Fundus Autofluorescence Characteristics of Nascent Geographic Atrophy in Age-Related Macular Degeneration

Abstract

 

Purpose

 

To examine the fundus autofluorescence (FAF) characteristics of nascent geographic atrophy (nGA), pathological features preceding the development of drusen-associated atrophy in eyes with age-related macular degeneration (AMD) that can be visualized using high-resolution optical coherence tomography (OCT).

 

Methods

 

Spectral-domain OCT (SD-OCT) and FAF imaging were performed longitudinally in 221 eyes of 181 participants with intermediate AMD (having at least drusen >125 μm). The FAF characteristics of areas that developed drusen-associated atrophy in these eyes were examined and categorized. These categories were then used to characterize areas of nGA or drusen-associated atrophy on SD-OCT identified in a cross-sectional study with 230 participants with bilateral intermediate AMD.

 

Results

 

Sequential imaging revealed that FAF characteristics in the atrophic areas could be grouped into three categories: predominantly hyperautofluorescent (hyperAF), both hyper- and hypoautofluorescence (mixed AF) or predominantly hypoautofluorescent (hypoAF). In the cross-sectional study, the FAF characteristics were significantly dependent on the type of atrophic area (P = 0.002), where areas of nGA appeared most commonly as being mixed AF (63%) while areas of drusen-associated atrophy most commonly as hypoAF (86%).

 

Conclusions

 

FAF imaging revealed that areas of nGA were most commonly characterized by both hyper- and hypoautofluorescent changes, which differs from areas of drusen-associated atrophy that most often appeared hypoautofluorescent. These findings provide important insights into the FAF characteristics of areas undergoing atrophic changes in eyes still considered to be in the early stages of AMD by current methods, and thus assist in the characterization of disease severity in these early stages.