Department of Cell Biology, Histology and Pharmacology, School of Medicine, University of Valladolid, Valladolid, Spain.
Ophthalmic Physiol Opt. 2012 Nov;32(6):478-84. doi: 10.1111/j.1475-1313.2012.00940.x. Epub 2012 Sep 17.
To determine the effects of intravitreal atropine on scleral growth in the form-deprived chick as an experimental model of myopia.
Five groups of five chicks were studied from day 0-12 post-hatching. One group remained untreated (C), and four were form-deprived by monocular light diffusers to induce myopia. Two groups (RL and A) wore diffusers for 9 days, and the other two groups (D and D + A) wore diffusers throughout the study. Group D received no further treatment (myopia positive control). Groups A and D + A received intravitreal injections of atropine for days 9-12. Measurements of refractive error and axial length were performed on days 0, 9, and 12. Sclera changes were assessed in cartilaginous and fibrous layers by histological analysis.
All form-deprived eyes had a myopic refractive error on day 9. All atropine-treated groups were hyperopic on day 12. The effect of atropine was most evident in Group D + A in which diffusers were maintained throughout treatment and changes in refractive error were statistically significant. The observed changes in axial length were in line with the changes in refractive error. The scleral fibrous layer thickness increased, and the sceral cartilaginous layer underwent a slight thinning compared to Group D, the myopia positive control.
If the signals that induce growth remain during atropine treatment, morphological changes in sclera are produced: the scleral fibrous layer thickened, and the sceral cartilaginous layer thinned. These changes resulted in refractive error recovery, and the ocular growth was stopped. The data suggested the atropine was acting throughout the scleral fibrous layer.
以形觉剥夺性近视小鸡模型为研究对象，观察玻璃体内给予阿托品对巩膜生长的影响。
本研究共纳入五组小鸡（每组五只），分别于孵出后 0-12 天进行研究。一组不做任何处理（C 组），其余四组通过单眼佩戴光扩散器造成形觉剥夺诱导近视。其中两组（RL 组和 A 组）佩戴光扩散器 9 天，另外两组（D 组和 D+A 组）则在整个研究期间佩戴光扩散器。D 组不做任何进一步的处理（近视阳性对照组）。A 组和 D+A 组在第 9-12 天给予玻璃体内注射阿托品。分别于第 0、9 和 12 天测量屈光度和眼轴长度。通过组织学分析评估软骨层和纤维层的巩膜变化。
所有形觉剥夺眼在第 9 天均表现为近视性屈光不正。所有给予阿托品处理的眼在第 12 天均表现为远视。在整个治疗期间持续佩戴光扩散器并给予阿托品治疗的 D+A 组，其治疗效果最明显，且屈光不正的变化具有统计学意义。观察到的眼轴长度变化与屈光不正的变化一致。与近视阳性对照组（D 组）相比，玻璃体内给予阿托品后，巩膜纤维层厚度增加，巩膜软骨层出现轻微变薄。
如果在给予阿托品治疗期间，诱导生长的信号仍然存在，那么巩膜会发生形态学变化：巩膜纤维层增厚，巩膜软骨层变薄。这些变化导致了屈光不正的恢复，眼轴的生长停止。数据表明阿托品可能在整个巩膜纤维层发挥作用。
