Evaluating the Repeatability and Effect of Sex and Age on Corneal Biomechanical Parameters Measured Using Corvis ST Tonometer

Purpose: To evaluate the repeatability of biomechanical readings by Corvis ST (Wetzlar, Germany) in healthy eyes and its relation with age and sex. Methods: Three consecutive measurements were performed on 100 eyes of 100 participants using the Corvis ST. Various parameters including first and second applanation length, first and second applanation velocity, first and second applanation time, peak distance, radius, deformation amplitude, corrected and non-corrected intraocular pressure (IOP), central corneal thickness (CCT), Corvis ST biomechanical index (CBI), and tomography and biomechanical index (TBI) were derived from the Corvis ST readings. Repeatability of each parameter and their correlation with age and sex were evaluated. Results: The mean IOP, CCT, CBI and TBI were 15.47 ± 2.24 mm Hg, 541.24 ± 38.90 μm, 0.048 ± 0.13 and 0.138 ± 0.17 respectively. Intra class correlation coefficient (ICC) for CCT, second applanation velocity and deformation amplitude were 0.985, 0.809 and 0.825 respectively. ICC was less than 0.8 for all other parameters. The device-specific readings showed no significant relationship with age and sex. Conclusion: The Corvis ST showed high repeatability in measuring CCT, second applanation velocity, and deformation amplitude parameters. No relation between Corvis ST readings and age or sex was observed.