Objective  Corneal alkali burn is a common cause of corneal neovascularization ( CNV ). Recent research has shown netrin-1 to promote neovascularization. Present study aims to investigate the expression of netrin-1 in cornea after alkali burn and explore its role in CNV.
Methods  CNV in Sprague-Dawley rats was induced by putting a filter paper ( immersed 1mol/L NaOH solution) on the central cornea for 40 seconds. The eyes were treated using the filter paper with normal saline solution as normal control group. CNV was observed by the slim-lamp biomicroscopy every day, and area of new vessels was calculated. The animals were sacrificed and corneal samples were obtained in day 3, 14, 28 after cautery. Western blot analyses were used to determine the expression of netrin-1 protein in cornea.
Results  CNV grew at the second day and reached the largest area in day 14 after cautery. The expression of netrin-1 was low in normal group but increased after alkali burn with the peak value in day 14 , showing a significantly difference with control group (p < 0.05). The netrin-1 expression level declined in day 28. The expression of netrin-1 showed the same tendency with the formation of CNV. The dynamic expressions of netrin-1 and area of CNV showed a significant positive correlation.
Conclusion  Netrin-1 level increases in rat cornea after alkali burn and may play a role in CNV development.