超高频Scheimpflug角膜生物力学性能分析仪在圆锥角膜诊断中的应用

目的评估新型超高频Scheimpflug角膜生物力学性能分析仪在圆锥角膜（KC）中的诊断阈值及诊断价值。方法描述性研究。应用角膜生物力学性能分析仪测量2013年12月至2015年7月在温州医科大学附属眼视光医院就诊随机选取的KC患者53例（93眼,实验组）和屈光不正者84例（84眼,对照组）的12个相关参数,由同一位研究者操作;根据Amsler-Krumeich KC分期标准对KC进行分期,比较实验组与对照组参数差异,依据受试者工作特征曲线（ROC）探寻各参数在KC诊断阈值（COP）,其后依据曲线下面积（AUC）评估各参数的诊断价值。结果对于诊断阈值,与对照组相比,实验组的12个参数除第1次压平长度、第2次压平时间、最大形变幅度外,其余参数2组间差异均有统计学意义（P＜0.05）。各参数诊断阈值分别为：第1次压平时间≤6.90 ms,第1次压平速度＞0.17 m/s,第2次压平长度≤1.49 mm,第2次压平速度＞0.42 m/s,最大形变峰间距≥4.78 mm,最大形变幅度＞1.24 mm,最大形变曲率≤5.66 mm,最大形变时间≤16.40 ms,眼压≤13.50 mmHg,中央角膜厚度≤494 µm;其中最大形变曲率、第1次压平速度与最大形变时间拥有中等诊断效果,其AUC分别为0.738（敏感度为47.3%,特异度为94.0%）、0.751（敏感度为61.3%,特异度为88.1%）、0.887（敏感度为77.4%,特异度为91.7%）,中央角膜厚度与最大形变峰间距具有良好诊断效果,其AUC分别为0.926（敏感度为82.4%,特异度为92.9%）与0.930（敏感度为92.5%,特异度为85.7%）。结论依靠ROC AUC发现部分CorVis-ST参数对KC具有中度到良好诊断效果,其中角膜厚度及最大形变峰间距具有较好诊断效果,提示CorVis-ST可协助临床诊断KC。     

不同进展期圆锥角膜生物力学研究

目的:探讨可视化角膜生物力学分析仪(Corvis ST)测量正常角膜、顿挫期圆锥角膜、亚临床期圆锥角膜、临床期圆锥角膜的生物力学变化,分析不同进展期圆锥角膜生物力学特征,为更早期地诊断圆锥角膜提供临床依据.方法:病例对照研究.选取顿挫期圆锥角膜15眼为顿挫组,亚临床期圆锥角膜23眼为亚临床期组,临床期圆锥角膜40眼为圆锥角膜组,欲行近视激光手术和正常角膜志愿者40眼为正常组(对照组),应用Corvis ST测定各组的生物力学参数,并进行比较分析,绘制受试者工作曲线(ROC).结果:正常角膜与顿挫期圆锥角膜生物力学各参数差异均无统计学意义(P>0.05).正常角膜与亚临床期组第二压平长度(AL2)、第一压平速率(AV1)、最大压陷曲率半径(HC-radius)、最大压陷深度(DA)间的差异有统计学意义(P<0.05).正常角膜与圆锥角膜组除第二压平速度(AV2)、最大压陷时间(HC-time)、最大压陷屈膝峰间距(PD)差异无统计学意义外,其余生物力学数据差异均有统计学意义(P<0.05),ROC曲线分析DA对于圆锥角膜诊断效率最高(曲线下面积0.891±0.028).结论:顿挫期圆锥角膜生物力学较正常角膜无改变,亚临床期圆锥角膜生物力学较正常角膜部分参数有改变,但其参数单独诊断圆锥角膜特异性和敏感性均较差.临床期圆锥角膜生物力学较正常角膜明显改变,DA诊断效率最高.     

圆锥角膜患者角膜光密度与形态及生物力学的相关性研究

目的:探讨圆锥角膜患者角膜光密度与角膜形态参数及生物力学特性的相关性。方法:回顾性病例研究。收集2020-01/12在郑州市第二人民医院就诊的原发性圆锥角膜患者48例70眼,使用Pentacam眼前段分析系统测量角膜形态,包括角膜前表面中央扁平子午线曲率(K₁)、角膜前表面陡峭子午线曲率(K₂)、角膜前表面中央平均曲率(K_m)、角膜前表面最大曲率(K_max)、角膜前表面高度(ACE)、角膜后表面高度(PCE)、最薄点角膜厚度(TCT),以及圆锥锥顶距角膜顶点的距离(DCA)。测量不同分区不同层次的角膜光密度。使用可视化角膜生物力学测量仪观察角膜形变过程并测量相关参数,包括第一次压平时间(AT₁),第一次压平长度(AL₁),第一次压平速度(V₁),第二次压平时间(AT₂),第二次压平长度(AL₂),第二次压平速度(V₂),最大压陷时间(HCT),最大压陷形变幅度(HCDA...     

正常角膜及圆锥角膜的生物力学特性比较研究

目的 了解正常角膜和圆锥角膜的角膜滞后量(CH)和阻力因子量(CRF),探讨圆锥角膜形态和结构改变后对角膜生物力学特性的影响.方法 病例对照研究.选取同时期46只圆锥角膜眼作为圆锥角膜组,96只正常角膜眼作为对照组.用眼反应分析仪(ORA)测定两组眼的CH和CRF,并进行比较分析.其中对照组按角膜散光又分为高度散光(≥3.00 D)和中低度散光(<3.00 D);圆锥角膜组按Amsler-Krumeich法分为轻度(Ⅰ级)、中度(Ⅱ级)和重度(Ⅲ/Ⅳ级).对组间CH和CRF差异比较采用t检验或单因素方差分析.CH和CRF与中央角膜厚度,角膜曲率,角膜散光以及后表面高度间进行直线相关和多重回归分析,绘制CH和CRF的接受者工作特征(ROC)曲线.结果 CH和CRF在圆锥角膜组为(7.1±1.6)和(6.3±1.5)mm Hg(1 mm Hg=0.133 kPa),明显低于对照组的(10.1±1.3)和(10.5±1.6)mm Hg(t=-11.813,-14.943;P<0.001),分别下降(3.0±0.3)和(4.2±0.3)mm Hg.CH和CRF在对照组中的高度角膜散光和中低度角膜散光组之间差异无统计学意义(t=0.373,0.095;P>0.05).CH和CRF大小与圆锥角膜病变程度呈负相关(r=-0.627,-0.587;P<0.001).多重线性回归分析中,圆锥角膜组CH与角膜厚度和曲率相关(r=0.320,-0.375;P<0.05),CRF与角膜曲率相关(r=-0.441,P<0.01),而在对照组中两者与角膜厚度显著相关(r=0.367,0.459;P<0.001),与角膜曲率、散光无关(P>0.05).CH与CRF的ROC曲线下面积分别为0.9282和0.9731(Z=20.462,38.305;P<0.0001),两者之间差异有统计学意义(Z=7.134,P=0.008).结论 圆锥角膜的CH和CRF较正常角膜明显降低,尤以CRF更明显.对CH和CRF进行长期随访,有助于评估圆锥角膜的病变进程.CH和CRF可纳入诊断圆锥角膜的辅助检测指标.     

应用可视化角膜生物力学分析仪评估不同阶段圆锥角膜生物力学特征

目的应用可视化角膜生物力学分析仪（Corvis ST）比较圆锥角膜和正常角膜的生物力学特征,探讨角膜生物力学参数在圆锥角膜诊断中的作用及其相关影响因素。方法病例对照研究。选取圆锥角膜患者65例（90眼）（圆锥角膜组）,并按照Amsler-Krumeich分级法分为轻度圆锥角膜46眼、中度圆锥角膜23眼和重度圆锥角膜21眼;选取正常角膜对照者90例（90眼）作为正常角膜组。分别应用Pentacam眼前节分析系统测量眼前节形态参数;应用Corvis ST测量角膜生物力学参数。采用独立样本t检验、Wilcoxon秩和检验、ANOVA、非参数检验对比各组眼前节形态参数及生物力学参数并分析各参数间的相关性,绘制受检者工作特征（ROC）曲线。结果除前房角、第一压平长度、最大压陷时间和最大压陷屈膝峰间距外,圆锥角膜组其余眼前节形态参数和角膜生物力学参数与正常角膜组均有明显差异。ROC曲线分析显示,所测量的生物力学参数中,角膜最大压陷深度对于圆锥角膜的诊断效率最高（曲线下面积0.865、敏感度84.5%、特异度75.6%、截断点1.14 mm）,并且随着圆锥角膜严重程度的升级其诊断效率逐渐提高。在2组中角膜最大压陷深度与眼内压、中央角膜厚度和角膜中央3 mm内体积呈负相关（正常角膜组和圆锥角膜组,眼内压：r=-0.707、-0.213;中央角膜厚度：r=-0.219、-0.357;角膜中央：3 mm内体积r=-0.212、-0.27;P值均<0.05）。结论Corvis ST能够有效测量角膜生物力学特征,其测量参数中角膜最大压陷深度对于圆锥角膜具有诊断意义,但其与眼内压和角膜厚度呈负相关,临床应用中需特别注意相关影响因素。     

正常角膜及圆锥角膜的生物力学特性比较研究

Objective To compare the corneal hysteresis (CH) and corneal resistance factor (CRF) measured with the Ocular Response Analyzer (ORA) in normal and keratoconic eyes. Methods It was a case-control study. Random selected 96 normal eyes and 46 keratoconic eyes in the same period were included in this study. Normal eyes were divided into 2 groups: high corneal astigmatism (≥3.00 D) and low-to-moderate corneal astigmatism (<3.00 D). Keratoconic eyes were also divided into 3 groups based on Amsler-Krumeich classification: mild (stage Ⅰ), moderate (stage Ⅱ) and severe (stage Ⅲ/Ⅳ). CH and CRF were compared between groups and the areas under ROC curves of the CH and CRF were calculated. Results The mean CH and CRF were (7.1±1.6) mm Hg and (6.3±1.5) mm Hg in keratoconic eyes compared with (10.1±1.3) mm Hg and (10.5±1.6) mm Hg in normal eyes. The difference were statistically significant(t=-11.813, -14.943 ;P<0.001). In normal eyes, there was no difference of CH or CRF between the high corneal astigmatism and low-to- moderate corneal astigmatism (t=0.373,0.095; P>0.05). In keratoconic eyes, there was a significant negative correlation between CH and the keratoconus grade (r=-0.627, P<0.001) and the same relationship was found between CRF and the keratoconus grade (r=-0.587, P<0.001). In multiple linear regression analysis, CH was correlated with central corneal thickness (CCT) and corneal curvature (r=0.320, -0.375;P<0.05) and CRF was correlated with corneal curvature in keratoconic eyes (r=-0.441 ,P<0.01), while they were only correlated with CCT in normal eyes (r=0.367,0.459;P<0.001). The areas under ROC curves of the CH and CRF were 0.9282 and 0.9731 (Z=20.462,38.305 ;P<0.0001), the difference between them was significant (Z =7.134,P=0.008). Conclusions The CH and CRF were significantly lower in keratoconic eyes than in normal eyes, especially on CRF. The long-term follow-up of CH and CRF may provide information for evaluation of progression of keratoconus. They may be included as indicators for detecting keratoconus.     

正常角膜及圆锥角膜的生物力学特性比较研究

Objective To compare the corneal hysteresis (CH) and corneal resistance factor (CRF) measured with the Ocular Response Analyzer (ORA) in normal and keratoconic eyes. Methods It was a case-control study. Random selected 96 normal eyes and 46 keratoconic eyes in the same period were included in this study. Normal eyes were divided into 2 groups: high corneal astigmatism (≥3.00 D) and low-to-moderate corneal astigmatism (<3.00 D). Keratoconic eyes were also divided into 3 groups based on Amsler-Krumeich classification: mild (stage Ⅰ), moderate (stage Ⅱ) and severe (stage Ⅲ/Ⅳ). CH and CRF were compared between groups and the areas under ROC curves of the CH and CRF were calculated. Results The mean CH and CRF were (7.1±1.6) mm Hg and (6.3±1.5) mm Hg in keratoconic eyes compared with (10.1±1.3) mm Hg and (10.5±1.6) mm Hg in normal eyes. The difference were statistically significant(t=-11.813, -14.943 ;P<0.001). In normal eyes, there was no difference of CH or CRF between the high corneal astigmatism and low-to- moderate corneal astigmatism (t=0.373,0.095; P>0.05). In keratoconic eyes, there was a significant negative correlation between CH and the keratoconus grade (r=-0.627, P<0.001) and the same relationship was found between CRF and the keratoconus grade (r=-0.587, P<0.001). In multiple linear regression analysis, CH was correlated with central corneal thickness (CCT) and corneal curvature (r=0.320, -0.375;P<0.05) and CRF was correlated with corneal curvature in keratoconic eyes (r=-0.441 ,P<0.01), while they were only correlated with CCT in normal eyes (r=0.367,0.459;P<0.001). The areas under ROC curves of the CH and CRF were 0.9282 and 0.9731 (Z=20.462,38.305 ;P<0.0001), the difference between them was significant (Z =7.134,P=0.008). Conclusions The CH and CRF were significantly lower in keratoconic eyes than in normal eyes, especially on CRF. The long-term follow-up of CH and CRF may provide information for evaluation of progression of keratoconus. They may be included as indicators for detecting keratoconus.     

正常角膜及圆锥角膜的生物力学特性比较研究

Objective To compare the corneal hysteresis (CH) and corneal resistance factor (CRF) measured with the Ocular Response Analyzer (ORA) in normal and keratoconic eyes. Methods It was a case-control study. Random selected 96 normal eyes and 46 keratoconic eyes in the same period were included in this study. Normal eyes were divided into 2 groups: high corneal astigmatism (≥3.00 D) and low-to-moderate corneal astigmatism (<3.00 D). Keratoconic eyes were also divided into 3 groups based on Amsler-Krumeich classification: mild (stage Ⅰ), moderate (stage Ⅱ) and severe (stage Ⅲ/Ⅳ). CH and CRF were compared between groups and the areas under ROC curves of the CH and CRF were calculated. Results The mean CH and CRF were (7.1±1.6) mm Hg and (6.3±1.5) mm Hg in keratoconic eyes compared with (10.1±1.3) mm Hg and (10.5±1.6) mm Hg in normal eyes. The difference were statistically significant(t=-11.813, -14.943 ;P<0.001). In normal eyes, there was no difference of CH or CRF between the high corneal astigmatism and low-to- moderate corneal astigmatism (t=0.373,0.095; P>0.05). In keratoconic eyes, there was a significant negative correlation between CH and the keratoconus grade (r=-0.627, P<0.001) and the same relationship was found between CRF and the keratoconus grade (r=-0.587, P<0.001). In multiple linear regression analysis, CH was correlated with central corneal thickness (CCT) and corneal curvature (r=0.320, -0.375;P<0.05) and CRF was correlated with corneal curvature in keratoconic eyes (r=-0.441 ,P<0.01), while they were only correlated with CCT in normal eyes (r=0.367,0.459;P<0.001). The areas under ROC curves of the CH and CRF were 0.9282 and 0.9731 (Z=20.462,38.305 ;P<0.0001), the difference between them was significant (Z =7.134,P=0.008). Conclusions The CH and CRF were significantly lower in keratoconic eyes than in normal eyes, especially on CRF. The long-term follow-up of CH and CRF may provide information for evaluation of progression of keratoconus. They may be included as indicators for detecting keratoconus.     

正常角膜及圆锥角膜的生物力学特性比较研究

Objective To compare the corneal hysteresis (CH) and corneal resistance factor (CRF) measured with the Ocular Response Analyzer (ORA) in normal and keratoconic eyes. Methods It was a case-control study. Random selected 96 normal eyes and 46 keratoconic eyes in the same period were included in this study. Normal eyes were divided into 2 groups: high corneal astigmatism (≥3.00 D) and low-to-moderate corneal astigmatism (<3.00 D). Keratoconic eyes were also divided into 3 groups based on Amsler-Krumeich classification: mild (stage Ⅰ), moderate (stage Ⅱ) and severe (stage Ⅲ/Ⅳ). CH and CRF were compared between groups and the areas under ROC curves of the CH and CRF were calculated. Results The mean CH and CRF were (7.1±1.6) mm Hg and (6.3±1.5) mm Hg in keratoconic eyes compared with (10.1±1.3) mm Hg and (10.5±1.6) mm Hg in normal eyes. The difference were statistically significant(t=-11.813, -14.943 ;P<0.001). In normal eyes, there was no difference of CH or CRF between the high corneal astigmatism and low-to- moderate corneal astigmatism (t=0.373,0.095; P>0.05). In keratoconic eyes, there was a significant negative correlation between CH and the keratoconus grade (r=-0.627, P<0.001) and the same relationship was found between CRF and the keratoconus grade (r=-0.587, P<0.001). In multiple linear regression analysis, CH was correlated with central corneal thickness (CCT) and corneal curvature (r=0.320, -0.375;P<0.05) and CRF was correlated with corneal curvature in keratoconic eyes (r=-0.441 ,P<0.01), while they were only correlated with CCT in normal eyes (r=0.367,0.459;P<0.001). The areas under ROC curves of the CH and CRF were 0.9282 and 0.9731 (Z=20.462,38.305 ;P<0.0001), the difference between them was significant (Z =7.134,P=0.008). Conclusions The CH and CRF were significantly lower in keratoconic eyes than in normal eyes, especially on CRF. The long-term follow-up of CH and CRF may provide information for evaluation of progression of keratoconus. They may be included as indicators for detecting keratoconus.     

正常角膜及圆锥角膜的生物力学特性比较研究

Objective To compare the corneal hysteresis (CH) and corneal resistance factor (CRF) measured with the Ocular Response Analyzer (ORA) in normal and keratoconic eyes. Methods It was a case-control study. Random selected 96 normal eyes and 46 keratoconic eyes in the same period were included in this study. Normal eyes were divided into 2 groups: high corneal astigmatism (≥3.00 D) and low-to-moderate corneal astigmatism (<3.00 D). Keratoconic eyes were also divided into 3 groups based on Amsler-Krumeich classification: mild (stage Ⅰ), moderate (stage Ⅱ) and severe (stage Ⅲ/Ⅳ). CH and CRF were compared between groups and the areas under ROC curves of the CH and CRF were calculated. Results The mean CH and CRF were (7.1±1.6) mm Hg and (6.3±1.5) mm Hg in keratoconic eyes compared with (10.1±1.3) mm Hg and (10.5±1.6) mm Hg in normal eyes. The difference were statistically significant(t=-11.813, -14.943 ;P<0.001). In normal eyes, there was no difference of CH or CRF between the high corneal astigmatism and low-to- moderate corneal astigmatism (t=0.373,0.095; P>0.05). In keratoconic eyes, there was a significant negative correlation between CH and the keratoconus grade (r=-0.627, P<0.001) and the same relationship was found between CRF and the keratoconus grade (r=-0.587, P<0.001). In multiple linear regression analysis, CH was correlated with central corneal thickness (CCT) and corneal curvature (r=0.320, -0.375;P<0.05) and CRF was correlated with corneal curvature in keratoconic eyes (r=-0.441 ,P<0.01), while they were only correlated with CCT in normal eyes (r=0.367,0.459;P<0.001). The areas under ROC curves of the CH and CRF were 0.9282 and 0.9731 (Z=20.462,38.305 ;P<0.0001), the difference between them was significant (Z =7.134,P=0.008). Conclusions The CH and CRF were significantly lower in keratoconic eyes than in normal eyes, especially on CRF. The long-term follow-up of CH and CRF may provide information for evaluation of progression of keratoconus. They may be included as indicators for detecting keratoconus.     

应用Corvis ST新参数分析圆锥角膜生物力学特性

目的：:应用可视化角膜生物力学分析仪（Corvis ST）新参数分析临床期圆锥角膜、亚临床期圆锥角膜及正常角膜的生物力学特性,评价其在圆锥角膜诊断中的价值。方法：:病例对照研究。选取2019年1月至2021年1月在襄阳爱尔眼科医院就诊的圆锥角膜患者68例（68眼）,其中亚临床期圆锥角膜（SKC）28例（28眼）为SKC...     

Biomechanical diagnosis of keratoconus: evaluation of the keratoconus match index and the keratoconus match probability

Purpose:  To evaluate the diagnostic capacity of the Ocular Response Analyser’s keratoconus match index (KMI) and keratoconus match probability (KMP) classification in a sample of keratoconus (KC) patients. Methods: Keratoconus match index and KMP from 114 KC eyes, randomly selected from 114 patients with bilateral keratoconus (KCG), were compared with the corresponding ones from 109 normal eyes (CG). Keratoconus match index’s predictive accuracy was assessed by receiver operating curves (ROC). Keratoconus match probability level of agreement was evaluated at the different KC stages of the Amsler–Krumeich classification. Correlations were estimated with topographic keratoconus classification (TKC), keratoconus index (KI), index of surface variance (ISV), vertical asymmetry (IVA), height asymmetry (IHA), height decentration (IHD), minimal radius (Rmin), central corneal thickness (CCT), thinnest corneal thickness (TCT) mean keratometry (Km) and intraocular pressure (IOPg). Results: Mean KMI in KCG and CG was 0.20 ± 0.38 and 0.98 ± 0.25, respectively (p < 0.01). Significant KMI differences (p < 0.01) were detected in different KC groups [range: 0.62 ± 0.38 (KC 1), ?0.62 ± 0.04 (KC 4)]. Significant correlation was detected between KC staging and KMI (r = ?0.56, p < 0.0001). Keratoconus match probability identified 22.03% of the CG eyes as suspect. Moreover, KMP identified 7.01% and 23.68% of the KCG eyes as normal and suspect, respectively. Receiver operating curves analysis for KMI parameter indicated a predictive accuracy of 97.7% (cut‐off point: 0.512, sensitivity: 91.18%, specificity: 94.34%). Conclusions: Keratoconus match index seems to be a reliable index in keratoconus diagnosis and staging. Keratoconus match probability identifies a significant percentage of topographically defined KC and CG eyes as suspect. Diagnostic capacity of these novel indexes needs to be further explored.     

圆锥角膜的超微结构研究

目的 观察圆锥角膜的超微结构变化,拟发现圆锥角膜的特异性改变,为探讨其发病机制提供依据。方法 行穿透角膜移植术的圆锥角膜片２０例,分别用光镜和电镜观察其各层次的改变。结果 圆锥角膜上皮层、基质层变薄,基底膜及前弹力层局限性断裂或破坏;上皮基底细胞水肿,角膜细胞形态、结构改变,并似有异常吞噬现象;基质排列紊乱,板层间可见微粒状沉积物。结论 提示圆锥角膜的原发病变可能在角膜基质细胞。     

Polymorphism Analysis of VSX1 and SOD1 Genes in Greek Patients with Keratoconus

Background: A number of mutations in the VSX1 and SOD1 genes have been reported to be associated with keratoconus (KC), however the results from different studies are controversial. In this study, we conducted the genotyping of common polymorphisms [VSX1: D144E, H244R, R166W, G160D; SOD1: intronic 7-base deletion (c.169?+?50delTAAACAG)], in a case–control sample panel of the Greek population.

Materials and methods: A case–control panel, with 33 KC patients and 78 healthy controls, were surveyed. DNA from each individual was tested for the VSX1: D144E, H244R, R166W, G160D and SOD1: intronic 7-base deletion (c.169?+?50delTAAACAG) polymorphisms by direct sequencing.

Results: We observed no polymorphisms of the VSX1 gene in the case–control panel. Concerning the SOD1 intronic 7-base deletion (c.169?+?50delTAAACAG), our findings suggest that heterozygous carriers are over-represented among KC cases compared to healthy controls (p?=?0.002).

Conclusions: We cannot confirm the previously reported association of the polymorphism in the VSX1 gene with KC. Our results suggest a possible causative role of SOD1 in the pathogenesis of KC. Further studies are required to identify other important genetic factors involved in the pathogenesis and progression of KC.     

The Effect of Corneal Epithelium on Corneal Curvature in Patients with Keratoconus

Abstract

Objective: To investigate the effects of corneal epithelium on corneal curvature in patients with keratoconus. Design: This is a prospective, nonrandomized study. Participants: Fifty-nine eyes of 47 patients diagnosed as keratoconus and for whom corneal collagen crosslinking (CXL) was recruited in this study. Methods: This study is a single-center clinical trial. Pregnancy, lactation, connective tissue disease, corneal thickness below 350?μm, severe dry eyes, or scar of corneal surgery were exclusion criteria. Before and during CXL procedure after removing the corneal epithelium, maximum values of corneal apical curvature, simulated keratometry 1 (Sim-K1), simulated keratometry 2 (Sim-K2), temporal and inferior curvature values, all of which are 1.5?mm from the corneal center, were calculated. These values before and after removal of epithelium were compared statistically. Results: Mean age of patients was 23.30?±?5.5 (12–38) years. Twenty-eight (59%) were male while 19 (41%) were female. Mean values measured before and after removing the corneal epithelium were: apical curvature; 59.19?±?7.2 (47.06–82.40) diopter (D) and 61.70?±?8.8 (49.19–92.66) D (p?=?0.001), SimK1; 47.57?±?4.3 (39.14–64.57) D and 48.23?±?4.3 (41.89–66.70) D (p?=?0.001), SimK2; 52.04?±?5.3 (43.56–69.34) D and 53.34?±?5.6 (43.73–70.89) D (p?=?0.001), inferior curvature; 53,85?±?5.2 (43.47–76.56) D and 55.05?±?5.8 (44.56–81.93) D (p?=?0.002), temporal curvature 49.49?±?5.1 (41.50–71.03) D and 51.53?±?5.4 (41.58–73.34) D (p?=?0.001), respectively. Conclusions: In keratoconus patients during CXL treatment, after removing the corneal epithelium, more steepness is detected in the curvature of the steeper area of the cornea. When evaluating patients with keratoconus, the masking effect of corneal epithelium on values of curvature should be taken into consideration.     

表层角膜镜片术治疗圆锥角膜

采用表层角膜镜片术联合前房穿刺，手术治疗18例21眼圆锥角膜患者，经术后3个月～1年8个月的随访，患者的视力、矫正视力明显提高，角膜屈光力显著降低，平均为45．83D。认为对确诊为圆锥角膜但尚无后弹力层破裂，或中央视区尚未形成瘢痕的患者，应早期行该术治疗，术后疗效确切，作用持久，稳定。     

圆锥角膜的病理观察

用光镜和透射电镜观察了８例（９只眼）圆锥角膜的组织病理学改变，均系施行穿透性角膜移植术的晚期病例。角膜各层均发生了病理变化。角膜上皮变薄、水肿，部分基底细胞呈杯状变，细胞核染色质凝集；前弹力膜破坏并上皮长入，浅层散在高密度物质沉积；基质层变薄前突，散在高密度纤维，后基质层有淀粉样蛋白沉淀；后弹力膜断裂或皱褶；内皮细胞变薄，空泡形成，胞膜破碎，核脱落。角膜上皮、基底膜、内皮可见铁沉积。     

Keratoconus in pre-teen children: Demographics and clinical profile

Purpose:To study the demographics and clinical profile of keratoconus (KC) presenting in pre-teen children in India.Methods:This was a retrospective case series conducted as a single-institutional study at a tertiary eye center in India. A total of 586 eyes from 294 KC patients (aged 12 years or less) without any active comorbid conditions of the eye were included in the study. Slit-lamp biomicroscopy was used to document the clinical signs of KC. Information on age; gender; reason for consultation; family history; history of allergy, atopy, and eye rubbing; manifest refraction; uncorrected and best-corrected distance visual acuity (UCVA and BCVA, respectively); clinical presentation; and contact lens usage were also analyzed, along with data on types of medical and surgical treatments for KC and their outcomes.Results:The mean age of this pediatric KC patient cohort was 9.3 ± 1.8 years, and there was a male (70%) preponderance. Baseline mean UCVA, BCVA, steep keratometry, and flat keratometry were 0.86 ± 0.58 logMAR, 0.44 ± 0.38 logMAR, 54.82 ± 8.4 D, and 48.21 ± 9.5 D, respectively. Progression, necessitating collagen crosslinking (CXL), was noted in 12.7% eyes. Post-CXL, visual and topographic parameters remained stable without any complications till 6 months posttreatment. However, in eyes that did not undergo CXL, significant progression over time (P < 0.001) was observed. A keratoplasty was required in 2.3% eyes.Conclusion:KC was present at an advanced stage in 25% of the pre-teens in our series, and therefore, it is an important diagnostic entity when a refractive error is diagnosed, even in very young children.     

圆锥角膜的免疫组织化学研究

目的：了解圆锥角膜基底膜免疫组化的变化,以发现圆锥角膜可能的特异性改变,为探讨其发病机制提供依据。方法：收集圆锥角膜在我院眼科行穿透性角膜移植术的角膜片,用链霉亲和素－生物素法（SP法）检测圆锥角膜、角膜白斑、正常角膜基底膜Ⅳ型胶原、Fn、Ln表达的异同,并进行统计学分析。结果：圆锥角膜基底膜Ⅳ型胶原,Fn染色较正常角膜显著升高,但与角膜白斑比较无显著性差异。结论：圆锥角膜基底膜的改变可能与创伤愈合有关。提示圆锥角膜原发病变可能在角膜基质细胞。眼科学报2000;17：65－67。