Grosvenor T
College of Optometry, University of Houston, Texas.
Am J Optom Physiol Opt. 1988 Sep;65(9):689-96. doi: 10.1097/00006324-198809000-00001.
Results of refractive component measurements have shown that eyes of Melanesian schoolchildren living in Vanuatu, almost all of whom are emmetropic, have relatively short axial lengths and relatively flat corneas in comparison to emmetropic eyes of children examined in England. Evidence is presented to suggest that the relation between the axial length of the eye and corneal radius--the axial length/corneal radius (AL/CR) ratio--may be a useful predictor of future refractive state. Mean axial length/corneal radius ratios for 6- to 19-year-old Melanesian school children were found to be 2.88 for boys and 2.86 for girls, as compared to mean AL/CR ratios for 6- to 19-year-old British schoolchildren of 3.05 for boys and 3.04 for girls. It is proposed that an eye having a high AL/CR ratio is at risk for the development of myopia, and that such an eye has maintained its state of emmetropia by virtue of a compensatory flattening of the crystalline lens. In order to test the proposition that an increase in axial length occurs as a precursor to the development of myopia, a prospective longitudinal study of a group of 6- to 7-year-old schoolchildren is proposed.
屈光成分测量结果表明，生活在瓦努阿图的美拉尼西亚学龄儿童的眼睛，几乎所有人都是正视眼，与在英国检查的儿童正视眼相比，其眼轴长度相对较短，角膜相对较平。有证据表明，眼轴长度与角膜半径之间的关系——眼轴长度/角膜半径（AL/CR）比值——可能是未来屈光状态的一个有用预测指标。6至19岁美拉尼西亚学龄儿童的平均眼轴长度/角膜半径比值，男孩为2.88，女孩为2.86，而6至19岁英国学龄儿童的平均AL/CR比值，男孩为3.05，女孩为3.04。有人提出，AL/CR比值高的眼睛有发生近视的风险，并且这样的眼睛通过晶状体的代偿性扁平而维持了正视状态。为了检验眼轴长度增加是近视发生的先兆这一命题，提议对一组6至7岁的学龄儿童进行前瞻性纵向研究。
