Chu Chin-Hung Geoffrey, Zhou Yongjin, Zheng Yongping, Kee Chea-Su
School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.
School of Medicine, Shenzhen University, Guangdong, China.
Vision Res. 2014 May;98:26-34. doi: 10.1016/j.visres.2014.03.002. Epub 2014 Mar 14.
This study aimed to characterize corneal accommodation in alert chicks with and without experimentally-induced astigmatism. Refraction and corneal biometry were measured in 16 chicks with experimentally-induced astigmatism (>1.00 D) and 6 age-matched control chicks (astigmatism ⩽ 1.00 D). Corneal accommodation was detected using a Placido-ring based videokeratography system, by measuring changes in corneal curvature from a series of consecutive images acquired from alert chicks. The correlation between the magnitudes of corneal accommodation and astigmatism was analyzed by including data from all 22 chicks. Data from all eyes showed obvious bi-directional changes in corneal accommodation. There was no significant difference in corneal accommodative changes between the fellow eyes of the treated birds, and the right and left eyes of control birds. However, positive accommodation (PA) and maximum magnitude of PA (MPA) were significantly higher in the astigmatic vs. the fellow eyes of treated chicks (mean ± SE: PA=+2.24 ± 0.44 D vs. +1.26 ± 0.20 D; MPA=+7.53 ± 0.81 D vs. +4.38 ± 0.53 D, both p<0.05). This was not the case for negative accommodation (NA) or maximum magnitude of NA (MNA) (NA=-0.46 ± 0.15 D vs. -0.33 ± 0.04 D; MNA=-0.92 ± 0.23 D vs. -0.73 ± 0.12D, respectively, p>0.05). Furthermore, higher PA and MPA were found to be correlated with higher refractive astigmatism (both r=0.34, p<0.05). These results suggest that the presence of astigmatism may interfere with accommodative function in chicks.
本研究旨在描述清醒状态下有或无实验性诱导散光的雏鸡的角膜调节情况。对16只患有实验性诱导散光（>1.00 D）的雏鸡和6只年龄匹配的对照雏鸡（散光⩽1.00 D）进行了屈光和角膜生物测量。使用基于Placido环的视频角膜照相系统检测角膜调节，通过测量从清醒雏鸡获取的一系列连续图像中的角膜曲率变化来实现。通过纳入所有22只雏鸡的数据，分析了角膜调节幅度与散光之间的相关性。所有眼睛的数据均显示角膜调节存在明显的双向变化。在接受治疗的雏鸡的对侧眼与对照雏鸡的右眼和左眼之间，角膜调节变化无显著差异。然而，散光雏鸡的正向调节（PA）和最大正向调节幅度（MPA）显著高于接受治疗雏鸡的对侧眼（平均值±标准误：PA = +2.24 ± 0.44 D对 +1.26 ± 0.20 D；MPA = +7.53 ± 0.81 D对 +4.38 ± 0.53 D，均p<0.05）。负向调节（NA）或最大负向调节幅度（MNA）则不然（NA = -0.46 ± 0.15 D对 -0.33 ± 0.04 D；MNA = -0.92 ± 0.23 D对 -0.73 ± 0.12D，p>0.05）。此外，较高的PA和MPA与较高的屈光性散光相关（r均 = 0.34，p<0.05）。这些结果表明，散光的存在可能会干扰雏鸡的调节功能。
