Short-term Changes in the Tear Matrix Metalloproteinase 9 Level and Ocular Surface Discomfort after Cataract Surgery

Purpose: We explored changes in the various clinical parameters of dry eye disease (DED), including the tear matrix metalloproteinase 9 (MMP-9) level, soon after cataract surgery. We sought correlations between such changes and ocular surface discomfort. Methods: In 106 patients (106 eyes) who underwent cataract surgery, we evaluated meibomian gland dysfunction, tear secretion, corneal sensitivity, tear break-up time, corneal erosion status, the Sjogren's International Collaborative Clinical Alliance (SICCA) ocular staining score, tear osmolarity, the tear MMP-9 level, and the ocular surface disease index (OSDI) before, and 1 week and 1 month after surgery. All eyes were instilled with topical moxifloxacin, a steroid, and a non-steroidal anti-inflammatory drug daily for 1 month postoperatively. The 1-month delta OSDI scores correlated with the 1-month delta DED parameters. We compared the latter parameters between patients in whom the MMP-9 level decreased (MMP-9-decreased group) at 1 month with those in whom it did not (MMP-9-not decreased group). Results: Overall, 89.5% of total patients exhibited preoperative DED. The tear MMP-9 level fell at 1 month postoperatively, tear secretion (evaluated using the Schirmer I test) decreased at 1 week, and the OSDI scores fell at both 1 week and 1 month. We found no significant correlation between the 1-month delta OSDI scores and the 1-month delta DED parameters. The 1-month OSDI score fell to a significantly greater extent in the MMP-9-decreased group. Conclusions: Routine, local anti-inflammatory treatment after cataract surgery may briefly reduce the tear MMP-9 level and ocular surface discomfort.