Asper Lisa, Leung Andrew, Tran Catrin, Suttle Catherine M, Watt Kathleen
*PhD, OD †BOptom, BSc(Hons) ‡PhD, MCOptom §BOptom(Hons) aDeceased School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales Australia (all authors); and Optometry and Visual Science, School of Health Sciences, City University London, United Kingdom (CMS).
Optom Vis Sci. 2015 Oct;92(10):1016-20. doi: 10.1097/OPX.0000000000000686.
Vertical yoked prisms (VYPs) have been recommended for the remediation of vergence dysfunction, but the evidence base for their use is mostly low level. This study investigates the effect of VYP on horizontal subjective dissociated heterophoria.
Phoria measurement was performed in primary gaze with the Modified Thorington technique at 3 m and at 40 cm on 40 nonpresbyopic young adults. Subjects were seated and head position was held constant. Baseline measures (without yoked prism) of distance and near phoria were measured. Phorias were measured again through the following range of VYP, randomly presented: 2 prism diopters (Δ) base up (BU), 2Δ base down (BD), 5Δ BU, and 5Δ BD. Twenty-six subjects also had their phorias measured with control lenses of +0.125 DS OU (because of unavailability of Plano trial lenses) randomly presented along the other conditions.
There was no significant difference overall between phoria measured in any of the yoked prism conditions, including the baseline measure, at distance or near. Neither was there evidence of a predictable esophoric or exophoric shift with either BU or BD prism.
Vertical yoked prisms did not exert any immediate effect on horizontal phoria in young adults when posture was controlled. This suggests that, if VYPs do indeed improve horizontal vergence problems, they do not do so by a direct or immediate impact on horizontal phoria.
垂直配适棱镜（VYPs）已被推荐用于矫治聚散功能障碍，但其使用的证据基础大多级别较低。本研究调查了VYP对水平主观分离性隐斜的影响。
采用改良的索林顿技术，在3米和40厘米处对40名非老视年轻成年人进行原眼位隐斜测量。受试者就座，头部位置保持固定。测量远距离和近距离隐斜的基线值（不使用配适棱镜）。通过以下随机呈现的VYP范围再次测量隐斜：2棱镜度（Δ）底朝上（BU）、2Δ底朝下（BD）、5Δ BU和5Δ BD。26名受试者还在其他条件下随机佩戴+0.125 DS OU的对照镜片测量隐斜（因为没有平光试验镜片）。
在任何配适棱镜条件下测量的隐斜，包括基线值，在远距离或近距离时总体上均无显著差异。也没有证据表明使用BU或BD棱镜会出现可预测的内隐斜或外隐斜偏移。
当姿势得到控制时，垂直配适棱镜对年轻成年人的水平隐斜没有立即产生任何影响。这表明，如果VYPs确实能改善水平聚散问题，它们并非通过直接或立即影响水平隐斜来实现。
