Fundus autofluorescence (488 NM) and near-infrared autofluorescence (787 NM) visualize different retinal pigment epithelium alterations in patients with age-related macular degeneration

Abstract

Purpose: The purpose of this study was to compare near-infrared fundus autofluorescence(NIA, excitation 787 nm, emission >800 nm) with fundus autofluorescence (FAF,excitation 488 nm, emission >500 nm) in patients with age-related macular degeneration(AMD).

Methods: Fundus autofluorescence and NIA were obtained using a confocal scanning laser ophthalmoscope (HRA2) in 308 eyes (172 patients) with AMD [age-related maculopathy(n 116), geographic atrophy (n 77), and neovascular AMD (n 115)].

Results: Retinal pigment epithelial alterations were detected with FAF and NIA in all eyes and showed a similar lesion size in 81.8%. In age-related maculopathy, spots of increased FAF (87.9%) were more frequent than spots of reduced FAF (26.7%). Spots of increased and reduced NIA were of similar frequency (66.4%). A higher relative intensity of FAF was more frequent (72.4%) than higher relative NIA intensity (16.4%), suggesting that loss of NIA usually precedes loss of FAF. The junctional zone of geographic atrophy presented with increased NIA (19.5%), increased FAF (10.4%), or an increase of both(22.1%). In neovascular AMD, exudative changes were better visualized with FAF (56.5%)compared with NIA (33.9%).

Conclusion: Patterns of FAF and NIA indicate different involvement of lipofuscin and melanin in the pathophysiological process and provide further insight into the development of AMD and noninvasive monitoring of future therapeutic interventions.