Effects of Intense Pulsed Light on Tear Film TGF-[beta] and Microbiome in Ocular Rosacea with Dry Eye

Purpose: To assess tear film transforming growth factor-beta (TGF-[beta]) and ocular microbiome changes after intense pulsed light with meibomian gland expression (IPL-MGX) vs only MGX in treating ocular rosacea with dry eye symptoms. Methods: Twenty patients were randomly assigned to IPL-MGX or MGX. Patients were examined, treated, and administered the ocular surface disease index (OSDI) survey every 4-6 weeks for four total treatments. Tear film and conjunctival samples were collected at first and last visits, and analyzed for TGF-[beta] concentration and 16s rRNA amplicon sequencing of ocular microbiome. Wilcoxon Rank Sum and Sign-Rank were used to examine changes from baseline. Results: OSDI revealed significantly greater improvement in symptoms after IPL-MGX (p=0.030) compared to MGX. There was no significant difference in mean TGF-[beta]1, 2, or 3 concentration after IPL-MGX (p=0.385, 0.709, 0.948, respectively). Quantities of Clostridium, Klebsiella, Brevibacterium, Lactobacillus, Neisseria, Streptococcus, Corynebacterium, Butyricicoccus, and Actinomyces were significantly reduced from baseline in both groups but without a significant difference between the two treatment groups. Conclusion: IPL-MGX improved dry eye symptoms more than MGX alone. IPL treatment offered no additional benefit to MGX in decreasing virulent bacteria present on the ocular surface and did not influence TGF-[beta] levels in tears. Prospective studies on IPL-MGX with larger sample sizes are needed to further investigate cytokines and IPL in patients suffering from ocular rosacea with dry eye symptoms. ClinicalTrials.gov Identifier: NCT03194698. Keywords: intense pulsed light, IPL, meibomian gland expression, dry eye disease, meibomian gland disorder, ocular rosacea, transforming growth factor-beta, TGF-[beta], tear cytokines, ocular microbiome, OSDI; ocular surface disease index