The effects of sclerocorneal limbal stem cell autograft transplantation in dogs with corneal wounds were studied. Eighteen dogs were divided in two groups (GI and GII). The animals of GI (n=12) underwent limbal transplantation 30 days after the destruction of limbal stem cells. The dogs of GII (n=6) only underwent destruction of stem cells (control group). Light microscopy examination of the right eye was performed on days 3, 7, 14, 30, 60, and 120 after limbal transplantation (GI), and on days 33, 37, 44, 60, 90, and 150 after limbal destruction (GII). Results showed a complete destruction of limbal stem cells with loss of corneal transparency. Limbal transplantation prevented conjunctivalization in grafted area. Corneal vascularization and a 360º corneal conjunctivalization were noted in the control dogs (GII). Corneal transparency was restored from day 60th after surgery. Histological examination did not distinguish the transition between the graft and the normal corneal epithelium at anytime. Goblet cells were found in control animals (GII) on 33, 37, 60, and 150 days, whereas a single grafted dog (GI) presented a few goblet cells on day 60th post-transplantation. Limbal autograft transplantation was effective in restoring corneal clarity with no development of ocular complications.

The consequences of complete removal of the sclerocorneal limbus epithelium were evaluated, as well as the model for such, in which n-heptanol and superficial keratectomy were used. The association of nheptanol and keratectomy allowed a complete excision of stem cells. Moreover, the destruction of these cells led to significant tectonic alterations that could be employed as a feasible model for clinical experimentation of corneal transplantation.Keywords: dog, stem cell, cornea RESUMO As conseqüências da completa remoção do epitélio do limbo esclerocorneano foram avaliadas

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The topical effects of autogenous, allogenous and xenogenous blood serum on wound healing of alkali corneal ulcers were determined in 52 dogs divided into four groups (GI, Gil, Glll and GIV). The effects of autogenous serum were studied in Gl animais, those of allogenous serum in Gil, and those of xenogenous serum in Glll. GIV animais received 0.9% buffered saline solution also by instillation. Events such as blepharospasm, secretion, conjunctival hyperemia and chemosis, corneal edema, neovascularization and pigmentation were evaluated macroscopically and statistically. The inflammatory response and evolution of corneal wound healing were analyzed by light microscopy. NÓ significant clinicai or histopathological differences were observed between groups. Corneal perforations occurred in tive Gl animais at 4, 10, 11, 16 and 18 days of treatment, and in three Gil animais at 4, 6 and 7 days. In Glll, one animal presented corneal perforations at 7 days and in GIV, two animais presented perforations at 8 days and one animal at 9 days of treatment. In the absence of perforations, the epithelium was found to be reconstituted, on average, at 15 days of treatment. Comparison of the groups showed no significant differences between treatments.Keywords: cornea, alkali, blood serum, dogs. ResumoForam comparados os efeitos tópicos dos soros sangüíneos autógeno, alógeno e xenógeno, sobre a reparação cicatricial em úlceras de córnea por álcali, em 52 cães, distribuídos em quatro grupos (GI, Gil, Glll e GIV). Nos animais do Gl, foram estudados os efeitos do soro sangüíneo autógeno. Nos do Gil, os do soro sangüíneo alógeno e nos do Glll, os do soro xenógeno. O GIV foi tratado com solução salina balanceada a 0,9%, também por instilação. Foram avaliados macroscopicamente e por análise estatística, eventos como blefarospasmo, secreção, hiperemia, congestão e quemose conjuntivais; edema, neovascularização e pigmentação corneanos. À microscopia óptica, avaliou-se a resposta inflamatória e a evolução da reparação cicatricial das córneas. Os resultados mostraram que entre os grupos não houve diferenças clínicas estatisticamente significativas e à histopatologia, também não foram notadas diferenças. Houve perfurações corneanas no Gl, em 5 animais, aos 4, 10, 11, 16 e 18 dias de tratamento. No Gil, elas foram observadas em 3 cães aos 4, 6 e 7 dias. No Glll, houve um caso aos 7 dias e, no GIV, elas ocorreram em 2 animais aos 8 dias e em 1 aos 9 dias de tratamento. Naqueles em que não houve perfurações, aos 15 dias de tratamento, em média, o epitélio já se encontrava refeito. Mediante comparação entre os grupos, pode-se admitir que não houve diferenças entre os tratamento empregados.

The effects of low-intensity pulsed ultrasound on wound healing were evaluated at the graft-cornea transition in dogs following lamellar keratoplasty using tunica vaginalis preserved in 98% glycerin. Twenty-one dogs were subdivided into three groups of seven animals. The first group (W/US) received daily treatment of low-intensity pulsed ultrasound (20 mW/cm2) for 15 min for the first 10 days post surgery. The second group (N/US) was submitted to the same procedure but with the ultrasound apparatus turned off. The third group, the control (CO), underwent the surgical procedure only. The animals were clinically evaluated during the initial (1-15 days), intermediate (16-30 days) and late (31-120 days) postoperative period. The corneas were evaluated by light microscopy at 1, 3, 7, 15, 30, 60 and 120 days after surgery. Clinically, there were no differences which would promote an advantage to any of the treatments. Light microscopy, however, revealed more extensive vascularization and more advanced wound healing in the W/US group, as well as a tendency towards early graft incorporation. Based on the present results, low-intensity pulsed ultrasound shows advantages, especially in situations where trophic support is a mandatory condition, facilitating better graft incorporation and rapid recovery of stromal organization.

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...