RESUMO
Corneal opacity is a leading cause of blindness worldwide. Corneal transplantation and keratoprosthesis can restore vision but have limitations due to the shortage of donor corneas and complications due to infection. A proposed alternative treatment using an intraocular projection prosthesis device can treat corneal disease. In this study, we perform a transient thermal analysis of the bionic eye model to determine the power the device can produce without elevating the eye tissue temperature above the 2°C limit imposed by the international standard for implantable devices. A 3D finite element model, including blood perfusion and natural convection fluid flow of the eye, was created. The device was placed 1.95 mm from the iris, which experienced less than 2°C rise in the tissue temperature at a maximum power dissipation of LED at 100 mW and microdisplay at 25 mW.
RESUMO
The cornea is a transparent tissue in front of the eye that refracts light and facilitates vision. A slight change in the geometry of the cornea remarkably affects the optical power. Because of this sensitivity, biomechanical study of the cornea can reveal much about its performance and function. In vivo and in vitro studies have been conducted to investigate the mechanics of the cornea and determine its characteristics. Numerical techniques such as the finite element method (FEM) have been extensively implemented as effective and noninvasive methods for analyzing corneal mechanics and possible disorders. This article reviews the use of FEM for assessing the mechanical behavior of the cornea. Different applications of FEM in corneal disease studies, surgical predictions, impact simulations, and clinical applications have been reviewed. Some suggestions for the future of this type of modeling in the area of corneal mechanics are also discussed.
Assuntos
Córnea/fisiologia , Topografia da Córnea , Análise de Elementos Finitos , Córnea/anatomia & histologia , Humanos , Propriedades de SuperfícieRESUMO
The cornea is a transparent tissue in front of the eye that refracts light and facilitates vision. A slight change in the geometry of the cornea remarkably affects the optical power. Because of this sensitivity, biomechanical study of the cornea can reveal much about its performance and function. In vivo and in vitro studies have been conducted to investigate the mechanics of the cornea and determine its characteristics. Numerical techniques such as the finite element method (FEM) have been extensively implemented as effective and noninvasive methods for analyzing corneal mechanics and possible disorders. This article reviews the use of FEM for assessing the mechanical behavior of the cornea. Different applications of FEM in corneal disease studies, surgical predictions, impact simulations, and clinical applications have been reviewed. Some suggestions for the future of this type of modeling in the area of corneal mechanics are also discussed.
A córnea é um tecido transparente na parte frontal do olho, que refrata a luz e torna a visão possível. Uma ligeira alteração na geometria da córnea notavelmente afeta a sua potência óptica. Devido a essa sensibilidade, o estudo biomecânico da córnea pode revelar muito sobre o seu desempenho e funcionalidade. Estudos in vivo e in vitro foram realizados para investigar a mecânica da córnea e para determinar suas características. Técnicas numéricas como o método dos elementos finitos (FEM) foram amplamente implementadas como métodos eficazes e não invasivos de análise mecânica da córnea e seus possíveis transtornos. Este artigo analisa o uso de FEM para avaliar o comportamento mecânico da córnea. Diferentes aplicações da FEM no estudo de doenças da córnea, previsões cirúrgicas, simulações de impacto e aplicações clínicas foram revistos. São discutidas algumas sugestões para o futuro deste tipo de modelagem na área de mecânica de córnea.