Objectives: Topical lubricants are the fundamental treatment for dry eye disease (DED). However, the molecular mechanisms underlying their efficacy remain unknown. Here, the protective effects of Thealoz® Duo with 3% trehalose and 0.15% hyaluronic acid are investigated in DED patients by a longitudinal clinical study and subsequent elucidation of the tear proteome and cell signaling changes. Methods: Participants were classified as moderate to severe DED (DRY, n = 35) and healthy (CTRL, n = 23) groups. Specific DED subgroups comprising evaporative (DRYlip) and aqueous-deficient with DRYlip (DRYaqlip) were also classified. Only DED patients received Thealoz® Duo. All participants were clinically examined before (day 0, T1) and after the application of Thealoz® Duo at day 28 (T2) and day 56 (T3). Next, 174 individual tear samples from all groups at three time-points were subjected to proteomics analysis. Results: Clinically, Thealoz® Duo significantly improved the ocular surface disease index at T2 vs. T1 (DRY, p = 1.4 × 10−2; DRYlip, p = 9.2 × 10−3) and T3 vs. T1 (DRY, p = 2.1 × 10−5; DRYlip, p = 1.2 × 10−4), and the tear break-up time at T3 vs. T1 (DRY, p = 3.8 × 10−2; DRYlip, p = 1.4 × 10−2). Thealoz® Duo significantly ameliorated expression of inflammatory response proteins (p < 0.05) at T3, which was observed at T1 (DRY, p = 3.4 × 10−4; DRYlip, p = 7.1 × 10−3; DRYaqlip, p = 2.7 × 10−8). Protein S100-A8 (S100A8), Alpha-1-antitrypsin (SERPINA1), Annexin A1 (ANXA1), and Apolipoprotein A-I (APOA1) were found to be significantly reduced in all the DED subgroups. The application of Thealoz® Duo showed the therapeutic characteristic of the anti-inflammatory mechanism by promoting the expression of (Metalloproteinase inhibitor 1) TIMP1 in all the DED subgroups. Conclusions: Thealoz® Duo substantially improved the DED symptoms and restored the functionality of the tear lipid layer to near normal in DRYlip and DRY patients by ameliorating inflammation. Notably, this study unravels the novel mechanistic alterations underpinning the healing effects of Thealoz® Duo in DED subgroups in a time-dependent manner, which supports the improvement in corresponding clinical attributes.
Perumal et al. (Tue,) studied this question.