Morphological characteristics of corneal endothelial cells in a healthy southern Han Chinese population across the entire life cycle and evaluation of age-associated endothelial morphological indicators

ObjectiveThe study aimed to observe the morphological changes in corneal endothelial cells in a healthy Han Chinese population in southern China over the entire life cycle, analyze age-associated morphological changes, and evaluate the potential utility of endothelial assessment parameters as candidate biomarkers.MethodsIn total, 13,820 healthy Han Chinese volunteers were examined by specular microscopy, and the endothelial descriptive indexes, including central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variation in average cell size (CV), percentage of regular hexagonal cells [hexagonality (HEX)], size of the smallest cell (Smin), size of the largest cell (Smax), average cell size (Savg), and cell area standard deviation (Ssd), as well as gender and age, were analyzed.ResultsThe average age of the participants in this study was 48.14 ± 23.47 (3–99) 14;years. There was no sex predominance, with 6,836 male participants (46.38%) and 6,984 female participants (53.62%). The mean CCT, ECD, CV, HEX, Smin, Smax, Savg, and Ssd were 524.95 ± 34.2 14;μm (415–650 14;μm), 2,843.15 ± 393.84 14;cells/mm2 (1,501–4, 180 14;cells/mm2), 32.07% ± 5.71% (16%–60%), 54.17% ± 12.87% (12%–99%), 146.30 ± 33.81 14;μm2, 790.60 ± 182.74 14;μm2, 357.92 ± 57.92 14;μm2, and 115.71 ± 33.05 14;μm2, respectively. CCT was not significantly associated with age (p = 0.061). The cross-sectional age-associated ECD decline was estimated at 0.42% per year of age (95% CI: 0.39%–0.45%). The ECD and hexagonality curves expressed the same linear trend. The CCT and endothelial evaluation indexes had no gender predominance (p > 0.05). ECD and HEX were significantly negatively associated with age (p = 0.001 or p < 0.001). CV, Smin, Smax, Savg, and Ssd were positively correlated with age (p < 0.001). Finally, CCT was not significantly associated with age (p = 0.061>0.05).ConclusionsThis study found that the ECD decrease rate was 0.42%/year for a healthy Han Chinese population in southern China during the entire life cycle. HEX showed the strongest age-associated sensitivity to morphological changes, while Smax and CV demonstrated the most consistent age-related specificity as morphological indicators of endothelial polymegathism and pleomorphism in the specular microscopy results.