Purpose: We evaluate a matrix metalloproteinase-9 (MMP-9) point-of-care immunoassay (InflammaDry) as a prognostic tool for topical cyclosporine treatment.
Methods: A total of 20 healthy subjects and 40 patients meeting >3 dry eye disease (DED) criteria (ocular surface disease index [OSDI] score ≥ 12, tear film breakup time [TBUT] ≤10 seconds, Schirmer I test result ≤10 mm/5 minutes, corneal staining ≥1) were included. DED patients were treated with topical cyclosporine ophthalmic emulsion 0.05% twice daily for 1 month. The InflammaDry test was used to grade MMP-9 levels in the tear film. Treatment response was monitored using the OSDI score, TBUT, and Schirmer, corneal staining, and InflammaDry tests.
Results: Of the eyes, 18 (22.5%) were negative, 29 (36.3%) trace-positive, 16 (20.0%) weak-positive, 11 (13.8%) positive, and six (7.5%) strong-positive for MMP-9 at baseline. MMP-9 levels correlated with OSDI (P = 0.049), TBUT (P = 0.001), corneal staining (P = 0.002), and Schirmer test (P = 0.027) results. MMP-9-positive patients displayed decreased post-treatment MMP-9 levels (P = 0.001) and corneal staining score (P < 0.001), improved OSDI score (P < 0.001), and increased TBUT (P < 0.001) and Schirmer (P = 0.009) test values.
Conclusions: Semiquantitative MMP-9 grading correlated well with DED symptoms and signs, and could be used to predict patient status and monitor treatment response. MMP-9-positive patients responded more favorably to topical cyclosporine than did MMP-9-negative patients. Thus, the InflammaDry test may inform decisions regarding initiating topical cyclosporine treatment.
Translational relevance: Semiquantitative MMP-9 could be used to predict patient status and monitor treatment response.
Keywords: dry eye disease; matrix metalloproteinase 9; semiquantitative method; topical cyclosporine.