Fundus autofluorescence and development of geographic atrophy in age-related macular degeneration

PURPOSE. TO describe the development of new and enlargement of preexisting atrophy confined to areas with abnormally high levels of in vivo autofluorescence in eyes with geographic atrophy (GA) associated with age-related macular degeneration (ARMD). METHODS, The spatial distribution and intensity of fundus autofluorescence as well as the spread of GA and occurrence of new GA was recorded over a period of 3 years in three patients with ARMD using a confocal scanning laser ophthalmoscope. RESULTS. A diffuse irregular increased autofluorescence at the posterior pole was recorded at baseline in the presence of unifocal or multifocal patches of geographic atrophy. Within these areas of elevated autofluorescence, new atrophic areas developed, and existing patches of atrophy enlarged during the review period, whereas this was not observed in areas with normal background autofluorescence. The total area of abnormal autofluorescence also showed enlargement over time. CONCLUSIONS. These preliminary findings suggest that areas of increased autofluorescence precede the development and enlargement of outer retinal atrophy in eves with ARMD. Because the dominant fluorophores of fundus autofluorescence are part of lipofuscin granules of RPE cells, the observations indicate that excessive RPE lipofuscin accumulation may be of significance in the pathogenesis of GA associated with ARMD. With GA being a major cause for severe visual loss in ARMD, in vivo fundus autofluorescence recording over time may allow identification of prognostic determinants and may give important clues to the understanding of mechanisms of disease.