Author: Katja Hatz
Co-authors: Laura Hoffmann, Luca Cedro
Abstract
Purpose: So far, the natural course of geographic atrophy (GA) progression in age-related macular degeneration (AMD) has primarily been investigated by fundus photography and fundus autofluorescence (FAF) imaging. The aim of this study was to show the enlargement rate (ER) of GA, defined as complete retinal pigment epithelium and outer retinal atrophy (cRORA) and to find predictors of progression.Setting: Long-term retrospective, observational clinical study at Vista Augenklinik Binningen, Switzerland.
Methods: All patients available in the database with follow-up of at least 24 months and existing GA in at least one eye, regardless of neovascular AMD (nAMD) being present initially or in the course of disease, were included. SD-OCT and FAF evaluations were performed according to a standardized protocol. The cRORA area ER (mm2/yr), the cRORA square root area ER (mm/yr), the FAF GA area and the condition of the outer retina (inner-/outer segment line (IS/OS) and external limiting membrane (ELM) disruption scores) were determined.
Results: 210 eyes of 133 patient (65% females) were included. Mean follow-up time was 4.0±2.3 (range 2-10) years. 109 (52%) eyes were classified as primary or secondary nAMD, 101 (48%) as exclusively dry AMD. The primary lesion was unifocal in 151 (72%) and multifocal in 59 (28%) eyes. A strong correlation was observed between the area of cRORA (SD-OCT) and the FAF GA area (r= 0.925; p<0.001). Mean ER was 1.44±1.6 mm2/yr and mean square root ER 0.29±0.19 mm/yr. There was no significant difference in mean ER between eyes without (dry AMD) and with intravitreal anti-VEGF injections (nAMD) (0.3±0.19 mm/yr vs. 0.28±0.20 mm/yr; p=0.466). Eyes with a multifocal GA pattern at baseline had a significantly higher mean ER compared to eyes with a unifocal pattern (0.34±0.19 mm/yr vs. 0.27±1.19 mm/yr; p=0.008). There were moderate significant correlations between ELM and IS/OS disruption scores and visual acuity at baseline, 5 and 7 years (all r values ca. -0.5; p<0.001). In multivariate regression analysis, a scattered cRORA pattern at baseline (p=0.022) and a smaller baseline lesion size (p=0.036) were associated with a higher mean ER.
Conclusions: SD-OCT evaluated cRORA area might serve as a GA parameter comparable to traditional FAF measurement. The dispersion pattern and baseline lesion size might be predictors of ER, whereas anti-VEGF treatment seems not to be associated with ER.
