Objective: To analyze the one year follow up changes and influencing factors of anisometropia among primary school students in Beihai, so as to provide data support for formulating targeted prevention and control strategies. Methods: In 2023 and 2024, visual acuity and refractive screening were conducted on primary school students in Beihai. A cohort matching method was used based on unique identifiers to link data from 2023 (baseline) Grades one to five with those from 2024 (follow up) Grades two to six, obtaining a total of 59 743 complete datasets. McNemar test and generalized estimating equations(GEE) model were employed to analyze the changing patterns of anisometropia. Results: The detection rate of anisometropia among primary school students in Beihai increased from 10.88% in 2023 to 12.30% in 2024 ( χ 2=97.12, P <0.01). Among them, the detection rate in Grade 1 decreased from 8.82% in 2023 to 7.50% in 2024, Grade 3 increased from 10.15% to 11.52%, Grade 4 increased from 12.10 % to 15.22%, Grade 5 increased from 14.61% to 17.88% ( χ 2=16.51,18.03,95.52,95.95,all P <0.05). The GEE results showed that the risk of anisometropia development was higher in girls than in boys ( OR =1.15), the risk of anisometropia increased by 16% with each 1 year increment in age ( OR =1.16) among primary school students, the risk of anisometropia development in Grade 5 was 2.20 times higher than that in Grade 1 ( OR =2.20)(all P <0.05). In lower grades, only the baseline anisometropia status in lower grades had a statistically significant effect on anisometropia among primary school students( OR =59.09), while the positive effects of gender and age difference gradually emerged and strengthened in middle and higher grades (all P ＜0.05). Conclusions The detection rate of anisometropia among primary school students in Beihai shows dynamic changes and influencing factors vary by grade level. It is necessary to develop stratified prevention and control strategies tailored to different grades.

AIM: To compare the diagnostic efficiency of binocular uncorrected distance visual acuity(UCDVA), pre-cycloplegia refraction spherical equivalent(PR-SE), axial length(AL)difference, and their different combinations in the screening of anisometropia in children and adolescents, and to evaluate the practical value of different indicator combinations in simplifying the screening process when taking cycloplegic retinoscopy results as the gold standard for diagnosing anisometropia.METHODS: This was a retrospective study. A total of 500 consecutive cases of children and adolescents aged 6-18 years with known refractive status were included. Taking cycloplegic retinoscopy results as the gold standard for anisometropia diagnosis, the binocular UCDVA, PR-SE, and AL difference were incorporated into ROC curve analysis to assess the diagnostic efficacy of each indicator. Furthermore, predictive models were constructed and reliability analysis was performed.RESULTS: The average age of the included cases was 10.75±2.24 years, including 239 males and 261 females. The AUC of the interocular PR-SE difference(0.972, 95%CI: 0.960-0.984)was significantly higher than that of other indicators. The Youden index was the largest when the bincular UCDVA difference was 0.25, the PR-SE difference was 0.743, and the AL difference was 0.31. When the interocular PR-SE difference used 0.743 and 1.00 D as screening cutoffs, the former had a higher AUC(AUC=0.924, 95%CI: 0.895-0.953). Comparison of different constructed predictive models showed that when the binocular PR-SE difference was ≥0.743 D, the negative predictive value reached 98.89%, making it suitable for initial screening. The combination of UCDVA+PR-SE+AL had the highest specificity and positive predictive value, while the PR-SE+AL combination had the highest consistency rate.CONCLUSION: The binocular PR-SE difference is the best choice for single-indicator screening. Combining UCDVA and AL can increase the specificity to 98.00% and the positive predictive value to 88.24%. The PR-SE+AL combination can achieve the highest consistency rate.

AIM: To evaluate the value of the ratio of axial length to corneal radius of curvature(AL/CR)in the diagnosis of myopia in children and adolescents.METHODS: The refraction and ocular biometric parameters of 2 182 cases of children and adolescents(4 364 eyes)who initially visited the optometry clinic of the Second People's Hospital of Beihai from January 2022 to December 2023 were collected and analyzed.RESULTS: The receiver operating characteristic curve(ROC curve)showed that AL/CR had a higher area under the curve(AUC=0.925, 95%CI: 0.917-0.933)in diagnosing myopia. When AL/CR was 3.053, the Youden index was the largest. As the threshold of AL/CR decreased, the sensitivity of myopia diagnosis increased, while the specificity decreased. Compared with screening myopia, the sensitivity of AL/CR=3.053 in diagnosing myopia was low, but the specificity was high, especially in the cases of hyperopia and pre-myopia.CONCLUSION: The accuracy of AL/CR in diagnosing myopia is superior to that of axial length and average corneal curvature, with higher specificity. As the threshold of AL/CR decreases, the sensitivity of diagnosing myopia increases, but the specificity decreases. In cases of hyperopia and pre-myopia, the specificity of AL/CR in diagnosing myopia is higher than that of screening myopia.