Matrix Metalloproteinase-1 and Matrix Metalloproteinase-9 in the Aqueous Humor of Diabetic Macular Edema Patients

PURPOSE: To assess the concentrations of matrix metalloproteinase (MMP)-1 and MMP-9 in the aqueous humor of diabetic macular edema (DME) patients. METHOD: The concentrations of MMP-1 and MMP-9 in the aqueous humors of 15 cataract patients and 25 DME patients were compared. DME patients were analyzed according to the diabetic retinopathy (DR) stage, diabetes mellitus (DM) duration, pan-retinal photocoagulation (PRP) treatment, recurrence within 3 months, HbA1C (glycated hemoglobin) level, and axial length. RESULTS: The concentrations of MMP-1 and MMP-9 of the DME groups were higher than those of the control group (p = 0.005 and p = 0.002, respectively). There was a significant difference in MMP-1 concentration between the mild non-proliferative diabetic retinopathy (NPDR) group and the proliferative diabetic retinopathy (PDR) group (p = 0.012). MMP-1 concentrations were elevated in PRP-treated patients (p = 0.005). There was a significant difference in MMP-9 concentrations between the mild NPDR group and the PDR group (p < 0.001), and between the moderate and severe NPDR group and the PDR group (p < 0.001). The MMP-9 concentrations in PRP treated patients, DM patients with diabetes ≥ 10 years and recurrent DME within 3months were elevated (p = 0.023, p = 0.011, and p = 0.027, respectively). In correlation analyses, the MMP-1 level showed a significant correlation with age (r = -0.48, p = 0.01,), and the MMP-9 level showed significant correlations with axial length (r = -0.59, p < 0.01) and DM duration (r = 049, p = 0.01). CONCLUSIONS: Concentrations of MMP-1 and MMP-9 were higher in the DME groups than in the control group. MMP-9 concentrations also differed depending on DR staging, DM duration, PRP treatment, and degree of axial myopia. MMP-9 may be more important than MMP-1 in the induction of DM complications in eyes.