Corneal sensitivity in five horse breeds / Sensibilidade corneana em cinco raças de equinos

ABSTRACT: This study aimed to determine and compare corneal sensitivity values in different regions of the cornea in five horse breeds. One hundred and forty five healthy horses, adults of both sexes, of the following breeds - Arabian horse (AH; n=20), Mangalarga Marchador (MM; n=50), Pure Blood Lusitano (PBL; n=35), Quarter Horse (QH; n=20), Brazilian Sport Horse (BSH; n=20)-were investigated. Corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer in five different corneal regions. Measurements of the median central CTT were: 4.50±0.50cm (AH), 3.50±0.56cm (MM), 3.00±0.25cm (PBL), 2.50±0.44cm (QH) and 2.50±0.00cm (BSH). The central region was the most sensitive and the dorsal region the least sensitive corneal region for all breeds. CTT values differed for corneal regions and horse breeds. The CTT values were different among the corneal regions and the horse breeds. Arabian horses presented higher sensitivity values being the most sensitive in all of the corneal regions.

RESUMO: Objetivou-se com o presente estudo, determinar e comparar valores de sensibilidade corneana em diferentes regiões da córnea em cinco raças de equinos. Foram investigados 145 equinos hígidos, adultos de ambos os sexos, das raças: Puro Sangue Árabe (PSA; n=20), Mangalarga Marchador (MM; n=50), Puro Sangue Lusitano (PBL; n=35), Quarto de Milha (QH; n=20) e Brasileiro de Hipismo (BSH; n=20). O limiar táctil da córnea (LTC) foi mensurado com o auxílio do estesiômetro de Cochet-Bonnet, em cinco diferentes regiões da córnea (central, nasal, ventral, temporal e dorsal). Os valores médios das mensurações do LTC central foram: 4,50±0,50cm (PSA), 3,50±0,56cm (MM), 3,00±0,25cm (PSL), 2,50±0,44cm (QM) e 2,50±0,00cm (BH). A região central foi a mais sensível e a região dorsal a menos sensível para todas as raças. Os valores de LTC diferiram para as regiões da córnea e entre as raças dos cavalos, sendo a raça Puro Sangue Árabe o que apresentou valores maiores de sensibilidade, desta forma sendo o mais sensível em todas as regiões corneanas.

Ophthalmic and anesthetic evaluation of topical 1 percent tetracaine and 0.5 percent proparacaine in dogs / Ação anestésica e oftálmica da administração de colírio de tetracaína 1 por cento e proparacaína 0,5 por cento em cães

The aim of this study was to establish the action of 1 percent tetracaine eye drops in combination with 0.1 percent phenylephrine in two different posologies and their effects on the eye compared to the 0.5 percent proparacaine drops in dogs. 22 animals were divided into two groups: TG (11 animals), received 1 percent tetracaine associated with 0.1 percent phenylephrine eye drops, one drop instilled in the left eye and two drops, with one-minute interval between each, instilled in the right eye; PG (11 animals) received 0.5 percent proparacaine eye drops following the same dosage. The average duration of the observed anesthetic action was 25 minutes for tetracaine and 15 minutes for proparacaine. The instillation of two drops increased anesthetic time in five minutes. No changes in intraocular pressure, pupil diameter and tear production was observed. The drops of tetracaine triggered chemosis in four (36.4 percent) animals. Topical anesthesia with proparacaine eye drops showed no adverse reactions and is thus recommended preferentially.

Estudou-se a ação do colírio de tetracaína 1 por cento, em associação com a fenilefrina 0,1 por cento em duas posologias diferenciadas, bem como seus efeitos oculares, comparando-a com a do colírio de proparacaína 0,5 por cento em cães. Vinte e dois animais foram separados em dois grupos. Os do GT (n=11) receberam colírio de tetracaína 1 por cento associada à fenilefrina 0,1 por cento, sendo uma gota instilada no olho esquerdo e duas gotas, com intervalo de um minuto entre cada, instiladas no olho direito; e os do GP (n=11), receberam colírio de proparacaína 0,5 por cento seguindo a mesma posologia. A média de duração da ação anestésica observada foi de 25 minutos para a tetracaína e 15 minutos para a proparacaína. A instilação de duas gotas aumentou o tempo anestésico em cinco minutos. Não ocorreram alterações na pressão intra-ocular, no diâmetro pupilar e na produção lacrimal. O colírio de tetracaína desencadeou quemose em quatro (36,4 por cento) animais. Na anestesia tópica do olho com proparacaína não ocorreram reações adversas sendo, assim, recomendada preferencialmente.

Changes in Corneal Sensitivity after Laser in-situ Keratom ileusis

To evaluate the changes of corneal sensitivity after LASIK, we measured corneal sensitivity threshold at 5 regions of cornea using Cochet-Bonnet aesthesiometer in 41 myopic eyes of 23 patients who underwent LASIK. Corneal sensitivities were tested in the Central, medial, superior, temporal and inferior region of cornea preoperatively and postoperatively. Central corneal sensitivity was reduced to 1.1+/-4.6% of preoperative sensation at 1 day postoperatively and gradually recovered showing 40.3+/-27.8% at 3 months postoperatively. The sensitivity of the central region was the lowest of all significantly and medial region was the highest(p0.05). There were no overall differences in the sensitivities of the superior, temporal and inferior regions(p>0.05) and their sensitivities were higher than that of central region and lower than that of medial region. The amount of preoperative myopia and the thickness of corneal flap showed no significant correlation with the decrease of postoperative corneal sensitivity(r0.05).