形觉剥夺性近视豚鼠巩膜形态学观察

Structural and ultrastructural changes of sclera in form-deprived eye of guinea pigs

目的观察形觉剥夺性近视豚鼠眼后极部巩膜的改变。方法4周龄豚鼠14只,随机分为正常对照组(Ⅰ组),形觉剥夺(FD)组(Ⅱ组)。Ⅱ组豚鼠右眼采用半透明眼罩遮盖的方法建立形觉剥夺近视模型,2周后检测其屈光度、眼轴长,并观察后极部巩膜组织的光镜、电镜改变。结果2周后剥夺眼屈光度相对于对照眼及年龄匹配对照组分别为-3.1 D±1.60 D,-3.2 D±1.72 D(P<0.01)。剥夺眼眼轴相对于对照眼(7.90 mm±0.13 mm、7.87 mm±0.17 mm,P<0.01)和正常眼(7.90 mm±0.13 mm、7.70 mm±0.16 mm,P<0.05)明显延长。剥夺眼后极部巩膜组织变薄,胶原纤维直径变小,纤维间空间增大。结论形觉剥夺刺激豚鼠眼巩膜组织变薄,其改变与人类近视巩膜组织改变相似。

Objective Sclera plays an important role in development of myopia. This study was to observe posterior sclera structural changes in form-deprived myopia in guinea pigs. Methods Fourteen four-week-old guinea pigs were randomly divided into two groups and seven animals for each group. Group Ⅰ was normal control group and group Ⅱ was form deprivation （FD） group. Form-deprived myopia model was established in the right eyes of FD group by using a translucent plastic occluder. Two weeks later, refraction, axial length and structure of posterior sclera were measured with light and transmission electron microscope（TEM）. Results Two weeks later, the relative refractive error in FD eyes was -3. 1 D ± 1.60 D compared with the fellow eyes （P〈0. 01）, and -3.2D ±1.72D compared with the normal control group （P〈0.01）. Axial length of the FD eye was significantly greater than the fellow eyes（7.90 ± 0. 13 mm vs 7.87 ± 0. 17 mm, P 〈 0. 01 ） and the normal control eyes （ 7.90 ± 0. 13 mm vs 7.70 ± 0. 16 mm, P 〈 0. 05 ） , respectively. Histopathologic examination showed thinning of posterior sclera. Collagen fibrillar diameters of sclera in the posterior segment of myopic eyes were obviously smaller and the space between the fibers was obviously larger than that of control eyes. Conclusion Form deprivation stimulates the alteration of posterior sclera. Changes of sclera in myopic eyes in guinea pig seem to be similar to that of human.