Clinical Assessment of Cognitive Function in Normal-Tension and High-Tension Glaucoma Patients: A Comparative Study

Background: Cognitive impairment is increasingly recognized in glaucoma, particularly in normal-tension glaucoma (NTG), which may involve neurodegenerative mechanisms independent of intraocular pressure (IOP). However, the relationship between cognitive function and glaucoma severity in NTG compared with high-tension glaucoma (HTG) remains unclear. Materials and Methods: In this hospital-based cross-sectional comparative study at a tertiary care centre in South India, 56 patients (28 NTG, 28 age-matched HTG) were enrolled. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Comprehensive ophthalmic evaluation included visual acuity, IOP, central corneal thickness (CCT), slit-lamp biomicroscopy, gonioscopy, and Humphrey visual field analysis. Associations between MoCA scores and visual field parameters—mean deviation (MD) and pattern standard deviation (PSD)—were analysed using correlation coefficients ( p < 0.05). Results: The NTG and HTG groups were comparable in age (52.1 ± 5.9 vs. 53.3 ± 5.3 years; p = 0.424) and sex distribution ( p = 0.181). Cognitive impairment (MoCA ≤25) was more prevalent in NTG (78.6%) than in HTG (42.9%) ( p = 0.006). In NTG, MoCA scores correlated positively with MD ( r = 0.577, p = 0.001) and negatively with PSD ( r = −0.563, p = 0.002; R 2 ≈ 0.32). No significant correlations were observed in HTG. CCT was not associated with cognitive function in either group. Conclusion: Cognitive screening may help identify NTG patients who could benefit from further neurological evaluation and multidisciplinary care.