Purpose: To assess the impact of trabeculectomy on corneal health by quantitatively analyzing changes in corneal endothelial parameters using non-invasive specular biomicroscopy.

Methods: A cross sectional, non interventional study was conducted on 30 patients in the Department of Ophthalmology at a tertiary eye care centre in central India. All patients attending the glaucoma clinic were evaluated using specular biomicroscopy to measure corneal endothelial cell loss both before and after trabeculectomy surgery over a period of 12 months. The following parameters were recorded before surgery and at 1,3, and 6 months post-trabeculectomy during specular biomicroscopy: endothelial cell density (ECD), percentage of hexagonal cells(6A), coefficient of variation in cell area (CV) and central corneal thickness (CCT).

Results: In this study, most glaucoma patients were aged 61–70 years (36%) with a female predominance (70%). Of 30 patients, 53.3% had Primary Angle Closure Glaucoma (PACG) and 46.7% had Primary Open-Angle Glaucoma (POAG). Specular microscopy revealed statistically significant (P<0.05) post-trabeculectomy reductions in endothelial cell density (from 2186.24 ± 225 to 1877 ± 236 cells/mm²), central corneal thickness, and hexagonality, along with increases in endothelial cell area and coefficient of variation (CV). ECD loss showed a positive correlation with CV and negative correlations with hexagonality, ECD, and CCT, indicating structural compromise of the corneal endothelium after trabeculectomy.

Conclusion: This study highlights that trabeculectomy significantly affects the corneal endothelium, with notable reductions in endothelial cell density (ECD), central corneal thickness (CCT), and hexagonality, along with increased in cell area and coefficient of variation (CV). A positive correlation with CV and negative correlations with ECD, CCT, and hexagonality indicate compromised endothelial integrity. As endothelium maintains corneal clarity and hydration, monitoring it before and after trabeculectomy is crucial to prevent long-term visual complications.