FUNDUS AUTOFLUORESCENCE IN AGE-RELATED MACULAR DISEASE IMAGED WITH A LASER-SCANNING OPHTHALMOSCOPE

Purpose. To image and quantify the spatial distribution of fundus auto fluorescence in normal subjects, to determine its age dependence, and to document the deviation from normal in patients with age-related mac ular disease. Methods, Using a confocal laser scanning ophthalmoscope (cLSO), the intensity and spatial distribution of fundus autofluoresce nce was studied in 33 normal subjects, 97 eyes with drusen only, and 1 11 eyes with visual loss caused by age-related macular disease. Result s. Fundus autofluorescence intensity in normal subjects was highest at the posterior pole and dipped at the fovea. Autofluorescence increase d with age at the posterior pale. Fundus in eyes with age-related macu lopathy showed localized high autofluorescence that did not correspond with drusen. Linear pigmentation at the level of the retinal pigment epithelium (RPE), whether detached or flat, fluoresced brightly, where as plaques of melanin did not. Areas of low and high levels of autoflu orescence were seen in lesions containing choroidal new vessels. In ar eas of geographic atrophy, autofluorescence was low. Conclusions. The spatial distribution of background fundus autofluorescence and the cor relation of autofluorescence with age in normal subjects imply that au tofluorescence is derived from lipofuscin at the level of the RPE. Foc al accumulation of autofluorescent material occurs at the level of the RPE in patients with drusen, but the drusen do not show marked increa ses in autofluorescence. It is likely that melanolipofuscin accounts f or the high levers of autofluorescence, corresponding to linear pigmen tation at the level of the RPE. Low-intensity autofluorescence occurs in the presence of retinal photoreceptor loss, and variable levels ove r disciform lesions probably relate to variations in metabolic activit y of the RPE.