Tear MMP-9 levels as a marker of ocular surface inflammation in conjunctivochalasis

Abstract

Purpose: To evaluate the efficacy of surgical treatment for conjunctivochalasis by monitoring matrix metalloproteinase (MMP)-9 levels in the tears of patients with conjunctivochalasis before and after surgery and their correlation with clinical signs and symptoms.

Methods: Twelve eyes of patients with symptomatic conjunctivochalasis were included in this study as well as five eyes of healthy volunteers. Ocular surface inflammation was measured in terms of the concentration of pro-MMP-9 in tears, by enzyme-linked immunosorbent assay and zymography. Tear analysis was performed before and 1 month after surgery. The surgical technique consisted of the excision of redundant tissue and the use of organic glue for wound closure.

Results: The concentration of pro-MMP-9 was significantly higher in the conjunctivochalasis eyes than in the healthy controls (223.4 ± 74.53 ng/mL vs. 20.32 ± 5.21 ng/mL; P < 0.001). Tear pro-MMP-9 levels decreased significantly after conjunctival resection in patients with conjunctivochalasis without dry eye compared with patients with conjunctivochalasis and dry eye associated. Zymographic analysis indicated that MMP-9 is present in its active form only in conjunctivochalasis tears. After a follow-up of 4.9 ± 1.3 weeks, all operated eyes were found to have recovered a smooth and stable conjunctival surface, epithelial defects had improved, and epiphora had been resolved in 89% of cases.

Conclusions: Our results indicate that inflammation is likely to play a relevant role in the pathogenesis of conjunctivochalasis. Appropriate surgery decreases inflammatory activity, leading to symptom improvement, and tear analysis may facilitate the treatment of the ocular surface.

Keywords: MMP-9; conjunctiva; conjunctivochalasis; inflammation; tear.