Injection of vascular endothelial growth Factor-C following trabeculectomy attenuates inflammation and reduces fibroblast proliferation in rabbit conjunctiva

This study aims to analyze the effects of Vascular Endothelial Growth Factor-C (VEGF-C) subconjunctival injection in attenuating inflammation after trabeculectomy in rabbits. Twelve healthy New Zealand Red Eye rabbits were divided into four treatment groups, each receiving an injection of recombinant Vascular Endothelial Growth Factor-C (VEGF-C) on doses of 1 µg, 3 µg, and 10 µg following trabeculectomy surgery in the right eye. The effects of the VEGF-C injection were measured and compared between treatment groups, including conjunctival Transforming Growth Factor-β (TGF-β) level using ELISA, neutrophil and lymphocyte count using hematoxylin-eosin stain, and α-Smooth Muscle Actin (α-SMA) expression with immunohistochemistry. The mean concentration of TGF- β in control group was 865 ng/L. In the groups treated with VEGF-C 1 µg, 3 µg, and 10 µg TGF- β levels were 544 ng/L, 566 ng/L, and 502 ng/L respectively (p=0.012). The average neutrophil count in the control group was 16 cells compared to 3 cells, 1 cell, and 3 cells in the groups treated with 1 µg, 3 µg, and 10 µg VEGF-C respectively (p=0.037). The mean percentage area of α-SMA expression in control group was 20.53% compared to 14.73%, 16.20%, and 8.80% in groups treated with VEGF-C 1 µg, 3 µg, and 10 µg respectively (p=0.001). In conclusion, VEGF-C injection in subconjunctiva was found to significantly reduce TGF-β level in conjunctiva, reduce infiltration and accumulation of neutrophils around bleb area, and lower proliferation of myofibroblast seen through α-SMA immunohistochemistry. These results suggest that VEGF-C may have beneficial effects in improving trabeculectomy surgery be attenuating inflammatory response.