频域OCT检测青光眼视网膜神经节细胞复合体厚度的研究

Quantitative measurement of macular ganglion cell complex thickness by spectral domain optical coherence tomography

背景青光眼以视网膜神经节细胞（RGCs）丢失为主要的病理特征，频域光学相干断层扫描（SD—OCT）可以检测黄斑区视网膜神经节细胞复合体（GCC）厚度。目的探讨黄斑区视网膜GCC厚度在原发性开角型青光眼（POAG）人群的分布特征。方法采用系列病例对照研究设计。利用SD—OCT（RTVue-100）和时域OCT（TD—OCT）技术分别检测POAG患者101例101眼和年龄、屈光度相匹配的正常对照者41例41眼视网膜的黄斑区整体平均GCC厚度（GCC—Avg）、上方平均GCC厚度（GCC—Sup）和下方平均GCC厚度（GCC—Inf）及对应区域视盘旁视网膜神经纤维层（RNFL）厚度，按照POAG的程度分为视野损害前POAG组、早期POAG组、进展期POAG组和晚期POAG组，比较各POAG组与正常对照组间上述3个GCC参数的差异，分析GCC厚度和RNFL厚度的相关性以及青光眼患者视野平均缺损值（MD）与GCC厚度的相关性。结果视野损害前POAG组、早期POAG组GCC—Avg、GCC—Sup和GCC—Inf值均明显低于正常对照组，差异均有统计学意义（GCC—Avg：t：5．411、10．247，P〈0．01；GCC—Sup：t=6．171、9．484，P〈0．01；GCC—Inf：t=5．281、8．592，P〈0．01）。进展期POAG组GCC．Avg、GCC—Sup和GCC—Inf值均明显低于早期POAG组，差异均有统计学意义（GCC—Avg：t=4．246，P〈0．01；GCC—Sup：t=2．419，P=0．019；GCC—Inf：t=4．636，P〈0．01），而晚期POAG组GCC—Avg、GCC—Sup和GCC—Inf值均明显低于进展期POAG组，差异均有统计学意义（GCC—Avg：t=2．095，P=0．040：GCC—Sup：t=2．756，P〈0．01；GCC—Inf：t=2．018，P：0．040）。GCC—Sup、GCC—Inf和GCC—Avg值与对应区域平均RNFL厚度值均呈高度正相关（r=0．802、0．825、0．856，P〈0．01），青光眼患者的视野MD值与GCC—Avg值呈正相关（r=O．601，P〈0．01）。结论SD—OCT能够定量测量并区分青光眼患者与正常人群的黄斑区GCC厚度，GCC厚度随青光眼病情的进展而逐渐变薄，并与RNFL和视野的损害有较好的相关性。

Background Glaucoma is primarily characterized by the damage of retinal ganglion cells. The macular ganglion cell complex （GCC）thickness can be quantitatively measured using spectral domain optical coherence tomography（SD-OCT）. Objective This clinical study was to explore the macular GCC thickness change in primary open-angle glaucoma （POAG） patient with SD-OCT. Methods A serial case-controlled study was designed. A total 101 eyes of 101 POAG patients and 41 normal eyes of 41 age- and refract power-matched normal subjects were enrolled in the study. POAG patients were assigned to normal perimetry POAG group,early stage POAG group,advanced POAG group and late stage POAG group. Average macular GCC thickness（GCC-Avg） ,superior GCC thickness（GCC-Sup） and inferior GCC thickness （GCC-Inf）of subjects were measured by SD-OCT and compared among POAG patients and normal controls. Peripapillary retinal nerve fiber layer（RNFL） thickness was measured with time domain OCT（TD-OCT）. The correlation between GCC thickness with RNFL thickness or mean deviation（MD） of perimetry were evaluated and analyzed. Informed consent was obtained from each patient prior to entering this study. Results GCC-Avg thickness,GCC-Sup thickness and GCC-Inf thickness were significantly decreased in the normal perimetry POAG group and early stage POAG group compared with the normal control group（ GCC-Avg：t = 5. 411, 10. 247,P〈 0.01 ; GCC-Sup： t = 6. 171,9. 484, P 〈 0.01 ; GCC-Inf： t = 5. 281,8. 592, P 〈 0.01 ）. Also, GCC-Avg thickness,GCC-Sup thickness and GCC-Inf thickness were significantly decreased in the advanced POAG group compared with the early stage POAG group（GCC-Avg：t=4. 246,P〈0.01 ;GCC-Sup：t = 2. 419,P=0. 019;GCC-Inf： t = 4. 636, P〈0.01 ） , and GCC-Avg thickness, GCC-Sup thickness and GCC-Inf thickness were significantly decreased in the late stage POAG group compared with the advanced POAG group （ GCC-Avg ： t = 2. 095, P = 0. 040 ; GCC-Sup ： t = 2. 756,P〈0.01 ： GCC-Inf： t = 2. 018, P = 0. 040）. The positive correlations were seen between GCC-Avg thickness, GCC-Sup thickness, GCC-Inf thickness and RNFL-Avg thickness, RNFL-Sup thickness, RNFL-Inf thickness respectively（ r = 0. 802,0. 825,0. 856, P 〈 0.01 ）. MD value of perimetry was positive correlated with GCC-Avg thickness in POAG patients （ r = 0. 601 , P 〈 0. O1 ）. Conclusions SD-OCT can quantitatively measure and differentiate the GCC thickness in POAG patients. The GCC thickness gradually decreases with the development of POAG. There exist a well correlation between visual field defect anti RNFL thinning.