Evaluation of Corneal Densitometry in Patients with Type 2 Diabetes Mellitus

Background and Objectives: Diabetes mellitus (DM) may induce structural and biochemical changes in the cornea that can potentially affect corneal transparency. This study aimed to compare corneal optical density (COD) between patients with type 2 diabetes mellitus (T2DM) and healthy controls and to evaluate its association with disease duration. Materials and Methods: This observational cross-sectional study included 90 eyes of 90 participants, with only one eye per participant included in the analysis. The study population comprised 45 eyes from patients with T2DM and 45 age- and gender-matched healthy control eyes. The study was conducted at a specialized ophthalmology center between September 2025 and April 2026. All participants underwent a comprehensive ophthalmic examination followed by corneal densitometry and pachymetry assessment using the Pentacam AXL (Oculus Optikgeräte GmbH, Wetzlar, Germany). COD was analyzed across the total, anterior, central, and posterior corneal layers within the 0–2 mm, 2–6 mm, and 6–10 mm annular zones. COD values and central corneal thickness (CCT) were compared between groups, and correlations between disease duration and COD parameters were evaluated. Results: No statistically significant differences in COD were observed between patients with T2DM and healthy controls across any of the analyzed corneal layers or annular zones (all p > 0.05). CCT also did not differ significantly between groups (p = 0.817). No significant correlations were identified between disease duration and COD parameters (all p > 0.05). Conclusions: In this age- and gender-matched cohort, patients with T2DM did not demonstrate statistically significant differences in corneal densitometry or CCT compared with healthy controls. Disease duration was not significantly associated with COD, suggesting that other factors, including long-term glycaemic control and disease severity, may contribute to diabetes-related corneal alterations.