Evaluation of peripheral fundus autofluorescence in eyes with wet age-related macular degeneration

Abstract

Purpose: Fundus autofluorescence (FAF) imaging is a noninvasive technique used to assess retinal pigment epithelium (RPE) abnormalities and chorioretinal diseases. We conducted a retrospective, observational clinical study to evaluate prevalence and types of abnormal peripheral fundus autofluorescence (pFAF) patterns in eyes with wet age-related macular degeneration (AMD) using wide field scanning laser ophthalmoscope (Optos^®200Tx).

Methods: Wide field FAF images were obtained from 67 eyes of 47 wet AMD patients (mean age 76±6.3 years) and 34 eyes of 20 control patients without AMD (mean age 72±7.3 years) using Optos^®200Tx. Wet AMD eyes were classified into 3 disease types: typical AMD (38 eyes of 29 patients), polypoidal choroidal vasculopathy (PCV) (22 eyes of 20 patients), and retinal angiomatous proliferation (RAP) (7 eyes of 4 patients). A central 30 degrees area from a fovea centralis was covered in each FAF image. All pFAF images were graded independently by 2 masked ophthalmologists for the presence of 3 abnormal pFAF pattern types: granular, mottled, and nummular, classified according to a study from Tan, et al (Ophthalmology, 2013). Discrepancies between 2 ophthalmologists’ grading were resolved by grading from a third masked ophthalmologist. Statistical differences of abnormal pFAF patterns in different groups were analyzed by chi-square tests.

Results: Abnormal pFAF patterns were found significantly more frequently in 34 out of 67 wet AMD eyes (51%) compared with 6 out of 34 control eyes (18%) (P<0.001). Abnormal pFAF patterns were found in 20 out of 38 typical AMD eyes (53%), 8 out of 22 PCV eyes (36%), and 6 out of 7 RAP eyes (86%), which are significantly higher in prevalence compared with 18% in control eyes (P<0.01). Odds ratios (OR) for abnormal pFAF prevalence were 5.2 (95%CI:1.7-15.4) in typical AMD eyes, 2.7 (95%CI:0.8-9.2) in PCV eyes, 28.0 (95%CI:2.8-277.4) in RAP eyes when compared with control eyes. In wet AMD eyes, mottled pattern in 30 eyes (45%), granular pattern in 21 eyes (31%), and nummular pattern in 11 eyes (16%) were found.

Conclusions: All types of abnormal pFAF patterns were found more frequently in wet AMD eyes when compared with control eyes. Potential relationships between each abnormal pFAF pattern type and prognosis in individual wet AMD disease types may be evaluated in a future study.