隐斜视测量技术对临床调节性集合与调节比率的影响。

Effect of heterophoria measurement technique on the clinical accommodative convergence to accommodation ratio.

作者信息

Escalante Jaime Bernal, Rosenfield Mark

机构信息

School of Optometry, Universidad Autonoma de Aguascalientes, Aguascalientes, Mexico.

出版信息

Optometry. 2006 May;77(5):229-34. doi: 10.1016/j.optm.2006.02.006.

DOI:10.1016/j.optm.2006.02.006

PMID:16651213

Abstract

BACKGROUND

Measurement of the stimulus accommodative convergence to accommodation (AC/A) ratio is a standard procedure in clinical optometric practice. Typically, heterophoria is assessed at several accommodative stimulus levels, and the gradient of the vergence to accommodation function computed. A number of procedures are available for the subjective measurement of heterophoria, but it is unclear whether the use of different vergence measurement techniques will alter the obtained AC/A value. Accordingly, the current study compared AC/A ratios measured using 3 clinical subjective heterophoria tests, namely the von Graefe (VG), Maddox Rod (MR), and Modified Thorington (MT) procedures.

METHODS

The AC/A ratio was measured in 60 visually normal subjects between 20 and 25 years of age using each of the 3 procedures listed above. The accommodative stimulus was varied by the introduction of +/-1.00 diopter (D) spherical lenses over the distance refractive correction while subjects viewed a target at a viewing distance of 40 cm. To examine the repeatability of each procedure, the AC/A ratio was measured on 2 separate occasions for each measurement technique, with the 2 sessions being separated by at least 24 hours.

RESULTS

Mean values of stimulus AC/A ratio measured using the VG, MR, and MT procedures were 3.47, 2.99, and 2.46Delta/D, respectively. These differences were significant (p=0.0001). In addition, the coefficient of repeatability for the 3 techniques was 2.22, 1.99, and 1.20 Delta/D, respectively.

CONCLUSIONS

Ratios obtained using the Modified Thorington technique with +/-1.00 D lenses showed the best repeatability, whereas the poorest repeatability was found with the von Graefe technique when only +1.00 D lenses were used to vary the accommodative stimulus. Accordingly, we recommend that that Modified Thorington procedure with +/-1.00 D lenses be used to quantify heterophoria during clinical measurement of the stimulus AC/A ratio.

摘要

背景

测量调节性集合与调节（AC/A）比值是临床验光实践中的标准程序。通常，在几个调节刺激水平下评估隐斜视，并计算集合与调节功能的梯度。有多种用于主观测量隐斜视的程序，但尚不清楚使用不同的集合测量技术是否会改变所获得的AC/A值。因此，本研究比较了使用三种临床主观隐斜视测试（即von Graefe（VG）、马多克斯杆（MR）和改良索林顿（MT）程序）测量的AC/A比值。

方法

使用上述三种程序中的每一种，对60名年龄在20至25岁之间的视力正常受试者测量AC/A比值。当受试者在40厘米的观察距离观看目标时，通过在远距屈光矫正上引入±1.00屈光度（D）的球面透镜来改变调节刺激。为了检验每种程序的可重复性，每种测量技术在两个不同的时间测量AC/A比值，两次测量之间至少间隔24小时。