Peripheral FAF and Clinical Findings in Neovascular and Non-neovascular AMD
The authors of the following clinic-based, cross-sectional study sought to characterize peripheral fundus autofluorescence (FAF) abnormalities in patients with age-related macular degeneration (AMD), correlate these with clinical findings, and identify risk factors associated with these FAF abnormalities.
They recruited 119 consecutive patients (100 patients with AMD [200 eyes] and 19 patients without AMD [38 eyes]). In a prospective study performed at the Doheny Eye Institute, University of Southern California, widefield 200-degree FAF and color images were obtained by the Optos 200Tx Ultra-Widefield device using a standardized imaging protocol. According to the authors, the FAF images were captured centered on the fovea, and additional images were captured after steering the field of view inferiorly and superiorly. All FAF and color images were graded independently by two masked ophthalmologists with respect to the presence, location, extent and type of peripheral (defined as outside the central 30 degrees) FAF abnormality. Main outcome measures were presence and type of peripheral FAF abnormalities.
Peripheral FAF abnormalities were evident in 164 eyes (68.9%), with several distinct FAF patterns identified: granular (46.2%), mottled (34.0%) and nummular (18.1%), the authors found. Additionally, they observed a 90% concordance of FAF patterns between both eyes. They also noted that abnormal FAF occurred more frequently in neovascular compared with non-neovascular AMD or normal eyes (86% vs. 72.8% vs. 18.4%, respectively, p<0.001). Significant risk factors for peripheral FAF abnormalities were AMD type (neovascular AMD odds ratio [OR], 12.7 and non-neovascular AMD OR, 6.2 compared with normal eyes, p<0.001), older age (OR, 6.5; 95% confidence interval [CI], 2.4–17.8; p<0.001 for the oldest quartile compared with the youngest), and female sex (OR, 4.1; 95% CI, 1.9–8.9; p<0.001). The study authors detected clinical features on color photography in 174 eyes (73.1%): peripheral drusen (51.7%), retinal pigment epithelium (RPE) depigmentation (34.9%), RPE hyperpigmentation (branching reticular pigmentation) (22.7%) and atrophic patches (16.8%). They also reported a high correlation between specific FAF and clinical findings: granular FAF with peripheral drusen (p<0.001) and mottled FAF with RPE depigmentation (p<0.001).
Several distinct patterns of peripheral FAF abnormalities were observed in 68.9% of patients, with AMD type, female sex and age being independent risk factors. The peripheral FAF patterns correlate strongly with specific clinical features seen in eyes with AMD.