Matrix Metalloproteinase-9 Point-of-Care Immunoassay after Dacryocystorhinostomy in Patients with Nasolacrimal Duct Obstruction

Abstract

PURPOSE To compare matrix metalloproteinase-9 (MMP-9) point-of-care immunoassay (InflammaDry) results before and after dacryocystorhinostomy (DCR) in patients with nasolacrimal duct (NLD) obstruction. METHODS Thirty-eight eyes of 38 patients who were diagnosed with unilateral NLD obstruction were treated with endoscopic DCR. Treatment response was monitored using InflammaDry test, tear meniscus height was measured by slit-lamp microscopy, and tear meniscus parameters (tear meniscus height, depth, and area) were measured by anterior segment optical coherence tomography at baseline and at 1 month after surgery. RESULTS In 38 patients, the positive percentage of MMP-9 in diseased eyes was 100% (38 eyes), much higher than that in healthy fellow eyes (13.2%, 5 of 38 eyes) at baseline (p<0.001, chi (2) test test). MMP-9 levels before and after surgery were significantly different (p<0.001), and MMP-9-positive eyes showed a significant improvement in MMP-9 grade after surgery (p< 0.0001; generalized McNemar test). Furthermore, other clinical parameters (tear meniscus area, tear meniscus height, and tear meniscus depth) showed a general improvement. CONCLUSION The concentration of MMP-9 increased in the tears of patients' eyes with NLD obstruction compared to the contralateral healthy eyes. These abnormal findings showed a significant improvement after DCR. The improvement of postoperative MMP-9 expression might be because of the improvement of tear retention.