Evaluation of the distribution of corneal biomechanical parameters in an elderly population
Mohammadreza Asadollahi1 *, Abbasali Yekta1 , Mehdi Khabazkhoob2
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
- Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Abstract: To determine the distribution of corneal biomechanical parameters in an elderly population and their correlation with some demographic and ocular variables.
Methods: This cross-sectional study was conducted in subjects above 60 years living in Tehran. The participants were selected using multi-stage cluster sampling. All of the subjects underwent optometric and ophthalmic examinations as well as imaging using the Pentacam and IOL Master. Corneal biomechanical parameters were measured in a subsample of this population randomly selected from subjects using the ORA.
Results: Of 470 subjects, the data of 420 participants aged over 60 years were analyzed (mean age=69.3±6.5 years). The mean CH and CRF was 8.37 mmHg (95% CI: 8.02-8.72) and 9.06 mmHg (95% CI: 8.69-9.44), respectively. The mean CH was 8.27 mmHg (95% CI: 7.92-8.62) in men and 9.25 mmHg (95% CI: 8.56-9.93) in women, and the mean CRF was 9.00 mmHg (95% CI: 8.60-9.40) in men and 9.63 mmHg (95% CI: 8.86-9.98) in women. According to the results of multiple linear logistic regression analysis, CH had a significant correlation with younger age (r2 = -0.05, P = 0.032), female sex (r2 = 1.83, P < 0.001), reduced maximum keratometry (r2 = -0.22, P = 0.060), and increased AC volume (r2 = 0.01, P = 0.007). The results also showed that CRF was significantly correlated with a younger age (r2 = -0.06, P =0.022), female sex (r2 = 1.01, P = 0.053), central corneal thickness (r2 = 0.02, P < 0.001), and reduced Kmax (r2 = -0.39, P = 0.010).
Conclusion: The mean CH and CRF are low in the Iranian population aged over 60 years indicating the weaker elasticity of the corneal connective tissue. Advanced age and male sex were associated with a decrease in corneal biomechanical parameters. Due to the relationship between CRF and Kmax, it seems that this parameter can be used to predict keratoconus in the elderly
