Monitoring of Geographic Atrophy Progression in Age-Related Macular Degeneration Using Fluorescence Lifetime Imaging Ophthalmoscopy

Purpose: The purpose of this study was to examine fluorescence lifetime (FLT) changes within the border zone of geographic atrophy (GA) due to age-related macular degeneration (AMD) using fluorescence lifetime imaging ophthalmoscopy (FLIO). Methods: Patients with GA due to AMD were included. Fundus autofluorescence (FAF) intensity, spectral-domain optical coherence tomography (OCT), color fundus photography, and FLIO imaging were carried out at baseline and approximately 5 years of follow-up. GA progression was measured based on FAF images. FLT were measured at five different regions of interest: fovea, retina unaffected by GA, GA, and two areas directly next to the border zone of atrophy. Results: Thirty-two eyes of 17 patients (9 female patients, mean age = 77.4 years) were included. The GA area increased by an average of 1.21 mm2/year. At the GA border, FLT gradually decreased toward the unaffected retina at each visit and gradually increased in all zones over time. The FLT gradient at the border zone correlated significantly with the GA growth rate (P = 0.02, r2 = 0.17). Conclusions: Areas of GA showed significantly prolonged FLT compared to unaffected surrounding retinal tissue, confirming previous reports. The border zone FLT gradient was predictive of GA progression rate.