RESUMO
Selective laser trabeculoplasty (SLT) has been indicated as a safe and efficient treatment for primary open-angle glaucoma; however, recent studies have also shown positive results with the use of SLT in some clinical conditions related to primary angle-closure glaucoma (PACG). Despite the potential benefits of SLT in selected cases of PACG, the mechanisms underlying the modifications in the trabecular meshwork tissue of patients with PACG are poorly understood. This narrative review approached both the current, limited knowledge about the histological changes observed in different forms of PACG and the clinical results of SLT treatment for PACG. Favourable outcomes of SLT in patients with PACG, specifically in areas of non-occluded angle, need further substantiation through large controlled clinical trials. A deeper understanding of the biomolecular changes of those areas is essential to improve both laser technical details and the clinical efficacy of SLT therapy.
Assuntos
Glaucoma de Ângulo Fechado/cirurgia , Iris/ultraestrutura , Terapia a Laser/métodos , Malha Trabecular/ultraestrutura , Trabeculectomia/métodos , Estudos de Viabilidade , Glaucoma de Ângulo Fechado/patologia , Gonioscopia , Humanos , Pressão Intraocular , Iris/cirurgia , Microscopia Eletrônica de Transmissão , Malha Trabecular/cirurgiaRESUMO
Aquatic mammals underwent morphological and physiological adaptations due to the transition from terrestrial to aquatic environment. One of the morphological changes regards their vision since cetaceans' eyes are able to withstand mechanical, chemical, osmotic, and optical water conditions. Due to insufficient information about these animals, especially regarding their sense organs, this study aimed to describe the morphology of the Humpback whale (Megaptera novaeangliae) eyeball. Three newborn females, stranded dead on the coast of Sergipe and Bahia, Brazil, were used. Samples were fixed in a 10% formalin solution, dissected, photographed, collected, and evaluated through light and electron microscopy techniques. The Humpback whale sclera was thick and had an irregular surface with mechanoreceptors in its lamina propria. Lens was dense, transparent, and ellipsoidal, consisting of three layers, and the vascularized choroid contains melanocytes, mechanoreceptors, and a fibrous tapetum lucidum. The Humpback whale eyeball is similar to other cetaceans and suggests an adaptation to diving and migration, contributing to the perception of differences in temperature, pressure, and lighting.
Assuntos
Olho/anatomia & histologia , Jubarte/anatomia & histologia , Animais , Câmara Anterior/anatomia & histologia , Câmara Anterior/ultraestrutura , Corioide/anatomia & histologia , Corioide/ultraestrutura , Corpo Ciliar/anatomia & histologia , Corpo Ciliar/ultraestrutura , Córnea/anatomia & histologia , Córnea/ultraestrutura , Olho/ultraestrutura , Feminino , Iris/anatomia & histologia , Iris/ultraestrutura , Cristalino/anatomia & histologia , Cristalino/ultraestrutura , Microscopia , Microscopia Eletrônica , Nervo Óptico/anatomia & histologia , Nervo Óptico/ultraestrutura , Retina/anatomia & histologia , Retina/ultraestrutura , Esclera/anatomia & histologia , Esclera/ultraestruturaRESUMO
BACKGROUND: Damage to the corneal epithelium causes not only a reaction for its repair but also affects other parts of the cornea as well as different components of the anterior segment of the eye. The purpose of this investigation was to analyze the consequences, following epithelial and limbal damage, to the iris of rabbits (Oryctolagus cuniculus). METHODS: The corneal epithelium was thoroughly scraped followed by surgical excision of the limbus. Next, (3)H-thymidine ((3)H-TdR) was injected intravitreally both into the right (experimental) and left (control) eyes which had their anterior segments processed for autoradiography at intervals of 2, 7 and 21 days after surgery (three rabbits per interval). The irises were also examined with scanning-electron and confocal microscopy after Evans blue injection. RESULTS: There was a high frequency of labeling in the cells of the iris blood vessels in the experimental eye, particularly the endothelial ones. The ratio of labeled cells between experimental and control irises was 40:1, with a population of nuclei increasing by 25% and remaining labeled up to 21 days. There was also an increase in the volume of the iris vasculature as shown by confocal microscopy. The high labeling frequencies of the vascular cells were observed throughout the iris from the ciliary to the pupillary regions. CONCLUSIONS: The lesions on the corneal epithelium elicit proliferation of the iris vascular cells, mainly its endothelium, as well as an early breakdown of the blood-aqueous barrier. The daughter cells resulting from the damage to the eye surface were detected up to 21 days after a single injection of (3)H-TdR, most likely due to their slow turnover. As a consequence of this proliferation, the vasculature of the iris increased in volume.
Assuntos
Proliferação de Células , Desbridamento , Endotélio Vascular/patologia , Epitélio Corneano/cirurgia , Iris/irrigação sanguínea , Limbo da Córnea/cirurgia , Animais , Autorradiografia , Barreira Hematoaquosa , Contagem de Células , Iris/ultraestrutura , Masculino , Microscopia Confocal , Microscopia Eletrônica de Varredura , Coelhos , CicatrizaçãoRESUMO
The so called alternative medicines are widely used and traditional physicians largely ignore them and their nature. So, it is necessary that medical practitioners are informed on the scientific bases about the alternative medicines and about the results of double-blind studies, if any, that show their usefulness, or lack of it. So, we reviewed the scientific rationales and the results of the available double-blind studies with placebo controls, both in conventional medical journals and textbooks as well as in those of the alternative medicine and produced by professionals of both conventional and alternative medicine. The scientific rationale of the alternative medicine is not based on the scientific method. Although there are some controlled, double-blind, placebo studies, those few with favorable results have not been successfully reproduced. The modalities known as alternative medicines have not shown any usefulness or advantage, aside from a placebo effect. Even more, they are not free from untoward or undesirable side effects, some of which are well documented. We conclude that there is not any real application for these therapeutic practices.
Assuntos
Terapias Complementares , Terapias Complementares/classificação , Terapias Complementares/psicologia , Terapias Complementares/estatística & dados numéricos , Europa (Continente) , Estudos de Avaliação como Assunto , Homeopatia , Humanos , Iris/ultraestrutura , México , Modelos Biológicos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Pacientes/psicologia , Reprodutibilidade dos Testes , Estados Unidos , UrinaRESUMO
Se comunica el caso de un lactante de 6 meses de edad, con lesión tumoral de color café amarillento, de rápido crecimiento, localizada a nivel de la raíz iridiana nasal de OD. Se realizó escisión sub-total de la lesión seguida por tratamiento esteroidal tópico. Un año más tarde, habiendo remitido completamente la lesión, la excentricidad de la pupila y la presencia de membrana pre-cristaliniana hicieron necesaria uba pupiloplastía. Durante esta cirugía se resecó pequeña pápula café amarillenta infraumbilical. El estudio histopatológico óptico y electrónico de las lesiones iridiana y cutánea concluyeron en xantogranuloma juvenil. Sus características clínicas y morfológicas se analizan y discuten
Assuntos
Humanos , Masculino , Lactente , Doenças da Íris/diagnóstico , Xantogranuloma Juvenil/diagnóstico , Dexametasona/uso terapêutico , Técnicas Histológicas , Iris/patologia , Iris/ultraestrutura , Microscopia Eletrônica , Timolol/uso terapêutico , Xantogranuloma Juvenil/patologia , Xantogranuloma Juvenil/cirurgiaRESUMO
We undertook a light and scanning electron microscopic study of the eye in the Magellanic penguin (Spheniscus magellanicus). The anatomical peculiarities of the eyeball shape in Sphenisciformes have been previously described by others; here, we show that they are accompanied by several modifications in the organization of the anterior segment of the eye. The main change was found in the portion of opaque sclera extending from the cornea to the anterior border of the scleral ossicles, which was much broader than in other avian eyes. This scleral region was made of a very dense fibrous tissue and was as difficult to cut as the ossicles. The corneo-scleral boundary was also different from that of other birds, since the aqueous humor channel and the pectinate ligament were located 1.0-1.5 mm posterior to the cornea. The osseous ring was formed by 13 bones, including three pairs of over- and underplates. There was a single ciliary muscle, with meridionally oriented striated fibers. They were inserted on a circumference along the boundary between the fibrous sclera and the ossicles, far away from the wall of the aqueous humor channel. On their posterior end, the muscle fibers formed a tendinous structure attached to the inner surface of the sclera and to the outer surface of the ciliary body. Only short zonular fibrils were observed. These anatomical features are probably relevant for the adaptation of penguin eyes to vision on land and in the aquatic environment.