青少年近视在不同阅读距离调节状态下眼前段结构的变化

目的分析和探讨不同程度青少年近视在不同阅读距离诱导的调节状态下眼前段结构的变化。方法收集我院屈光门诊14～18岁间青少年近视95例（95眼），正视眼34例（34眼）作对照，其中男66例，女63例。所有被试者行主觉验光、调节幅度测定，眼前节OCT测量在不同阅读距离诱导的调节状态下（OD、3D、6D）的前房深度、晶状体厚度及瞳孔直径，采用SPSS11．5forWindows行统计学分析。结果①在调节放松情况下，随着近视度数增加，暗瞳直径明显减小（P〈0．05），各组间晶状体厚度差异无显著性，前房深度差异有显著性（P〈0．05）。（D随着阅读距离的减小，调节运用的增加，各组前房深度变浅值、晶状体厚度变厚值、暗瞳直径变小值均显著增加（P〈0．01）。③随着近视度数增高，诱发3D调节时前房深度变浅值显著增加（P〈0．01），晶状体厚度变厚值明显增加（P〈0．05），暗瞳直径变小值差异无显著性。④随着近视度数增高，诱发6D调节时前房深度变浅值显著增加（P〈0．01），晶状体厚度变厚值明显增加（P〈0．05），暗瞳直径变小值显著增加（P〈0．01）。结论在青少年中，随近视程度加深，阅读距离减小，运用调节量的增加可引起眼前房显著变浅，晶状体明显变厚：暗瞳直径缩小值在诱发6D调节时随近视度数增高而增大。

Analysis of the anterior segment of the eyes of adolescent myopes when accommodation is induced by different reading distances

Objective To discuss the changes in the anterior segment of the eyes of adolescents with different degrees of myopia when accommodation is induced by different reading distances. Methods Ninety-five myopic subjects and 34 emmetropic subjects ranging in age from 14 to 18 years were enrollod in the study. Measurements were taken of every subject under different levels of accommodation （0 D, 3 D, 6 D） and included refraction with an MPMVA, accommodative amplitude, anterior chamber depth, crystalline lens thickness and pupil diameter with the Visante OCT. SPSS11.5 statistics software was used for analysis. Results （1）Pupil diameter significantly decreased in the dark with an increase in the degree of refractive error. There was no significant difference in crystalline lens thickness between each group but there was a significant difference in anterior chamber depth. （2）With a decrease in reading distance and an increase in accommodation, anterior chamber depth significantly decreased in all groups; crystalline lens thickness significantly increased; and pupil diameter significantly decreased in the dark. （3）With an increase in the degree of myopia, under an accommodation of 3 degrees, anterior chamber depth significantly decreased for all groups; crystalline lens thickness significantly increased; while pupil diameter did not significantly change in the dark. （4）With an increase in the degree of myopia, under an accommodation of 6 diopters, anterior chamber depth significantly decreased in all groups; crystalline lens thickness significantly increased; and pupil diameter significantly decreased in the dark. Conclusion In adolescents, with an increase in the degree of myopia, a decrease in reading distance and an increase in accommodation can significantly induce a decrease in anterior chamber depth and an increase in crystalline lens thickness. Under an accommodation of 6 D, pupil diameter significantly decreased in the dark with an increase in the degree of myopia.