Factors Associated with Corneal Hysteresis in an Elderly White Population: The Thessaloniki Eye Study.

Prcis: In 801 participants, corneal hysteresis (CH) was positively associated with female gender and central corneal thickness, and negatively with age and axial length. Diabetes showed no significant association with CH in the adjusted models.

Purpose: To provide values of corneal hysteresis (CH) in an elderly, healthy Greek population and to investigate its association with demographic, ocular, and systemic factors.

Methods: Cross-sectional population-based study. Out of 1,092 participants in the incidence cohort of the Thessaloniki Eye Study (TES) who were re-examined between 2013 and 2015, there were 801 eligible subjects in this study according to pre-specified criteria. All subjects underwent an interview and a comprehensive clinical examination. Demographic data and medical and ophthalmic, family, and smoking histories were recorded. CH was evaluated with Ocular Response Analyzer (ORA).

Results: The mean age of study subjects was 79.7±3.9 years and 345 out of 801 participants (43.1%) were female. The mean CH among all subjects was 10.1±1.5 mmHg. After adjusting for age, gender, central corneal thickness (CCT), axial length (AL), and diabetes, CH was positively associated with female gender (β=0.446; P<0.0001) and CCT (β=0.017; P<0.0001), and negatively associated with age (β=-0.024; P=0.038) and AL (β=-0.181; P<0.0001). There was no association between CH and diabetes (β=0.186; P=0.10). In a supplementary multivariable analysis of a smaller sample size, where we included corneal curvature (CC) as an additional covariate, no association was found between CH and CC (β=-0.235; P=0.26) or age (β=-0.023; P=0.09).

Conclusion: This study outlined variations in CH among a Greek population. CH decreased with advancing age while women had greater CH compared to men. In addition, eyes with thinner corneas and longer AL had lower CH values. No significant associations were found between CH and CC or the presence of diabetes.