Peripheral defocus does not necessarily affect central refractive development
Peripheral defocus does not necessarily affect central refractive development
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DOI：
10.1016/j.visres.2006.05.008
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发表时间：
2006-10-01
期刊：
影响因子：
1.8
通讯作者：
Schaeffel, Frank
中科院分区：
文献类型：
--
作者：
Schippert, Ruth;Schaeffel, Frank
目的。最近在猴子身上进行的实验表明，仅在视野外围施加的剥夺可以诱发中央凹近视。这提出了一种假设，即由眼镜镜片矫正造成的外周屈光不正也可能影响人类的中央凹屈光发育。我们已经在小鸡身上验证了这个假设。雏鸡分别佩戴全视野镜片（+6.9 D/-7 D）和中心孔直径分别为4、6、8 mm的镜片，每组6只。采用a型超声扫描法测定中央视野、-45度（颞部）、+45度（鼻部）屈光度及轴向长度。如前所述，全视野镜片在4天内大部分得到补偿（阳性镜片的折射变化：+4.69 +/- 1.73 D，阴性镜片的折射变化：-5.98 +/- 1.78 D, p < 0.001，与未治疗的对照组相比）。在透镜中心有孔的情况下，中心折射仍然是非对称的，甚至没有折射变化的趋势（所有组：p > 0.5， Dunnetts测试）。在45度时，尽管有4/6/8毫米的中心孔，镜头还是得到了部分补偿；正镜：+2.63/+1.44/+0.43 D，负镜：-2.57/-1.06/+0.06 D。鸡对施加的屈光不正有广泛的局部补偿。对于测试的孔尺寸，外围施加的离焦不影响中心折射发展。为了改变中心屈光发展，中央视野中未被遮挡的部分可能必须非常小（孔尺寸小于4毫米，透镜顶点距离为2-3毫米）。(c) 2006 Elsevier Ltd.版权所有。
Purpose. Recent experiments in monkeys suggest that deprivation, imposed only in the periphery of the visual field, can induce foveal myopia. This raises the hypothesis that peripheral refractive errors imposed by the spectacle lens correction could influence foveal refractive development also in humans. We have tested this hypothesis in chicks.Methods. Chicks wore either full field spectacle lenses (+6.9 D/-7 D), or lenses with central holes of 4, 6, or 8 mm diameter, for 4 days (n=6 for each group). Refractions were measured in the central visual field, and at -45 degrees(temporal) and +45 degrees(nasal), and axial lengths were measured by A-scan ultrasonography.Results. As previously described, full field lenses were largely compensated within 4 days (refraction changes with positive lenses: +4.69 +/- 1.73 D, negative lenses: -5.98 +/- 1.78 D, both p < 0.001, Dunnett's test, to untreated controls). With holes in the center of the lenses, the central refraction remained emmetropic and there was not even a trend of a shift in refraction (all groups: p > 0.5, Dunnetts test). At 45 degrees, the lenses were partially compensated despite the 4/6/8 mm central holes; positive lenses: +2.63/+1.44/+0.43 D, negative lenses: -2.57/-1.06/+0.06 D.Conclusions. There is extensive local compensation of imposed refractive errors in chickens. For the tested hole sizes, peripherally imposed defocus did not influence central refractive development. To alter central refractive development, the unobstructed part in the central visual field may have to be quite small (hole sizes smaller than 4 mm, with the lenses at a vertex distance of 2-3 mm).(c) 2006 Elsevier Ltd. All rights reserved.