Comparison of waveform‐derived ORA parameters in clinical keratoconus, subclinical keratoconus and healthy subjects

Aims/Purpose: The aim of this study was to comparison of waveform‐derived Ocular Response Analyser (ORA) parameters in clinical keratoconus (KC), subclinical keratoconus (SKC) and healthy subjects. Methods: This retrospective comparative case series study included 24 eyes with SKC, 24 eyes with KC and 48 eyes of age‐ and sex‐matched healthy subjects. Keratoconus diagnosis was based on clinical examinations, and Scheimpflug corneal tomography. SKC was defined as the presence of the following: (1) normal biomicroscopic findings and topography; (2) anterior (≤7 μm) and posterior (≤16 μm) elevation difference map marked green or yellow; (3) mean keratometry