Adler Paul M, Cregg Mary, Viollier Ann-Julie, Margaret Woodhouse J
Ophthalmic Physiol Opt. 2007 Jan;27(1):22-30. doi: 10.1111/j.1475-1313.2006.00418.x.
This study was designed to investigate if the use of different target types or the RAF rule affected the measurement of near point of convergence (NPC).
The subjects comprised three groups: (1) 20 children aged 6-9 years (2) 17 children aged 11-13 years (3) 14 adults aged 20-30 years. Five targets were used to measure the NPC: (1) pencil tip, (2) fingertip, (3) penlight, (4) N5 letter and (5) vertical line target on the RAF rule.
There was no significant difference in NPC measurements between the pencil tip, fingertip and N5 target in free space. The penlight resulted in significantly more remote NPC break and recovery points compared with the fingertip and pencil tip (p < 0.05). The RAF rule influences the NPC obtained (p < 0.001). The greatest difference in NPC measurements was observed when comparing the RAF line target and the finger in free space; the former resulted in NPC values of 1.9 times (95% CI 1.6-2.2 times) as much as those obtained with the finger.
Use of the penlight and RAF rule resulted in a more distant NPC break point compared with other targets. The effect of the RAF rule was more apparent for more receded NPC points.
本研究旨在调查使用不同的目标类型或RAF规则是否会影响集合近点（NPC）的测量。
受试者分为三组：（1）20名6至9岁的儿童；（2）17名11至13岁的儿童；（3）14名20至30岁的成年人。使用五个目标来测量NPC：（1）笔尖；（2）指尖；（3）笔灯；（4）N5字母；（5）RAF规则上的垂直线目标。
在自由空间中，笔尖、指尖和N5目标之间的NPC测量值没有显著差异。与指尖和笔尖相比，笔灯导致的NPC破裂和恢复点明显更远（p < 0.05）。RAF规则会影响获得的NPC（p < 0.001）。在自由空间中比较RAF线目标和手指时，观察到NPC测量的最大差异；前者得出的NPC值是用手指获得的NPC值的1.9倍（95%置信区间为1.6至2.2倍）。
与其他目标相比，使用笔灯和RAF规则会导致NPC破裂点更远。RAF规则对更靠后的NPC点的影响更为明显。
