MR三维成像在高度近视中的应用探讨

Application of MR three-dimensional imaging in high myopia

目的：采用MR三维成像比较高度近视眼和正视眼的眼球径线和容积，探讨高度近视眼球的径线、容积与屈光度的相关性。方法：研究对象为高度近视眼40例共80眼（患者组）和正视眼40例共80眼（对照组）。所有受试者均行MR三维成像检查，测量并比较2组受试者的眼球径线及眼球容积。结果：所有受试者的眼球三维MR图像清晰。高度近视眼球呈不同程度扩张，80眼中57眼可见后巩膜葡萄肿形成。患者组眼球前后径、左右径、上下径及容积分另1为（29．38±2．31）、（25．58±1．80）和（24．94±1．49）mm及（10．78±1．91）cm^3，对照组分别为（22．98±0．66）、（22．59±0．62）和（23．17±1．04）mm及（7．57±0．70）cm^3，两组间差异均有统计学意义（P〈O．05），其中以前后径的差值最大。高度近视眼球的径线、容积与屈光度均呈正相关（r值0．383～O．542，P〈O．001）。结论：高度近视眼球的径线及容积较正视眼明显增大。MR三维成像可以清晰显示眼球的形态，高度近视眼球的径线及容积与屈光度间有一定相关性。

Objective：To compare eyeball diameter and volume between myopia and emmetropia using MR three-di- mensional imaging,and to study the correlation of eyeball diameter and volume with refractive diopter in high myopia pa-tients. Methods：The subjects of the study were 40 cases （80 eyes） of high myopia （patient group） and 40 cases （80 eyes） of emmetropia （control group）. All subjects underwent MR three-dimensional imaging to measure the eyeball diameter and volume. Results：The 3D images of eyeballs were clear. Different degree of expansion was found in all of the 80 eyes in pa- tient group, posterior scleral staphyloma was found in 57 eyes. The anteroposterior, left-right and vertical diameter and volume of eyeball in patient group was （29.38±2.31）,（25.58± 1.80） and （24.94±1.49）mm,and （10.78±1.91）cm^3 ; and in control group they were （22.98±0.66）,（22.59±0.62） and （23.17±1.04）mm,and （7.57±0.70）cm^3 ,respective- ly;there were significant differences between the two groups （P〈0.05）, especially in the anteroposterior diameter. The eyeball diameter and volume in high myopia group were positively correlated with spherical equivalent refraction, the r values were 0. 383 -0. 542 （P〈0. 001）. Conclusion： The diameter and volume of eyeball with high myopia were significantly increased compared with emmetropia. MR three-dimensional imaging could clearly display the shape of eyeball, and there exists certain correlation between eyeball diameter and volume with refractive diopter in patients with high myopia.