Abstract
Purpose :
Ocular alkali burns trigger inflammatory response, neovascularization and scar, and constitute a leading cause of permanent visual impairment. Currently, there are no available treatments for ocular alkali burns. Melatonin has remarkable anti-oxidant, anti-inflammatory and immunomodulatory properties. Our aim was analysing the effect of melatonin in the corneal damage and inflammation after alkali burns.
Methods :
In this study, BALB/c mice were used to perform the ocular alkali burn model, and subconjunctival inject melatonin daily were practiced after the injury. Then clinical evaluations were performed by slit lamp biomicroscopy. AS-OCT and hematoxylin-eosin staining was used to detected the corneal thickness and pathological alterations. Moreover, inflammatory cell infiltration and neovascularization were determined by corneal whole-mount immunostaining and immunohistochemistry. To estimate the cellular apoptosis, cryosections were stained by the TUNEL method. Protein concentration was determined by western blotting. Additionally, the levels of cytokines related to inflammation were detected using qRT-PCR.
Results :
We found that subconjunctival injection of melatonin attenuated corneal thickness and neovascularization, accompanied with promoting opacity. Histological results revealed that melatonin ameliorated corneal morphology. Melatonin significantly reduced macrophage and neutrophils recruitment, and inflammatory factors release following alkali injury. TUNEL assay revealed that melatonin protected ocular cells against apoptosis, as inferred from a higher number of viable cells and a lower number of TUNEL+ cells. Furthermore, the signaling pathways of TNF-α/IKK/NF-κB were restricted with melatonin treatment.
Conclusions :
These findings suggest that melatonin ameliorated ocular alkali burn-induced inflammation and neovascularization by inhibiting TNF-α/IKK/NF-κB signaling pathways. The role of melatonin as an adjuvant treatment in patients with ocular alkali burn deserves further clinical studies.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.