目的：了解成都市青羊区3～18岁儿童和青少年近视患病现况，为近视防控工作提供依据。

方法：横断面调查研究。2019-10/2020-01对成都市青羊区38所学校进行近视筛查，共计72 270名学生，男37 278名(51.58%)，女34 992名(48.42%)，年龄3～18(平均10.22±3.22)岁。分析其近视的患病率、高度近视患病率、屈光参差患病率、屈光状态和眼轴发育情况。

结果：近视患病率57.50%，高度近视患病率3.33%，中度屈光参差患病率9.80%，高度屈光参差患病率4.24%。相邻年龄组间两两比较：近视患病率6～14岁之间差异有统计学意义(均P<0.0033)，高度近视患病率9～14岁、15～16岁之间差异有统计学意义(均P<0.0033)，中度屈光参差患病率7～11岁、12岁与13岁之间差异有统计学意义(均为P<0.0033)，高度屈光参差患病率5岁与6岁、8～12岁之间差异有统计学意义(均为P<0.0033)。眼轴长度：右眼23.658±1.258mm，左眼23.611±1.246mm，5～18岁左、右眼眼轴长度之间差异有统计学意义(均P<0.05)，且右眼比左眼轴长； 同年龄段正视眼和近视眼眼轴长度比较(取右眼分析)，6～18岁差异有统计学意义(均P<0.01)。屈光状态与眼轴的关系(取右眼分析)：随着年龄增长，眼轴增长，远视逐渐降低，正视化后，近视逐渐增加，3～6岁等效球镜(SE)均值为正值，从7岁开始，SE均值变为负值，呈近视化改变，眼轴为22.923±0.759mm； 不同屈光状态下的眼轴长度，远视为22.489±0.853mm，正视为23.023±0.802mm，轻度近视为23.860±0.965mm，中度近视为25.137±0.929mm，高度近视为26.252±1.040mm。

结论：近视患病率、高度近视患病率与以往相比，呈上升趋势。预防近视在7岁之前，而防止向高度近视发展应当在10岁时开始，建议8岁以前形成良好的用眼卫生习惯，防止中高度屈光参差的发生与发展。7岁开始呈近视化改变，右眼更容易出现近视，我们可以通过不同年龄眼轴长度来预测近视趋势，还可以通过眼轴长度评估近视的严重程度。

METHODS: A cross-sectional study was designed. A total of 72 270 students, including 37 278 males(51.58%)and 34 992 females(48.42%), aged from 3 to 18 years old were screened in 38 schools in Qingyang District of Chengdu from October 2019 to January 2020, with an average age of(10.22±3.22)years old. The incidence of myopia, high myopia, anisometropia, refractive status and axial development were analyzed.

RESULTS: The incidence of myopia is 57.50%, high myopia 3.33%, moderate anisometropia 9.80%, and high anisometropia 4.24%. The age group between two adjacent two comparison: the myopia prevalence of 6-14 years old difference was statistically significant(all P<0.0033), high myopia incidence between 9-14 and 15-16 difference was statistically significant(all P<0.0033), the incidence of moderate anisometropia 7-11, 12 and 13 years old(all P<0.0033), high incidence of anisometropia, 5 and 6, and 8-12 years old(all P<0.0033). Axial length: the axial length of the right eye(23.658±1.258)mm, the left eye(23.611±1.246)mm, and the axial length of the left and right eyes between 5 and 18 years old showed statistical differences(all P<0.05), and the axial length of the right eye was longer than that of the left eye. The axial length of emmetropia and myopia of the eyes(take the right eye)in the same age group was statistically significant between the ages of 6 and 18(all P<0.01). The relationship between the refractive state and the axial length(right eye analysis): with the increase of age, the axial length increased, and the refractive index of the equivalent spherical mirror of hyperopia decreased gradually, and myopia increased gradually after emmetropia. The mean value of the equivalent spherical mirror(SE)was positive between 3-6 years old. From the age of 7, the mean value of SE turned to a negative value, presenting a myopic change, and the axial length was 22.923±0.759mm. Under different refractive conditions, the axial length was hyperopia as 22.489±0.853mm, and the emmetropia as 23.023±0.802mm, low myopia as 23.860±0.965mm, moderative myopia as 25.137±0.929mm, and high myopia as 26.252±1.040mm.

CONCLUSION: Compared with the past, the prevalence of myopia and the incidence of high myopia are on the rise. Prevention of myopia before the age of 7, and prevention of the development of high myopia should start at the age of 10. It is suggested that good eye hygiene habits should be formed before the age of 8 to prevent the occurrence and development of moderate and high refractive errors. Myopia changes at the age of 7, and myopia is more likely to occur in the right eye. We can predict the trend of myopia by axial length at different ages, and also assess the severity of myopia by axial length.