Central Corneal Thickness and Anterior Scleral Thickness in Korean Patients With Open-angle Glaucoma: An Anterior Segment Optical Coherence Tomography Study

Purpose: To assess the correlation between central corneal thickness (CCT) and anterior scleral thickness (AST) in Korean patients with normal tension glaucoma (NTG) and primary open angle glaucoma (POAG). Patients and Methods: Consecutive patients with POAG, NTG, and normal individuals were recruited. Anterior segment optical coherence tomography (AS-OCT, Visante) was used to measure CCT and AST. The AST was measured 2mm posterior to the scleral spur in the temporal meridian. Statistical analysis of the data included ANOVA and Pearson correlation analysis. Results: One hundred and eight participants (36 with NTG, 35 with POAG, and 37 normal individuals) were enrolled. The CCT (NTG 514.81 + 25.03 mu m; POAG 534.43 + 34.79 mu m; controls 536.70 + 32.11 mu m) was found to be thinner in patients with NTG compared with POAG and the control eyes (P = 0.023; P = 0.009). The AST (NTG 738.53 + 53.63 mu m; POAG 771.86 + 53.75 mu m; controls 783.62 perpendicular to 57.03 mu m) was thinner in the patients with NTG compared with POAG and the normal controls (P = 0.032; P = 0.002). No significant difference in AST was found among the POAG and control eyes (P = 0.636). A correlation between CCT and AST was found only among the patients with NTG (r = 0.469, P = 0.004). However, no correlation was observed between CCT and AST in patients with POAG and controls. Conclusions: Anterior scleral thickness was correlated with CCT in the NTG group, but this correlation was not observed among the POAG or control groups.