角膜地形图与角膜曲率计在白内障手术前后评价

本文应用计算机辅助的角膜地形图系统TMS-1和角膜曲率计TOPCONOM-4同时测定了200例(278眼)的角膜地形图和中央角膜屈光状态。比较了角膜地形图的模拟角膜曲率SIMK值和角膜曲率计的垂直和水平屈光度。结果显示,白内障术前组116例150眼的SIMK平均值分别为44.22D(垂直轴)和44.26D(水平轴),角膜曲率计的中央屈光度垂直轴平均为44.16D,水平轴为44.23D。统计学处理表明,2种组方法的结果之间差异无显著性(P>0.05),第2种术后组67例90眼的SIMK平均值分别为46.37D(垂直轴)和43.06D(水平轴),角膜曲率计的中央屈光度垂直轴平均为46.09D,水平轴平均为42.88D,统计学处理二种方法的结果之间差异无显著性(P>0.05)。研究提示,角膜地形图系统的模拟角膜曲率SIMK值和角膜曲率计的屈光度无论在白内障手术前还是在手术后其结果是一致的,临床应用具有同等的价值。但是,当角膜中央屈光度异常范围小于3毫米,角膜混浊,角膜严重不规则散光时,角膜曲率计不能满足临床需要。而计算机辅助的角膜地形图系统则具有极大的诊断及检测价值。眼科学报 1994;10:85—89。     

Paracentral Corneal Dellen： A Rare Sign of Graves Ophthalmopathy

Purpose:To report a rare sign, paracentral corneal dellen that developed in a middleaged female patient with Graves ophthalmopathy.Methods:A paracentral corneal dellen developed in the left eye in a 42-year-old woman who was diagnosed as Graves ophthalmopathy. The patient had remarkable upper eyelid retraction, upper eyelid lag and upward motility restriction. The Graves ophthalmopathy was classified as Grade Ⅳ according to NOSPECS classification.Results:Local artificial tear film and 0.3％ Tobramycin eye drops were administered to both eyes.Twenty-four hours later, the left corneal dellen disappeared.Conclusions:Graves ophthalmopathy can lead to paracentral corneal dellen because of severe upper eyelid retraction and upward motility restriction of the eye in spite of the lack of lagophthalmos. Artificial tear drop and antibiotic eye drop therapy helped even though the patient did not have corneal exposure. Eye Science 2003;19:174-175.     

572例近视眼患者中央角膜厚度测量报告

本文作者在572例(1144只眼)近视眼患者拟行角膜放射状切开(RK)手术前,对角膜不同部位厚度进行了测量,对其值作统计学处理,均值及标准差为0.527±0.037mm,标准误为0.002,说明我国95％的近视眼患者中央角膜厚度范围为0.455—0.600mm。提示我国成人各年龄组左、右眼角膜厚度与左、右眼屈光度、性别、眼别无关。强调RK手术前对角膜厚度测量的重要性,但手术预后优劣为多因素所致。     

抽空房水C3F8充填前房中期全眼球湿房角膜保存的实验研究

采用抽空房水Ｃ３Ｆ８（全氟丙烷）充填前房全眼球湿房保存角膜内皮细胞活性。通过内皮细胞显微照相、内皮细胞活性染色（锥蓝联合茜素红染色）、扫描电镜、保存后的兔角膜行实验性同种异体穿透角膜移植，证实保存７天内皮细胞结构完整，功能良好。     

实验性单纯疱疹病毒Ⅰ型感染兔眼部扫描电镜观察研究

应用ＤＭＳＯ（Ｄｉｍｅｔｈｙｌｓｕｌｆｏｘｉｄｅ二甲基亚砜）冷冻割断制样扫描电镜技术首次动态观察了不同感染阶段（ｐｏｓｔＩｎｆｅｃｔｉｏｎ，ＰＩ）实验性单纯疱疹病毒性角膜炎（ＨＳＫ）兔的角膜、三叉神经节（ＴＧ）泪腺等组织的病变情况。初步报告并分析了各组织病变的扫描图像结果，并对冷冻割断法观察扫描电镜的原理及优缺点予以讨论，认为该技术应用于眼部单疱病毒感染的研究图像清晰、直观、简便可行，是一种有实用价值的方法。     

抗氧化剂对准分子激光兔角膜切削术后角膜组织的影响

目的 探讨局部应用抗氧化剂VitC、VitE对准分子激光屈光性角膜切削术(PRK)术后角膜组织的影响。方法 将24只实验免分成2组，每组12只，行双眼一5．0DPRK。一组术后左眼每日结膜下注射VitC0．1g，右眼为对照；另一组术后左眼每日结膜下注射VitE25mg，有眼为对照。于术后1、3、7、14天测定角膜组织超氧化物歧酶(super—oxide dismutase，SOD)、丙二醛(malondialdehyde，MDA)及谷肮甘肽过氧化物酶(glutathioneperoxNe，GSH—PX)的变化，观察其病理变化。结果 术后1、3天角膜SOD、GSH—Px活性小于对照组(P＜0．01)，MDA的水平高于对照组(P＜0．01)。局部应用抗氧化剂组其角膜SOD、GSH—PX活性高于单纯激光组(P＜0．01)，MDA水平低于单纯激光组(P＜0．01)。结论 准分子激光屈光性角膜切削术后，存在着氧自由基性的组织损伤破坏，局部应用VitC、VitE能降低角膜的自由基损伤。     

近视眼393例角膜偏心率与相关参数

目的 :研究近视眼患者的角膜偏心率 (e值 )及其与屈光度、角膜曲率、角膜散光之间的相互关联 .方法 :采用计算机辅助角膜地形图测量 ,对门诊屈光不正患者 393例 (76 2只眼 )的e值、屈光度、角膜曲率、角膜散光进行统计学分析 ;运用SPSS 10 .0统计软件作角膜偏心率的均数、标准差及其与各参数之间的相关分析 .结果 :本组患者的e值范围为 0～1.18(右 0～ 0 .73,左 0～ 1.18) ;e值为 0 .39± 0 .12 (右 0 .39±0 .11,左 0 .39± 0 .13) .e值与角膜散光呈负相关 (右眼Pear sonCorrelation =- 0 .10 5 ,P <0 .0 5 ;左眼PearsonCorrelation =- 0 .111,P <0 .0 5 ) .本组患者的e值与年龄、屈光度、角膜曲率均无显著关联 .结论 :角膜偏心率是屈光矫正的一项重要参数 ,推荐 0 .4作为年龄在 35岁以下的近视患者验配硬性隐形眼镜的e值     

A corneal model for slit-scanning elevation topography

Computerised videokeratography is increasing in sophistication and accuracy. The Orbscan II Videokeratographer combines the advantages of Placido derived and slit-scanning derived topography, to acquire shape information on the posterior surface of the cornea. The purpose of this paper is to construct a model of slit-scanning elevation topography and highlight potential sources of variation in this methodology. Ray tracing calculations were performed on a defined, theoretical, spherical model to obtain a pachymetric measurement. These calculations were tested by comparing the pachymetry measurement derived from the model, over a refractive index shift from 1.376 to 1.400 with the pachymetry measurement obtained by Orbscan II, of a human eye, with an identical alteration in refractive index. The two methods of measurement differed by only 0.157 microm, suggesting that the model is a good representation of slit-scanning elevation topography, and that refractive index variations have only a minimal effect on Orbscan II pachymetry measurement.     

Linear birefringence measurements of the in vitro human cornea

This paper presents results of an in vitro investigation of the optical anisotropy of the human cornea. Computer controlled imaging polarimetry and the Jones formalism were used to investigate the distribution of the birefringence and the azimuth angle across the surface of 12 corneas taken from the corneal bank. Each map of the birefringence and the azimuth angle has no rotational symmetry and is different for each cornea. The minimal value of the birefringence always appears in the corneal centre and varies from 9 to 43 degrees for different corneas. Birefringence of the cornea increases monotonically more than one order in the direction of the corneal periphery. Close to the centre of the cornea the azimuth angle is almost constant and varies significantly away from the optical part of the cornea.