Light intensity modulates corneal power and refraction in the chick eye exposed to continuous light
Light intensity modulates corneal power and refraction in the chick eye exposed to continuous light
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DOI：
10.1016/j.visres.2008.07.010
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发表时间：
2008-09-01
期刊：
影响因子：
1.8
通讯作者：
Polat, Uri
中科院分区：
文献类型：
--
作者：
Cohen, Yuval;Belkin, Michael;Polat, Uri
持续的光照会导致严重的远视，伴随着眼前节的变化，如严重的角膜扁平。由于在完全黑暗中饲养雏鸡只会导致轻微的远视和角膜曲率的轻微变化，我们推测在连续光照下，光强度可能在屈光变化的发展中起作用。为了验证这一假设，我们研究了在不同的连续光照强度下饲养雏鸡的效果。更具体地说，我们研究了雏鸟眼睛的屈光参数，避免了光循环对眼睛发育的影响。为此，38只雏鸡被饲养在24小时的白炽光下，三种不同的光照强度：10,000勒克斯(n=13)，500勒克斯(n=12)和50勒克斯(n=13)。他们的眼睛接受了重复的验光、角膜曲率测量和超声生物测量，以及眼球摘除后的卡尺测量。屈光度和角膜屈光度都与光线强度有关。在孵化后第90天，10000、500和50lux的光照强度分别导致+11.97+/-3.7(平均+/-SD)+7.9+/-4.08和+0.63+/-3.61屈光度(D)。角膜屈光度分别为46.10±3.62、49.72±4.16和56.88±4.92D。眼轴长度在不同组之间没有显著差异。高强度组玻璃体腔较低强度组明显深。因此，在持续光照的雏鸡的早期生活中，光照强度会影响玻璃体的深度和眼前段的参数，最明显的是角膜。激光强度越高，角膜扁平程度越重，远视越严重，而低强度连续照射则会导致正视。因此，光强是研究屈光发育时应考虑的一个重要因素。(C)2008爱思唯尔有限公司。保留所有权利。
Continuous exposure of chicks to light was shown to result in severe hyperopia, accompanied by anterior segment changes, such as severe corneal flattening. Since rearing chicks in complete darkness results only in mild hyperopia and minor changes in corneal curvature, we hypothesized that light intensity may play a role in the development of refractive changes under continuous light illumination. To test this hypothesis, we examined the effects of rearing chicks under various continuous light intensities. More specifically, we investigated the refractive parameters of the chicks' eyes, and avoided light cycling effects on ocular development. To this end, thirty-eight chicks were reared under 24-h incandescent illumination, at three different light intensities: 10,000 lux (n = 13), 500 lux (n = 12), and 50 lux (n = 13). Their eyes underwent repeated retinoscopy, keratometry, and ultrasound biometry, as well as caliper measurements of enucleated eyes. Both refraction and corneal refractive power were found to be correlated with light intensity. On day 90 after hatching, exposure to light intensities of 10 000, 500, and 50 lux resulted in hyperopia of +11.97 +/- 3.7 (mean +/- SD) +7.9 +/- 4.08 and +0.63 +/- 3.61 diopters (D), respectively. Under those intensities, corneal refractive power was 46.10 +/- 3.62, 49.72 +/- 4.16, and 56.88 +/- 4.92 D, respectively. Axial length did not differ significantly among the groups. The vitreous chamber was significantly deeper in the high than in the low-intensity groups. Thus, during the early life of chicks exposed to continuous lighting, light intensity affects the vitreous chamber depth as well as the anterior segment parameters, most notably the cornea. The higher the intensity, the more severe was the corneal flattening observed and the hyperopia that developed, whereas continuous illumination at low intensities resulted in emmetropia. Thus, light intensity is an important factor that should be taken into account when studying refractive development. (C) 2008 Elsevier Ltd. All rights reserved.