Evaluation of ocular surface disease in elderly patients with glaucoma: expression of matrix metalloproteinase‐9 in tears

Abstract

PurposeTo evaluate the symptoms and signs of ocular surface disease (OSD) and tear film matrix metalloproteinase‐9 (MMP‐9) overexpression using point‐of‐care testing (InflammaDry test) in patients with primary open‐angle glaucoma (POAG).MethodsThis prospective, case‐control study included sixty‐seven patients diagnosed with POAG and forty‐seven healthy control subjects. The OSD assessment included Schirmer‐I test, the Oxford corneal stain scale, tear breakup time (TBUT), and the 5‐Item Dry Eye Questionnaire (DEQ‐5). Measurement of extracellular MMP‐9 was performed using the InflammaDry test. The OSD parameters and MMP‐9 expression levels were compared between the POAG and control groups. Additional subgroup analysis in the POAG group was performed according to the number of topical glaucoma medications (1, 2, or 3 bottles).ResultsThere were significant differences between the control and POAG groups for all OSD parameters. MMP‐9 overexpression was observed in 71.6% of POAG group, whereas only 31.9% of control group showed MMP‐9 overexpression. The subgroup analysis revealed that DEQ‐5, Oxford stain score, Schirmer‐I, and MMP‐9 overexpression demonstrated no significant difference among the three groups. Abnormal TBUT (≤ 5sec) was observed in 37.5%, 59.1%, and 76.2% of each subgroup according to number of medications (1, 2, and 3), and strong MMP‐9 overexpression was detected in 25.0%, 40.9%, and 61.9%, respectively (p = 0.032, p = 0.043).ConclusionsThe use of preservative‐containing medications may affect the ocular surface in patients with POAG. Graded measurement of tear‐film MMP‐9 could provide more information on OSD and might be a more useful marker for inflammation than conventional results obtained using an MMP‐9 kit.