Antiscarring effect of intraoperative bevacizumab in experimental glaucoma filtration surgery / Efeito antifibrótico do uso intraoperatório de bevacizumab em cirurgia filtrante experimental

ABSTRACT Purpose: To determine the effects of bevacizumab and mitomycin C alone and in combination on intraocular pressure and the scarring process after modified glaucoma filtration surgery in rabbits. Methods: The rabbits underwent modified glaucoma filtration surgery and were allocated into three groups to receive intraoperative treatment with subconjunctival bevacizumab (group A), mitomycin C and subconjunctival bevacizumab (group B), or mitomycin C (group C). Intraocular pressure was measured immediately preoperatively and on postoperative days 8, 14, 17, 21, 26, and 30. The scarring process was assessed 30 days after surgery by tissue section using hematoxylin and eosin, Masson's trichrome, and picrosirius. Expression of vascular endothelial growth factor (VEGF) was assessed by immunohistochemical analyses. All analyses were performed by a masked observer. Results: Animals in group A had higher intraocular pressure than those in groups B and C (p<0.01). Intraocular pressure did not differ significantly between groups B and C. The amount of fibrosis was similar with all stains used: group A had the highest level of fibrosis compared with groups B and C (p>0.05). There was less VEGF expression in group A than in groups B and C (p<0.01). Groups B and C did not differ in VEGF expression. Conclusion: Mean intraocular pressure and fibrosis were lower in animals receiving bevacizumab in combination with mitomycin C but did not differ from values in animals receiving mitomycin C alone. Inhibition of VEGF was greater when bevacizumab was used alone than when bevacizumab was combined with mitomycin C.

RESUMO Objetivo: Determinar os efeitos do bevacizumab, combinados ou não à mitomicina C (MMC), na pressão intraocular e processo cicatricial pós-cirurgia filtrante anti-glaucomatosa modificada em coelhos. Métodos: Os coelhos foram submetidos à cirurgia filtrante anti-glaucomatosa modificada e alocados em três grupos de acordo com o tratamento instituído - Grupo A: bevacizumab subconjuntival; Grupo B: bevacizumab subconjuntival e à mitomicina C ; Grupo C: à mitomicina C. A pressão intraocular foi aferida no período pré-operatório imediato e nos dias 8, 14, 17, 21, 26 e 30. O processo cicatricial foi avaliado no trigésimo dia de pós-operatório por meio de análise histopatológica utilizando-se hematoxilina eosina, tricrômio de Masson e picrosirius. A expressão do fator de crescimento do Endotélio Vascular (VEGF) foi avaliada por meio de análise imuno-histoquímica. Todas as análises foram feitas por um observador mascarado. Resultados: O Grupo A apresentou maior pressão intraocular que os grupos B e C (p<0.01). Não foram encontradas alterações significativas entre os grupos B e C. A quantidade de fibrose encontrada nos grupos foi similar com os 3 corantes utilizados: o Grupo A apresentou maior nível de fibrose em relação aos grupos B e C (p>0,05). Houve menor expressão de Fator de Crescimento do Endotélio Vascular no Grupo A em relação aos grupos B e C (p<0,01). Não houve diferença estatisticamente significante na expressão de Fator de Crescimento do Endotélio Vascular entre os grupos B e C. Conclusão: O bevacizumab associado à MMC apresentou pressões intraoculares mais baixas e menos fibrose, mas estes não foram estatisticamente significantes quando comparados ao uso da mitomicina C isolada. Uma maior inibição do fator de crescimento do endotélio vascular foi encontrada quando o bevacizumab foi usado isoladamente, em detrimento do seu uso associado à mitomicina C.

Antiscarring effect of intraoperative bevacizumab in experimental glaucoma filtration surgery.

PURPOSE: To determine the effects of bevacizumab and mitomycin C alone and in combination on intraocular pressure and the scarring process after modified glaucoma filtration surgery in rabbits. METHODS: The rabbits underwent modified glaucoma filtration surgery and were allocated into three groups to receive intraoperative treatment with subconjunctival bevacizumab (group A), mitomycin C and subconjunctival bevacizumab (group B), or mitomycin C (group C). Intraocular pressure was measured immediately preoperatively and on postoperative days 8, 14, 17, 21, 26, and 30. The scarring process was assessed 30 days after surgery by tissue section using hematoxylin and eosin, Masson's trichrome, and picrosirius. Expression of vascular endothelial growth factor (VEGF) was assessed by immunohistochemical analyses. All analyses were performed by a masked observer. RESULTS: Animals in group A had higher intraocular pressure than those in groups B and C (p<0.01). Intraocular pressure did not differ significantly between groups B and C. The amount of fibrosis was similar with all stains used: group A had the highest level of fibrosis compared with groups B and C (p>0.05). There was less VEGF expression in group A than in groups B and C (p<0.01). Groups B and C did not differ in VEGF expression. CONCLUSION: Mean intraocular pressure and fibrosis were lower in animals receiving bevacizumab in combination with mitomycin C but did not differ from values in animals receiving mitomycin C alone. Inhibition of VEGF was greater when bevacizumab was used alone than when bevacizumab was combined with mitomycin C.

Alteraçöes refrativas induzidas pelo óleo de silicone intraocular / Refractive change from use of intraocular silicone oil

Os autores determinaram as variaçöes refracionais induzidas pelo óleo de silicone intra-ocular em onze fácicos e em 13 olhos afácicos. Nos olhos fácicos houve um aumento na hipermetropia de 6,4 D, em média, e nos afácicos houve uma reduçäo na hipermetropia de 7,4 D, em média. Essas variaçöes refracionais säo devidas, fundamentalmente, ao maior índice de refraçäo do silicone, quando comparado com os índices de refraçäo dos meios dióptricos oculares