Drusen patterns predisposing to geographic atrophy of the retinal pigment epithelium.

This report discusses the recognition of drusen referred to as "hard" which appear to predispose the eye to the development of geographic atrophy of the retinal pigment epithelium. When numerous, small hard drusen tend to become arranged in clusters. On the temporal side in particular, this grouping may be so close as to resemble larger confluent drusen within which the small drusen can only be distinguished by fluorescein angiography. The approximate interval before geographic atrophy involves the fovea can be estimated by noting the distribution of drusen and the state of the pigment epithelium between the drusen. A stage of incipient atrophy can be recognised as an area of diffuse hyperfluorescence in which pigment clumping or reticular pigment figures and fading of drusen occur.