角膜后表面屈光力理论计算值与Orbscan测量值的比较

目的 比较角膜后表面屈光力理论计算值与角膜地形图(Orbscan)测量值之间的差异,评价Orbscan在角膜屈光手术领域的应用价值。 方法 应用球面折射公式计算64例64眼角膜后表面屈光力;Orbscan测量受试者角膜后表面屈光力。结果 角膜后表面屈光力Orbscan平均测量值为-6.59 D±0.22 D,平均理论计算值为-5.04 D±0.14 D,Orbscan平均测量值与平均理论计算值差异为-1.55 D±0.19 D(P<0.01)。 结论 角膜后表面屈光力Orbscan测量值大于理论计算值-1.55 D。Orbscan测量角膜后表面屈光力的准确性尚需进一步探讨。     

Orbscan与EyeSys角膜地形图、角膜曲率计测量角膜曲率的比较

目的比较裂隙扫描角膜地形图/角膜测厚系统(Orbscan Corneal Topography     

ORBSCAN Ⅱ在不同年龄组的临床应用研究

目的　观察 Orbscan 眼前节分析诊断系统在测量不同年龄组角膜屈光力、角膜厚度、前房深度及角膜前后表面高度等方面的临床应用价值。方法　选择青年组 77只眼、老年组 5 0只眼 ,采用 Orbscan 眼前节分析诊断系统进行检查 ,分别计算角膜屈光力、角膜厚度、前房深度及角膜前后表面高度 ,并进行比较。结果　两组在角膜屈光力、前房深度及角膜前表面高度均存在显著差异 ,而在角膜厚度、角膜后表面高度方面两组差异无显著意义。结论　 Orbscan 眼前节分析诊断系统是一种无创伤的眼前部生物测量仪器 ,测量范围广 ,精确性高 ,具有较高的应用价值     

Orbscan角膜地形图系统测量误差的分析

目的：探讨Orbscan角膜地形图系统（Orbscan系统）的测量误差及其影响因素,为临床使用提供依据。方法：使用Orbscan系统和A超仪,测量200例（400只眼）行准分子激光原位角膜磨镶术（laser in situ keratomileusis,LASIK）患者和50例（100只眼）行准分子激光屈光性角膜切削术（photorefractive keratectomy,PRK）患者手术前、后的角膜厚度和中央前房深度;分别于PRK和LASIK手术前、后使用Orbscan系统测量患者的角膜后表面屈光力,并对测量值进行分析比较。结果：Orbscan系统测量的角膜厚度值LASIK和PRK术前低于A超仪的测量值,差值为18.83-24.29μm;LASIK和PRK术后与A超仪测量值的差值为56.32-139.52μm,明显高于术前。LASIK和PRK手术前、后Orbscan系统测量的中央前房深度值与A超仪测量值的差值为0.16-0.25mm,无临床意义。LASIK手术前、后Orbscan系统测量的角膜后表面屈光力差值约为-0.60D;PRK手术前、后Orbscan系统测量的角膜后表面屈光力差值低度组为-0.51D,中度组为-1.12D。结论：Orbscan系统测量值的精确性尚待进一步提高;LASIK和PRK术后角膜雾状混浊和角膜前表面屈光力的改变是导致Orbscan系统测量误差较大的主要原因;Orbscan系统的测量误差是临床工作不可忽视的重要问题。     

裂隙扫描角膜地形图角膜测厚系统的临床与科研应用

90年代中期发展起来的裂隙扫描角膜地形图/角膜测厚系统（Orbscan corneal topography system)基于光学裂隙扫描原理，能一次性测量角膜前后表面曲率，角膜前后表面隆起度和角膜厚度，目前研究已经显示其在角膜屈光手术，接触镜验配，干眼症和圆锥角膜的诊断及眼眼库眼球角膜的筛选等诸多领域的应用价值。本综述结合新近相关文献。概述了Orbscan在上述领域的应用。     

超声角膜测厚仪和Orbscan测量LASIK术后角膜厚度的比较

目的　比较不同的方法测量LASIK术后角膜厚度的差异及其相关性。方法　分别用美国DGH 40 0 0型超声角膜测厚仪和Orbscan Ⅰ眼前节系统测量LASIK术后 3个月以上的患眼角膜厚度 ,各测量 3次 ,取其平均值并进行比较。结果　超声角膜测厚仪测量值平均为 (4 4 5 66± 3 2 16) μm ,Orbscan测量值平均为 (3 95 5 0± 3 8 5 0 ) μm ,两者相差(5 0 17± 15 2 7) μm ,在统计学上有显著性差异 (P <0 0 1)。将两种方法测量结果作相关性分析 (r =0 92 2 ,P <0 0 1) ,呈显著正相关。回归方程如下 :超声角膜测厚仪测量值 (μm ) =14 1 0 3 3 1+ [0 770 2×Orbscan测量值 (μm ) ]。 讨论　Orbscan的软件设计是引起两种检测方法差异的主要原因之一 ,LASIK术后角膜的改变也可影响测量结果。对于外伤性角膜疾病及屈光手术后角膜厚度的测量 ,应将两种方法互为参照     

不同角膜曲率测量方法结果的比较

目的:比较Orbscan眼前节系统与RKT-7700自动式角膜曲率计及手动式角膜曲率计测量角膜曲率的差异。方法:对50例100眼分别进行Orbscan、自动式和手动式角膜曲率计角膜曲率测量。结果:Orbscan、RKT-7700自动式及手动式角膜曲率计角膜曲率测量值分别为:43.42±1.45,43.63±1.50,42.33±1.37D。测量的K1,K2,K,d值均以RKT-7700自动式角膜曲率计为最高,手动式曲率计值最低,手动式角膜曲率计测量值较Orbscan角膜曲率测量值偏低1.0838D(P<0.000);手动式角膜曲率计较RKT-7700自动式角膜曲率计低1.296D(P<0.000);自动式角膜曲率计比Orbscan角膜曲率测量值高0.212D(P=0.294)。Orbscan-II眼前节系统与RKT-7700自动式角膜曲率计间各测量值均无显著性差异。各检测方法间角膜散光值(d)均无显著性差异。手动式角膜曲率计测量的K1,K2,K值与Orbscan-II眼前节系统及RKT-7700自动式角膜曲率计有显著性差异。结论:不同角膜曲率测量仪的测量结果有一定的差异。RKT-7700自动式角膜曲率计测量值最高,手动式角膜曲率计测量值最低,Orbscan眼前节系统与RKT-7700自动式角膜曲率计测量值差异没有显著性。     

Orbscan系统在白内障超声乳化手术前后的应用研究进展

近年来Orbscan系统被逐步应用于临床,关于其对角膜屈光力、散光度、角膜厚度及前房深度等方面也有较多研究.文中重点分析并比较Orbscan系统在研究白内障超声乳化手术前后测量角膜屈光力、散光度、角膜厚度及前房深度等指标中的应用,及其与其他传统测量方式的分析比较.     

三种角膜测厚仪测量近视患者中央角膜厚度的对比

目的:利用LenstarLS900,OrbscanⅡ系统及A超角膜测厚仪测量近视眼患者中央角膜厚度(central corneal thickness,CCT),探讨三种测量方法的差异,并对结果进行相关性和一致性评价,为临床应用提供理论依据。方法:随机选取角膜屈光手术术前近视眼患者35例70眼分别用Lenstar LS900,OrbscanⅡ及A超角膜测厚仪依次重复测量CCT3次,取其平均值进行统计学分析。不同方法测量CCT之间采用随机区组方差分析,组内两两比较采用LSD-t检验,三种测量方法之间的相关性采用直线相关分析,一致性检验采用Bland-Altman分析。以P<0.05为差异有统计学意义。结果:Lenstar LS900,OrbscanⅡ及A超角膜测厚仪测得的近视眼患者CCT均数分别为542.75±40.06,528.74±39.59,538.54±40.93μm。Lenstar LS900的测量值较A超角膜测厚仪的测量值大4.21±8.78μm,较OrbscanⅡ测量值大14.01±13.39μm,OrbscanⅡ测量值较A超角膜测厚仪小9.8±10.57μm,差异均有统计学意义(P<0.05)。3种不同仪器测量结果均具有显著相关性,Lenstar LS900和A超角膜测厚仪、OrbscanⅡ测量值呈正相关:r=0.977(P<0.05),r=0.944(P<0.05)。Bland-Altman方法分析:Lenstar LS900和A超角膜测厚仪95%一致性区间上下值为-13.0～21.4μm,1.4%的点在95%的一致性界限以外,OrbscanⅡ与A超角膜测厚仪95%一致性区间上下值为-30.5～10.9μm,7.1%的点在95%一致性界限以外,LenstarLS900和A超角膜测厚仪一致性更好。结论:LS900与A超角膜测厚仪和OrbscanⅡ系统测量CCT一致性及相关性好,Lenstar LS900可以作为近视患者CCT的非接触式测量工具。     

基于角膜地形图仪系统的数据获取研究与实现

目的 应用Orbscan II角膜地形图仪系统,设计开发角膜数据分析软件来自动获取角膜数据,为角膜的临床诊断提供自动分析功能。方法 实验研究。在现有的角膜地形图仪系统的基础上,角膜数据分析软件通过API Hook挂接到Orbscan进程,在检查测量角膜过程中,由程序即时获取数据,并通过共享内存文件的方式,将数据读取到角膜数据分析软件的程序进程当中,实现角膜数据的采集、获取及分析。结果 对获取的数据进行偏微分分析和拟合回归处理,计算产生360条半子午线的Q值。在VC++6.0开发环境下,利用OpenGL绘图技术,形象地展示了个体化角膜表面的非球面性质及形态图形。结论 角膜数据分析软件能自动获取Orbscan II角膜地形图仪系统中的角膜数据,达到软件开发上的无缝链接,提供实际三维角膜形态与Q值分布图,更好地扩展了角膜地形图仪系统的功能,为角膜的进一步研究提供数据基础和自动分析功能。     

美容性角膜覆盖术疗效观察

目的:评价美容性角膜覆盖术治疗角膜(角巩膜)葡萄肿的临床效果。方法:对22例角膜(角巩膜)葡萄肿患者进行了美容性角膜覆盖术治疗。术后对所有病例的临床效果进行了随访观察。结果:22例均治愈,残留部分视力的2例的视力术后有所改善(2例2眼从术前手动/眼前到术后指数/眼前)。22例无1例发生排斥,角膜覆盖片的颜色除第1例因缺乏经验术眼的颜色明显深于对侧正常或正常人群眼的颜色外,其它无1例褪色。结论:应用角膜覆盖术治疗角膜(角巩膜)葡萄肿22例(22眼)临床证明疗效确实、安全可靠。     

Influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis and corneal resistance factor

Background: This study investigated the influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis (CH) and the corneal resistance factor (CRF) in a group of normal Chinese persons. Methods: Ninety‐five participants were recruited and data from the eye with higher corneal astigmatism were analysed. The anterior corneal curvature was measured by corneal topography. The Goldmann‐correlated intraocular pressure (IOPg), corneal‐compensated intraocular pressure (IOPcc), CH and CRF at different meridians (default horizontal position, 10°, 20° and 30° along the superotemporal and inferonasal meridians) were obtained from an ocular response analyser. The corneal powers at these specific meridians also were calculated. Results: At the default position, the IOPg and CRF had weak correlations with corneal astigmatism, while the IOPcc and CH were not significantly correlated with corneal astigmatism. Both the IOPg and IOPcc were measured significantly higher at the default position. The CH and CRF were lower at the default position but the difference in the CRF from obliquity could not reach statistical significance. The CH was not significantly correlated with the corneal power at all meridians. The CRF correlated with the corneal power only at 30° superotemporal. Conclusion: Corneal astigmatism and head tilt did not have much effect on the measurement of CH and the CRF, both of which were lowest along the horizontal meridian. Clinically, the difference was small. The influence of corneal power on CH and the CRF was minimal.     

Anterior amorphous corneal opacity and corneal thinning

PurposeTo present the clinical features of four cases with bilateral anterior amorphous corneal opacity.MethodsA retrospective study in four patients with bilateral anterior amorphous corneal opacity was conducted. Examinations included visual acuity, keratometry, slit-lamp biomicroscopy, confocal microscopy, anterior segment optical coherence topography, and histology.ResultsThree female and one male patients (mean age, 52.3 ± 8.9 years) showed bilaterally oval, amorphous sheetlike corneal opacities with central depression and thinning. Superior limbal opacities were observed in two of these patients. The best-corrected visual acuity ranged from 20/50 to 20/400, and the mean of the keratometry was 39.81 ± 3.97 D (diopters). They had mild dry eyes. The anterior segment optical coherence topography demonstrated hyporeflective abnormalities in the anterior depressed stroma in these four patients. Confocal microscopy revealed large round cells at the epithelial layer in one patient, and amorphous opacities with some strand-shaped opacities in the anterior stroma in all four patients. The mean of the corneal endothelial cells density in the eight eyes was 1521 ± 402 cells/mm². Central corneal stromalysis occurred in three patients, and descemetocele developed in two eyes. One patient received penetrating keratoplasty and two underwent lamellar keratoplasty. The histology of the corneal specimen revealed edematous basal epithelial cells, focal collagen disorganization in the thin stroma, and wartlike excrescences in a thickened Descemet's membrane.ConclusionAnterior amorphous corneal opacity is a rare keratopathy and may be one kind of rare corneal degeneration or dystrophy. Corneal stromalysis may occur in hyporefrective amorphous opacities and progress to descemetocele.     

角膜生物力学与光密度相关性研究

目的:探究角膜生物力学与角膜光密度的相关性。方法:前瞻性研究。选取2019-03/06在云南省第二人民医院拟行角膜屈光手术术前检查的患者为研究对象。采用Pentacam HR眼前节分析系统进行角膜光密度测量,以角膜顶点为中心,分为0~2mm、> 2~6mm、> 6~10mm直径范围3个区域,以角膜厚度分为前、中、后3层。选取Pentacam HR中角膜最薄点厚度值纳入研究。采用Corvis ST角膜生物力学分析仪测量,相关参数包括第一次压平的长度(AP1L)和速率(AP1V)、第2次压平的长度(AP2L)和速率(AP2V)、最大凹陷时顶点距离(PD)、曲率半径(HCR)和形变幅度(DA)。运用Pentacam&Corvis ST生物力学联合诊断平台软件综合分析检查结果,得出综合角膜生物力学参数(CBI)以及其它独立参数包括硬度参数(SP)、综合半径(IR)、Ambrosio相关厚度-水平方向(ARTh)、形变幅度比(DAR)。各区域光密度间差异采用方差分析,角膜生物力学各项参数与各区域光密度的相关性采用Pearson或Spearman分析。结果:不同直径范围、不同层面间光密度有差异(F=35.101,P<0.01;F=1002.897,P<0.01),CBI与独立生物力学参数中AP2L、AP2V、PD、DA、SP、IR、ARTh、DAR具有相关性(rs=-0.502,P<0.01;rs=-0.457,P=0.001;rs=0.428,P=0.002;rs=0.539,P<0.01;rs=-0.687,P<0.01;rs=0.716,P<0.01;rs=-0.728,P<0.01;rs=0.750,P<0.01)。CBI与角膜0~2mm范围内光密度呈正相关(r=0.343,P=0.015)。0~2mm范围内光密度与独立生物力学参数中AP2L、IR、ARTh、DAR有相关性(rs=-0.298,P=0.035;rs=0.368,P=0.009;rs=-0.419,P=0.002;rs=0.493,P<0.01)。结论:角膜中央区域光密度与角膜生物力学具有显著的关联,临床中可以通过光密度和生物力学对角膜健康状况进行综合评价。     

角膜基质透镜在角膜溃疡或穿孔修复中的应用

目的：研究由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植材料治疗角膜溃疡的临床疗效。

方法：回顾性病例研究。收集本院2017-01/06角膜溃疡患者6例6眼,其中细菌性、真菌性、深层异物伴感染各1例1眼,角膜穿孔3例3眼。采用由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植的材料进行修复手术,确保植片与角膜层间无空气间隙。术后随访1～6(平均3.71±1.56)mo,观察手术前后视力、角膜移植物存活情况及术后并发症发生情况等。

结果：所有患者均在控制感染下顺利完成手术,无术中并发症。术后所有角膜植片透明。末次随访时,患者最佳矫正视力(best corrected visual acuity,BCVA)较术前明显改善(0.48±0.12 vs 1.50±0.08),差异具有统计学意义(P<0.01)。

结论：来源于全飞秒激光屈光手术的角膜基质透镜用于角膜溃疡修复是安全有效的,但植片的远期疗效尚需进一步观察。     

角膜内皮炎的角膜内皮细胞形态改变

目的探讨角膜内皮炎对患者中央角膜内皮细胞形态的影响。方法用EM-1000型接触式角膜内皮镜对10例单眼角膜内皮炎愈后4-12周的患者的双眼分别摄取中央角膜内皮像并对其图像进行电脑分析。患眼作为实验组。健眼作为对照组。观察其角膜内皮细胞密度。六角形细胞的百分比及异形性的变化。用计量资料配对设计的2样本均数的t检验进行统计分析（双侧检验，P〈0．01为统计学有差异）。结果在10例临床诊断角膜内皮炎愈后的患者中，中央角膜内皮细胞密度实验组平均为（1981±181）／mm^2。对照组平均为（2284±315）／mm^2。六角形细胞比例实验组平均为34％，对照组平均为43％．变异系数实验组平均为53％，对照组平均为45％．以上各项观察指标实验组与对照组之间在统计学上都存在显著性差异（P〈0．01）。结论角膜内皮炎对角膜内皮细胞造成损伤，导致严重的形态改变，在临床工作中应给予充分重视。[眼科新进展2007；27（2）：138-139]     

Alcohol delamination of the corneal epithelium for recurrent corneal erosion syndrome

AIM: To evaluate the outcomes of alcohol delamination (ALD) of the corneal epithelium for the treatment of recurrent corneal erosion syndrome (RCES) and to implement a standardized treatment protocol for this condition utilizing evidence based practice and the findings of an internal audit. METHODS: A retrospective analysis of 42 eyes of 40 patients diagnosed with RCES who were treated with ALD between January 2006 and March 2016 was conducted. Patients had 20% alcohol applied to the cornea with the use of a well for 40s. Patients were reviewed one week later in the Outpatient Department. Outcome criteria were established based on standards from other studies in the medical literature. These included, a treatment success rate of at least 72% (defined as complete resolution of symptoms one month after treatment), a postoperative complication a rate of <5% (mainly infective keratitis, and subepithelial haze), and the absence of any detrimental effect on visual acuity in ≥95% of patients. RESULTS: The mean age at the time of ALD was 41.17±13.44y. Patients were followed for an average of 12.8±15.65mo. The majority were female (52.5%, n=21) and the majority of eyes treated with ALD were left eyes (62.9%, n=26). Trauma was the primary aetiology in our study population. Treatment was successful in 73.8% (n=31) of eyes and in 75% (n=30) of patients. Recurrence occurred in 26.2% of eyes at a mean of 10.41±12.63mo post treatment. CONCLUSION: ALD is an efficacious and cost-effective primary surgical intervention for RCES.     

Orbscan-II角膜地形图仪与超声角膜测厚仪角膜测厚结果的对比分析

目的:探讨Orbscan-II角膜地形图仪与角膜测厚仪对角膜测厚的结果差异的统计学及临床意义。方法:选115例204眼(右104眼,左100眼)分别行Orb-scan-II及超声测厚法测量角膜厚度,经统计学检验后进行分析。结果:204眼Orbscan-II所得结果为527.20±37.83,超声测厚法所得结果为525.25±34.83,行配对t检验,t=2.407,P=0.017,认为两种测量方法结果的差异有统计学意义。进一步将角膜厚度分4组进行配对t检验,角膜厚度<500μm时,Orbscan-II测厚(478.36±14.47)与超声测厚(478.3±20.15)差异无统计学意义,角膜厚度≥500,<550μm时,Orbscan-II测厚(527.88±17.32)与超声测厚(525.32±12.92)差异有统计学意义(P=0.027),角膜厚度≥550,<600μm时,Orbscan-II测厚(571.24±14.89)与超声测厚(568.04±13.82)差异有统计学意义(P=0.022),角膜厚度≥600μm时,Orbscan-II测厚(615.33±8.50)与超声测厚(615.33±14.29)差异无统计学意义。结论:传统的超声测厚与Orbscan-II对角膜测厚结果有一定差异,并具统计学意义,但在临床意义上二者仍有较好的相符性。     

配戴软性角膜接触镜对角膜中央厚度影响的临床研究

目的:探讨配戴软性角膜接触镜对中央角膜厚度的影响。方法:应用超声角膜测厚仪检测中央角膜厚度,在我院近视患者中随机抽取配戴软性角膜接触镜者及不戴镜者各100例200眼,做统计分析。再在近视患者中按戴镜时间<1a,1～3a,3～5a,5～7a,≥7a分组,每组随机抽取60例120眼,做统计分析。结果:配戴软性角膜接触镜者与不戴镜者的角膜厚度比较,差异有统计学意义(P<0.05)。戴镜时间<1a,1～3a,3～5a,5～7a者的角膜厚度比较,差异有统计学意义(P<0.05)。结论:配戴软性角膜接触镜者平均中央角膜厚度薄于不戴角膜接触镜者,并且配戴软性角膜接触镜的时间越长中央角膜厚度越薄。     

Construction of a full-thickness human corneal substitute from anterior acellular porcine corneal matrix and human corneal cells

AIM: To construct functional human full-thickness corneal replacements. METHODS: Acellular porcine corneal matrix (APCM) was developed from porcine cornea by decellulariztion. The biomechanical properties of anterior-APCM (AAPCM) and posterior-APCM (PAPCM) were checked using uniaxial tensile testing. Human corneal cells were obtained by cell culture. Suspending ring was designed by deformation of an acupuncture needle. MTT cytotoxicity assay was used to check the cytotoxicity of suspending ring soaking solutions. A new three-dimensional organ culture system was established by combination of suspending ring, 48-well plate and medium together. A human full-thickness corneal substitute was constructed from human corneal cells with AAPCM in an organ coculture system. Biochemical marker expression of the construct was measured by immunofluorescent staining and morphological structures were observed using scanning electron microscopy. Pump function and biophysical properties were examined by penetrating keratoplasty and follow-up clinical observations. RESULTS: There were no cells in the AAPCM or PAPCM, whereas collagen fibers, Bowman’s membrane, and Descemet’s membrane were retained. The biomechanical property of AAPCM was better than PAPCM. Human corneal cells grew better on the AAPCM than on the PAPCM. There was no cytotoxicity for the suspending ring soaking solutions. For the constructed full-depth human corneal replacements keratocytes scattered uniformly throughout the AAPCM and expressed vimentin. The epithelial layer was located on the surface of Bowman’s membrane and composed of three or four layers of epithelial cells expressing cytokeratin 3. One layer of endothelial cells covered the stromal surface of AAPCM, expressed Na+/K+ATPase and formed the endothelial layer. The construct was similar to normal human corneas, with many microvilli on the epithelial cell surface, stromal cells with a long shuttle shape, and zonula occludens on the interface of endothelial cells. The construct withstood surgical procedures during penetrating keratoplasty. The corneal transparency increased gradually and was almost completely restored 7d after surgery. CONCLUSION: AAPCM is an ideal scaffold for constructing full-thickness corneal replacement, and functional human full-thickness corneal replacements are successfully constructed using AAPCM and human corneal cells.