Comparison of biomicroscopic fluorescein tear breakup time with noninvasive tear breakup time in diabetic patients with dry eyes

Abstract Objectives: This study aimed to compare biomicroscopic fluorescein tear breakup time (TBUT) with noninvasive tear breakup time (NI-TBUT) using Sirius topography in diabetic patients with dry eyes. We evaluated the correlation between Ocular Surface Disease Index (OSDI) scores, tear film stability, and diabetes duration to assess the effectiveness of NI-TBUT as a diagnostic tool. Materials and Methods: A comparative cross-sectional observational study was conducted on 100 patients (200 eyes) diagnosed with Type II diabetes mellitus and dry eye symptoms (OSDI >23). NI-TBUT was measured using Sirius topography, followed by fluorescein TBUT assessment. Statistical analyses included paired comparisons, correlation with OSDI scores, and the effect of diabetes duration on tear film stability. Results: The mean TBUT was significantly lower than NI-TBUT in both eyes ( P < 0.000). NI-TBUT values were consistently longer, indicating better tear film stability. A significant positive correlation was observed between diabetes duration and OSDI scores ( r = 0.3864, P < 0.00), as well as between hemoglobin A1c levels and dry eye severity. Discussion and Conclusion: NI-TBUT provides a more stable and reliable assessment of tear film integrity than fluorescein TBUT, making it a valuable noninvasive diagnostic tool. Its integration into routine diabetic eye examinations can enhance early detection and management of dry eye syndrome in diabetic patients.