ABSTRACT
CLINICAL FEATURES OF GEOGRAPHIC ATROPHY GA is easily recognized clinically, as it appears as a well-demarcated area of decreased retinal thickness, compared with the surrounding retina, with a relative change in color that allows for increased visualization of the underlying choroidal vessels. Both the location and pattern of the atrophy may vary in appearance. Drusen, usually a mixture of the soft and calcifi c types, are present in most eyes until the GA becomes so extensive as to resorb the macular drusen (2). There may be pigmentary alteration, either hypopigmentation or hyperpigmentation preceding and later surrounding the macular atrophy. Forty percent of eyes with macular GA also have peripapillary GA, which may become confl uent with the macular atrophy (7). Peripheral reticular degeneration of the pigment epithelium is present in about 41% of eyes (7). The increased choroidal vessel detail in the area of GA is usually the most
easily identifi ed fundus change and further refl ects the extent of RPE attenuation. On fl uorescein angiography, this translates into an area of hyperfl uorescence that corresponds to the ophthalmoscopic borders of the GA, secondary to transmission defect and staining. The intensity of hyperfl uorescence from the choroidal fl ush may vary depending on the presence or absence of the underlying choriocapillaris (4). Fluorescein angiography may also aid in distinguishing GA from occult choroidal neovascularization, which may otherwise appear clinically indistinguishable. A recent paper suggests that an area that satisfi es one color photographic criterion of GA and also shows hyperfl uorescence on FA may be considered GA, allowing for earlier defi nition of this condition (11).
