Uncorrected low hyperopia in young subjects induces postural instability even in those with clear visual acuity
Uncorrected low hyperopia in young subjects induces postural instability even in those with clear visual acuity
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年轻受试者未矫正的低度远视会导致姿势不稳定，即使对于那些视力清晰的人也是如此
作者：
Byeong;H. Cho;Dong;Sang
有报道指出近视模糊对体位稳定性的影响。本研究的目的是探讨通过不同程度的远视和近视引起的最小屈光不正对体位稳定性的显著影响。入组40例，平均年龄22.95±2.21岁。所有受试者均采用MPMVA（最大至加最大视敏度）主观屈光矫正屈光不正。采用±1.0、±2.0、±3.0、±4.0、±5.0、±6.0 D的球型镜片放置在矫正状态下的试验镜架上，作为MPMVA（睁眼式MPMVA），诱导远视和近视。在不同的屈光不正条件下，分别在MPMVA开眼和闭眼条件下，分别在患者直立位置用固定板的Tetrax体位仪测量各子系统的总稳定性（ST）和频率偏转功率（SP）。MPMVA患者闭眼时ST显著大于睁眼时ST （p < 0.001）。圣显著增加了-1.0 D诱导远视(p < 0.001)小数视力为1.07±0.17,诱发近视+ 3.0 D (p = 0.011)小数视力为0.16±0.09,相比,在与MPMVA睁眼。-6.0 D诱发远视与闭眼无显著性差异。诱发性远视的前庭外周信号中低频区SP显著升高，且-6.0 D晶状体诱发的远视与MPMVA裸眼诱发的远视差异显著。尽管年轻受试者可以获得清晰的视力，但未矫正的低度远视可能导致体位不稳。在稳定的体位调整中，屈光不正尤其是远视的矫正状态比视力更重要。
Reports have indicated the effect of myopic blur on postural stability. The objective of this study was to investigate the minimum refractive error to significantly affect postural stability through a various levels of hyperopia and myopia induced by ophthalmic lenses. Forty subjects with a mean age of 22.95 ± 2.21 years were enrolled. In all subjects, the subjective refraction with MPMVA (Maximum to Plus Maximum Visual Acuity) was performed to correct refractive error. To induce hyperopia and myopia, spherical lenses of ±1.0, ±2.0, ±3.0, ±4.0, ±5.0 and ±6.0 D were used on top of the trial frame with corrected condition as MPMVA (eyes-open with MPMVA). Under each induced-refractive error condition, general stability (ST) and sway power (SP) in frequencies by each subsystem were measured with Tetrax posturography with firm plates at patient’s upright position, after performed the measurements under the conditions of eyes-open with MPMVA and eyes-closed. ST at eyes-closed was significantly greater than that at eyes-open with MPMVA (p < 0.001). ST was increased significantly for induced hyperopia of -1.0 D (p < 0.001) with decimal visual acuity of 1.07 ± 0.17 and for induced myopia of +3.0 D (p = 0.011) with decimal visual acuity of 0.16 ± 0.09, as compared to that at eyes-open with MPMVA. No significant difference was observed between induced hyperopia of -6.0 D and those at eyes-closed only. SP was increased significantly at low medium-frequencies of the peripheral vestibular signals in induced hyperopia, moreover, hyperopia induced at -6.0 D lenses was significantly different compared to that at eyes-open with MPMVA. Uncorrected low hyperopia in young subjects may lead to postural instability, although they can obtain clear vision. The corrected state of ametropia, especially hyperopia, is a more important factor of appropriate visual input in stable postural adjustment than visual acuity.