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

## TL;DR

This study uses OCT to show that wearing silicone hydrogel contact lenses for weeks reduces tear film stability and thickness, which could lead to discomfort and eye issues.

## Contribution

The study introduces OCT-based monitoring of post-lens tear film stability in silicone hydrogel contact lenses.

## Key findings

- PLTF stability decreased significantly after 2-4 weeks of contact lens wear.
- PoLTF thickness in the central cornea reduced significantly after prolonged lens use.
- Monitoring tear film parameters with OCT can help prevent contact lens intolerance.

## Abstract

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.

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.

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).

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.

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.