激光偏振光扫描测定不同病程开角型青光眼视网膜神经纤维层的厚度

Measurement of Retinal Nerve Fiber Layer Thickness in Different Stages of Open-Angle Glaucoma Using Scanning Laser Polarimetry

【目的】探讨激光偏振光扫描仪对开角型青光眼诊断的临床应用价值。【方法】收集正常人159例252眼及不同病程开角型青光眼共107例175眼,采用激光偏振光扫描仪(GDxVCC)进行视网膜神经纤维层(RNFL)厚度测量,测量参数包括:RNFL厚度上方平均值、下方平均值、全周平均值、TSNIT标准差、双眼对称性及神经纤维层指数(NFI)。独立样本t检验比较正常组与青光眼组RNFL厚度及正常组与早期青光眼组RNFL厚度,单因素方差分析比较早、中、晚期青光眼RNFL厚度,对GDxVCC诊断青光眼的效能进行ROC曲线下面积分析。【结果】GDxVCC测量的正常人全周RNFL厚度为(58±5)μm,青光眼患者全周RNFL厚度为(48±11)μm,较正常人明显变薄(P<0.001)。早期青光眼患者的全周、上方、下方RNFL厚度均较正常人变薄,差异有统计学意义(P=0.000);但早期青光眼患者的双眼对称性仍较好,与正常人相比差异无统计学意义(P=0.058)。随着青光眼的进展,早、中、晚期青光眼患者的全周、上方、下方RNFL厚度明显变薄,TSNIT标准差及双眼对称性明显减低,神经纤维指数明显增高(P<0.005)。GDxVCC各参数诊断青光眼的ROC曲线下面积达到0.743～0.992。【结论】GDxVCC可定性和定量测量RNFL厚度,其各参数诊断青光眼的效能较高,对青光眼的早期诊断有较高的临床应用价值。

[ Objective ] To assess the clinical application of scanning laser polarimetry in the diagnosis of open-angle glaucoma. [Methods] Two hundred and fifty-two eyes from 159 normal subjects and 175 eyes from 107 patients with different stages of open-angle glaucoma were enrolled in the present study. Scanning laser polarimetry （GDxVCC） was used to obtain the retinal nerve fiber layer （RNFL） thickness. The parameters of RNFL measurement included superior RNFL thickness, inferior RNFL thickness, mean RNFL thickness, temporal-superior-nasal-inferior-temporal （TSNIT） standard deviation, symmetric value of right and left eyes and the nerve fiber index （NFI）. Paircd-t test was used to compare the RNFL thicknesses between the normal subjects and the glaucomatous patients, and the normal subjects and the patients with early stage glaucoma. One-way ANOVA analysis was used to compare the RNFL thicknesses among the early, advanced, and late stage glaucoma. Area under ROC curves was used to analyze the diagnostic value of GDxVCC on glaucoma. [ Results ] The mean RNFL thickness of normal subjects measured by GDxVCC was （58 ± 5）μm, which was much thicker than that of glaucomatous patients [ （48 ± 11）μm, P 〈 0.001 ]. The mean, superior, and inferior RNFL thickness of the patients with early stage glaucoma were statistically thinner than those of normal subjects （P = 0.000）. However, the symmetric value of right and left eyes in the patients with early stage glaucoma showed no difference with that of normal subjects （P = 0.058）. With the progression of glaucoma, the mean, superior and inferior RNFL thicknesses became thinner and thinner, the TSNIT standard deviation and the symmetric value of right and left eyes decreased, and the nerve fiber index increased significantly （P 〈 0.005）. And the area under ROC curves of RNFL measured by GDxVCC were 0.743-0.992. [Conclusion] The RNFL thickness could be measured by GDxVCC qualitatively and quantitatively, whicb could discriminate the patients with open-angle glaucoma from normal subjects. The early diagnosis of glaucoma with GDxVCC is reliable.