目的：分析学龄儿童近视前期的危险因素，基于危险因素构建其列线图模型，并探讨平光离焦镜对其的近视防控效果。

方法：本研究为前瞻性随机对照临床试验。选取2024年7月至2025年1月来本院体检的学龄儿童为研究对象，依据睫状肌麻痹后验光及眼轴测量结果将研究对象分为试验组(近视前期患儿)与对照组(正常屈光儿童)。收集两组临床资料，采用Logistic回归方程分析学龄儿童近视前期的危险因素，并基于其危险因素构建列线图模型。同时采用随机数字法将试验组患儿分为A组(标准行为+平光离焦镜干预)与B组(标准行为干预)，对治疗前后的眼生物学参数、验光指标进行比较。

结果：本研究纳入学龄儿童236例，其中试验组80例(A组40例，B组40例)，对照组156例。试验组年龄8.88±1.11岁，男27例，女53例。对照组年龄8.92±1.05岁，男91例，女65例。A组年龄8.79±1.22岁，男14例，女26例。B组年龄8.91±1.07岁，男13例，女27例。Logistic多因素结果显示：父母近视家族史、握笔姿势、电子产品使用时长是学龄儿童近视前期的危险因素(均P<0.05)； 每日户外活动时长、每日睡眠时长是其保护因素(均P<0.001)。列线图模型的AUC为0.970，95%CI：0.951-0.990，灵敏度为0.900，特异度为0.942； 校准曲线线性关联接近完美校准，拟合性较好； 决策曲线示临床适用性高； SHAP总结图示每日户外活动时长是影响学龄儿童近视前期发生的最关键因素。平光离焦镜干预后，A组AL增长量显著低于B组(P<0.05)，脉络膜厚度、睫状肌麻痹后球镜度数显著高于B组，裸眼远视力(LogMAR)显著低于B组(均P<0.05)。

结论：父母近视家族史、握笔姿势、电子产品使用时长是学龄儿童近视前期的危险因素，每日户外活动时长、每日睡眠时长是其保护因素，基于上述因素构建的列线图预测准确率较好，可用于早期筛查高风险儿童。平光离焦镜能够延缓近视前期学龄儿童眼轴进展，稳定屈光状态，发挥积极的近视防控效果。

METHODS: A prospective randomized controlled clinical trial. School-aged children receiving physical examinations in the hospital between July 2024 and January 2025 were enrolled. All subjects were divided into the experimental group(children with pre-myopia)and the control group(children with normal refraction)according to the results of cycloplegic refraction and axial length measurement. Clinical data of the two groups were collected. Logistic regression analysis was adopted to identify the risk factors for pre-myopia, and a corresponding nomogram model was constructed. The children in the experimental group were further assigned to Group A(standard behavioral intervention+plano defocus lenses)and Group B(standard behavioral intervention alone)via the random number method. Ocular biological parameters and refractive indices before and after intervention were compared between groups.

RESULTS: A total of 236 school-aged children were enrolled in this study, including 80 children in the experimental group(40 cases in group A and 40 cases in group B)and 156 children in the control group. The age of children in the experimental group was 8.88±1.11 y, with 27 males and 53 females. The age of children in the control group was 8.92±1.05 y, with 91 males and 65 females. Group A had an average age of 8.79±1.22 y(14 males and 26 females), and group B had an average age of 8.91±1.07 y(13 males and 27 females). Multivariate Logistic regression analysis revealed that parental myopia history, pencil-grip posture and duration of electronic device use were risk factors for pre-myopia among school-aged children(all P<0.05); daily outdoor activity duration and daily sleep duration were protective factors(all P<0.05). The nomogram model yielded an AUC of 0.970(95%CI: 0.951-0.990), with a sensitivity of 0.900 and specificity of 0.942. The calibration curve indicated nearly perfect linear calibration and good fitting performance. Decision curve analysis demonstrated high clinical applicability. SHAP summary plots showed that daily outdoor activity duration was the most critical factor affecting the onset of pre-myopia in school-aged children. After intervention with plano defocus spectacles, the axial length elongation in group A was significantly lower than that in group B(P<0.05). Choroidal thickness and cycloplegic spherical refraction were significantly higher, and uncorrected distance visual acuity(LogMAR)was significantly lower in group A compared with group B(all P<0.05).

CONCLUSION: Parental myopia history, pencil-grip posture, and duration of electronic device use are risk factors for pre-myopia in school-aged children, while daily outdoor activity duration and daily sleep duration are protective factors. The nomogram constructed based on the above factors exhibits favorable predictive accuracy and can be applied for early screening of high-risk children. Plano defocus spectacles can slow axial length progression, stabilize refractive status, and exert positive effects on myopia prevention in school-aged children with pre-myopia.