Abstract
Abstract: :
Purpose: On fluorescein angiography, cuticular drusen and early–adult onset grouped drusen exhibit regions of hyperflourescence that are noticeably smaller than the drusen appear with color photography. This suggests that drusen associated with certain disorders possess clinically detectable, substructural domains (i.e., drusen cores). Recently, missense variations in the fibulin 5 gene were identified in seven patients with age–related macular degeneration (AMD). These patients all had small, round, uniform (i.e., cuticular–like) drusen. In this study, we examined whether patients with fibulin 5 mutations have findings suggestive of drusen substructure. Methods: Prior IRB approval was obtained for this study. Of the seven patients with missense variations in the fibulin 5 gene, five had fluorescein angiography and color fundus photography performed on the same visit. The color and angiographic images of these five patients were evaluated by scanning the images on a Nikon Super Coolscan 4000 at 4,000 pixels per inch. These scanned images were normalized, registered and processed utilizing Adobe PhotoShop 7.0 to perform color fundus – flourescein angiogram image subtraction. Drusen and hyperflourescent core sizes were measured by overlaying the Zeiss 30° fundus images with the Age Related Eye Disease Study (AREDS) template. Results: All five patients displayed evidence of coaxial central hyperflourescent cores (CCHC) associated with a subset of drusen ranging in size from 63 to 180 µm. CCHC were not evident in any drusen larger than 180 µm. CCHC were found in several fibulin 5 phenotypic backgrounds such as scattered small macular drusen, near–confluent macular drusen, and in the presence of occult choroidal neovascularization. Conclusions: Patients with missense variations in the fibulin 5 gene have drusen that exhibit drusen substructure. Further evaluation of this genotype and other patients with age–related macular degeneration will help to elucidate the pathophysiologic mechanisms underlying these cores as well as their prognostic significance.
Keywords: drusen • age-related macular degeneration