幼猫近视模型眼眼轴、屈光度及眼球壁形态的变化

A study of axial length,refractive state and morphological changes in a model of myopia in cats

目的研究形觉剥夺性近视幼猫模型的屈光状态、眼轴长度变化，并观察眼轴增长后巩膜，特别是视网膜的组织形态学的变化，为探讨近视进展的病理机制打下基础。方法选用出生4-5周的健康幼猫15只，随机分为两组，对照组5只，实验组10只。记录对照组和实验组幼猫屈光状态及眼轴长度的变化。并于眼睑缝合后第14周处死实验组及对照组幼猫，做病理切片，观察后极部视网膜、巩膜的组织形态学变化。结果实验组幼猫形觉剥夺后第14周屈光度值为（-2．45±0．33）D，眼轴长为（18．95±0．27）mm，对照组屈光度值为（-0．43±0．33）D，眼轴长为（16．95±0．34）mm，两组比较差异有显著性（P〈0．01）。另观察到有明显的组织形态学改变：实验组巩膜胶原纤维排列紊乱。视网膜的有核细胞层胞核数减少，神经节细胞的胞体小，胞浆内Nmsl体减少或消失，视杆与视锥层水肿，细胞结构被破坏。结论形觉剥夺可导致幼猫眼轴增长，诱发轴性近视。伴随形觉剥夺近视的形成，剥夺眼的巩膜、视网膜发生退行性改变。

Objctive To establish an animal model of myopia by suturing the eyelid of young cats, and to study refractive state, axial length, and histological changes in the sclera and retina of these cat eyes,so the pathological factors of myopia progression can be investigated. Methods Fifteen healthy cats, 4 -5 weeks old, were randomly divided into 2 grouts： 10 in the experimental group and 5 in the control group. The experimental group and the control group were examined to detect changes in refractive state and axial length. The eyes of all the cats were removed 14 weeks after eyelid suture to examine the pathological changes in the. retina and sclera under light microscopy. Results The sutured eyes of the experimental group were myopic after 14 weeks of form deprivation. Axial length was longer in the experimental group than in the control group and the difference was significant （ p 〈 0.01）. The arrangement of the collagen fiber in the sclera was disturbed. There was a reduction in the number of nuclei in the retinal nuclear layer. The ganglion cell bodies had become smaller in size. Cellular Nissl bodies were reduced or absent. The cones and rods showed the properties of edema and cellular structure was unclear. Conclusion Axial myopia can be induced in young cats by suturing the eyelid. Degenerative changes in the retina and sclera occurred when form deprivation was used to induce myopia in young cats.