Association of corneal hysteresis with lamina cribrosa curvature in primary open angle glaucoma

Abstract

PURPOSE. To investigate whether corneal biomechanical properties are associated with the lamina cribrosa (LC) curvature in eyes with primary open angle glaucoma (POAG). METHODS. Corneal biomechanical properties and LC curvature were assessed in 65 treatment-naïve POAG patients. Corneal biomechanical properties, including corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc), were measured using an ocular response analyzer (ORA; Reichert Ophthalmic Instruments). LC curvature was assessed by measuring the LC curvature index (LCCI) on B-scan images obtained using spectral-domain optical coherence tomography (OCT). The LCCI was determined by measuring LC curve depth on the anterior LC surface and the width of the reference line. RESULTS. The LCCI was correlated with CH (P ¼ 0.001), CRF (P ¼ 0.012) and IOPcc (P ¼ 0.001) in the univariate analysis. To adjust multicollinearity, principal component analysis was performed, and multivariate regression analyses were conducted using one variable from each component. The larger LCCI was associated with larger IOPcc (P < 0.001), smaller CRF (P ¼ 0.001) and smaller CH (P < 0.001). CONCLUSIONS. Lower CH was associated with a more posteriorly curved LC in treatment naïve POAG patients. This finding may provide a basic explanation for the reported association between CH and an increased risk for glaucoma development and progression, and support a potential value of CH for risk assessment for glaucoma. Copyright 2019 The Authors