Differences in corneal biomechanical parameters in normal tension glaucoma versus normotensive glaucoma suspect eyes

Multicenter retrospective study to evaluate differences in corneal biomechanical parameters provided by Corvis ST to discriminate normal tension glaucoma (NTG) from glaucoma suspect eyes. We included only newly diagnosed and treatment-naïve patients. A total of 200 eyes from 100 NTG patients and 200 eyes from 100 controls were included. Between-group comparisons were performed using generalized estimating equations to account for inter-eye correlation. Corneal velocity at second applanation (A2) was significantly different between groups (-0.267 ± 0.064 m/s in controls versus − 0.225 ± 0.082 m/s in NTG, P < 0.001, q < 0.001). Biomechanical glaucoma factor (BGF) was also significantly higher in NTG (0.667 ± 0.221) than controls (0.564 ± 0.233; P < 0.001, q = 0.001). In multivariable analysis, BGF remained independently associated with NTG status (OR 1.73, 95% CI 1.23–2.48; P = 0.002). The diagnostic performance of BGF was modest, with AUC values of 0.608 (worse eye), 0.642 (mean of both eyes), and 0.629 (pooled eyes). Addition of BGF to a clinical model increased AUC from 0.636 to 0.682, although without statistical significance ( P = 0.151). Significant corneal biomechanical differences were identified between NTG and glaucoma suspect eyes. BGF and A2 may provide adjunctive biomechanical information for NTG evaluation, although their standalone discriminatory ability remains limited.