眼前节相干光断层扫描测量下方泪河高度及其在干眼症诊断中的应用

Application of anterior segment optical coherence tomography for measuring the tear meniscus height in the diagnosis of dry eye diseases

目的探讨应用眼前节相干光断层扫描仪（AS—OCT）测量下方泪河高度（TMH）的可行性及其对干眼症的临床诊断价值。方法诊断试验的评价。选择2007年11月至2008年8月就诊于中山大学中山眼科中心的36例（36只眼）不同程度干眼症患者和38例（38只眼）正常志愿者，应用AS—OCT和测微目镜测量下方泪河高度，采用配对t检验、组内相关系数、单因素方差分析及Spearman秩相关分析等方法，比较正常人组与干眼症患者组、两研究者同一时间获取分析同一组人的TMH值、两研究者分析同一检查者获取的TMH值、同一研究者1周前后重复的测量值，以及比较AS—OCT与裂隙灯显微镜下测微目镜的TMH值。结果同一时间两研究者独立获取分析22只正常眼TMH值分别为（0．256±0．052）mm／和（0．265±0．066）mm，同一研究者不同时间获取分析20只正常眼TMH值分别为（0．265±0．056）mm和（0．272±0．052）mm，两研究者分析20只正常眼TMH值分别为（0．266±0．059）mm和（0．259±0．062）mm，差异均无统计学意义（t=1．881，P=0．074；t=1．306，P=0．207；t=2．048，P=0．065）；AS-OCT与测微目镜测量TMH结果呈正相关（r=0．713，P=0．000）；正常人泪河高度明显高于干眼患者（t=9．368，P=0．000），正常眼和2、3、4级程度干眼组TMH值[（0．228±0．036）mm，（0．145±0．056）mm，（0．084±0．048）mm]的组间有明显差异（F=55．763，P=0．000）。绘制受试者工作特征曲线（ROC曲线），将诊断界别值定为0．213mm，其敏感性为77．8％，特异性为71．7％。结论应用眼前节相干光断层扫描测量泪河高度具有良好的可重复性和可靠性，有望作为临床上诊断水样液缺乏性干眼症的客观指标之一。

Objective To investigate the reproducibility and repeatability of anterior segment optical coherence tomography （AS-OCT） for measuring the tear meniscus height （TMH） and to evaluate its clinical application in the diagnosis of dry eye diseases. Methods Evaluation of diagnostic test. The inferior tear meniscus height of 36 eyes of 36 patients with dry eyes and 38 eyes of 38 normal volunteers were measured by AS-OCT and slit lamp marker lens in Zhongshan Ophthalmic Center, Sun Yat-sen University from November 2007 to August 2008. Then the paired t test, intra-class correlation coefficiency test, ANOVA and Spearman test were used for comparing TMH values between normal subjects and dry eye patients, two different examiners, two analysts, the repeated examines within a week, and AS-OCT group and slit lamp reticle lens group. Results There are no significant differences between different observers for the same 22 subjects It = 1.881, P =0.074; TMH： （0.256 ±0.052） mm and （0.265 ±0.066） mm], the same observer in different check-points for 20 subjects [ t = 1. 306, P = 0. 207 ; TMH ： （0. 265 ± 0. 056） mm and （0. 272 ± 0. 052） mini as well as different analyzers for the same 20 AS-OCT pictures [ t = 2. 048, P = 0. 065 ; TMH ： （0. 266 ±0. 059） mm and （0. 259 ± 0. 062） mm ]. There is a positive correlation betweenAS-OCT and reticule reading in measuring TMH （r = 0. 713 ,P = 0. 000） ; there are significant differences between normal subjects and patients with dry eye （t = 9. 368 ,P = 0. 000）, and between groups of dry eye at different degree （F=55. 763 ,P =0. 000） [TMH： grade Ⅱ, （0. 228 ±0. 036） mm; grade Ⅲ, （0. 145 ± 0. 056） ram; and grade Ⅳ, （0. 084±0. 048） mm]. The sensitivity and specificity of TMH value with ASOCT for dry eye diagnosis was 77. 8% and 71.7% when the diagnostic value was set to be 0. 213 mm under the instruction of receptor operating characteristics curve （ ROC ）. Conclusion AS-OCT has excellent reproducibility and repeatability for measuring the inferior tear meniscus height, and can be taken as an objective clinical imaging method for the diagnosis of aqueous deficiency dry eye.