Use of an allogenous tunica vaginalis conserved in 98% glycerine for keratoplasty in dogs

Abstract

We evaluated the use of an allogenous tunica vaginalis conserved in 98% glycerine for lamellar keratoplasty in dogs. Seven dogs were submitted to keratoplasty and clinically evaluated during the initial (1 to 15 days), intermediate (16 to 30 days) and late (31 to 120 days) postoperative periods. The corneas were evaluated by light microscopy at 1, 3, 7, 15, 30, 60 and 120 days after surgery. Photophobia, epiphora, blepharospasm, corneal edema, ocular secretion and chemosis were observed during the initial periods, and tended to disappear during the intermediate periods. Vascular neoformation started around the 4th day, with a maximum intensity on the 25th day and a gradual regression thereafter, and tended to disappear between the 60th and 120th day. The graft itself and adjacent areas showed a tendency towards the reestablishment of transparency during the late postoperative periods. With respect to morphology, an inflammatory infiltrate characterized by the invasion of polymorphonuclear and mononuclear leukocytes was observed which disappeared by the 60th postoperative day, when the graft was found to be incorporated and the stroma returned to normal. The present results led us to conclude that the allogenous tunica vaginalis conserved in 98% glycerine was feasible and efficient for lamellar keratoplasty in dogs.Keywords: cornea, keratoplasty, tunica vaginalis, allogenous graft, dogs. ResumoAvaliou-se a túnica vaginal alógena, conservada em glicerina a 98%, na ceratoplastia lamelar em cães. Sete cães foram submetidos à ceratoplastia e avaliados clinicamente em períodos iniciais (1 a 15 dias), intermediários (16 a 30 dias) e tardios (31 a 120 dias) de pós-operatório. As córneas foram avaliadas em microscopia de luz aos um, três, sete, 15, 30, 60 e 120 dias de pós-operatório. Fotofobia, epífora, blefarospasmo, edema corneano, secreção ocular e quemose foram observados nos períodos iniciais, tendendo a desaparecerem nos períodos intermediários. Neoformação vascular iniciou-se próximo aos dos quatro dias, apresentando intensidade máxima aos 25 dias de pós-operatório, quando iniciou regressão gradativa para tender à ausência entre 60 e 120 dias. Nas áreas próprias e adjacentes aos enxertos houve tendência ao reestabelecimento da transparência nos períodos tardios de pós-operatório. Quanto à morfologia, o infiltrado inflamatório caracterizou-se pela invasão de leucócitos polimorfonucleares e mononucleares, tendendo à ausência aos 60 dias de pós-operatório, quando notou-se que o enxerto foi incorporado e o estroma tendeu à normalidade. Os resultados obtidos com a pesquisa permitem admitir que a túnica vaginal alógena, conservada em glicerina a 98%, mostrou-se factível e eficaz na ceratoplastia lamelar em cães.Palavras-chave: córnea, ceratoplastia, túnica vaginal, enxerto alógeno, cães. lntroductionAmong the lesions affecting the cornea, ulcers, abrasions, lacerations and perforations characterized by the loss of epithelium and of variable portions of the stroma have been emphasized (Startup, 1984). Particula...