视黄酸在早期形觉剥夺性近视豚鼠后巩膜中的变化

目的检测豚鼠早期形觉剥夺性近视（FDM）眼巩膜中视黄酸（RA）的水平,探讨RA在FDM眼后极部巩膜中的作用。方法3周龄三色豚鼠30只随机分组,正常对照组6只,形觉剥夺15d组和形觉剥夺24d组各12只,左眼用气球头套分别遮盖15d和24d,右眼为自身对照。实验前后均测量屈光度,实验结束后摘除眼球,测量眼轴长,应用高效液相色谱法（HPLC）测定后极部巩膜RA含量。结果形觉剥夺15d组、形觉剥夺24d组动物实验眼诱导出明显的相对近视,且与正常组比较差异有统计学意义（F=23.053,P〈0.05）。形觉剥夺15d组、形觉剥夺24d组实验眼眼轴均长于自身对照眼（P〈0.05）。形觉剥夺15d组、形觉剥夺24d组实验眼巩膜中RA水平较自身对照眼均明显升高（P〈0.01）,但形觉剥夺15d组、形觉剥夺24d组间比较差异无统计学意义（P=0.857）。结论形觉剥夺可诱导近视,且近视程度在早期随时间递增,形觉剥夺眼眼轴增长。豚鼠早期形觉剥夺眼后极部巩膜RA含量增多,但在15～24d时段内差异无统计学意义。

Changes of retinoic acid level in guinea pig sclera of early form deprivation myopia

Objective Researches showed that retinoic acid may be a signal molecular in the regulation of ocular axial length.Sclera is a target tissue of the pathogenesis of form deprivation myopia.Recently,guinea pigs are used to the study of the pathogenesis of form deprivation myopia.However,seldom studies are found in the change of retinoic acid level in the sclera of guinea pigs.This study was designed to investigate the role of retinoic acid of early form deprivation myopia in guinea pigs sclera.MethodsMonocular form deprivation models were established in 24 3-week-old guinea pigs by occluding the left eyes with facemask and randomly divided into form deprivation 15 days group and 24 days group.Other 6 normal guinea pigs were used as control group.The fellow eyes were used as internal control.Refraction was measured before and after experiment by using retinoscopy.Eyeballs were extracted immediately at the corresponding time points and ocular axial length was measured with outside micrometer.The level of retinoic acid in scleral samples was detected by high performance liquid chromatography.The use of animal followed the Regulations for the Administration of Affairs Concerning Experimental Animals by the State Science and Technology Commission.ResultsRefractive diptor reduced by -3.14±1.50 D in experimental eyes after form deprivation,showing statistically differences among before and various time points after form deprivation(F=23.053,P=0.000),and no significant difference was seen in reduce of refractive diptor in fellow eyes after form deprivation( -1.24±1.99 D)(F=1.506,P=0.240).The axial length was considerably increased in form deprivation eyes after experiment (F=14.551,P=0.000) but no evident change in fellow eys (F=3.612,P=0.060).The diopter and ocular axial length was significantly different between form deprivation eyes and fellow eyes (P＞0.05).The expression of retinoic acid in sclera of form deprivation eyes was higher than fellow eyes in both form deprivation 15 days and 24 days(P＜0.01).There was no significant difference in the level of retinoic acid between form deprivation 15 days and 24 days(P＞0.05).ConclusionForm deprivation myopia can be induced in 15 days after monocular occlusion.Retinoic acid levels in guinea pig sclera increased significantly during early form deprivation.