OCT-Based Analysis of Post-Lens Tear Film Stability in Silicone Hydrogel Contact Lenses.

Purpose: This study aimed to evaluate the stability of post-lens tear film (PoLTF) and pre-lens tear film (PLTF) in three different silicone hydrogel contact lenses (CLs) using optical coherence tomography (OCT) and multifunctional topography. Materials and methods: A total of 158 participants were assigned to three groups based on the CL material: Group 1 (Lotrafilcon B), Group 2 (Senofilcon A), and Group 3 (Samfilcon A). Non-invasive average break-up time (NIAvgBUT) of the PLTF was measured after a few hours of lens wear during the first visit and after 2-4 weeks of continued use in the second visit. PoLTF thickness was assessed in five corneal quadrants using OCT, measured both indirectly and manually. Results: The mean participant age was 21.9±5.0 years. The NIAvgBUT of the PLTF was significantly higher at the first visit than at the second visit (9.5±2.9 s vs. 8.3±2.1 s, p=0.0001). Similarly, the PoLTF thickness in the central corneal area showed a significant reduction after 2-4 weeks of lens wear (p=0.001). Discussion: Our results emphasize the clinical importance of monitoring both pre-lens and post-lens tear film parameters during routine follow-up visits. By integrating OCT-based measurements into daily practice, clinicians may identify early tear film instability and prevent contact lens intolerance. This is particularly relevant for younger patients who are at risk of long-term ocular surface changes due to extended lens wear. Conclusion: A significant decrease in PLTF stability (NIAvgBUT) and PoLTF thickness in the central corneal area was observed after 2-4 weeks of CL use. These findings suggest that prolonged CL wear affects tear film stability and surface wettability, highlighting the importance of monitoring these changes over time.