Department of Ophthalmology, Chongqing Key Laboratory of Ophthalmology, First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, 1 Youyi Road, Chongqing, 400016, China.
Department of Ophthalmology, Chongqing General Hospital, University of Chinese Academy of Sciences, 104 Pipashan Road, Chongqing, 400014, China.
BMC Ophthalmol. 2022 May 11;22(1):212. doi: 10.1186/s12886-022-02436-5.
To investigate the prevalence of myopia in Chinese primary school students and their ocular biometrics including axial length (AL), corneal radius of curvature (CRC) and spherical equivalent refraction (SER). To analyze their association with potential myopia risk factors, such as body mass index (BMI), cram school, time of outdoor activity and electronic screen use.
In this cross-sectional study of 4500 primary school students from 5 schools, participants underwent refraction using non-cycloplegic autorefractor and visual acuity testing. A follow-up study in the same schools was conducted in 2022. Myopia was defined as SER ≤ -0.50 diopter (D) and uncorrected visual acuity (UCVA) < 0.00 logMAR (6/6). Logistic regression models were used to determine factors associated with myopia.
After excluding 389 participants, the overall prevalence of myopia was 33.6%. The prevalence of high myopia was 0.6%. The prevalence of myopia in girls was significantly higher than that in boys (37.6% vs. 30.0%, p < 0.001). The height, weight and BMI were significantly associated with AL (r = 0.471, r = 0.440, r = 0.276, p < 0.001, respectively). AL/CRC ratio was more highly correlated with SER than AL alone. Regression analysis showed that AL/CRC and hyperopia reserve were associated with myopia onset in the subsequent year (F = 201.557, p < 0.001; F = 68.934, p < 0.001). The cut point of hyperopia reserve for myopia in the subsequent year for grade 1 students was + 0.31D. Age (p < 0.001), parental myopia (p = 0.001) and lack of outdoor activity between classes (p = 0.049) were independently associated with higher prevalence rates of myopia.
The prevalence of myopia among Chinese schoolchildren is alarming high. Consistent with previous cross-sectional data, AL/CRC and hyperopia reserve could function as myopia detection indicators. The hyperopia reserve among children aged between 6 ~ 7 years was low. Healthcare providers need to raise parents' awareness of the importance of regular eye examination and proper optical correction.
调查中国小学生近视的流行情况及其眼生物测量学指标，包括眼轴（AL）、角膜曲率半径（CRC）和等效球镜屈光度（SER）。分析它们与潜在近视危险因素的关系，如体重指数（BMI）、课外辅导班、户外活动时间和电子屏幕使用时间。
在这项来自 5 所学校的 4500 名小学生的横断面研究中，使用非睫状肌麻痹自动折射仪进行屈光检查和视力测试。在 2022 年对同一学校进行了随访研究。近视定义为 SER≤-0.50 屈光度（D）和未矫正视力（UCVA）<0.00 对数视力表（6/6）。使用逻辑回归模型确定与近视相关的因素。
排除 389 名参与者后，近视总患病率为 33.6%。高度近视患病率为 0.6%。女生近视患病率显著高于男生（37.6%比 30.0%，p<0.001）。身高、体重和 BMI 与 AL 显著相关（r=0.471、r=0.440、r=0.276，p<0.001）。AL/CRC 比值与 SER 的相关性高于 AL 单独的相关性。回归分析显示，AL/CRC 和远视储备与次年近视的发生有关（F=201.557，p<0.001；F=68.934，p<0.001）。一年级学生次年近视的远视储备切点为+0.31D。年龄（p<0.001）、父母近视（p=0.001）和课间缺乏户外活动（p=0.049）与近视患病率的增加独立相关。
中国学龄儿童近视的患病率令人震惊。与之前的横断面数据一致，AL/CRC 和远视储备可作为近视检测指标。6~7 岁儿童的远视储备较低。医疗保健提供者需要提高家长对定期眼部检查和适当光学矫正的重要性的认识。
