Corneal biomechanics predict the outcome of selective laser trabeculoplasty in medically uncontrolled glaucoma

Abstract

To evaluate the predictive value of clinical parameters, including biomechanical properties on the outcome of selective laser trabeculoplasty (SLT) in medically uncontrolled open angle glaucoma (OAG). Sixty-eight eyes from 68 patients with OAG and IOP insufficiently regulated by topical medications were enrolled. Patients' follow-up occurred 6 and 12 months after the procedure. The recorded parameters intraocular pressure (IOP), angle characteristics, central corneal thickness (CCT) and biomechanical properties of the eyes, including corneal hysteresis CH and corneal resistance factor CRF measured with the Ocular Responses Analyzer (ORA, Reichert Ophthalmic Instruments) were tested on their predictive value of SLT-induced IOP lowering effect using correlation analyses and regression models. Mean IOP reduction 12 months after SLT was 4.2 ± 5.7 mmHg (23.2%, from baseline 18.1 ± 5.2 mmHg). The preoperative IOP correlated significantly with IOP reduction (maximum Spearman's correlation r = 0.75, p < 0.001). In linear regression analysis, the corneal biomechanical properties (CH and CRF) together with the baseline IOP revealed good modelling for the IOP lowering effect of SLT (R(2) = 0.64, respectively). In addition to the baseline IOP biomechanical properties (CH and CRF) are significant predictors of SLT induced IOP lowering effect in medically uncontrolled OAG.