Efficacy and safety of topical doxycycline reduce MMP-9 expression towards populations with corneal alkali burn

Introduction: Alkali ocular injury causes disintegration of the cornea by changes in pH level, proteolysis, ulceration, and impairment of collagen synthesis. Doxycycline was found to alter the remodeling of human conjunctival and skin fibroblasts. Doxycycline also reduced collagenolytic degradation of the cornea due to chemical injury by inhibiting matrix metalloprotease (MMP) activity, including in other non-infectious corneal ulcers. This study aimed to determine the efficacy and safety of topical doxycycline to manage corneal alkali burns. A systematic review was conducted in adherence to the PRISMA statement. Method: Searching was conducted in five databases and inclusion and exclusion criteria were applied afterwards. Three studies were found, considered good, and eligible for inclusion after appraisal using SYRCLE critical appraisal tools for animal studies. All studies used mice models. Result: We found a significant reduction of IL-1β, IL-6, MMP-8, MMP-9, α-SMA, and NF-κB by doxycycline usage starting from two days of usage. In addition, mRNA angiogenic factors and corneal neovascularization decreased after doxycycline usage. This contributes to better corneal repair after trauma, reflected by better corneal healing and opacity scores after doxycycline usage compared to other groups. Conclusion: Doxycycline management improved outcomes for patients with corneal alkali burn by decreasing inflammatory cytokine and promoting tissue repair.