外源性视黄酸诱导的豚鼠近视模型的建立

A myopic model of guinea pig induced by exogenous retinoic acid

目的建立豚鼠外源性视黄酸诱导近视模型,观察外源性视黄酸在三色豚鼠眼轴生长和屈光变化中的作用。方法选取体质量100g左右3～4d三色豚鼠20只,随机分为正常对照组和视黄酸诱导组。视黄酸诱导组予连续5d喂饲24mg.kg-1花生油调配的视黄酸0.5mL,正常对照组喂饲0.5mL花生油,喂饲前和喂饲后第5天分别测量其眼轴长度、屈光度,观察其变化。用HE染色测量视黄酸诱导组豚鼠巩膜和正常对照组豚鼠巩膜的厚度变化并通过透射电镜观察巩膜成纤维细胞的变化及胶原纤维的改变。结果实验前豚鼠的屈光状态和眼轴长度,两组之间差异均无统计学意义(均为P>0.05)。实验第5天,视黄酸诱导组豚鼠眼轴增长,正常对照组豚鼠的眼轴长度为(7.628±0.009)mm,视黄酸诱导组豚鼠眼轴长度为(7.743±0.005)mm,两组比较差异具有统计学意义(P<0.01);正常对照组的豚鼠眼的屈光度为(+6.50±1.60)D,视黄酸诱导组的豚鼠眼的屈光度(+1.73±0.80)D。与正常对照组相比,视黄酸诱导组的豚鼠眼屈光度平均增加了-4.80D,屈光度差异有统计学意义(P<0.01)。后极部巩膜HE染色显示,视黄酸诱导组巩膜比对照组巩膜薄。透射电镜结果显示,视黄酸诱导组巩膜胶原纤维数量减少,直径变小。结论外源性视黄酸能稳定有效地诱导眼轴增长,形成相对性的近视漂移并直接引起巩膜重塑。

Objective To establish the myopic model of guinea pig after exogenous application of all-trans retinoic acid,and observe the effect of all-trans retinoic acid（RA） on eyes growing and of refractive status development.Methods Twenty 3-4 day-old pigmented guinea pig with a weight of 100 g were randomly divided into control group and treatment group.Guinea pigs were fed 0.5 mL of RA（24 mg.kg-1） for treatment groups and 0.5 mL of carrier peanut oil for control groups.On the fifth day,the axial length and refraction were measured and then their changes were observed.The changes of the sclera thickness in two groups were assessed by HE staining.The changes of scleral fibroblasts and collagen fiber were observed by transmission electron microscope.Results There was no statistical difference in axial length and refraction between two groups before the experiment（both P〉0.05）.On the fifth day,the axial length in control group and treatment group were（7.628±0.009） mm and（7.743±0.005） mm,respectively,there was significant difference（P〈0.01） ;The diopter in control group and treatment group were（＋6.50±1.60） D and（＋1.73±0.80） D,respectively,RA treatment caused a myopic shift in refractive error of-4.80 D,there was significant difference（P〈0.01）.HE staining showed the sclera thickness of treatment group was thinner than that of control group.The numbers and diameter of sclera collagen fiber in treatment group were decreased.Conclusion The exogenous RA can accelerate the ocular elongation of guinea pigs and induce myopic shift,which indicate RA can affect sclera remodeling.