Corneal Biomechanical Metrics by Corvis ST in a Mexican Population: Normative Data and Population-Specific Implications for Intraocular Pressure Assessment.
Abstract
Purpose
To establish normative corneal biomechanical parameters measured with the Corvis ST (Oculus Optikgeräte GmbH) in a healthy Mexican population and to evaluate the influence of intraocular pressure (IOP) and central corneal thickness (CCT) on dynamic corneal response metrics relevant to refractive surgery screening.
Methods
In this cross-sectional study, healthy adults undergoing refractive surgery were assessed using the Corvis ST. When image quality criteria were met, both eyes were included. Dynamic corneal response parameters, IOP, and CCT were recorded. Reference intervals were calculated using the Hoffmann method. Associations between CCT, IOP, and biomechanical parameters were analyzed using Pearson correlation coefficients. Comparative analyses with previously published normative datasets from other populations were performed. A multivariable linear regression model was developed to explore a population-specific approach to biomechanically corrected IOP (bIOP).
Results
A total of 511 eyes were analyzed. Several Corvis ST-derived biomechanical parameters showed statistically significant differences when compared with previously reported data from other ethnic populations. CCT demonstrated weak but significant correlations with multiple biomechanical metrics, whereas IOP showed stronger associations, particularly with deformation amplitude, peak distance, and second applanation time (all P < .001). No clinically meaningful correlation was observed between IOP and the Corvis Biomechanical Index. A regression-based population-specific bIOP estimate differed significantly from the standard Corvis ST-derived bIOP (P < .0001) while maintaining a strong positive correlation.
Conclusions
Corneal biomechanical behavior measured with the Corvis ST demonstrates population-specific characteristics in healthy Mexican eyes. IOP exerts a substantial influence on several dynamic corneal response parameters, underscoring the importance of pressure-aware interpretation in refractive surgery screening. Population-specific calibration of biomechanical metrics, including bIOP estimation, may enhance the accuracy of biomechanical assessment for ectasia risk stratification and preoperative refractive evaluation.