Comparison of the effects of subconjunctival and topical anti-VEGF therapy (bevacizumab) on experimental corneal neovascularization.

PURPOSE: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. METHODS: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8), subconjunctival bevacizumab treatment (n=8), and topical bevacizumab treatment (n=8). Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg) bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. RESULTS: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730). The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05). The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05). Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05). CONCLUSIONS: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn.

Comparison of the effects of subconjunctival and topical anti-VEGF therapy (bevacizumab) on experimental corneal neovascularization / Comparação do efeito da terapia anti-VEGF (bevacizumab) subconjuntival e tópica na neovascularização corneana experimental

Purpose: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. Methods: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8), subconjunctival bevacizumab treatment (n=8), and topical bevacizumab treatment (n=8). Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg) bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. Results: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730). The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05). The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05). Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05). Conclusions: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn. .

Objetivo: Comparar o efeito de bevacizumab aplicado subconjuntival e topicamente em um modelo de neovascularização de córnea de ratos induzida por queimadura alcalina. Métodos: Córneas direitas de 24 ratos Wistar-Albino foram cauterizados por nitrato de prata. Os indivíduos foram divididos aleatoriamente e igualmente em três grupos: controle (n=8), o bevacizumab subconjuntival (n=8), o bevacizumab tópico (n=8). Imediatamente após a cauterização, 0,05 ml (1,25 mg) de bevacizumab foi injetado no grupo subconjuntival. Grupo tópico foi inculcado com 10 mg/ml de bevacizumab duas vezes por dia. O grupo controle recebeu solução salina normal, topicamente, duas vezes ao dia. A graduação do estímulo da queimadura e a graduação da neovascularização foram avaliados utilizando a técnica descrita por Mahoney e Waterbury. Fotografias digitais foram obtidas dos olhos serem enucleados. Seções da córnea foram analisadas por histopatologia. Resultados: A média da graduação do estímulo da queimadura foi de 1,86 ± 0,6 e não houve diferença estatisticamente entre os grupos (p=0,730). As médias das graduações da neovascularização no grupo bevacizumab subconjuntival e no grupo bevacizumab tópico foram estatisticamente menores do que o grupo controle (p<0,05). A percentagem média de área de neovascularização da córnea foi de 82,5 ± 22,1 no grupo controle, 42,7 ± 15,0 no grupo subconjuntival e 55,8 ± 18,2 no grupo tópico. As diferenças entre os grupos de tratamento e grupo de controlo foram estatisticamente significativos (p<0,05). A histopatologia mostrou que os grupos de tratamento apresentavam menos neovascularização, inflamação e atividade de fibroblastos do que o grupo controle (p<0,05). ...