Photoreceptor Damage Surrounding Geographic Atrophy in Dry Age-related Macular Degeneration

Abstract

 

Purpose

 

To quantify the area with photoreceptor damage surrounding geographic atrophy (GA), and to evaluate the relationship between structural abnormalities and retinal function in eyes with dry age-related macular degeneration (AMD).

 

Methods

 

Twenty one eyes of 21 patients with GA associated with dry AMD underwent a full ophthalmologic examination, including spectral-domain optical coherence tomography (SD-OCT, 20 X 30 degrees, distance between B-scans:120uμm), fundus autofluorescence (FAF), and microperimetry (MP, covering central 20 degrees, 57 stimulation points). Ellipsoid zone band on SD-OCT was objectively evaluated using Image J, and areas with photoreceptor damage were measured. Hypofluorescent areas of FAF image were measured as areas with RPE damage. Correlation of photoreceptor damage, RPE damage, and retinal sensitivity shown by MP was investigated.

 

Results

 

The mean size of photoreceptor damage area was 7.54 ± 5.7 mm². The mean size of photoreceptor damage areas was significantly greater than the mean size of RPE damage areas (3.91 ± 3.6 mm², P<0.001). Photoreceptor damage areas surrounding RPE damage areas was larger in eyes with pseudodrusen (n=7), compared with eyes without pseudodrusen (n=14) (5.04 mm² vs 1.89 mm², P=0.027). The mean size of RPE damage areas and the mean size of photoreceptor damage areas were negatively correlated with mean retinal sensitivity (P<0.001 for both). Multiple regression analysis revealed that the only significant predictor of decreased retinal sensitivity was the size of photoreceptor damage areas (P<0.001).

 

Conclusions

 

In eyes with dry AMD, photoreceptor damage was seen in widespread areas surrounding RPE damage, and correlated with visual function. Evaluation of photoreceptor damage surrounding GA is important in dry AMD.