Photoreceptor Damage and Reduction of Retinal Sensitivity Surrounding Geographic Atrophy in Age-Related Macular Degeneration

PurposeTo quantify the area of photoreceptor damage surrounding geographic atrophy (GA) and evaluate the relationship between structural abnormalities and retinal function in eyes with GA.DesignProspective cross-sectional study.MethodsTwenty-five eyes of 25 patients with GA associated with age-related macular degeneration underwent a full ophthalmologic examination, including spectral-domain optical coherence tomography (SDOCT), fundus autofluorescence (FAF), and microperimetry. ImageJ software was used to quantify the disruption of the ellipsoid zone on SDOCT images. Hypofluorescent areas of the FAF images indicated areas of retinal pigment epithelium (RPE) loss. Areas of interest graded by SDOCT (photoreceptor damage) and FAF (RPE loss) were registered with microperimetry within a 6-mm circle centered on the fovea.ResultsThe mean area of photoreceptor damage was 7.69 ± 5.36 mm2, which was significantly greater than the mean area of RPE loss (4.57 ± 4.07 mm2, P < .001). The average retinal sensitivity of the area with photoreceptor damage outside the area of RPE loss was lower than that of the area without photoreceptor damage (6.57 ± 4.13 dB vs 11.27 ± 3.78 dB, P < .001). The area of photoreceptor damage surrounding the area of RPE loss was larger in eyes with pseudodrusen than in eyes without pseudodrusen (4.96 mm2 vs 1.91 mm2, P = .008). The only significant predictor of decreased retinal sensitivity was the area of the photoreceptor damage (P < .001).ConclusionsWidespread photoreceptor damage surrounding sites of RPE loss occurred in eyes with GA, and it correlated with visual function. Evaluation of photoreceptor damage surrounding sites of RPE loss using OCT is important in patients with GA associated with AMD.