Abstract
Purpose :
There is mounting evidence linking inflammation with age related macular degeneration (AMD). While innate immunity and macrophage infiltration are linked to choroidal neovascularization in wet AMD, the role of macrophages in dry AMD remains unclear. Recently recognized as potential inflammatory biomarkers in retinal disease, macrophage-like cells (MLCs) can be non-invasively visualized in vivo using en face optical coherence tomography (OCT). Our study aims to assess these cells in patients with dry AMD, comparing those with and without geographic atrophy (GA).
Methods :
This is a retrospective study including patients with dry AMD who underwent OCT angiography (OCTA) between January 2017 and July 2021. Baseline data was derived from the first OCTA visit, and the 2-year follow-up data was obtained from the nearest visit within 6 months of the 24-month mark with accessible OCTA. Using Fiji software, we registered and averaged the 3-μm slab above the internal limiting membrane to visualize and count the number of MLCs. We compared the number of MLCs at baseline and two-year follow-up. We also compared the number of cells in the subgroup of eyes that developed GA at 2 years.
Results :
We included a total of 79 patients with dry AMD. Mean age of patients was 76.83 ± 8.44 years, and the majority were female (70.9%). Mean retinal MLC counts was 98.77 ± 51.28 at baseline and decreased to 88.20 ± 45.06 after 2 years (p = 0.06). The eyes that had GA at baseline (n = 11) exhibited a higher number of MLCs, but this difference did not reach statistical significance (120.55 ± 45.02 vs. 95.25 ± 51.65, p = 0.07). Seven eyes developed GA after 2 years (incident GA). These eyes exhibited a higher number of MLCs at baseline compared to the eyes that did not develop GA, but the difference was not statistically significant (108.57 ± 83.91 in eyes with incident GA vs. 93.72 ± 47.46 in eyes without incident GA, p = 0.81).
Conclusions :
Our findings revealed a decrease in retinal MLC counts over a 2-year period. While patients with baseline GA showed a trend toward higher MLC counts, this difference did not reach statistical significance. The development of GA after 2 years was associated with elevated baseline MLC counts, although this association did not achieve statistical significance.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.