Implications Of Optic Disc Tilt In The Progression Of Primary Open-Angle Glaucoma

PURPOSE. To evaluate the effect of optic disc tilt on the progression of glaucoma in myopic glaucomatous eyes.METHODS. The disc tilt ratio was estimated on disc photographs. Glaucomatous progression was determined either by stereoscopic optic disc/retinal nerve fiber layer photographs or serial visual field data. All participants were categorized into two groups according to tilt ratio (nontilted [<1.3] or tilted [>1.3]). Kaplan-Meier life-table analysis was used to compare the survival experiences (time to confirmed glaucomatous progression) between groups. The hazard ratios (HRs) for the associations between potential risk factors and progression were determined by using Cox proportional hazards modeling.RESULTS. A total of 85 eyes in 85 myopic glaucoma patients (axial length > 24 mm; mean follow-up, 4.1 years) were included. Among them, 42 eyes (49.4%) demonstrated progression and 43 eyes (50.6%) were stable on follow-up. The mean disc tilt ratio was significantly smaller, and the prevalence of disc hemorrhage higher, in the progression than the stable group (P = 0.032, P = < 0.001, respectively). The cumulative probability of progression was 24.7% in the tilted group and 68.7% in the nontilted group (P = 0.005). Disc hemorrhage (HR = 3.317; P = 0.001) and the tilt ratio (HR = 0.110; P = 0.046) were predictive of progression.CONCLUSIONS. Myopic eyes with tilted disc demonstrated a smaller probability of glaucomatous progression. Optic disc tilt may be protective against glaucoma progression, or tilted myopic glaucomatous eyes may have less progressive characteristic by nature.