视网膜神经纤维层的圆环及圆圈厚度分析方式的可重复性研究

Study on repeatability of retinal nerve fibers layer thickness measurement by two OCT protocols: circle method and ring method

目的研究在相干光断层扫描仪(OCT)检测中,使用圆圈及圆环两种分析方法计算环视盘视网膜神经纤维层(RNFL)厚度的可重复性。方法对25名健康人(25只眼)在3个不同时期中进行OCT扫描,每个时期相差最长不超过1周。将OCT扫描得到的RNFL厚度数据矩阵导出,通过自行开发的程序矫正随访造成的位置偏移,以1.73 mm半径圆圈及内外径分别为1.4 mm、2.00 mm的圆环,读取环视盘RNFL厚度数据,计算全周平均RNFL厚度和各象限上的平均RNFL厚度。比较两种方法得出的RNFL厚度差异,用组内相关系数评估其可重复性,并比较这两种方法的可重复性的差异。结果以1.73 mm半径圆圈测得的全周平均RNFL厚度为(101.60±10.24)μm,以及内外径为1.4 mm和2.00 mm的圆环测量全周平均RNFL厚度为(114.48±11.29)μm:在各象限上,圆环测量的RNFL厚度大于以圆圈测得的全周平均RNFL厚度。以圆圈及圆环方式测得RNFL厚度均具有很好的可重复性(组内相关系数≥95)。两种方法的组内相关系数没有统计学差异。结论利用OCT进行RNFL厚度测量是一种可靠的方法,以圆环或圆圈方式测量平均RNFL厚度数值不同。这两种方式均具有很好的可重复性且没有可重复性的差异。

Objective To study the repeatability of the circumpapillary retinal nerve fiber layer（ RNFL） thickness detection of two protocols in optical coherence tomography（ OCT） ： the circle method and ring method. Methods Twentyfive healthy subjects（ 25 eyes） underwent OCT scans at three different days. The interval between different visits days was less than 7 days. The RNFL thickness data matrix was exported from the Cirrus OCT device. A self-developed program was used to adjust the bias of eye movement at different visits. RNFL thickness data were read with a circle with the radius of1. 73 mm,and a ring with the inner and outer radii of 1. 4 mm and 2. 00 mm,respectively. The average global RNFL thickness and the average RNFL thickness at each quadrant were calculated. The RNFL thickness measured by two methods were compared; and the intra-class correlation coefficient was used to evaluate the repeatability. The repeatability of the two methods was also compared. Results For the protocol of circle with a radius of 1. 73 mm,and the protocol of ring with the inner and outer radii of 1. 4 mm and 2. 00 mm,the mean global RNFL thickness was 101. 60 ± 10. 24μm and 114. 48 ±11. 29μm,respectively. For each quadrant,the RNFL thickness measured by the protocol of ring was thicker than the results measured by the protocol of circle. RNFL thickness measurement analyzed by both protocols showed high repeatability（ intra-group correlation coefficient ≥95）. There was no statistical difference of the intra-group correlation between these two methods. Conclusions The RNFL thickness measurement using OCT is a reliable method. The values of the average RNFL thickness measured by the protocol of circle and ring were different. Both approaches showed good and equal repeatability.