This study has been conducted to evaluate the ocular biomechanical parameters given by the CorVis ST tonometer in healthy eyes of Iranian society.

This observational and cross-sectional study contained 100 eyes. Three consecutive measurements were performed on one eye of each patients using the CorVis ST device. Various parameters including first applanation length, first applanation velocity, first applanation time, second applanation length, second applanation velocity, second applanation time, peak distance, radius, deformation amplitude, corrected and non-corrected intraocular pressure (IOP), central corneal thickness (CCT), CorVis biomechanical index (CBI), and tomography and biomechanical index (TBI)were derived from the CorVis ST. Repeatability of each parameter evaluatedandtheir correlation with age and sex are also tested.

Mean age of volunteers were37.68 ± 12.09 years old. Mean IOP was 15.47 ± 2.24 mm Hg, mean CCT was 541.24 ± 38.90μm, mean CBI was 0.048 ± 0.13, and mean TBI was 0.138 ± 0.17.Intraclass correlation coefficient (ICC) for IOP, CCT, CBI, and TBI were 0.763, 0.985, 0.582, and 0.764 respectively. ICC was 0.809 for second applanation velocity and 0.825 for deformation amplitude, and less than 0.8 for all other parameters. The device-specific data showed no significant relationship with age and sex.

The CorVis ST showed high repeatability for IOP, CCT, second applanation velocity, and deformation amplitude parameters while single measurement is not reliable for other ones. The results of this study can be used as a benchmark in comparison to other similar studies in various countries and also for studying corneal biomechanical variables in different conditions. In addition, none of age and sex of patients have any effect on CorVis ST parameters.