Retinal Function in X-linked Ocular Albinism (OA1)

Abstract

Purpose: To characterize retinal function in human recessive X-linked ocular albinism (OA1) across the normal lifespan. Methods: Retinal function was evaluated in 14 OA1 patients (ages 11 to 71 years) and five obligate carriers (ages 41 to 50 years) and compared to normal controls using full-field and multi-focal electroretinograms (ERG and mERG, respectively) and electro-oculography (EOG). Results: No consistent differences in ERG response parameters were observed when OA1 patients were compared as a group to normal controls. A trend in the direction of better correlations of response parameters with age was, however, observed in OA1. EOG Arden ratios were normal or hypernormal for all patients, but were uncorrelated with age. Central retinal function measured with the mERG suggested a flat response topography with depressed macular function compared to normal controls. Conclusions: Panretinal function in OA1 is within normal limits at all ages, consistent with previous reports in generalized albinism. The stronger correlations with age in OA1 may suggest a different rate of age-related change in OA1 compared to normal populations, but the precise nature of this change must await an appropriate prospective study. The topography of mERG amplitudes in OA1 is relatively flat across the central retina with a reduction in amplitude in the macular region consistent with anatomical studies demonstrating an underdeveloped macular region in albinism.

KEYWORDS:

• albinism
• electroretinogram
• light damage
• light toxicity
• OA1
• retinal function