眼轴长度与角膜曲率半径及其比值对儿童青少年屈光不正的影响和定性评估

目的：探讨眼轴长度(AL)与角膜曲率半径(CR)及其比值(AL/CR)对儿童青少年屈光状态的影响，评估AL/CR比值对青少年儿童近视的作用和意义。

方法：横断面研究。选取2017-12/2018-12在我院首诊的3～16岁疑似屈光不正儿童青少年816例1 632眼，检测AL和CR，并行双眼睫状肌麻痹后验光，记录等效球镜度数(SE)。

结果：本研究纳入受检者816例，检出屈光不正者773例(94.7%)，其中近视患者以7～14岁者居多(88.6%)。不同屈光度组受检者右眼AL和AL/CR比值均有差异(P<0.001)。近视和中度远视受检者的SE与AL和AL/CR比值均具有较强的相关性，年龄越大的受检者其SE与AL和AL/CR比值的相关性越强。以睫状肌麻痹验光结果为金标准，AL/CR比值诊断近视的灵敏度为0.880，特异度为0.916，准确度为89.2%，Kappa系数为0.760，ROC曲线下面积为0.954。

结论：中度远视、近视、年龄越大的儿童青少年SE与AL、AL/CR比值的相关性更强，其中AL/CR比值对近视的定性诊断价值更高。

Effect of axial length and corneal curvature radius and their ratio on refractive errors in children and adolescents

AIM: To analyze the association between refractive status and refractive factors, and to explore the effectiveness of mean ocular axial length(AL), mean corneal radius of curvature(CR)and their ratio in the assessment of amitropia in children and adolescents.

METHODS: Cross sectional study, 816 cases(1632 eyes)aged 3-16 years old suspected ametropia were selected in the Affiliated Eye Hospital of Nanjing Medical University from December 2017 to December 2018. Uncorrected visual acuity(UCVA), mean AL and mean CR were tested. Autorefraction was performed after cycloplegia, which was measured as the spherical equivalent(SE).

RESULTS: Among 816 cases of children and adolescents aged 3-16, 773 were ametropia, accounting for 94.7%, with the highest proportion aged 7-14. The difference(one eye)in the mean AL, and AL/CR ratio of different refractive groups were statistically significant(P<0.05). In different refractive states, the mean AL and AL/CR ratio showed a low correlation with SE in emmetropes and low hyperopes but higher correlation in moderately hyperopic and myopic children. The mean AL, AL/CR ratio were higher correlation with SE increased with age. Sensitivity was 0.880, specificity was 0.916, and accuracy was 89.2%. The area under ROC curve was 0.954.

CONCLUSION: The proportion of myopia among children and adolescents gradually increases and shows a large increase after 7 years old. The AL and AL/CR ratio showed higher correlation in moderate hyperopes, myopes and older ages. The AL/CR ratio is highly accurate in the diagnosis of myopia in adolescents and children.