In this study, asymmetries in corneal hysteresis (CH) between eyes of glaucoma patients were significantly associated with asymmetries in rates of visual field loss, suggesting a role of hysteresis as a risk factor for disease progression.
The purpose of this study was to investigate the relationship between asymmetries in rates of glaucoma progression and asymmetries of corneal properties between eyes of subjects with primary open-angle glaucoma.
Participants and Methods:
This prospective study followed 126 binocular subjects with glaucoma for an average of 4.3±0.8 years. CH was measured at baseline using the Ocular Response Analyzer. Standard automated perimetry (SAP) and intraocular pressure were measured at baseline and every 6 months. Rates of visual field progression were calculated using ordinary least square regression of SAP mean deviation (MD) values over time for each eye. Eyes were defined as “better” and “worse” based on the slopes of SAP MD. Pearson correlation test, and univariable and multivariable regression models were used to investigate the relationship between inter-eye asymmetry in CH and central corneal thickness and inter-eye differences in rates of visual field progression.
Only asymmetry of CH was significantly associated with the asymmetry in SAP MD rates of change between eyes (r=0.22; P=0.01). In a multivariable model adjusting for age, race, central corneal thickness, mean intraocular pressure and baseline disease severity, CH asymmetry remained significantly associated with asymmetric progression (P=0.032).
CH asymmetry between eyes was associated with asymmetry on rates of visual field change, providing further support for the role of CH as a risk factor for glaucoma progression.