Daum K M, Rutstein R P, Houston G, Clore K A, Corliss D A
School of Optometry/The Medical Center, University of Alabama, Birmingham.
Optom Vis Sci. 1989 Apr;66(4):218-28. doi: 10.1097/00006324-198904000-00008.
The purpose of this study was to assess a new criterion for binocular comfort analogous to the classical Sheard's criterion. Instead of equating the fusional demand with the monocular phoria as is done when Sheard's criterion is applied, the new criterion uses a calculated binocular fusional demand. The binocular demand was derived using a clinical measurement of the convergence accommodation per convergence (CA/C) ratio. Sheard's criterion was also evaluated. Other commonly used indicators of binocularity (heterophoria, vergences, accommodative amplitude, facility and response, fixation disparity, and the associated phoria) were measured. One hundred subjects (52 males, 48 females; mean age 26 years) were classified as either symptomatic or asymptomatic by an interviewing clinician. The examining clinician was intentionally masked as to the classification of the subjects. We hypothesized that the new criterion would best discriminate between the two groups of patients inasmuch as it is based on currently accepted dual-interaction models of accommodation and vergence. Our analysis confirmed that the CA/C ratio corresponded closely to those published previously (mean = 0.06 D/delta). Significant differences (p less than 0.05) were determined between the symptomatic and asymptomatic groups for gender, near phoria through a +2.00 D add, accommodative amplitude, positive vergences at near, and both the classical Sheard's and the new criterion. The new criterion was the best discriminator between the groups, identifying 72% correctly, an improvement of 6% over the classical Sheard's. However, various stepwise discriminant analysis procedures consistently failed to demonstrate that the calculated binocular fusional demand or the new criterion was superior to the near phoria or the classical Sheard's value. These results suggest potential clinical utility for new procedures based on recently described models of accommodation and vergence, but further development appears necessary.
本研究的目的是评估一种类似于经典谢尔德准则的双眼舒适度新标准。新标准并非像应用谢尔德准则时那样将融合需求与单眼隐斜相等同，而是使用计算得出的双眼融合需求。双眼需求是通过对每单位集合的集合性调节（CA/C）比值进行临床测量得出的。同时也对谢尔德准则进行了评估。还测量了其他常用的双眼视功能指标（隐斜、聚散度、调节幅度、调节灵活度及反应、注视差异以及相关隐斜）。100名受试者（52名男性，48名女性；平均年龄26岁）由一名临床访谈医生分为有症状组或无症状组。检查医生对受试者的分类情况故意不知情。我们假设新标准能最好地区分这两组患者，因为它基于目前被认可的调节和聚散的双相互作用模型。我们的分析证实，CA/C比值与先前发表的结果密切相符（平均值 = 0.06 D/棱镜度）。有症状组和无症状组在性别、通过 +2.00 D 附加镜测量的近距隐斜、调节幅度、近距正聚散度以及经典谢尔德准则和新标准方面存在显著差异（p < 0.05）。新标准是两组之间最佳的区分指标，正确识别率为72%，比经典谢尔德准则提高了6%。然而，各种逐步判别分析程序始终未能证明计算得出的双眼融合需求或新标准优于近距隐斜或经典谢尔德准则值。这些结果表明基于最近描述的调节和聚散模型的新程序具有潜在的临床应用价值，但似乎仍有必要进一步完善。
