Keratoconus staging, monitoring & corvis biomechanical analysis

Keratoconus remains one of the leading indications for penetrating keratoplasty worldwide. Since it can be effectively stabilized today, its early diagnosis and progression assessment is of particular importance. Detection and progression assessment are no longer limited to slit lamp examination and corneal topography, but comprise nowadays increasingly corneal tomography and biomechanics. Because keratoconus has a decreased resistance to deformation when compared to healthy corneas, measuring and analyzing the corneal deformation behavior has been reported to enable distinction between healthy and keratoconus corneas. The main Corneal Visualization Scheimpflug Technology (Corvis ST®, Oculus, Wetzlar, Germany) indices Corvis Biomechanical Index (CBI) and Tomographic Biomechanical Index (TBI) aim to distinguish between healthy and keratoconus corneas in a quasi‐binary manner, whereas the Biomechanical E‐Staging is based on the linear term of the CBI and provides information about keratoconus severity, thus enabling a biomechanical severity staging and progression assessment.