Topical and subconjunctival ranibizumab (lucentis) for corneal neovascularization in experimental rat model

To compare the effectiveness of the topical and subconjunctival (SC) ranibizumab treatment in experimental corneal neovascularization (NV) model in rats.

A model of NV was generated by cauterizing right corneas of 30 Sprague-Dawley rats with silver nitrate. The animals were separated into five groups randomly. first group (control group) received topical artificial tear drops two times daily while second and third groups received topical ranibizumab four times daily at concentrations of 5 mg/mL and 10 mg/mL, respectively. Forth and fifth groups were given 0.5 mg/0.05 mL and 1 mg/0.1 mL of SC ranibizumab in the 1st, 3rd and 7th days. The measurements (percentage of NV area and number of vessels) from digital photographs of the corneas were determined and analyzed using analysis software (ImageJ, v1.38). The animals were sacrificed on the 10th day and their corneas were subjected to hemotoxylin-eosin histopathological staining and antisera against CD34 and von-Willebrand factor to evaluate microvascular structures immunohistochemically.

The percentage of the corneal NV area and number of vessels in all treatment groups was found to be significantly lower than the control group. There was no significant difference in relation to the percentage of NV area and number of vessels in the treatment groups. Score of the corneal edema was determined to be significantly less in the groups that undertook treatment. Number of vessels and inflammatory cells were significantly lower in the histological and immunohistochemical sections in the treated groups than in the control group. In all treatment groups, fibroblast intensity was significantly lower than the control group (p = 0.005).

Topical or SC administration of ranibizumab seems to be a promising and effective medication in the treatment of corneal NV. Further research is recommended to assess the potential side effects and effective dose.