灌注的人眼和兔眼角膜前后基质的超微结构。与透明度的关系。

Ultrastructure in anterior and posterior stroma of perfused human and rabbit corneas. Relation to transparency.

作者信息

Freund D E, McCally R L, Farrell R A, Cristol S M, L'Hernault N L, Edelhauser H F

机构信息

Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723-6099, USA.

出版信息

Invest Ophthalmol Vis Sci. 1995 Jul;36(8):1508-23.

PMID:7601631

Abstract

PURPOSE

The authors sought to discover whether there are differences in the degree of spatial order in the fibrillar ultrastructure between anterior and posterior stroma.

METHODS

Human corneas were obtained from eye bank eyes. Although they had been classified as normal, some swelling remained after 3 hours of deturgescence. Freshly excised, unswollen rabbit corneas also were used. Image analysis methods were applied to transmission electron micrographs of the anterior, middle, and posterior stroma of these corneas to determine the positions and radii of fibrils, the fraction of total area occupied by fibrils, and the fibril number density. Results were used to calculate the interference factor that appears in the direct summation of the fields for light scattering theory and to estimate the total scattering cross-section per fibril. The interference factor is a measure of the spatial order in the positions and sizes of the fibrils.

RESULTS

Electron micrographs showed anterior-posterior variations in size and number density of fibrils. The interference factor at wavelengths of visible light was lower in posterior stroma than in anterior stroma for humans and rabbits. In some instances in humans, the anterior interference factor was characteristic of mildly swollen cornea. When averaged for the electron micrographs analyzed, the anterior stroma was predicted to scatter approximately twice as much light per unit depth as the posterior stroma in humans (at any given wavelength) and approximately three times as much in rabbits.

CONCLUSIONS

Calculations of the interference factor showed that there were differences in the anterior-posterior spatial ordering of fibrils. In human corneas, the differences could have been caused by intrinsic in vivo differences between anterior and posterior stroma; however, possible anterior-posterior variations in swelling between the two regions in vitro also could have affected the results.

摘要

目的

作者试图探究角膜前基质和后基质的纤维超微结构在空间排列程度上是否存在差异。

方法

从眼库获取人角膜。尽管这些角膜被归类为正常，但在脱水3小时后仍有一些肿胀。还使用了刚摘除的、未肿胀的兔角膜。将图像分析方法应用于这些角膜前、中、后基质的透射电子显微照片，以确定纤维的位置和半径、纤维占据的总面积比例以及纤维数密度。结果用于计算光散射理论中场的直接求和中出现的干涉因子，并估计每根纤维的总散射截面。干涉因子是纤维位置和大小空间排列的一种度量。