RESUMO
PURPOSE: To describe the presence of iris neovascularization in a rabbit-model of retinal neovascularization induced by the intravitreal injection of latex-derived angiogenic fraction microspheres (LAF). MATERIALS AND METHODS: Eight New Zealand rabbits received one intravitreal injection of PLGA (L-lactide-co-glycolide) microspheres with 50 ug of LAF in the right eye (Group A). Microspheres without the LAF (0.1 ml) were injected in controls (Group B; n = 8). Follow-up with clinical evaluation and iris fluorescein angiography was performed after 4 weeks when eyes were processed for light microscopy. RESULTS: All eyes from Group A showed significant vascular dilation, conjunctival hyperemia and neovascularization on the iris surface, after LAF injection. No vascular changes were observed in Group B. CONCLUSIONS: The intravitreal injection of microspheres containing the LAF can induce rubeosis iridis in rabbits and could be used as a simple experimental model for iris neovascularization.
Assuntos
Indutores da Angiogênese/toxicidade , Glaucoma Neovascular/etiologia , Iris/irrigação sanguínea , Látex/toxicidade , Neovascularização Patológica/induzido quimicamente , Indutores da Angiogênese/administração & dosagem , Animais , Modelos Animais de Doenças , Progressão da Doença , Portadores de Fármacos , Feminino , Angiofluoresceinografia , Fundo de Olho , Glaucoma Neovascular/patologia , Injeções Intravítreas , Iris/efeitos dos fármacos , Ácido Láctico , Látex/administração & dosagem , Microesferas , Neovascularização Patológica/complicações , Neovascularização Patológica/patologia , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Fatores de RiscoRESUMO
Describir el comportamiento de la rubeosis del iris luego de la aplicación de triamcinolona subtenoniana. Se realizó un estudio descriptivo de corte longitudinal con 25 pacientes para un total de 32 ojos con diferentes afecciones oculares. Se efectuaron pruebas estadísticas con las variables del estudio y en algunas se utilizó la prueba de los signos de comparación para datos pareados y en otras se aplicó chi cuadrado. Se caracterizaron las variables: edad, sexo, causa de rubeosis del iris y sus estadios, síntomas y tratamiento con láser de panfotocoagulación retiniana. La retinopatía diabética proliferativa fue la afección más frecuente en el 76 por ciento de los pacientes, seguida de la oclusión de la vena central retiniana. Del total de pacientes tratados, el 37,5 por ciento evolucionó satisfactoriamente el estado de la rubeosis del iris. Fue mayor el número de pacientes que mejoraron el grado de la rubeosis con tratamiento combinado de láser y triamcinolona subtenoniana, aunque estadísticamente no fue significativo. El estado de la rubeosis mejoró en más de la mitad de los pacientes con tiempo de evolución menor de 6 meses. En aquellos con un tiempo mayor de 6 meses y neovascularización del iris grado III, se pudo estabilizar el glaucoma neovascular. Se plantea que la triamcinolona subtenoniana constituye una alternativa para el manejo de este tipo de pacientes.
To describe the behaviour of iris rubeosis after using intravitreal triamcinolone. A longitudinal descriptive study was performed on 25 patients for a total number of 32 eyes with several ocular diseases. Statistical tests were made with the study variables; sign comparison for paired data and Chi square tests were applied. The variables were age, sex, cause of iris rubeosis and its staging, symptoms and treatment with retinal photocoagulation laser. Proliferative diabetic retinopathy was the most common disease in 76 percent of patients, followed by central retinal vein occlusion. Of the total number of treated patients, 37,5 percent had satisfactory recovery in terms of the iris rubeosis condition. The number of patients that improved rubeosis condition after a combined therapy of laser and intravitreal triamcinolone was higher but not statistically significant. Rubeosis condition improved in over 50 percent of patients whose rubeosis had developed in less than six months. However, in those patients with the disease affecting them for more than 6 months and third grade iris neovascularization, neovascular glaucoma could be stabilized. Intravitreal triamcinolone is an alternative for the management of this type of patients.