Abstract
Purpose :
Alkali burns, which penetrate the cornea to a significant degree, typically cause severe injury to corneal tissues. Alkali burns can trigger inflammatory and immune-mediated pathways that upregulate the expression of several angiogenesis factors. We investigated the effect of a catechin on experimental corneal alkaline burns in rabbits.
Methods :
Corneal neovascularization (NV) was induced by applying an 8-mm filter paper soaked in 1 N NaOH to the right central corneas of rabbits for one minute. Seven days later, the rabbits were randomly divided into three groups: the alkaline burn group (n=5, normal saline instilled four times per day), and the 10 mg/mL catechin group (n=5, 10 mg/mL catechin instilled four times per day). The left eyes were used as controls. On the 10th day after eyedrops, clinical outcomes and histological changes of corneal structure were analyzed. Also we investigated the effects of catechin on the expression of corneal NV markers, identifying the mechanism of catechin suppression of corneal NV.
Results :
The alkaline burn produced significant NV (2.4±0.5) and increased corneal thickness (961.4±17.36 μm). On day 10 after 10 mg/mL chatechin treatment, NV (1.4±0.5) and thickness (544.8±22.3 μm) of the cornea were markedly decreased in the catechin group (p<0.05). In addition, the catechin improved the healing of the cornea following alkaline burn, disrupting the corneal epithelial proliferation and reducing the fibrotic changes of the stroma. The hallmarks of angiogesis and inflammation including VEGF, CD31, MMP9, macrophage, TNFα, ICAM-1, VCAM-1 and IL-1β were significantly induced in the cornea by the alkaline burn, and these expression were also suppressed by catechin. Furthermore, we demonstrated that catechin suppressed alkali burn-induced corneal pathophysiological changes by the NF-κB inacivation via blocking the Akt signaling pathway.
Conclusions :
In this study, we demonstrated that catechin was markedly effective in healing alkali-burned corneas by modulating the corneal opacity, NV, fibrosis and inflammation via blocking the NF-κB. Therefore, catechin is possible promising material for treatment of ocular surface disease related inflammation.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.