豚鼠短期形觉剥夺性近视屈光度眼轴及巩膜改变

Biology and the sclera morphology changes in short-term guinea pig form deprivation myopia model

目的:观察豚鼠短期形觉剥夺性近视(form deprivationmyopia,FDM)眼轴、屈光度变化及后极部巩膜病理性改变。方法:4周龄健康豚鼠40只,随机分成形觉剥夺实验组和年龄匹配正常对照组各20只。形觉剥夺实验组分为剥夺1,4,7和14d4个亚组,右眼为剥夺眼,采用半透明眼罩遮盖诱导轴性近视,左眼不予处理。对剥夺前后实验组和对照组双眼屈光度、眼轴进行测量,并对后极部巩膜进行HE染色光镜观察和透射电镜观察。结果:形觉剥夺7d近视程度和眼轴长度改变迅速,之后减慢并趋于平稳。4个实验亚组剥夺眼与实验前比较相对近视-0.30±0.45D,-3.65±0.78D,-6.98±0.65D,-8.68±1.12D,相对眼轴延长4.8±3.2,129.0±12.6,159.0±10.1,184.4±10.4μm。其中4,7,14d实验亚组剥夺眼与对照眼差别有统计学差异(P<0.01),剥夺眼后极部巩膜明显变薄,成纤维细胞密度降低,细胞外基质增多。1,4,7,14d实验亚组形觉剥夺眼后极部巩膜胶原纤维平均直径102.0,67.4,52.2,49.8nm,与正常对照眼比较差别有统计学意义(P<0.05)。结论:4周龄豚鼠单眼形觉剥夺4d即可出现轴性近视,1d即有巩膜病理改变,形态学改变先于生物学改变,形觉剥夺7d为近视发展高峰期。

AIM： To observe the axial length, refractive error and the pathology changes of guinea pigs in short-term form deprivation myopia （ ST-FDM ） and to explore the peculiarity and pathogenesis of the ST-FDM. METHODS： Forty four weeks of age guinea pigs were randomly divided into normally group （20） and form deprivation group （20 ）. The latter group is divided into four sub-group （deprived 1 day, deprived 4 days, deprived 7 days, deprived 14 days）. Right eyes of the experimental groups were covered a translucent plastic occluder, the left eyes were opened. Refraction, axial lenth, structure and ultrastructure of sclera were measured respectively before the experimental and after 1 day, 4,7,14 days. RESULTS： The axial length and degree of myopia changed rapidly in the first week of form deprivation, then slowed down and stabilized. The relative refractive error of the four experimental sub-group were -0. 30 ± 0.45D, -3.65± 0.78D, -6.98 ± 0.65D, -8.68 ± 1. 12D. The relative axial length of the four experimental sub-group were 4.8 ± 3.2, 129.0 ± 12.6,159.0 ± 10.1,184.4 ± 10.4μm. The differences of the 4,7,14days were statistically significant （ P〈 0.01 ）. Histopathologic examination showed thinning of posterior sclera in treated eyes. The average fibers diameter of four sub-group of form deprivation eyes were 102. 0, 67. 4, 52.2, 49.8nm respectively. The difference was statistically significant （ P〈 0.05）. CONCLUSION. Form deprived 4 days make the guinea pigs axial myopia and form deprived 1 day can make the structure of the posterior sclera changed. The sclera morphology changes ealier than the biology. The first week of form deorivation is the fastigium.