune mechanism.

Keywords: retina: distal (photoreceptors, horizontal cells, bipolar cells) • degenerations/dystrophies • autoimmune disease