Layer-by-layer tear film measurement in patients with dry eye and meibomian gland dysfunction.

AIM: To evaluate parameters measured using the tear film imager (TFI) prototype, a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers. METHODS: In this cross-sectional study, patients with dry eye, meibomian gland dysfunction (MGD), and non-dry eye/MGD from February 2020 to January 2021 were analyzed. Quantified TFI outputs included lipid layer thickness (LLT), mucoaqueous layer thickness (MALT), MALT rate of change (MALTR), and lipid breakup time. Two other interferometry devices, LipiView2 and DR-1α, were used for comparison. TFI outputs and other clinical parameters were analyzed using correlation coefficients. Each patient underwent one or several study visits. Baseline values of three device outputs, other clinical parameters, and their changes were examined. RESULTS: This study involved 28 patients (8 patients with dry eyes, 13 with MGD, and 7 with non-dry eye/MGD). Baseline TFI, LipiView2, and DR-1α values were associated with various clinical parameters. The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid (r=-0.42). Several TFI values have correlated better than LipiView2 and DR-1α, particularly with questionnaire scores. MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness (SPEED) and dry eye-related quality of life score (DEQS) scores (r=0.59, 0.43), respectively. CONCLUSION: TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters, which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.