Czy抖音看这里!文献导读 | 邹海东教授：屈光度数为0不能作为正视化的终点

文章来源：安研社马英妍

研究俗观

通过研究学龄前儿童屈光及屈光参数的一年变化，上海市眼病预防中心赵海东、许昕、何先溪、马英渊、林林等联合澳大利亚李安摩根教授、阿根廷拉斐尔Iri Barren教授等发表的研究结果显示，屈光度0在传统认识上不能成为直视化的终点。

Ma Y, Lin S, Morgan IG, Rozema JJ, Iribarren R, Zhu J, Zhao R, Zhang B, Yin Y, Shao Y, He X, Xu X, Zou H. Eyes grow towards mild hyperopia rather than emmetropia in Chinese preschool children. Acta Ophthalmol. 2021 May 3. doi: 10.1111. Epub ahead of print. PMID: 33942521.

研究目的

研究正常学龄前儿童屈光及屈光参数一年的变化及变化规律。

研究方法

在上海市城乡结合区，随机纳入7所幼儿园，纳入其中3-5岁，小班及中班儿童，并随访一年。基线研究在2014年11月至12月间展开，随访在2015年11月至12月间展开。眼轴采用IOL Master 5.02测量。纳入研究的儿童也接受了裂隙灯、眼压、散瞳、及散瞳后的屈光度数、角膜曲率检查及主觉验光。经眼科医师评判后，认为可以接受散瞳验光的儿童，予以散瞳检查。眼轴、屈光度数、角膜曲率均取三次测量平均值。由于没有测量前房深度和晶体厚度，因此，我们采用第二主焦点的方法对晶体度数进行估算。研究采用右眼数据进行分析。由于考虑严重屈光不正眼屈光发育的规律可能与正常眼不同，因此，本研究将患有严重屈光不正的眼排除，仅纳入正常眼进入分析，即屈光度数的SE在-0.5D至+3.0D范围内，散光度数的绝对值小于2D的眼。

研究结果

基线时，共903名儿童接受了散瞳检查。其中，857名儿童（94.9%）接受了随访，其中613人（67.9%）在随访时散瞳。

就整体而言，一年时间内，仅眼轴和晶体屈光力发生了显著变化。眼轴的改变随着年龄的增长有变慢的趋势。晶体屈光力的变化也随着年龄的增加而减少。球镜、柱镜、等效球镜及角膜曲率在各年龄组间，一年内均没有显著改变。

基线屈光度数对个体层面屈光力改变的影响：基线屈光力与屈光力的改变具有显著线性相关性。当基线SE在1.25D左右时，1年内SE的改变约为0D。当基线SE＞1.25D时，SE改变更多发生近视漂移；而当基线SE＜1.25D时，SE改变更多发生远视漂移。无论在3，4，5岁组，基线SE均与SE改变存在线性相关。

此外，基线SE与眼轴或者角膜曲率的改变未表现出显著相关。基线SE与晶体屈光力的改变，在5岁儿童组，表现出显著相关：基线SE越小，晶体屈光力的减少越多。

多元回归的结果显示：采用稳健回归，调整了性别和年龄后，基线SE与SE改变显著相关。基线SE增加1D，SE的改变就减少0.15D。采用bootstrap法得到，当基线SE为1.05D时，SE改变为0D。回归结果也显示，基线SE与眼轴的改变没有相关性（p=0.957），与角膜曲率变化也没有相关（p=0.263）。而基线SE与晶体屈光力变化存在相关性（p=0.013）。

结论与启示

本研究得到，对于正常儿童，虽然在整体层面3-5岁儿童，一年内SE没有显著变化，但在个体层面上，由于眼轴及晶体屈光力的变化，SE仍处于活跃的改变中，而SE的改变与基线SE显著相关。当基线SE小于1D时，晶体屈光力的减少会大于眼轴的增长带来的屈光力改变，导致SE远视漂移；然而当基线SE大于1D时，晶体屈光力的减少会小于眼轴的增长带来的屈光力改变，导致SE近视漂移。本研究得到的正常学龄前儿童屈光变化的模式，结果佐证了人类正视化的过程，即保持轻度远视作为正视化的终点，而非屈光度数为0作为传统认识上正视化的终点。本文也细致地展示了在3-5岁年龄段的儿童正视化的过程，及屈光发育的过程中是如何将屈光度数保持在轻度远视的机制。

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