Regional growth kinetics of geographic atrophy in age‐related macular degeneration with and without fovea‐sparing
Daniel R. Muth, Abinaya P. Venkataraman, Alberto Dominguez‐Vicent, Goran Petrovski, Pete A. Williams, Laurence Quérat, Filippo Locri, Sandrine A. Zweifel, Anders KvantaAbstract
Purpose
Fovea‐sparing geographic atrophy (GA) patients retain near‐normal central vision. To better understand GA progression in relation to the fovea, we performed a semi‐automated image analysis of regional atrophy growth in a long‐term GA natural‐history cohort.
Methods
Prospective‐observational, single‐centre‐study (02/2013–07/2025) at the Division of Eye and Vision, Karolinska Institutet/St. Erik Eye Hospital, Stockholm, Sweden. Longitudinal square‐root‐transformed GA area and distance‐growth rates [mm/year] in all retinal quadrants were calculated from fundus autofluorescence images. Eyes were stratified based on best‐corrected visual acuity: fovea‐sparing (≥65 ETDRS) and fovea‐involving (<65 ETDRS).
Results
65 eyes (65 patients) presented fovea‐sparing and 91 eyes (91 patients) fovea‐involving. Median follow‐up was 18 months (range: 5–125). The fovea‐involving group decreased in BCVA (Wilcoxon, p < 0.001). Total area growth was faster for fovea‐sparing than fovea‐involving lesions: 0.34 vs. 0.26 (Mann–Whitney U , p = 0.0019). The same was true for the superior, inferior, and temporal quadrants (Mann–Whitney U , all p < 0.0472). Fovea‐sparing lesions showed slower distance growth towards the fovea than outwards in all quadrants: superior 0.09 vs. 0.21; nasal 0.08 vs. 0.18; inferior 0.06 vs. 0.17; temporal 0.09 vs. 0.20 (Wilcoxon, all p < 0.001). Lesions closer to the fovea (≤500 μm) at baseline showed decreased regional growth towards the fovea. Outwards growth was not related to lesion location.
Conclusions
In this longitudinal cohort, fovea‐sparing lesions showed faster total and regional growth than fovea‐involving lesions, mainly caused by a faster outward expansion component. Location 500 μm or closer to the fovea resulted in slower growth, which supports a foveal self‐protecting mechanism. These are relevant findings for patients with fovea‐sparing lesions.