眼前节OCT技术对人眼水平直肌止端解剖结构的研究

A study on structure of human horizontal rectus insertion by anterior segment optical coherence tomography

背景眼外肌止端距离和厚度的测量对于眼外肌病变的诊断至关重要，但常用的影像学检测手段为接触性检查方法。眼前节光学相干断层扫描（OCT）可避免常规影像学检查的缺点，但尚未见到其用于眼外肌检测的报道。目的研究眼前节OCT（Visante OCT）在人眼外直肌止端解剖结构观察中的应用。方法收集不同屈光力受试者58例114眼，按照屈光力程度的不同分为低屈光力组（≤-3．00D）43眼，中屈光力组（〉-3．00D，≤-6．00D）49眼；高屈光力组（〉-6．00D）22眼，用Visante OCT测量水平直肌止端后沿到巩膜突的距离以及肌止端的厚度，对屈光力与直肌止端距离和及肌止端厚度的关系进行分析。结果外直肌、内直肌止端后沿到巩膜突的平均距离分别为（5．23±O．50）to／Y／和（3．81±0．46）mm。外直肌、内直肌止端平均厚度分别为（0．39±0．06）mm和（0．39±0．06）mm，与文献中超声生物显微镜（UBM）所测值比较差异无统计学意义（P=0．338；P=0．759）。低屈光力组的外直肌、内直肌止端距离分别为（5．25±0．45）mm和（3．74±0．53）mm，中屈光力组为（5．22±0．60）mm和（3．81±0．42）mm，高屈光力组为（5．20±0．35）mm和（3．904±0．42）mm，3组之间外直肌、内直肌止端距离的总体比较差异均无统计学意义（外直肌X^2=0．054，P=0．974；内直肌F=0．508，P=0．604）。外直肌、内直肌止端厚度低屈光力组分别为（0．41±0．06）mm、（0．40±0．06）mm，中屈光力组分别为（0．40±0．07）mm、（0．37±0．07）mm，高屈光力组分别为（0．36±0．05）mm、（0．39±0．05）mm，3组之间的外直肌止端厚度总体比较差异有统计学意义（，=4．922，P=0．009），其中高屈光力组外直肌止端厚度较低屈光力组变薄（P〈0．05），3组间内直肌止端厚度差异无统计学意义（F=2．152，P=0．125）。屈光力与外直肌止端的厚度呈正相关（r=0．284，P〈0．01）。结论Visante OCT是可用来观察人眼外直肌止端解剖结构的新方法，其测量值显示人眼水平直肌中，外直肌止端的厚度随着近视屈光力的增高有变薄趋势，高度近视组变薄明显。

Background The measurement of the extraocular muscle is critical for the diagnosis of extraocular muscle diseases,but conventional medical imaging techniques present some shortcomings because of the contact pattern. The anterior segment optical coherence tomography （OCT） is thought to be an in vivo noninvasive optical diagnostic imaging method. Objective This clinical study attempted to seek an available approach to the evaluation of the anatomic structure of human horizontal rectus insertion with Visante OCT. Methods One hundred and fourteen eyes of 58 subjects were included in this study and were divided into the low refractive power group （〈-3.00 D） with 43 eyes, moderate refractive power group（ 〉-3.00 D-≤-6.00 D） with 49 eyes and high refractive power group（ 〉-6.00 D） with 22 eyes. The horizontal rectus insertion distance to the scleral spur and its thickness were measured by Visante OCT. The correlation of the refractive power with the rectus insertion distance or thickness was analyzed. Written informed consent was obtained from each subject before medial assessment. Results The average distance from the scleral spur to the lateral and medial rectus insertion were （5. 23±0. 50）mm and （3.81± 0. 46）mm respectively. The average thickness of the lateral and medial rectus insertions were （0. 39±0.06）mm and （0. 39± 0. 06 ） mm respectively, showing no significant differences in comparison with those of ultrasound biomicroscopy （P=0. 338 ,P= 0. 759 ）. The lateral and medial rectus insertion distances were （5.25±0. 45 ）mm and （3.74±0.53）mm in the low refractive power the group, （5.22±0.60）mm and （3.81±0.42）mm in the moderate group and （5.20±0.35）mm and （3.90±0.42）mm in the high refractive power group, presenting inconsiderable difference among these three groups （ lateral rectus ： X^2 = 0. 054, P = 0. 974 ; medial rectus ： F = 0. 508, P = 0. 604 ）. The thickness of the lateral and medial rectus insertions were （0. 41±0. 06）mm and （0. 40＋0. 06）mm in the lowrefractive power group, （0.40±0. 07 ）mm and （0.37±0.07 ）mm in the moderate refractive power group, （0.36±0.05 ）mm and （0.39±0.05）mm in the high refractive power group with a significant difference among lateral rectus （F=4. 922,P=0. 009） but not medial rectus （F=2. 152,P=0. 125）. The lateral rectus insertions thickness in the high refractive power group was thinner than that in low refractive power group （P〈0.05）. A positive correlation was found between refractive power and the thickness of lateral or medial rectus insertions （r= 0.284,P〈0.01 ）. Conclusion Visante OCT is a uscful way in measuring the distance and thickness of the extraocular muscles. Lateral rectus insertions thickness tends to be thinner with the worsening of myopia,which is obvious in high myopia.