[Study on the rat models of corneal neovascularization induced by alkali burn]

The aim of this series of experiments was to test appropriate rat models of corneal neovascularization (CNV) induced by alkali injury.

All animals (n=48) were randomly assigned to four groups, each consisting of twelve eyes. Alkali injury was induced on day 0 by application of iN NaOH to right eyes of S-D rats for 15 30 AG and 6Os respectively. Biomicroscopic features including corneal neovascularization, corneal ulceration and hyphema were observed for 28 days.

Corneal neovascularization began to invade pericornea on day 3 and flourished on day 7, then reached its developmental peak on day 14, and regressed gradually after day 14. The induced rate of CNV for groups 15s, 30s, 40, 60s, were 16.7%, 75%, 100%, 100% respectively, the induced rate of corneal neovascularization in all groups increased with time prolonging. CNV distributed sparsely in group iSs and its length was more shorter. CNV in group 30s reached the margin of burn area and distributed sparsely. There had uniform growth of CNV in group 40s and the hyphema was not more excessive than that of group 60s which was difficult to observe CNV. Significant difference (P < 0.05) was found between Group 30s and 40s in length and area of CNV respectively. The rate of hyphema was 16.7%, 83.3% respectively between Group 40s and 60s and significant difference (P < 0.05) was also found. The rate of corneal ulceration and perforation was 50% and 33.3% respectively in Group 60s.

The appropriate induced time for S-D rat models of corneal neovascularization by using filter paper which diameter is 3 mm and inmerged solution of 1 mol/L sodium hydroxide was 40s. It's an ideal animal model for CNV induced by chemical injuries.