Intensity of lid wiper epitheliopathy staining with alterations of dye amounts and timing of observation

PURPOSE- The purpose of this study was to observe the absorption of lissamine green (LG) on the upper eyelid as a function of time and dosage (one vs two instillations). Two primary aims investigated LG staining intensity to determine: (1) the best time point, post-dye instillation, to view lid wiper epitheliopathy (LWE); (2) whether instillation of one or two drops is best to identify LWE. METHODS- 37 participants with LWE were enrolled in this study. 1% LG (10 μL) was applied to the superior bulbar conjunctiva in the OD. The eyelid was everted before digital photographs were captured. Photographs of the lid margin were taken at 1, 3, and 5 minutes post-LG dosing. Measurements were repeated in the same eye with two instillations of 1% LG (10 μL). Images were analyzed for stain intensity using a software suite (Advanced Concepts in Imaging Software, Saint Contest, FR) that automatically detects and measures dye stained-eye images. The data was analyzed using a linear mixed model with fixed effects of time, number of drops and their interaction. RESULTS- Results showed that both main effects (drop dosing and time) were significant (drop p=0.002; time p<0.001). The analysis indicated that change in minimum intensity did occur over time, and that, overall a difference in minimum intensity exists between the drops conditions. In the 1 drop instillation condition, the increase in intensity of dye absorption was statistically significant between the 1-minute time inspection when compared to the 3-minute and 5-minute inspection times (p=0.017 and p=0.001, respectively). Similarly, for 2 drops of LG, the difference between 1 and 3 minutes (p=0.005) and between 1 and 5 minutes revealed more intense staining with the increased time (p=0.018). CONCLUSION- The time point of visual inspection of LG staining and the amount of LG used should be purposeful when assessing LWE. This research suggests that when LG is used, a 3-minute to 5-minute delay in inspection is preferred over a 1-minute inspection.