Inhibition of corneal neovascularization by a peroxisome proliferator-activated receptor-γ ligand

Purpose. To determine the efficacy of the peroxisome proliferator-activated receptor γ agonist, pioglitazone, in inhibiting corneal neovascularization. Methods. Twenty-six adult male Sprague-Dawley rats were randomly divided into three groups. Each group received intrastromal polymer micropellets containing one of the following: Group 1, no active ingredient (n=10); Group 2, vascular endothelial growth factor (VEGF) (n=7); Group 3, VEGF and pioglitazone (n=9). Neovascularization was evaluated 7 days after pellet implantation. After systemic India ink injection, digital photographs of the eyes were taken. The area and density of neovascularization were measured using imaging software. Results. Mean area of neovascularization was 0.43±0.18 mm² for Group 1, 2.87±0.48 mm² for Group 2 and 2.10±0.22 mm² for Group 3. Statistical analysis showed significant differences between Groups 1 and 2 and Groups 1 and 3. There was no significant difference between Groups 2 and 3. Mean density of neovascularization was 2.16±0.66 for Group 1, 27.14±2.93 for Group 2 and 12.02±2.24 for Group 3. All comparisons between groups were statistically significant (P<0.01). Conclusions. Pioglitazone is effective in decreasing the density of angiogenesis in a VEGF-induced neovascular rat cornea model. There is possibility of even greater effect with higher doses of the drug. Pioglitazone is a promising drug for the treatment of ocular neovascularization.