Optimal methodology for lid wiper epitheliopathy identification

Purpose: Lid wiper epitheliopathy (LWE) is a clinical sign that has been associated with dry eye disease. This study used a semi-automated method to identify the effect of drop instillation and post-dye viewing time on the absorption of lissamine green (LG) and sodium fluorescein (NaFl) on the upper eyelid in order to ascertain the optimal identification for LWE assessment. Methods: In 37 participants with LWE, 1-drop of 1% LG (10 μL) was applied to the superior bulbar conjunctiva in the right eye, and photographs of the lid margin were taken 1, 3, and 5 min after instillation. Measurements were repeated in the same eye following instillations of 2-drops of 1% LG. The same procedures were followed for application of 2% NaFl (2 μL) to the left eye. Staining area was determined using software to detect and measure dye-stained images. Analysis used a linear mixed model with fixed effects of time, number of drops and their interaction. Results: For LG, multivariate analysis showed that time of drop instillation was significant (p = 0.0091) as was the area of staining in the 2-drop versus 1-drop condition (p < 0.0001). For NaFl, there was a significant effect of time (p < 0.0001), drops (p < 0.0001), and a time/drops interaction (p < 0.0134), suggesting that both time and number of drops are important. Conclusion: A single drop of dye is insufficient to reveal the full extent of LWE staining. A 2-drop instillation is recommended and observation is recommended between 1 and 5 min (LG) and between 3 and 5 min (NaFl).