前节OCT在观察后发性白内障方面的应用价值

The value of anterior segment optical coherence tomography on posterior capsular opacification

目的 了解前节OCT在观察后发障的类型及后囊膜混浊情况等方面的应用价值。方法 前瞻性病例对照研究。收集2015年8月至2016年7月在天津市眼科医院就诊的40例（42只眼）后发障患者，采用眼前节像和前节OCT扫描观察后发障的混浊程度，并测量瞳孔区3 mm内混浊的平均厚度；行Nd：YAG激光后囊切开术，测量手术前后视力，了解后囊膜混浊程度与术后视力变化的关系。结果 后发障行Nd：YAG激光切开术后视力明显提高，logMAR视力由术前平均0.641提高到术后0.202，差异有明显统计学意义（P〈0.001）；术后视力提高程度与后囊膜混浊的厚度无明显相关性，r=0.084 P〉0.05，因为后发障对视力的影响不仅与混浊的厚度相关，还和混浊的类型以及混浊的密度相关。在OCT图上，珍珠样小体型后发障表现为多个大小不一的白色圆形或椭圆形高反射信号；纤维化型后发障表现为质地致密的白色条索状高反射信号；混合型后发障表现为为珍珠样小体型和纤维型的混合；液性后发障表现为人工晶状体与后囊膜之间均一的高反射信号。结论 后发性白内障行Nd：YAG激光切开术后视力明显提高；不同类型后发障在前节OCT扫描图像上各不相同；前节OCT可定性定量观察后发障的混浊程度。

Objective To recognize the value of Anterior Segment Optical Coherence Tomography （ASOCT） on the types and severity of posterior capsular opacification （PCO）.Methods A prospective case-control study was performe on 40 pseudophakic patients （42 eyes） with PCO from August 2015 to July 2016 in Tianjin Eye Hospital were included in this study. Slit-lamp digital camera combined with ASOCT was used to observe PCO, and the average thickness of opacity within pupil size 3 mm was measured. The VA was determined before and after Nd：YAG laser posterior capsulotomy, and to understand the relationship between the posterior capsular opacity and postoperative vision.Results Significant improvement in visual acuity was observed after Nd：YAG laser posterior capsulotomy, mean logMAR visual acuity increased from 0.641 to 0.202, P 〈0.001; No obvious correlation between visual acuity and the thickness of opacity, r=0.084, P 〉0.05, because the impact on the vision was not only related to the thickness of the opacity, but also on the types and density of PCO. Multiple sizes round or oval hyperintense signal was seen among the pearl type opacification cases. And fibrosis type opacification showed funicular hyperintense signal on OCT examining. Mixed-type PCO was defined as PCO with the characteristics of both the fibrosis and pearl types. A hyperintense signal was seen in the space between the posterior chamber intraocular lens and the posteriorly bowed posterior capsule in the liquefied after cataract cases.Conclusions After Nd：YAG laser posterior capsulotomy, the BCVA is significantly improved. Different types of PCO on ASOCT scanning images are not identical. ASOCT can observe PCO quantitatively.