Evaluation of choroidal thickness in AMD: A 10‐year follow‐up study

Abstract

Purpose: To evaluate choroidal thickness (CT) progression in patients with Age‐related macular degeneration (AMD) according to different phenotypes. Methods: Retrospective review of patients followed on AMD outpatient clinic from our hospital. Subfoveal CT was measured recurring to cross‐sectional spectral‐domain optical coherence tomography (SD‐OCT) images. Annual measurements were performed for each patient. Demographics, visual acuity and number of intra‐vitreal treatments were also collected. Results: One hundred and seventeen eyes from 87 patients (mean age 81.6 ± 6.6 years) were included. Intermediate AMD (group 1) was present in 14 eyes, exudative AMD (group 2) in 83 eyes, and atrophic AMD (group 3) in 14, while six eyes did not present any relevant pathology (group 4). Significant CT reduction was evident during the follow‐up of all the groups (p < 0.001, CT at beginning vs 5‐year follow‐up). No statistical differences in initial or 5‐years CT were noted between the groups (p = 0.123 and p = 0.126, respectively). After 5 years, CT presents a further significant annual reduction in AMD eyes (p < 0.001) while eyes without signs of AMD stabilize. The degree of choroidal thinning seems to vary between groups, especially during the 5 to 10 years follow‐up. At 10‐years follow‐up (N = 65), CT is statistically different among groups (p = 0.04) with atrophic AMD showing the lowest CT (mean CT 149.0 ± 38.0 μm, CT variation −42.7 ± 35.4 μm) and healthy eyes the lowest reduction (mean CT 313 ± 43.5 μm, CT variation −9.6 ± 9.2 μm). CT variation correlates with macular retinal thickness and the number of intravitreal injections in group 2 (p < 0.01). Visual acuity did not correlate with CT (p = 0.07) although thinner choroids present better visual acuities. Conclusions: AMD eyes showed a significant choroidal thinning during the follow‐up, more marked in atrophic AMD. Macular retinal thickness seems to be a predictor of CT. Further studies, with a higher number of eyes are needed to validate our results.