Dynamic Scheimpflug Analyzer (Corvis ST) for measurement of corneal biomechanical parameters. A praxis-related overview

Topographic and tomographic parameters alone are often not sufficient for early detection of corneal changes. Pathological alterations in the microstructure of the cornea occur before changes in topography and tomography can be detected. Biomechanical parameters show a strong correlation with microscopic structural changes. The aim of the study was to gain information about the microscopic structure and consistency of the cornea by measuring biomechanical parameters. The deformation behavior of the cornea was analyzed with the Dynamic Scheimpflug Analyzer (Corvis ST; OCULUS, Wetzlar, Germany). Deformation parameters and biomechanical indices were derived from the deformation response of the cornea. Deformation parameters and indices in keratoconus patients differ significantly from healthy subjects. Alterations of the cornea can be detected before topographic and tomographic changes occur. The repeatability and reproducibility of relevant deformation parameters is good to very good. In glaucoma patients a modified deformation behavior of the cornea can be observed, which might be related to structural changes. The Corvis ST allows a reliable characterization of the tissue structure and consistency of the cornea.