Changes in the expression of matrix metalloproteinase-9 after intense pulsed light therapy combined with meibomian gland expression in moderate and severe meibomian gland dysfunction

Abstract

Purpose: To evaluate the combined effect of intense pulsed light (IPL) therapy and meibomian gland expression on extracellular matrix metalloproteinase-9 (MMP-9) levels and clinical outcomes of moderate and severe meibomian gland dysfunction (MGD) treatment.

Methods: This retrospective study was conducted on 45 eyes of 23 patients with moderate and severe MGD. Each eye underwent three IPL sessions and meibomian gland expression at 2-week intervals. In this study the evaluated parameters included tear film break-up time (TBUT), corneal and conjunctival fluorescein staining scores, biomicroscopic examination of lid margins and meibomian glands, ocular surface disease index (OSDI) questionnaire score, and extracellular MMP-9 levels using the immunoassay device before and two weeks after the last treatment session. Linear mixed model and generalized estimating equations model were used to evaluate possible differences. Results: There were significant improvements in TBUT (P < 0.001), SICCA ocular staining score (P = 0.008), Oxford staining score (P = 0.023), lid margin irregularity (P < 0.001 for upper and lower eyelids), lid thickness (P < 0.001 for upper and lower eyelids), meibomian gland plugging (P = 0.010 and P = 0.012 for upper and lower eyelids), meibum color (P = 0.044 and P < 0.001 for upper and lower eyelids), meibum consistency (P < 0.001 for upper and lower eyelids), MGD grade (P < 0.001), and OSDI questionnaire score (P < 0.001). Incidence of positive results for MMP-9 immunoassay significantly decreased from 84.0% to 56.0% (P = 0.031) after treatment.

Conclusion: In patients with moderate to severe MGD, three sessions of IPL combined with meibomian gland expression improved objective findings, subjective symptoms, meibomian gland function, and MMP-9 immunoassay results. The results support the combination of IPL and meibomian gland expression for treating moderate to severe MGD.