%0 Journal Article
%T Corneal Biomechanical Properties in Different Ocular Conditions and New Measurement Techniques
%A Nery Garcia-Porta
%A Paulo Fernandes
%A Antonio Queiros
%A Jose Salgado-Borges
%A Manuel Parafita-Mato
%A Jose Manuel Gonz¨¢lez-M¨¦ijome
%J ISRN Ophthalmology
%D 2014
%R 10.1155/2014/724546
%X Several refractive and therapeutic treatments as well as several ocular or systemic diseases might induce changes in the mechanical resistance of the cornea. Furthermore, intraocular pressure measurement, one of the most used clinical tools, is also highly dependent on this characteristic. Corneal biomechanical properties can be measured now in the clinical setting with different instruments. In the present work, we review the potential role of the biomechanical properties of the cornea in different fields of ophthalmology and visual science in light of the definitions of the fundamental properties of matter and the results obtained from the different instruments available. The body of literature published so far provides an insight into how the corneal mechanical properties change in different sight-threatening ocular conditions and after different surgical procedures. The future in this field is very promising with several new technologies being applied to the analysis of the corneal biomechanical properties. 1. Introduction Corneal biomechanics is a branch of science that studies deformation and equilibrium of corneal tissue under the application of any force [1]. The structure and hence the properties of a soft tissue, such as the cornea, are dependent on the biochemical and physical nature of the components present and their relative amounts. The mechanical properties of a tissue depend on how the fibres, cells, and ground substance are organized into a structure [2]. Collagen and elastin are responsible for the strength and elasticity of a tissue, while the ground substance is responsible for the viscoelastic properties. All these terms are important because the cornea is considered a viscoelastic material and some devices try to measure and even differentiate between the different components of the biomechanical behavior of the living corneal tissue [3]. In the specific case of the human cornea, collagen in Bowman¡¯s layer and stroma accounting for over 80% of the dry weight of the cornea would be the major contributor to corneal elasticity. The ground substance, formed mostly by proteoglycans and keratocytes or fibroblasts, would provide the viscous behaviour. The corneal epithelium accounting for 10% of the central corneal thickness could also contribute to the viscous behaviour. It is important to bear in mind that the corneal epithelium is easily deformable and is the reference surface for most of the biomechanical corneal measurements. Over the past two decades, researchers have developed a variety of techniques that can alter corneal surface
%U http://www.hindawi.com/journals/isrn.ophthalmology/2014/724546/