Purpose: To investigate photopic and scotopic sensitivity of retinal areas that show increased fundus autofluorescence (FAF) in patients with age-related maculopathy (ARM).
Methods: FAF was imaged with a modified confocal scanning laser ophthalmoscope (cSLO). Fine matrix mapping (FMM) was performed with a modified field analyzer. Photopic and scotopic thresholds were obtained at 100 locations on a 9 degrees x 9 degrees matrix with 1 degrees spacing, centered on a macular area of increased FAF. Inclusion criteria included ARM fundus changes, areas of increased FAF, central and stable fixation, and visual acuity of 20/40 or better.
Results: FAF images were reviewed in 436 patients with age-related maculopathy (ARM), of whom 38 met the inclusion criteria. FMM was performed in seven eyes of seven patients. Areas of increased FAF in patients with late ARM (choroidal neovascularization or geographic atrophy) showed normal or only mildly abnormal photopic, but severely reduced scotopic, sensitivity. The central area of increased FAF corresponding to a large foveal druse in a patient with ARM showed moderately reduced photopic and severely reduced scotopic sensitivity. In the other patients with ARM with drusen, areas of increased FAF showed normal or near-normal photopic sensitivity, but moderately reduced scotopic sensitivity.
Conclusions: In retinal areas of increased FAF in patients with ARM, scotopic sensitivity loss considerably exceeded photopic sensitivity loss. This finding is in line with histologic data that have demonstrated a preferential loss of rods in ARM, but does not explain the magnitude of sensitivity loss. The study shows that increased FAF in ARM has a functional correlate.