北京市羊坊店学区两个年级组小学生AL/CR分布情况的分析

Analysis to distribution of AL/CR ratio in the students of two grades from Yangfangdian district in Beijing

目的:比较眼轴长度与角膜曲率半径比值(AL/CR)>3的人数在不同人群中所占比例的差异,探寻近视防治的监控点。方法:选择北京市羊坊店学区全部小学的一年级、四年级学生2970例。采用标准对数视力表测量远视力(DVA),光学相干生物测量仪(IOL Master)测量眼轴长度(AL)及角膜曲率半径(CR)。取有眼测量值统计分析。结果:一年级组1 282例,年龄6.44±0.52岁;四年级组1688例,年龄9.25±0.46岁。一年级组与四年级组相比,AL明显较短(P=0.000);DVA明显较好(P=0.000);AL/CR明显较小(P=0.000);角膜曲率半径值(CR)无显著性差异(P=0.31)。男性与女性相比,AL明显较长(P=0.000);DVA较好(P=0.01);AL/CR明显较大(P=0.000);CR明显较长(P=0.000)。四年级组AL/CR>3人数的比例显著高于一年级组(x^2=644.929,P=0.000)。高龄组中AL/CR>3人数的比例显著高于低龄组(x^2=644.807,P=0.000)。随着远视力的下降,一年级组与四年级组中AL/CR>3人数的比例均显著增高(x^2=82.914,x^2=297.236;P=0.000)。结论:不同学龄组小学生眼球生物学参数的对比分析表明学龄的延长影响学生的视力和眼轴发育。随着年龄的增长和远视力的下降,存在近视患病危险因素的人数比例增加,群体中近视患病的危险性也相应增加。在对大规模样本进行的眼科研究活动中,应用IOL Master测量眼球的生物学参数具有显著优势。

AIM： To compare the distinctions of percentages of students with axial length/corneal radius ratio（AL/CR） 〉 3 in different groups, and find out a key to monitoring for prevention and cure to myopia. METHODS, Totally 2970 students from the grade 1 and 4 of total primary schools, Yangfangdian district in Beijing had accepted examinations of distant visual acuity（DVA） by the standard logarithmic visual acuity chart and AL or CR by IOLMaster. The statistical analyses were performed using data for the right eye. RESULTS; Students of grade 1 （ n = 1282, mean age 6.44±0,52 years） and grade 4 （n=1688, mean age 9.25 ± 0.46 years） were examined. Compared with grade 4, the grade 1 had shorter AL, better DVA and smaller AL/CR ratio （P= 0. 000）, but no significant difference in CR（ P= 0.31）. The male had longer AL, better DVA and larger AL/CR ratio and CR than the female. Percentage of students with AL/CR 〉 3 in grade 4 were higher than that in grade 1 （X^2 = 644. 929, P = 0. 000）. Percentages of students with AL/CR 〉 3 in older group were higher than those in younger grouP（X^2 = 644. 807, P = 0. 000）. The worse the DVA, the higher the percentages of students with AL/CR 〉 3 in two groups （X^2 = 82.914,X^2 = 297.236; P =0. 000）. CONCLUSION： Distance visual acuity and axial length growth are affected by the prolonging of age. With the age growing and visual acuity decreasing, the percentages of students with myopia risk factor would increase and myopia attack rate of groups would increase accordingly. IOLMaster has advantages in the ocular biometric parameters measurement for ophthalmology research.