RESUMO
This study developed an air-liquid interface (ALI) corneal model using explants bovine eyes for ocular toxicity assessment of ten chemicals and seven hair straightening mixtures. It was successfully maintained physiologically viable and normal for six days. Both eye damage (GHS cat. 1) and irritating (GHS cat. 2) chemicals induced corneal injury in our model. However, cat. 2 irritants triggered moderate damage when compared to cat. 1 agents, which induced a marked cytotoxicity profile. The mixtures were also able to trigger viability reduction associated with histopathological changes in the corneal tissues, especially when the exposure was via aerosol particles. Thus, the chemical exposure microenvironment simulation seemed to provide more reliable toxicological data. Moreover, mixture-induced corneal damage correlated with increased ROS levels, suggesting a close correlation between tissue death and oxidative stress. Besides mixtures showing the potential to induce moderate/mild ocular toxicity, we could verify that the corneal tissue damage showed reversibility due to the recovery from the injury after exposure to some of the mixtures. Hence, our ex vivo corneal model seems to be a simple and cost-effective approach for future studies related to further investigating the reversibility of damage in the cornea triggered by chemicals and their mixtures.
Assuntos
Alternativas aos Testes com Animais , Neuropatia Óptica Tóxica , Bovinos , Animais , Testes de Toxicidade , Irritantes/toxicidade , Córnea/patologia , CabeloRESUMO
La ptosis palpebral se define como la caída del párpado superior. Analizar los resultados obtenidos con su corrección quirúrgica y determinar la efectividad terapéutica con diferentes técnicas y vías de abordaje. Se realizó un estudio descriptivo, prospectivo y longitudinal con una casuística de 32 pacientes (50 ojos) operados de ptosis entre mayo de 2005 a marzo de 2006. La técnica y vía de abordaje quirúrgico que se aplicó la en cada caso, según el grado de severidad clínica (ligera moderada o severa) y su efectividad, se evaluó según la disminución en mm de la distancia margen-reflejo posoperatoria. Las técnicas quirúrgicas fueron: reforzamiento y reinserción de la aponeurosis, supramáxima, suspensión al frontal y abordaje posterior. La distancia margen-reflejo posoperatoria disminuyó de 1,2, 2,2 y 3,5 mm en ptosis ligeras moderadas y severas respectivamente. Si se selecciona adecuadamente la vía de abordaje, ambas aportan buenos resultados en la corrección de la ptosis.
Palpebral ptosis is defined as the upper eyelid fall. To analyze the results of the surgical correction of palpebral ptosis and to determine its therapeutical effectiveness with various techniques and approach methods. A prospective, longitudinal and descriptive study was performed on 32 patients (50 eyes) operated on from ptosis covering May, 2005 through March, 2006. The surgical technique and approach method applied to each case, taking clinical severity into account (slight, moderate and severe), and their effectiveness were evaluated based on postoperative margin-reflex distance reduction in mm. The surgical techniques were reinforcement and reinsertion of aponeurosis, supramaxima, frontalis suspension and posterior approach. Postoperative margin-reflex distance was reduced by (1.2, 2.2 and 3.5 )mm in slight, moderate and severe ptosis respectively. The right selection of the surgical technique and the approach method helps in achieving good results in ptosis correction.