Corneal Biomechanics Assessment with Ultra High Speed Scheimpflug Camera in Primary Open Angle Glaucoma Compared with Healthy Subjects: A meta-analysis of the Literature

Purpose The aim of this meta-analysis of the literature is to provide a comprehensive analysis of the differences in Corvis ST dynamic corneal response (DCR) parameters between primary open-angle glaucoma (POAG) patients and healthy controls.Methods A quantitative meta-analysis was conducted on articles published before September 10, 2021 identified by searching PubMed, EMBASE, and Web of Science. Prospective studies comparing DCR Corvis ST parameter in high tension POAG and healthy controls were included. The random-effects model was conducted. Assessment of heterogeneity was based on the calculation of I2. Funnel plots evaluation and meta-regression were performed in case of detection of high heterogeneity.Results The selection process resulted in the inclusion of six articles. Pooled analysis revealed that POAG corneas respond to mechanical stimulus with a smaller concavity, showing lower deformation amplitude (DA) (CI95% −0.991 to −0.578; p < .001; I2 = 0%), higher highest concavity radius (HCR; confidence interval [CI]95% −0.01 to 0.34; p = .058; I2 = 6.7%), and lower peak distance (PD; CI95% −1.06 to −0.024; p = .040; I2 = 86.5%). They also show a slower loading phase, with lower highest concavity time (HCT; CI95% −0.39 to −0.02; p = .029; I2 = 3.3%) and lower applanation velocity-1 (CI95% −0.641 to −0.127; p = .003; I2 = 34.6%), and a faster restoration to the original form, shown by lower applanation time-2 (CI95% −1.123 to −0.544; p = .001; I2 = 44.8%) compared to healthy subjects.Conclusions High tension POAG patients are characterized by stiffer corneas compared to healthy controls. These differences are valid also after removing the effect of age, corneal thickness, and intraocular pressure (IOP).