Mayer D L
Invest Ophthalmol Vis Sci. 1986 Jul;27(7):1148-53.
Tests of grating acuity often underestimate amblyopia and underrefer esotropic infants with a fixation preference. To evaluate the effect of the large grating field used in preferential looking (PL) procedures, an eight-alternative, small field (about 1 degrees) grating acuity test was devised. Gratings contained at least eight cycles. Thirty-seven strabismic and/or anisometropic amblyopes, ages 3-13 yr, were tested. In most amblyopic eyes, grating acuities were better than recognition acuities; the difference was reduced, however, in the small field test compared to the large field (6 degrees test (means, 1 oct vs. 1.6 oct; paired-t = 5.5, P less than .001). Nevertheless, the same relation between grating and recognition acuities occurred for small as for large fields: an increased discrepancy between grating and recognition acuities accompanied poorer acuity. This larger discrepancy is attributed to increased probability summation of amblyopic eyes for low spatial frequencies. For preschool children who can be tested by both procedures, the eight-alternative grating acuity test may be preferable to operant PL because it is more easily administered and materials are simpler.
光栅视力测试常常会低估弱视情况，并且较少转诊有注视偏好的内斜视婴儿。为了评估优先注视（PL）程序中使用的大光栅视野的效果，设计了一种八选一的小视野（约1度）光栅视力测试。光栅至少包含八个周期。对37名年龄在3至13岁的斜视和/或屈光参差性弱视患者进行了测试。在大多数弱视眼中，光栅视力优于识别视力；然而，与大视野（6度测试）相比，小视野测试中这种差异减小了（平均值，1倍频程对1.6倍频程；配对t检验 = 5.5，P <.001）。尽管如此，小视野和大视野中光栅视力与识别视力之间的关系是相同的：随着视力变差，光栅视力与识别视力之间的差异增大。这种较大的差异归因于弱视眼对低空间频率的概率总和增加。对于可以通过两种程序进行测试的学龄前儿童，八选一光栅视力测试可能比操作性PL更可取，因为它更容易实施且材料更简单。
