Myopia is an important cause of visual impairment and has become a public health problem all over the world. In China, myopia has a high incidence rate and age of onset of which is becoming younger. There is no clinical method to reverse myopia in children. Therefore, it is important to standardize the screening for ametropia to realize early detection and intervention of myopia. As a primary care institution, a community health center may accurately understand the prevalence of myopia in teenagers in its service coverage area. So giving full play to the role of community health center has important practical significance for the containment of myopia in children and adolescents.

To explore the feasibility of community-based prevention and control of myopia in school-age children.

A cohort study was conducted. The information about visual acuity and refractive status of students in a primary school in Beijing's Chaoyang District from September 2019 to September 2021 were collected for statistical analysis, among which four groups of data in September 2019, September 2020, March 2021 and September 2021 were finally included according to the inclusion and exclusion criteria, with a total of 5 558 records. Then, based on the data, an electronic students' refractive database was established, with uncorrected visual acuity, corrected visual acuity, refractive status (power of a spherical lens, power of a cylindrical lens, axis) , prevalence of wearing glasses or orthokeratology incorporated. The warning levels of vision screening were set to be 0, 1, 2 and 3 from low to high. The visual change, visual warning level, spherical equivalent (SE) of students were compared by grade. The visual changes and warning level evolution at different times were compared at the individual level. Corresponding interventions were implemented for different warning levels, and the intervention results were analyzed and discussed.

There were statistically significant differences in uncorrected distance visual acuity (UDVA) among students by grade (F=100.413, P<0.05) . The UDVA differed significantly in male or female students (F=47.168, 53.042, P<0.05) . Compared with the lower grade students (grades 1 and 2) , middle and higher grade students (grades 3, 4, 5 and 6) had lower UDVA (P<0.003) . The UDVA decreased with the increase in grade in male and female students, and the decline in female students was faster. The composition of the warning levels of myopia risk assessed based on the UDVA in male and female students in all grades was similar, mainly composed of 0, 1, and 3 levels. With the increase in grade, the number of low warning level (level 0) gradually decreased, while that of high warning level (level 3) gradually increased. The SE in students differed obviously by grade (F=474.728, P<0.05) . The SE also differed much in male or female students (F=121.704, 123.807, P<0.05) . With the increase of grade, SE tended to be negative, and the difference in SE between left and right eyes was statistically significant (t=-4.67, P<0.05) . The negative trend of SE for the right eye was more remarkable, suggesting that the warning level of the right eye was higher, and the right eye was more prone to myopia. The follow-up of three consecutive years for assessing individual visual changes revealed that the results of four UDVA screening differed significantly in all students and female students (F=8.727, 10.221, P<0.05) . The UDVA result screened in March 2021 for all students decreased significantly compared with that screened in September 2019 or September 2020 (P<0.008) , so did the UDVA result screened in September 2021 (P<0.008) . During the evolution of warning level, higher warning level was associated with lower possibility of returning to the low warning level, and the possibility of progressing to a higher warning level increased with the growth of warning level.

The visual acuity and refractive status of students in this primary school in Beijing's Chaoyang District were not optimistic. With the increase in grade, the UDVA decreased and the number of high warning level gradually increased. To actively contain myopia in school-age children, it is suggested to establish a community-based vision screening and warning mechanism, and to promote the containing of myopia by home-school-community collaboration efforts.

近视是导致视觉损害的重要病因，已经成为世界范围内的公共卫生问题。近视在我国有着高发病率和低龄化趋势。目前临床上尚无儿童近视的逆转方法，因此规范化开展屈光不正的筛查工作，实现近视的早发现、早干预极其重要。社区卫生服务中心作为最基层的卫生健康专业机构，能够准确掌握本地儿童青少年近视的分布情况。有效发挥社区卫生服务中心的作用，对于儿童青少年近视防控有着重要的实践意义。

探讨基于社区卫生服务的学龄儿童近视防控干预模式的可行性。

本研究为队列研究，收集2019年9月至2021年9月北京市朝阳区某小学学生视力与屈光状态资料进行统计分析，根据纳入、排除标准最终纳入2019年9月、2020年9月、2021年3月、2021年9月4组数据5 558条记录。建立学生电子屈光档案，包括裸眼远视力、矫正视力、屈光状态（球镜度数、柱镜度数、轴位）、是否戴镜、角膜塑形镜佩戴情况。设立视力筛查警戒级别从低到高分别为0、1、2和3级，分别对不同年级学生视力变化情况、视力警戒级别、等效球镜度数（SE）以及同一学生不同时间视力变化情况和警戒级别演变过程进行比较，针对不同警戒级别实施相应的干预措施，分析并讨论干预结果。

不同年级学生、男生、女生裸眼远视力比较，差异均有统计学意义（F=100.413、47.168、53.042，P<0.05）；与低年级（1、2年级）学生相比，中高年级（3、4、5、6年级）学生裸眼远视力均降低（P<0.003）。男生和女生裸眼远视力随年级增加而降低，其中女生比男生下降更快。各年级男、女生裸眼远视力警戒级别组成类似，主要由0、1和3级组成；随着年级增加，低警戒级别（0级）人数逐渐减少，高警戒级别（3级）人数逐渐增加。不同年级学生、男生、女生SE比较，差异均有统计学意义（F=474.728、121.704、123.807，P<0.05）；随着年级的增加，SE愈偏向负值，且左、右眼SE比较，差异有统计学意义（t=-4.67，P<0.05），右眼SE负值化的趋势更加显著，提示右眼警戒级别更高，右眼更易趋于近视化。追踪同一学生连续3年视力变化情况，结果显示，4次视力检测的学生、女生裸眼远视力比较，差异均有统计学意义（F=8.727、10.221，P<0.05）；与2019年9月和2020年9月相比，2021年3月和9月学生裸眼远视力均下降（P<0.008）。在警戒级别演变过程中，警戒级别越高，恢复为低警戒级别的可能性越低，各警戒级别向更高警戒级别进展程度随级别增高而增高。

北京市朝阳区某小学学生视力与屈光状态现状不容乐观，学生裸眼远视力随年级增加而降低，高警戒级别人数随年级增加而增加。在社区卫生服务的基础上建立视力筛查警戒机制，推进学龄儿童近视防控的三级预防进校园，联合家-校-医三方，有望在学龄儿童近视防控中起到积极作用。