The Relationship between Corneal Biomechanics and Refractive Status

Abstract

Objective: This study aimed to determine the relationship between corneal biomechanical properties and refractive status. Methods: The study included patients who underwent routine eye examination and were divided into 3 groups based on refractive status: hyperopia group (spherical equivalent >+0.50 diopters), myopia group (spherical equivalent <-0.50 diopters), and emmetropia group (spherical equivalent within +/- 0.50 diopters). Corneal biomechanical parameters (corneal hysteresis and corneal resistance factor) and intraocular pressure were measured via an ocular response analyzer (Reichert, Corp., Buffalo, NY). Corneal biomechanical properties were compared between the three groups. Pearson's correlation analysis, one-way ANOVA, and multivariate analysis of covariance were used to evaluate the study data. Results: Corneal hysteresis and age were significantly correlated in the hyperopia, myopia, and emmetropia groups based on Pearson's correlation analysis (P<0.05). Corneal hysteresis and corneal resistance factor values were adjusted for the age variable. Mean corneal hysteresis was 11.34 +/- 0.40 mmHg, 11.35 +/- 0.34 mmHg, and 11.65 +/- 0.33 mmHg in the hyperopia, myopia, and emmetropia groups, respectively (P=0.021, one-way ANOVA). Mean corneal resistance factor was 11.05 +/- 0.35 mmHg, 10.85 +/- 0.30 mmHg, and 11.04 +/- 0.29mmHg in the hyperopia, myopia, and emmetropia groups, respectively (P=0.047, one-way ANOVA). Corneal hysteresis and corneal resistance factor were significantly correlated based on Pearson's correlation analysis (P<0.001). Moreover, according to Pearson's correlation analysis, there was no significant correlation between corneal hysteresis and spherical equivalent, but corneal resistance factor and spherical equivalent were significantly correlated (P=0.502 and P=0.001, respectively). Conclusion: Myopes have lower corneal hysteresis and corneal resistance factor than hyperopes and emmetropes. Refractive status should always be a consideration when assessing corneal biomechanical properties.