Evaluation of corneal deformation analyzed with a Scheimpflug based device

Purpose: To evaluate the correlation between corneal biomechanical and morphological data in healthy eyes. Methods: A complete clinical eye examination of naïve eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany) and biomechanical (Corvis ST, Oculus, Wetzlar, Germany) evaluation. Linear regression between central corneal thickness (CCT), corneal volume (CV) and anterior corneal curvature measured with Sim'K (SK), versus corneal deformation parameters measured with Corvis ST have been run using SPSS software version 18.0. Results: Seventy-six eyes of 76 healthy subjects (44 women and 32 men) with a mean age of 36.84±10.74 years and a mean refractive error of -0.55±1.68D (measured as spherical equivalent) were evaluated. Corneal deformation parameters were weakly correlated with corneal morphological parameters and with spherical equivalent. Although the correlations between deformation amplitude versus SK and between SK versus Velocity of Applanation 2, were higher than the others (R2=0.28 and 0.26 respectively), none of them was statistically significant (p>0.01). Conclusions: According with these findings, Corvis ST seems to be able to provide an analysis of corneal deformation independent from corneal morphological characteristics. If these data will be confirmed in further studies, this device could be useful in the management and screening of eyes with corneal diseases.