Nakanishi Yoriko, Nakamura Makoto, Tatsumi Yasuko, Nagai-Kusuhara Azusa, Negi Akira
Department of Organs Therapeutics, Division of Ophthalmology, Kobe University Graduate School of Medicine, 650-0017, Kobe, Japan.
Graefes Arch Clin Exp Ophthalmol. 2006 Nov;244(11):1480-4. doi: 10.1007/s00417-006-0327-1. Epub 2006 Apr 21.
A relative afferent pupillary defect (RAPD) is known to develop only when more than 25% of retinal ganglion cells are ablated in monkeys' eyes. However, there was no prior study to estimate biometrically the degree of retinal nerve fiber layer (RNFL) thickness reduction leading to the development of RAPD in live human eyes. The purpose of this study was to examine the correlation between the amount of RNFL thickness reduction and the depth of a clinically detectable RAPD in patients with unilateral optic atrophy.
Enrolled were 20 patients with optic atrophy of various etiologies. We quantified RAPD by performing the swinging flashlight test with log-scaled neutral density filters placed over the unaffected eye. Average RNFL thickness was measured by OCT3000 with the average RNFL thickness program. Linear regression analysis was used in assessing the relationship between RAPD and the ratio of affected to unaffected average RNFL thickness.
The mean of average RNFL thickness was 95.6+/-17.3 microm in the unaffected eyes and 50.7+/-19.3 microm in the affected eyes (P<0.001). Regression analysis between RAPD and the ratio of affected to unaffected average RNFL thickness revealed a correlation coefficient R2=0.48 (P=0.0007). The regression line intersected the y-axis at 0.77.
RAPD was not clinically detected until at least approximately 25% of the retinal nerve fibers were lost when compared with the unaffected eyes. Substantial retinal ganglion cell damage is required for the development of RAPD.
已知仅当猴子眼睛中超过25%的视网膜神经节细胞被切除时才会出现相对性传入瞳孔障碍（RAPD）。然而，此前尚无研究从生物测量学角度估计活体人眼视网膜神经纤维层（RNFL）厚度降低导致RAPD出现的程度。本研究的目的是检查单侧视神经萎缩患者RNFL厚度降低量与临床可检测到的RAPD深度之间的相关性。
纳入20例各种病因导致的视神经萎缩患者。我们通过在未受影响的眼睛上放置对数刻度的中性密度滤光片进行摆动手电筒试验来量化RAPD。使用OCT3000的平均RNFL厚度程序测量平均RNFL厚度。采用线性回归分析评估RAPD与患侧和未患侧平均RNFL厚度之比之间的关系。
未受影响眼睛的平均RNFL厚度为95.6±17.3微米，患侧眼睛为50.7±19.3微米（P<0.001）。RAPD与患侧和未患侧平均RNFL厚度之比的回归分析显示相关系数R2 = 0.48（P = 0.0007）。回归线与y轴相交于0.77。
与未受影响的眼睛相比，当视网膜神经纤维至少损失约25%时，临床上才会检测到RAPD。RAPD的出现需要大量视网膜神经节细胞受损。
