ABSTRACT
A rabbit eye model of neural ischaemia is described that uses an increased pressure in the anterior eye chamber to block the capillary supply to the retina. A microdialysis probe placed very close to the retinal surface was used to monitor release of amino acids during ischaemia. A large (two- to threefold) increase in the release of glutamate and O-phosphoserine (twofold), but not of six other amino acids monitored, occurred during initial ischaemia. During reperfusion after release of intraocular pressure, much larger (five- to 10-fold) increases in the release of these amino acids were observed. Parallel ischaemic retinal tissue damage was observed. This damage was prevented by ketamine applied locally via a superfusion needle, suggesting that glutamate released during ischaemia, and particularly during reperfusion, was responsible for cell death.
Subject(s)
Glutamates/metabolism , Ischemia/metabolism , Retinal Vessels , Amino Acids/metabolism , Animals , Dialysis/methods , Glutamic Acid , Ischemia/pathology , Ketamine/pharmacology , Male , Rabbits , Reperfusion , Retina/drug effects , Retina/metabolism , Retina/pathology , Retinal Diseases/metabolism , Retinal Diseases/pathologyABSTRACT
Os autores apresentam os resultados obtidos em 39 olhos com catarata secundaria a uveite, que foram operados via pars plana, usando a tecnica de Girard de facofragmentacao. Foram observados os seguintes resultados. l. Resultados anatomicos: bons, sem casos de persistencia de opacidade cristalinianas ou vitreas. 2. Resultados visuais: dependeram da presenca de alteracoes previas tais como lesoes de retina e nervo optico. Nao foram observados, em nenhu,m caso, inflamacao grave, recurrencia de toxoplasmose ocular, nem exarcebacao da uveite. Foram observadas as seguintes complicacoes: - edema cistico de macula: frequente. - hipopio esteril: um caso que melhorou com o uso de esteroides. - descolamento de retina: um caso operado com sucesso. - lesao de retina causada pelo ultrasom: um caso