光学相干断层扫描测量下方泪河高度诊断2型糖尿病患者眼干燥症的可行性

Feasibility of OCT for measuring the tear meniscus height in diagnosis of ophthalmoxerosis in patients with type 2 diabetes

目的探讨应用光学相干断层扫描(optical coherence tomography,OCT)测量下方泪河高度(tear meniscus height,TMH)诊断2型糖尿病患者眼干燥症的可行性。方法选择2011年3月至12月就诊于哈尔滨医科大学附属第四医院眼科的48例(48眼)不同程度2型糖尿病眼干燥症患者和50例(50眼)正常志愿者,应用OCT和测微目镜测量下方TMH值,采用配对t检验、组内相关系数、两独立样本t检验、单因素方差分析及Spearman秩相关分析等方法,比较正常眼组与2型糖尿病眼干燥症患者组TMH值、两研究者分析同一检查者获取的TMH值、两研究者同一时间获取的同一组人的TMH值、同一研究者1周前后重复的测量值,以及比较OCT获得的TMH值与裂隙灯显微镜下测微目镜获得的TMH值。结果 OCT检测结果表明,正常眼下方TMH值[(0.257±0.048)mm]明显高于2级、3级、4级2型糖尿病眼干燥症组下方TMH值[(0.217±0.037)mm、(0.125±0.048)mm、(0.072±0.039)mm],差异均有统计学意义(均为P<0.05),且不同程度糖尿病眼干燥症患者组间TMH值亦有明显差异(F=54.683,P=0.000)。绘制受试者工作特征曲线,将诊断临界值定为0.221mm,其敏感性为76.9%,特异性为72.6%。两研究者分析22只正常眼下方TMH值分别为(0.257±0.048)mm和(0.253±0.059)mm,同一时间两研究者独立获取并分析的24只正常眼的下方TMH值分别为(0.253±0.048)mm和(0.267±0.058)mm,同一研究者不同时间获取的22只正常眼下方TMH值分别为(0.264±0.049)mm和(0.264±0.041)mm,差异均无统计学意义(均为P>0.05)。OCT与测微目镜测量下方TMH值[(0.251±0.032)mm]结果呈显著正相关(r=0.658,P=0.000)。结论应用OCT测量下方TMH值具有良好的可靠性和可重复性,有望成为临床上诊断2型糖尿病患者眼干燥症的客观指标之一。

Objective To investigate the feasibility of OCT for measuring the inferior tear meniscus height （ TMH） in the diagnosis of ophthalmoxerosis in patients with type 2 diabetes.Methods The inferior TMH of 48 patients （ 48 eyes） suffering type 2 diabetes of different degree and ophthalmoxerosis,and 50 eyes of 50 normal volunteers were measured by anterior segment OCT and micrometer eye-piece in the Forth Affiliated Hospital of Harbin Medical University.Then the paired t test,intra-class correlation coefficiency test,and independent sampler t test,one-factor ANOVA and Spearman test were conducted to analyze and compare the TMH values between normal subjects and patients with type 2 diabetes and ophthalmoxerosis,between that of one examinee measured by two different examiners,and between that of one group measured by two analysts at the same time,and between the TMH values two examinations measured by a examiner within a week,between that measured using anterior segment OCT and using slit lamp with micrometer eye-piece.Results There were significant differences in TMH value between normal subjects [（ 0.257±0.048） mm] and patients with patients with type 2 diabetes [grade 2： （ 0.217 ±0.037） mm; grade 3： （ 0.125±0.048） mm; and grade 4： （ 0.072±0.039） mm] and ophthalmoxerosis（ all P 0.05） ,and between groups of patients with different degrees of type 2 diabetes（ F = 54.683,P = 0.000） .The sensitivity and specificity of TMH value in patients with type 2diabetes and ophthalmoxerosis measured with OCT were 76.9% and 72.6% when the diagnostic threshold value was set to be 0.221 mm under the instruction of receptor operating characteristics curve.There was no significant difference between TMH values of the same 22 subjects measured by different examiners [（ 0.257±0.048） mm and （ 0.253±0.059） mm],between TMH values of the same 22 subjects measured by a same observer in different check-points [（ 0.264±0.049） mm and （ 0.264±0.041） mm]and between TMH values of the same 24 subjects measured by different analyzers at the same time[（ 0.253±0.048） mm and （ 0.267±0.058） mm]（ all P 0.05） .There was a highly positive correlation between TMH values measured by OCT and slit lamp with micrometer eye-piece（ r = 0.658,P = 0.000） .Conclusion OCT has excellent reliability and repeatability for measuring the inferior TMH,and can be taken as an objective clinical method on the diagnosis of ophthalmoxerosis in patients with type 2 diabetes.