Four‐year longitudinal choroidal thickness changes and tessellated fundus progression in an eastern Chinese population

Purpose To assess the longitudinal change of choroidal thickness (ChT) and tessellated fundus progression in Chinese adults over 4 years. Methods In this population‐based longitudinal cohort study, 1646 right eyes of 1646 participants were examined. Fundus photographs were obtained and ChT was measured using swept‐source optical coherence tomography. Participants were categorized into high‐myopia, low‐myopia, and non‐myopia groups, and the tessellated fundus was graded 0–3 based on the fundus photographs. Results The mean baseline age, refractive error, axial length (AL), and macular ChT were 62.51 ± 9.89 years, −0.48 ± 3.18 D, 23.71 ± 1.58 mm, and 199.7 ± 77.3 μm, respectively. At the 4‐year follow‐up, a significant reduction in macular ChT of 4.05 ± 6.24, 4.44 ± 6.87, and 3.51 ± 5.17 μm per year was observed in the non‐myopia, low‐myopia, and high‐myopia groups, respectively. Age, baseline ChT, and AL changes (with β non‐M = −78.439, β HM = −56.505) were independently related to the rate of macular ChT change (all p < 0.05). Furthermore, the decrease in the ChT distribution pattern varied with different refractive groups. Moreover, 4.31% of the participants had tessellated fundus progression; these participants had more ChT reduction over 4 years than those without tessellated fundus progression ( p < 0.001). Conclusions Choroidal thinning was found to be associated with age and AL elongation. For every 1 mm increase in AL, the decrease rate of ChT in the high‐myopia group was slower than that in the non‐myopia group. Progression of tessellated fundus was associated with a faster decrease in ChT, highlighting its potential as a biomarker for myopia progression.