Specular microscopy of the corneal endothelial cells of bovines: an ex vivo study.

Background: The endothelium is the most posterior layer of the cornea and is essential for maintaining corneal transparency. Due to variations in corneal endothelial parameters among different species, knowledge of the normal parameters for each species is crucial. Aim: To evaluate the corneal endothelium of bovines using contact specular microscopy. Methods: Twenty eyeballs from 10 male Brangus (Bos taurus) aged 24 months were evaluated. Contact specular microscopy was performed on the central corneal area. The analyzed parameters were endothelial cell density (ECD) and endothelial cell morphology. Results: The ECD in the central area was 1,277 cells/mm2. Regarding the morphology, mainly cells with six (74.3%), five (14.7%) and seven sides (10%) were found. There were no significant differences in ECD and morphology between left and right eyes. Conclusion: Contact specular microscopy facilitated the analysis and measurement of corneal endothelial parameters in bovines. The data obtained will serve as a reference for the analysis of bovine corneal endothelium.

Acute effects of ropivacaine hydrochloride on corneal endothelial cell ultrastructure of horses: ex vivo study / Efeitos agudos do cloridrato de ropivacaína na ultraestrutura das células endoteliais da córnea de equinos: estudo ex vivo

ABSTRACT: The objective of this study was to evaluate the acute effects of ropivacaine hydrochloride on the corneal endothelium of horses. Forty-eight eyes were obtained from a commercial slaughterhouse and were randomly divided into three groups. In group A, the corneal endothelium was exposed to 0.75% ropivacaine hydrochloride for 60 seconds. In group B, the corneal endothelium was exposed to 0.75% ropivacaine hydrochloride for 15 minutes. In group C, the corneal endothelium was exposed to a balanced saline solution for 60 seconds. Afterwards, all samples were prepared for evaluation with scanning electron microscopy. Random electromicrographs were obtained from each sample. The images were analysed and, with the aid of software, areas with no endothelial cells were measured. The average endothelial loss, expressed as a percentage in relation to the total area, of the samples in group A was 5.28%. The average endothelial loss of samples from group B, expressed as a percentage in relation to the total area, was 20.39%. The damage to the corneal endothelium was significantly greater in group B compared to groups A and C. It was possible to conclude that 0.75% ropivacaine hydrochloride induced acute damage to corneal endothelium cells.

RESUMO: Objetivou-se avaliar os efeitos agudos do cloridrato de ropivacaína no endotélio da córnea de equinos. Quarenta e oito olhos de equinos foram divididos aleatoriamente em três grupos. No grupo A o endotélio da córnea foi exposto a cloridrato de ropivacaína a 0,75% por 60 segundos. No grupo B o endotélio da córnea foi exposto a cloridrato de ropivacaína a 0,75% por 15 minutos. No grupo C o endotélio da córnea foi exposto à solução salina balanceada por 60 segundos. As amostras foram preparadas para avaliação com microscopia eletrônica de varredura. Eletromicrografias eletrônicas de varredura foram obtidas aleatoriamente de cada amostra. As imagens foram analisadas e, com o auxílio de um programa para morfometria foram medidas as áreas sem células endoteliais. A perda endotelial média foi expressa em porcentagem em relação à área total das amostras do grupo A foi de 5,28%. A perda endotelial média de amostras do grupo B foi expressa em porcentagem em relação à área total, foi de 20,39%. O dano ao endotélio da córnea foi significativamente maior no grupo B, comparado aos grupos A e C. O cloridrato de ropivacaína a 0,75% induziu dano agudo nas células do endotélio da córnea de equinos.