Relationship between Inter-Eye Asymmetries in Corneal Hysteresis and Visual Field Severity in Patients with Primary Open-Angle Glaucoma.

This study investigated the influence of asymmetric corneal hysteresis (CH) on asymmetric visual field impairment between right and left eyes in patients with primary open-angle glaucoma (POAG) without a history of intraocular surgery. CH, corneal resistance factor (CRF), and corneal compensated intraocular pressure (IOPcc) were measured using the Ocular Response Analyzer. Differences between the eyes (right eye-left eye: DIF RL ) and CH-based and in target parameters (higher CH eye-lower CH eye: DIF CH ) were calculated in the same patient. In 242 phakic eyes of 121 patients, older age ( p < 0.001), lower CH ( p = 0.001), and lower CRF ( p = 0.007) were significantly associated with worse standard automated perimetry (SAP) 24-2 mean deviation (MD). The DIFs RL in axial length ( p = 0.003), IOPcc ( p = 0.028), and CH ( p = 0.001) were significantly associated with the DIF RL in SAP24-2 MD, but not in central corneal thickness (CCT), Goldmann applanation tonometry (GAT) measurement, and CRF. When dividing the patients into two groups based on the median of the CH DIFs CH (0.46), the DIFs CH in CRF ( p < 0.001), IOPcc ( p < 0.001), CCT ( p = 0.004), SAP24-2 MD ( p < 0.001), and SAP10-2 MD ( p = 0.010) were significantly different between the groups. Large inter-eye asymmetry in CH is an important explanatory factor for disease worsening in patients with POAG.