Gall R, Wick B, Bedell H
College of Optometry, University of Houston, Texas, USA.
Optom Vis Sci. 1998 Oct;75(10):727-30. doi: 10.1097/00006324-199810000-00017.
Target suppression-cues are considered important for valid binocular accommodative facility response. However, there are no comparable recommendations concerning the effect of target type on vergence facility response.
Ten subjects ages 16 to 19 years of either sex and any race were pooled, based on the lack of any asthenopic symptoms determined by a verbal interview with the investigator. Inclusion/exclusion criteria included vision correctable to 6/6 (20/20) Snellen acuity or better in each eye, and near-normal phorias. Vergence facility response was tested over a 1-min period using 8 delta base-in (BI) and 20 delta base-out (BO) loose prisms at near (0.4 M) for 3 different vertically oriented targets: 6/9 (20/30) Snellen letters, back-illuminated anaglyphic shapes, and modified Wirt circles.
For the group, the mean facility response was similar among the target types [Snellen letters: 9.5 cycles per minute (cpm) +/- 5.6; anaglyphic shapes: 9.0 cpm +/- 6.3; and Wirt circles: 9.4 cpm +/- 4.5]. Group response-differences were not significantly different by one-way ANOVA polynomial regression testing at the 0.05 level (F-value = 0.03, p = 0.97, df = 2).
Whereas a binocular accommodative facility target must have additional vectographic or anaglyphic suppression-cues, vergence facility testing may incorporate a simple and available vertical row of 6/9 (20/30) Snellen letters, which provide inherent fusional suppression-cues, for a valid binocular response.
目标抑制线索被认为对有效的双眼调节功能反应很重要。然而，关于目标类型对聚散功能反应的影响，尚无类似的建议。
基于对受试者与研究者的口头访谈确定其没有任何眼疲劳症状，选取了10名年龄在16至19岁之间、性别和种族不限的受试者。纳入/排除标准包括每只眼睛视力可矫正至6/6（20/20）Snellen视力或更好，以及近眼位基本正常。在近距（0.4米）使用8棱镜底向内（BI）和20棱镜底向外（BO）的松散棱镜，对3种不同垂直方向的目标进行1分钟的聚散功能反应测试：6/9（20/30）Snellen字母、背投式互补色立体图形和改良的维尔特环。
对于该组受试者，不同目标类型的平均功能反应相似[Snellen字母：每分钟9.5周（cpm）±5.6；互补色立体图形：9.0 cpm±6.3；维尔特环：9.4 cpm±4.5]。通过单向方差分析多项式回归测试，在0.05水平上组间反应差异无显著统计学意义（F值 = 0.03，p = 0.97，自由度 = 2）。
虽然双眼调节功能测试目标必须具有额外的矢量图或互补色立体抑制线索，但聚散功能测试可以采用简单且现成的垂直排列的6/9（20/30）Snellen字母，其提供固有的融合抑制线索，以获得有效的双眼反应。
