频域OCT检测视乳头形态及视网膜神经纤维层厚度在青光眼诊断中的作用

Significance of optic disc topography and retinal nerve fiber layer thickness measurement by spectral-domain OCT in diagnosis of glaucoma

目的 探讨频域相干光断层扫描（OCT）检测视乳头形态及视网膜神经纤维层（RNFL）厚度在青光眼诊断中的作用.方法 为非干预性、观察性研究.应用RTVue OCT检测60例正常人和97例青光眼患者的视乳头各参数,以及平均和各个区域的RNFL厚度.采用单因素方差分析对以上各参数组间进行比较.用受试者工作特性曲线下面积（AUC）和特异性≥80%的敏感性来评价每一个检测参数区分正常与各期青光眼的能力大小.结果 除视乳头面积外,正常人和各期青光眼患者各参数测量值之间差异均有统计学意义（F=1.024,P=0.596;F=36.519,54.464,27.659,36.176,20.562,63.833,30.031, 54.652,98.146,78.705,99.839,43.728,75.720,45.709,39.380, 33.590,66.887,78.335,45.485;P=0.000）.其中,平均RNFL厚度正常人为109.950μm,早期青光眼患者为93.313 μm,中期青光眼患者为80.374μm,晚期青光眼患者为65.570 μm.在视乳头周围8个RNFL区域中,正常人最厚的为颞下150.066μm和颞上146.285μm.各期青光眼患者最厚的均为颞上,分别为早期108.569 μm,中期103.420μm,晚期88.708μm,其次为颞下,分别为早期108.201μm,中期102.830 μm,晚期86.369 μm.而鼻侧（NU＋NL）和颞侧（TU＋TL）无论在正常人还是青光眼患者中均较薄.在视乳头形态各参数中,各期青光眼诊断效能最高的均为垂直杯盘比,其AUC值在早、中、晚期青光眼患者中分别为0.762,0.946和0.988,它们特异性在80%时的敏感性分别为62.2%,76.5%和99.2%.在RNFL厚度参数中,早期青光眼诊断效能最高的是颞上区域RNFL厚度,其AUC值为0.915,特异性在80%时的敏感性为89.5%;中期青光眼诊断效能最高的是下方平均RNFL厚度,其AUC值为0.967,特异性在80%时的敏感性为94.1%;晚期青光眼诊断效能最高的是平均RNFL厚度,其AUC值为0.985,特异性在80%时的敏感性为99.2%.在视乳头周围8个RNFL区域中,诊断效能最高的是颞上区域（ST）,其AUC值在早、中、晚期青光眼患者中分别为0.915,0.926和0.966,它们特异性在80%时的敏感性分别为89.5%,88.2%和92.9%.诊断效能较低的是颞侧（TU＋TL）和鼻侧（NU＋NL）.结论 RTVue OCT具有较好的区别正常人和各期青光眼患者的能力,在青光眼诊断方面是一个有用的工具.

Objective To study the significance of optic disc tomography and retinal nerve fiber layer （ RNFL） thickness measurement by spectral-domain optical coherence tomography （ OCT） in the diagnosis of glaucoma. Methods It was a noninterventional, observational study. The optic disc topographic parameters and total and regional RNFL thickness were measured by RTVue OCT in 60 normal eyes and 97 glaucomatous eyes. One-way analysis of variance was used to compare the parameters above mentioned between mormal and glaucomatous groups. The area under the receiver operating characteristic curve （AUC） and the sensitivity at 80% specificity were used to assess the ability of each testing parameter in the differentiation between normal and glaucoma eyes. Results There were statistically significant differences in all RTVue OCT measurement parameters （ F = 1. 024, P = 0. 596; F = 36. 519,54. 464, 27.659,36.176,20. 562,63. 833,30. 031,54. 652,98. 146,78. 705,99. 839,43.728, 75. 720,45. 709, 39. 380,33.590,66. 887,78.335,45.485;P=0. 000） except disc area. The average RNFL thickness in normal, early, moderate and advanced glaucomatous eyes was 109.950, 93.313, 80.374 and 65.570 μm, respectively. Among the eight regions around the optic disc, the thickest RNFL was located at the inferotemporal （150. 066 μm） and superotemporal （146. 285 μm） regions in normal eyes, and the superotemporal （108.569, 103.420 and 88.708 （μm in early, moderate and advanced glaucomatous eyes, respectively） and inferotemporal （ 108. 201, 102. 830 and 86. 369 μm in early, moderate and advanced glaucomatous eyes, respectively） regions in glaucomatous eyes. Both in normal and glaucomatous eyes, the thinnest RNFL was located at the nasal and temporal regions, respectively. For optic disc topographic parameters, the highest AUC was vertical cup/disc ratio （AUC =0. 762, 0. 946 and 0. 988 in early, moderate and advanced glaucomatous eyes, respectively）, and the sensitivity at 80% specificity was 62. 2% , 76. 5% and 99.2% in early, moderate and advanced glaucomatous eyes, respectively. For RNFL thickness, the highest AUC was superotemporal region RNFL thickness （AUC =0. 915） and the sensitivity at 80% specificity was 89. 5% in early glaucomatous eyes. The highest AUC was inferior average RNFL thickness （AUC = 0.967） and the sensitivity at 80% specificity was 94.1 % in moderate glaucomatous eyes. The highest AUC was average RNFL thickness （ AUC = 0.985） and the sensitivity at 80% specificity was 99.2% in advanced glaucomatous eyes. Among the eight regions around the optic disc, RNFL thickness of region ST （AUC = 0. 915, 0. 926 and 0. 966 in early, moderate and advanced glaucomatous eyes, respectively） achieved the highest AUC. RNFL thicknesses of the nasal and temporal regions showed the lowest AUCs. Conclusions RTVue OCT shows fair discriminating ability in distinguishing normal from glaucomatous eyes. RTVue OCT is a useful equipment for the diagnosis of glaucoma.