Expression of Matrix Metalloproteinase-8 (MMP-8) and Tissue Inhibitors of Metalloproteinase-1 (TIMP-1) after cryotherapy in Aspergillus flavus keratitis at Dr. Soetomo General Academic Hospital, Surabaya, Indonesia

Background: Fungal keratitis is one of the most difficult forms of microbial keratitis to treat successfully. Aspergillus flavus is a type of filamentous fungus that often causes suppurative keratitis. Complications that often arise from fungal keratitis are corneal perforation and blindness due to scar tissue formation. Methods: Aspergillus flavus was injected into the corneas of 28 Sprague Dawley rats intrastromal and divided into 4 groups, with each group consisting of 7 rats, fungal injection into the cornea as a fungal injection without therapy, natamycin therapy, cryotherapy, and combination therapy. Therapy was given five days after the fungal injection into the cornea and the formation of keratitis and corneal central thinning. After four days of therapy, the eyes were enucleated to determine the effect of cryotherapy on MMP-8 and TIMP-1 expression in the cornea with an immunohistochemistry (IHC) staining examination. The differences in MMP-8 and TIMP-1 expressions between groups were analyzed using the Kruskal Wallis test and Mann-Whitney post hoc test with a significant p<0.05. Data were analyzed using SPSS version 26 for Windows. Results: The highest MMP-8 expression was found in the natamycin therapy group (3), and the lowest was in the negative control group and cryotherapy (1). There were no significant differences in MMP-8 expression in the 4 groups (p=0.482). The highest TIMP-1 expression was found in the negative control group (8) and the lowest was in the cryotherapy group (2). There were significant differences in TIMP-1 expression in the 4 groups (p=0.002). Conclusion: It was found that the expression of TIMP-1 and MMP-8, although the last one was not significant, were lower in the cryotherapy group than in the non-cryotherapy group.