Differences in Corneal Structure and Biomechanics between Sexes across Age Groups.

Abstract

Abstract: PURPOSE: To investigate sex-related differences in corneal morphologic and biomechanical parameters in healthy adults, with a particular focus on age-related variations that may reflect hormonal influences.

Abstract: METHODS: In this cross-sectional study, 413 healthy volunteers (189 women, 224 men) were examined using the Pentacam HR, IOLMaster 700, Corvis ST, and Ocular Response Analyzer. Parameters included mean keratometry (K_mean), white-to-white distance (WTW), anterior chamber volume (ACV), axial length (AL), central and peripheral corneal thickness (CCT, PAC and PACDiff 3 - 9 mm), Ambrosio's relational thickness (ARTh), stiffness parameter at first applanation (SP-A1), stress-strain index (SSI), corneal biomechanical index (CBI), and corrected corneal hysteresis (CHcorr). Participants were stratified into two age groups: < 50 years (pre-menopausal) and ≥ 50 years (post-menopausal). Group comparisons were performed using t-tests or Mann-Whitney U tests with Bonferroni correction (p < 0.004).

Abstract: RESULTS: Men showed larger ACV and WTW values (all p < 0.001), whereas women exhibited steeper K_mean (p < 0.001). The peripheral increase in corneal thickness tended to be greater in women (PACDiff7: p = 0.038; PACDiff9: p = 0.047), particularly among younger participants (PACDiff5: p = 0.017; PACDiff7: p = 0.004; PACDiff9: p = 0.005). ARTh and SSI displayed a trend toward sex-related differences (p = 0.01 and p = 0.012), and younger women had non-significantly higher CHcorr values (p = 0.028). CBI did not differ between sexes.

Abstract: CONCLUSION: Subtle sex-related differences in corneal morphology and biomechanics occur mainly in the premenopausal age group, potentially reflecting hormonal modulation of corneal hydration and elasticity. The CBI seems independent of sex and may be applied without gender-specific adjustment in clinical practice.