Accuracy of the ratio of axial length to corneal radius in the assessment of myopia in children and adolescents / 国际眼科杂志(Guoji Yanke Zazhi)

ABSTRACT

AIM: To explore the accuracy of the ratio of axial length(AL)to the average corneal radius(CR)(AL/CR value, i.e., axial ratio)in assessing myopia in children and adolescents.METHOD:Cross-sectional study. A total of 340 cases(680 eyes)of children and adolescents aged 4-16 years old were collected from the ophthalmology clinic of Shangyu People's Hospital of Shaoxing between January 2022 and October 2022. All patients were subjected to optometry after cycloplegia to obtain spherical equivalent(SE), check and record the patient's AL, average CR, and calculate the AL/CR value.RESULTS:All subjects in this study underwent optometry after cycloplegia, and a total of 609 eyes(89.6%)were found to have myopia(SE≤-0.50 D), 58 eyes(8.5%)with hyperopia(SE≥+0.50 D)and 13 eyes(1.9%)with emmetropia(-0.50 D>SE>+0.50 D). There was a statistically significant difference in SE, AL and AL/CR values among different refractive states(P<0.01), but there was no difference in CR(P>0.05). All subjects have refractive parameters SE +8.75--8.75(average -2.25±2.38)D; AL 19.91-27.54(average 24.41±1.22)mm; CR 7.17-8.71(average 7.83±0.27); AL/CR values range from 2.50-3.50(average 3.12±0.14), correlation analysis showed a relative strong negative correlation between SE and AL/CR and AL(r=-0.891, P<0.01; r=-0.758, P<0.01), but no significant correlation between SE and CR(r=0.067, P>0.05), there was a positive correlation between AL and CR(r=0.483, P<0.01). The linear relationships between SE and AL/CR, AL were SE=45.026-15.162×AL/CR, R2=0.794, SE=33.741-1.474×AL, R2=0.574, respectively. The gold standard was based on the optometric results of cycloplegia, the sensitivity, specificity, misdiagnosis rate and missed diagnosis rate of AL/CR value for myopia were 0.962, 0.839, 0.169, 0.038, respectively, and the accuracy was 94.85%, the Kappa coefficient was 0.742, and the area under the ROC curve was 0.972.CONCLUSION:With high qualitative diagnostic value for myopia and a certain clinical significance for myopia monitoring, AL/CR value can be used to guide myopia prevention and control and other related ophthalmic clinical work.