白化豚鼠高度近视眼的发生与视网膜超微结构的关系

目的:观察白化豚鼠与有色豚鼠眼球屈光状态及视网膜形态结构,探讨白化豚鼠高度近视眼的发生与黑色素合成的联系.方法:随机选取220～250g(5～6周龄)的白化豚鼠与有色豚鼠各12只,行视网膜镜检影验光以检测屈光度,A超和游标卡尺测眼轴长度,光镜和电镜观察视网膜结构.结果:白化豚鼠的平均屈光度为-19.17D,有色豚鼠的屈光度为 0.63D,白化豚鼠较有色豚鼠眼轴延长,差异有统计学意义(P＜0.05).形态学观察发现,白化豚鼠视网膜变薄,视网膜色素上皮(retinal pigment epithelium,RPE)层细胞色素颗粒稀少,所含膜盘吞噬体减少,膜盘间隙变窄.有色豚鼠视网膜较厚,RPE细胞含大量色素颗粒、内含较多膜盘吞噬体,膜盘间隙较宽.结论:白化豚鼠为高度近视眼,有色豚鼠为低度的远视眼或正视眼.白化豚鼠与有色豚鼠的视网膜存在着结构差异.白化豚鼠RPE的结构异常,为其高度近视眼提供了光学基础和结构基础.

High myopia and retinal ultrastructure of albino guinea-pigs

OBJECTIVE: To explore the relationship between melanin synthesis and the congenital high myopia of albino guinea-pigs. METHODS: Twelve albino guinea-pigs and 12 pigmented guinea-pigs of 220~250 grams (aged 5~6 weeks) were chosen at random. The eyes were examined with retinoscopy, A-scan ultrasonography and vernier caliper. The retinal structures were examined with light and electronic microscope. RESULTS: The diopter was -19.17 D in albino guinea-pigs and +0.63 D in pigmented guinea-pigs on average. Compared with the pigmented guinea-pigs, the axial dimensions of the albino guinea-pigs were elongated. There was significant difference between the albino guinea-pigs and the pigmented guinea-pigs. The retinal thickness, pigment granules and membrane disc of the outer segment of the visual cells decreased in the albino guinea-pigs, and the membrane disc space became narrow. The normal retinal thickness, plenty of pigment granules , membrane disc and wide membrane disc space could be observed in the pigmented guinea-pigs. CONCLUSION: Albino guinea-pigs have high myopia, and pigmented guinea pigs have light hyperopia. There are structural differences in the retina between albino guinea-pigs and pigmented guinea-pigs. The abnormity of albino guinea-pigs provides optical foundation for its high myopia.