The study of the use of a latex biomembrane and conjunctival autograft in rabbit conjunctiva wound healing

: RESUMO Objetivo: Estudar o uso da biomembrana de latex e o transplante conjuntival autologo na cicatrizacao conjuntival em coelhos. Metodos: Em nove coelhos albinos, neo-zelandeses, machos foram removidas areas retangulares identicas, do quadrante supero nasal, adjacente ao limbo, de ambos os olhos. As areas desnudas da camada esclerotica nos olhos direitos foram recobertas com biomembrana de latex e a dos olhos esquerdos com enxerto conjuntival autologo. Os animais foram sacrificados em grupos de tres, aos 7, 14 e 21 dias apos a cirurgia. Os tecidos do local cirurgico, incluindo a cornea, foram fixados em formaldeido, antes de serem processados em parafina e corados com hematoxilina e eosina. A natureza e a intensidade da resposta inflamatoria e o padrao de epitelizacao da superficie conjuntival foram avaliados sob microscopia optica, em secoes histologicas longitudinais, passando pelo centro dos especimes anatomicos. Resultados: Ate o decimo quarto dia pos-operatorio, o grupo que recebeu a biomembrana apresentou reacao inflamatoria mais intensa do que o grupo com auto enxerto conjuntival. Aos 14 dias, os olhos com biomembrana apresentavam-se menos inflamados e com estroma mais espesso do que aos 7 dias. Aos 21 dias, a reparacao conjuntival de ambos os grupos apresentavam caracteristicas semelhantes. Conclusao: Apesar de apresentar uma cicatrizacao mais lenta, a biomembrana de latex se mostrou tao eficaz quanto o auto enxerto conjuntival na reconstrucao da superficie ocular apos tres semanas de cicatrizacao pos-operatoria. Devido as suas baixas toxicidade e alergenicidade, este material parece ser uma opcao terapeutica promissora na reconstrucao da conjuntiva.ABSTRACT Purpose: To study a latex biomembrane and conjunctival autograft with regard to the promotion of conjunctival healing in rabbits. METHODS: The study included nine male albino rabbits. In these rabbits, a rectangular area of the conjunctiva was surgically removed from the superonasal quadrant adjacent to the limbus in both eyes. The bare area of the sclerotic coat of the right eye was reconstructed with a latex biomembrane, and the corresponding site of the left eye was reconstructed with a conjunctival autograft. The animals were killed in groups of three at 7, 14, and 21 days after surgery. The tissues from the surgical site, including the cornea, were fixed in formaldehyde, and were then processed in paraffin and stained with hematoxylin and eosin. The nature and intensity of the inflammatory response and the epithelial pattern at the conjunctival surface were evaluated under optical microscopy with longitudinal histological sections through the center of the anatomical specimens. RESULTS: Until the 14th postoperative day, the inflammatory reaction was greater in the biomembrane group than in the conjunctival autograft group. In the latex biomembrane group, inflammation was less intense and the stroma was thicker on the 14th postoperative day than on the 7th postoperative day. After three weeks, conjunctival healing in both groups showed similar characteristics. CONCLUSION: Although healing was slower with a latex biomembrane, tissue reconstitution was almost the same as that with a conjunctival autograft by three weeks. A latex biomembrane is as effective as a conjunctival autograft for the reconstruction of the ocular surface. Owing to the lack of toxicity and allergenicity, a latex biomembrane appears to be a promising therapeutic option for conjunctival reconstruction.