Drusen and photoreceptor abnormalities in African-Americans with intermediate non-neovascular age-related macular degeneration

Abstract Purpose/Aim: To investigate the relationship of drusen and photoreceptor abnormalities in African-American (AA) patients with intermediate non-neovascular age-related macular degeneration (AMD). Materials and methods: AA patients with intermediate AMD (n = 11; age 52-77 years) were studied with spectral-domain optical coherence tomography. Macular location and characteristics of large drusen (≥125 μm) were determined. Thickness of photoreceptor laminae was quantified overlying drusen and in other macular regions. A patient with advanced AMD (age 87) was included to illustrate the disease spectrum. Results: In this AA patient cohort, the spectrum of changes known to occur in AMD, including large drusen, sub-retinal drusenoid deposits and geographic atrophy, were identified. In intermediate AMD eyes (n = 17), there were 183 large drusen, the majority of which were pericentral in location. Overlying the drusen there was significant thinning of the photoreceptor outer nuclear layer (termed ONL⁺) as well as the inner and outer segments (IS + OS). The reductions in IS + OS thickness were directly related to ONL⁺ thickness. In a fraction (∼8%) of paradrusen locations with normal lamination sampled within ∼280 μm of peak drusen height, ONL⁺ was significantly thickened compared to age and retinal-location-matched normal values. Topographical maps of the macula confirmed ONL thickening in regions neighboring and distant to large drusen. Conclusions: We confirm there is a pericentral distribution of drusen across AA-AMD maculae rather than the central localization in Caucasian AMD. Reductions in the photoreceptor laminae overlying drusen are evident. ONL⁺ thickening in some macular areas of AA-AMD eyes may be an early phenotypic marker for photoreceptor stress.