Effects of lid debris debridement combined with meibomian gland expression on the ocular surface MMP-9 levels and clinical outcomes in moderate and severe meibomian gland dysfunction

BACKGROUND: To evaluate the effects of lid debris debridement and meibomian gland expression (MGX) on extracellular matrix metalloproteinase-9 (MMP-9) levels and clinical outcomes of moderate and severe MGD. METHODS: In this retrospective case series study, a total 48 eyes of 24 patients with moderate and severe MGD underwent one session of lid debris debridement using the BlephEx combined with MGX. We evaluated the tear film break-up time (TBUT), corneal and conjunctival fluorescein staining scores, Schirmer 1 test, biomicroscopic examination of lid margins and meibomian gland (MG), ocular surface disease index (OSDI) questionnaire score, and extracellular MMP-9 levels using a point-of-care MMP-9 immunoassay device before and 4 weeks after lid debris debridement and MGX. Linear mixed model and generalized estimating equations model were used to evaluate possible differences. RESULTS: There were significant improvements in the TBUT (P = 0.002), SICCA and Oxford staining scores (all P < 0.001), lid margin telangiectasia (P < 0.001 for upper and lower eyelids), lid thickness (P < 0.001 for upper and lower eyelids), MG orifice plugging (P < 0.001 for upper and lower eyelids), meibum color (P = 0.026 for upper eyelid, P < 0.001 for lower eyelid), meibum consistency (P < 0.001 for upper and lower eyelids), meibum grade (P < 0.001), MGD stage (P < 0.001), and OSDI score (P = 0.002). MMP-9 immunoassay positivity rate significantly decreased from 83.3 to 50.0% 4 weeks after treatment (P = 0.014). CONCLUSIONS: In patients with moderate to severe MGD, lid debris debridement using the BlephEx combined with MGX improved clinical findings, subjective symptoms, meibomian gland function, along with ocular surface MMP-9 level. We hereby suggest lid debris debridement using BlephEx combined with MGX as an effective clinical strategy for treatment of moderate to severe MGD.