Ocular Surface Quantitative Microbiota of Mild and Moderate Meibomian Gland Dysfunction Before and After Intense Pulsed Light Therapy

Abstract

Background Intense Pulsed Light (IPL) is a promising treatment for meibomian gland dysfunction (MGD). While the ocular surface microbiome is associated with various eye conditions including MGD, evidence of the effect of IPL on the ocular surface microbiome has been lacking. Methods Patients with mild and moderate MGD underwent IPL treatment and standard eyelid hygiene every two weeks for a total of four sessions. Eyelid scraping and eyelash samples before and after IPL therapy were evaluated by microbiome analysis based on 16S ribonucleic acid gene sequencing as well as dry eye speed score, lid margin abnormalities, corneal and conjunctival fluorescein staining, meibum grading score, and meibography. Results Before IPL, the relative abundance of Propionibacterium acnes (12.79%) in mild MGD was the highest, followed by Faecalibacterium prausnitzii (6.35%) and Family Lachnospiraceae (4.74%). In moderate MGD, the relative abundance of Bifidobacterium unclassified (8.46%) was the highest, followed by Rhodoplane unclassified (6.65%) and A. Ellin 6513 (4.95%). After IPL treatment, the relative abundance of Bifidobacterium adolescentis and Mitsuokella multacida in mild MGD were significantly reduced, from 0.88 % to 0.0044% and from 0.2 to 0.0065%, respectively. The relative abundance of Family Bradyrhizobiaceae, Order Rhizobiale, Order Solibacterales, and Bacillus unclassified in moderate MGD were significantly reduced whereas the relative abundance of Bifidobacterium unclassified has increased five times (8.46% to 45%). In mild MGD, the abundance of Phylum Proteobacterium after IPL was the most positively correlated with clinical parameters (correlation coefficient 0.25 to 0.36) and the abundance of Order RB41 after IPL were significantly negatively correlated with clinical parameters (correlation coefficient -0.7 to -0.84). In moderate MGD, the abundance of several microbiota after IPL was significantly positively correlated with clinical parameters whereas Bifidobacterium, Family Bifidobacteriaceae, Class Actinobacteria were significantly negatively correlated with clinical parameters. Conclusion The relative abundance of microbiota in mild and moderate MGD after IPL is associated with changes in clinical parameters.