RESUMO
BACKGROUND: Actinic conjunctivitis is an ocular photosensitivity reaction found mainly in children in certain populations in the Andean regions of South America, Mexico, and in the southwestern United States. Its clinical features, treatment, and possible relation to duration of sun exposure have not been fully described in the ophthalmologic literature. METHODS: A 20-member ophthalmic team traveled to an Andean region of Ecuador to provide ophthalmic care to children. All children with conjunctivitis were examined. A novel 3-stage classification of actinic conjunctivitis, devised by one of the authors, was used to stage the disease. The parents of each child with actinic conjunctivitis were asked how much time the child spent outside. Histopathological evaluations were performed on children who underwent surgery. RESULTS: A total of 206 children were examined, of whom 36 had changes consistent with actinic conjunctivitis. Stage 1 disease was diagnosed in 17 children, stage 2 in 9, and stage 3 in 10 in the most severely affected eye. The amount of time the child spent outside correlated with disease severity (r = 0.77, p < 0.001). Histopathologic samples showed an intense inflammatory response with hyperplasia of the vascular endothelium, pigmentary migration, and occasional eosinophilia. CONCLUSIONS: Actinic conjunctivitis is prevalent among children of the highlands of Ecuador. Although it has an allergic component, our data suggest that the severity of the disease is significantly associated with sun exposure. The finding that the lesions are found only in the exposed conjunctiva supports the hypothesis that UV exposure is the main cause of the disease.
Assuntos
Túnica Conjuntiva/patologia , Túnica Conjuntiva/efeitos da radiação , Conjuntivite/etiologia , Transtornos de Fotossensibilidade/etiologia , Luz Solar/efeitos adversos , Adolescente , Criança , Pré-Escolar , Conjuntivite/etnologia , Conjuntivite/patologia , Conjuntivite/cirurgia , Equador/epidemiologia , Exposição Ambiental , Feminino , Humanos , Indígenas Sul-Americanos/estatística & dados numéricos , Masculino , Transtornos de Fotossensibilidade/etnologia , Transtornos de Fotossensibilidade/patologia , Transtornos de Fotossensibilidade/cirurgia , Prevalência , Índice de Gravidade de DoençaRESUMO
Se realizó ciclofotocoagulación experimental con láser semiconductor de diodo mediante sonda de contacto (G-probe, Iris Medical) en una serie de conejos, los que fueron sacrificados en forma secuencial para poder observar los efectos producidos en el cuerpo ciliar a nivel histológico. Después de realizar el procedimiento bajo un mismo protocolo, se pudo observar que las principales lesiones producidas son el blanqueamiento y contracción de los procesos ciliares a nivel macroscópico. Se examinaron a nivel microscópico y ultraestructural las lesiones producidas, observándose necrosis de coagulación del epitelio ciliar en sus dos estratos y dispersión de pigmento. En etapas tardías se agregó hiperplasia del epitelio pigmentado ciliar, con marcada fibrosis del estroma. También fueron observadas y fotografiadas las microexplosiones tisulares producidas por el uso de energía excesiva (o "supraumbral"), que demuestran una destrucción completa y localizada del complejo ciliar. Estos hallazgos demuestran la gran precisión y poder de penetración del láser diodo al ser aplicado directamente sobre la esclera, y nos ilustran acerca de la mejor forma de aplicarlo y de su mecanismo de acción a nivel del cuerpo ciliar