School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Invest Ophthalmol Vis Sci. 2021 Feb 1;62(2):27. doi: 10.1167/iovs.62.2.27.
To determine the effects of optically imposed astigmatism on myopia development in chickens.
Chicks were randomly assigned to wear either spherical (-10D, "LIM", n = 14) or sphero-cylindrical lenses (n ≥ 19 in each group) monocularly for a week from 5 days of age. All lenses imposed the same magnitude of spherical-equivalent hyperopic defocus (-10D), with the two astigmatic magnitudes (-8D or -4D) and four axes (45°, 90°, 135°, or 180°) altered to simulate four subtypes of clinical astigmatism. At the end of the treatment, refractive state was measured for all birds, whereas ocular axial dimensions and corneal curvature were measured for subsets of birds.
Sphero-cylindrical lens wear produced significant impacts on nearly all refractive parameters (P < 0.001), resulting in myopic-astigmatic errors in the treated eyes. Compared to LIM, the presence of astigmatic blur induced lower myopic error (all except L180 group, P < 0.001) but with higher refractive astigmatism (all P < 0.001) in birds treated with sphero-cylindrical lenses. Distributions of the refractive, axial, and corneal shape parameters in the sphero-cylindrical lens-wear groups indicated that the astigmatic blur had directed the eye growth toward the least hyperopic image plane, with against-the-rule (ATR) and with-the-rule (WTR) astigmatisms typically inducing differential biometric changes.
The presence of early astigmatism predictably altered myopia development in chicks. Furthermore, the differential effects of WTR and ATR astigmatisms on anterior and posterior segment changes suggest that the eye growth mechanism is sensitive to the optical properties of astigmatism.
确定光学诱导的散光对鸡近视发展的影响。
从 5 天大的鸡开始，小鸡被随机分配单眼佩戴球形（-10D，“LIM”，n = 14）或球镜柱镜（每组 n≥19）一周。所有镜片都施加相同大小的等效远视离焦量（-10D），通过改变两个散光量（-8D 或-4D）和四个轴（45°、90°、135°或 180°）来模拟四种临床散光亚型。在治疗结束时，对所有鸟类进行屈光状态测量，而对部分鸟类进行眼轴尺寸和角膜曲率测量。
球镜柱镜的佩戴对几乎所有的屈光参数都有显著影响（P<0.001），导致治疗眼产生近视性散光误差。与 LIM 相比，散光模糊的存在导致较低的近视误差（除 L180 组外，均 P<0.001），但治疗眼的屈光性散光更高（均 P<0.001）。在佩戴球镜柱镜的鸟类中，屈光、轴向和角膜形状参数的分布表明，散光模糊使眼球生长向最远视的像平面，逆规散光（ATR）和顺规散光（WTR）通常会引起不同的生物测量变化。
早期散光的存在可预测性地改变了小鸡的近视发展。此外，WTR 和 ATR 散光对前节和后节变化的差异影响表明，眼球生长机制对散光的光学特性敏感。
