AbstractPurposeWe sought to evaluate the expression of matrix metalloproteinase-9 (MMP-9) in dry eyes treated with 0.05% cyclosporin A and 3.0% diquafosol tetrasodium.MethodsOne-hundred ninety-five eyes of 195 patients with dry eye were divided into three groups as follows: group 1, cyclosporin group (n= 69); group 2, diquafosol group (n= 59); and group 3, artificial tears eyes (n= 67). All eyes were treated and followed up for three months. Schirmer I Test, corneal staining, tear-film break-up time (TBUT), and tear-film MMP-9 content were measured at three months and compared between groups. The expression of MMP-9 was confirmed using a point-of-care test device (InflammaDry®; RPS Diagnostics, Sarasota, FL, USA) and graded as zero to four points.ResultsAt the third month, MMP-9 expression was lower in group 1 as compared with in groups 2 and 3 (p =0.020 and 0.006, respectively). The mean MMP-9 grade according to point-of-care testing was also lower in group 1 than in groups 2 or 3 (p =0.002 and 0.038, respectively). MMP-9 showed a correlation with corneal staining in both groups 1 and 2 (allp< 0.001) and with Schirmer I Test and TBUT in group 1 (p= 0.018 and 0.015, respectively).ConclusionsMMP-9 expression and grade were lower after treatment with cyclosporin than after treatment with diquafosol in the dry eye disease. Anti-inflammatory treatment can decrease ocular MMP-9 levels in dry eye disease.