Changes in ocular dimensions and refraction with accommodation
Changes in ocular dimensions and refraction with accommodation
复制标题
DOI：
10.1111/j.1475-1313.1997.tb00518.x
复制
发表时间：
1997-01-01
影响因子：
2.9
通讯作者：
Yap, MKH
中科院分区：
文献类型：
--
作者：
Garner, LF;Yap, MKH
本研究的目的是测量眼的尺寸与调节的变化，特别是参考曲率半径的后表面的晶体透镜。眼的屈光力随调节的增加被认为主要是由于透镜前表面曲率半径的减小而引起的，后表面的作用有些不清楚。我们测量了11名受试者的眼轴尺寸（A-扫描超声检查）、角膜曲率半径（角膜曲率计）、屈光不正（自动验光仪）和晶状体表面曲率半径（视频晶状体测量法），平均年龄21.2 ± 2.6岁，5个水平的眼调节，最高达8.00 D。在最大调节下，平均变化为前房深度减少0.24 mm，透镜厚度增加0.28 mm，透镜前表面曲率半径减少4.95 mm，后表面曲率半径减少1.34 mm。对于透镜的等效折射率为1.422，透镜状表面的光焦度的相应增加对于前表面和后表面分别为5.53 D和3.10 D。眼轴长度和玻璃体腔深度无明显变化。我们的结论是，当晶体透镜功率计算的基础上的等效折射率，在透镜的后表面的变化有助于约三分之一的增加透镜功率与8.00 D的眼调节。Copyright（C）1996 The College of Optometrists.
The purpose of this study was to measure the changes in ocular dimensions with accommodation, with particular reference to the radius of curvature of the posterior surface of the crystalline lens. The increase in power of the eye with accommodation is considered to arise primarily from a decrease in the radius of curvature of the anterior surface of the lens, with the role of the posterior surface somewhat unclear. We measured the axial dimensions (A-Scan ultrasonography), corneal radius of curvature (keratometry), refractive error (autorefractor) and radii of curvature of the lenticular surfaces (video phakometry) for 11 subjects, mean age 21.2 +/- 2.6 years, for five levels of ocular accommodation up to 8.00 D. At maximum accommodation the mean changes were a decrease in anterior chamber depth of 0.24 mm, an increase in lens thickness of 0.28 mm, a decrease in radius of curvature of the anterior surface of the lens of 4.95 mm and 1.34 mm for the posterior surface. The corresponding increase in power of the lenticular surfaces for an equivalent refractive index of 1.422 for the lens was 5.53 D and 3.10 D for the anterior and posterior surfaces respectively. No significant changes were recorded in axial length or vitreous chamber depth. We conclude that when crystalline lens power is calculated on the basis of an equivalent refractive index, changes in the posterior surface of the lens contribute around one third of the increase in lens power associated with 8.00 D of ocular accommodation. Copyright (C) 1996 The College of Optometrists.