COMPARATIVE ASSESSMENT OF TEAR FILM DYSFUNCTION AND CORNEAL NERVE SENSITIVITY IN PATIENTS WITH AND WITHOUT DIABETES MELLITUS

Abstract

Background: Diabetes mellitus can affect the ocular surface and corneal nerves, leading to tear film instability, dry eye changes, reduced corneal sensitivity, and delayed epithelial healing.

Objective: To compare tear film dysfunction and corneal nerve sensitivity in patients with and without diabetes mellitus.

Methods: This comparative cross-sectional study was conducted at Opthalmogology department, Mughal Eye Hospital Lahore from November 2024 to August 2025, included 35 participants, divided into a diabetic group (n = 18) and a non-diabetic control group (n = 17). Demographic and clinical data were recorded. Tear film dysfunction was assessed using tear breakup time, Schirmer test, and fluorescein staining.

Results: Diabetic patients showed significantly reduced tear breakup time compared with non-diabetic participants (6.1 ± 2.0 vs 10.2 ± 2.7 seconds; p < 0.001). Schirmer test values were also significantly lower in the diabetic group (8.4 ± 3.1 vs 14.0 ± 4.2 mm/5 min; p < 0.001), while fluorescein staining scores were higher (1.44 ± 0.92 vs 0.47 ± 0.62; p = 0.001). Tear film dysfunction was more frequent among diabetic patients than controls (77.8% vs 29.4%; p = 0.004).

Conclusion: Patients with diabetes mellitus had significantly greater tear film dysfunction and reduced corneal nerve sensitivity compared with non-diabetic individuals.