Martin Heiner, Guthoff Rudolf, Terwee Thom, Schmitz Klaus-Peter
University of Rostock, Institute for Biomedical engineering, Germany.
Vision Res. 2005 Oct;45(22):2910-5. doi: 10.1016/j.visres.2005.05.030.
The accommodation process of the human eye is still a controversial subject. Coleman assumes that the lens, together with the zonula fibers, forms a diaphragm which is held in a catenary shape due to the pressure difference between the aqueous and vitreous body of the lens. The aim of the paper is to compare the results of two simulations (according to the Helmholtz and to the Coleman theories) with ultrasonographic data.
An axisymmetric static finite element model of the lens was generated using the literature data for geometry, material properties and loads. The refractive power of the lens was calculated for two different ages (29 and 45 years).
The application of a pressure to the posterior lens surface did not yield an increase in refractive power change during accommodation. Rather a decrease in accommodation related refractive power was found.
Physiologically relevant refractive power changes are obtained by a simulation in accordance with the Helmholtz theory. A simulation in accordance with the Coleman theory does not yield physiological values of refractive power change.
人眼的调节过程仍是一个有争议的话题。科尔曼认为，晶状体与小带纤维一起形成一个隔膜，由于晶状体房水和玻璃体之间的压力差，该隔膜呈悬链线形状。本文的目的是将两种模拟结果（根据亥姆霍兹理论和科尔曼理论）与超声数据进行比较。
利用文献中的几何形状、材料特性和载荷数据，生成了晶状体的轴对称静态有限元模型。计算了两个不同年龄（29岁和45岁）时晶状体的屈光力。
对晶状体后表面施加压力并不会使调节过程中屈光力变化增加。相反，发现与调节相关的屈光力有所下降。
根据亥姆霍兹理论进行的模拟可获得生理上相关的屈光力变化。根据科尔曼理论进行的模拟无法得出屈光力变化的生理值。
