根据超声生物显微镜和眼前节OCT图像对房角关闭机制进行分型的一致性研究

The reproducibility of mechanism categories of angle closure using ultrasound biomicroscopy and anterior segment optical coherence tomography

背景 房角关闭是引起原发性房角关闭性疾病（PACD）的病理基础,了解不同类型的房角关闭机制对于PACD的危险因素评估、预防及诊治有重要意义.临床多采用超声生物显微镜（UBM）对房角关闭机制进行分型,但该检查为接触性,在使用中具有一定的局限性.眼前节OCT（AS-OCT）是一种非接触性的眼前节成像方法,能够对房角结构进行定性和定量评估. 目的 探讨根据UBM图像和AS-OCT图像对中国PACD患者房角关闭机制进行分型的一致性.方法 采用横断面研究.纳入2013年9-10月在北京同仁医院就诊并接受UBM和AS-OCT检查的PACD患者.UBM检查采集每眼上方、下方、鼻侧和颞侧4个方位的眼前节图像,AS-OCT检查采取四线扫描模式（包括0°～ 180°、45°～225°、90°～ 270°和135°～315°）对眼前节进行成像.根据UBM图像和AS-OCT图像分别进行房角关闭机制分型,并分为瞳孔阻滞型、睫状体前位型和周边虹膜肥厚型.每例受检眼的4张UBM图像及4张AS-OCT图像中分别至少2张显示相同的房角关闭机制分型作为该眼的UBM及AS-OCT分型.纳入符合标准的患眼,若双眼均符合标准则纳入右眼.用Kappa系数评估AS-OCT和UBM 2种方法对房角关闭机制分型结果的一致性.结果 最终纳入PACD患者40例40眼,其中右眼27眼,左眼13眼.根据UBM图像及房角关闭机制的分型标准,瞳孔阻滞型12眼,占30.0％;睫状体前位型23眼,占57.5％;周边虹膜肥厚型5眼,占12.5％.根据AS-OCT图像及房角关闭机制的分型标准,瞳孔阻滞型为12眼,占30.0％.睫状体前位型21眼,占52.5％;周边虹膜肥厚型7眼,占17.5％.两种房角关闭机制分型方法间的Kappa值为0.872,即高度一致. 结论 成功建立了根据AS-OCT图像对中国PACD患者房角关闭机制分型的标准,根据AS-OCT图像和UBM图像对房角关闭机制进行分型的判断结果高度一致.

Background Angle closure is the pathological basis of primary angle-closure disease （PACD）.Understanding different types of angle closure mechanisms is significant for evaluation of risk factors,prevention,diagnosis and treatment of PACD.Ultrasound biomicroscopy （UBM） is commonly used for investigating the types of angle closure mechanisms in clinical works.However,UBM is a contact examination,which limits its application.Anterior segment optical coherence tomography （AS-OCT） is a non-contact examination of anterior segment imaging,through which qualitative and quantitative evaluations of the anterior chamber angle can be made.Objective This study was to investigate the reproducibility of mechanism categories of angle closure based on AS-OCT images and UBM images.Methods Cross-sectional study was performed.PACD outpatients from September to October in 2013 in Beijing Tongren Hospital were enrolled and received both UBM and AS-OCT examinations.UBM images were obtained in superior,inferior,nasal and temporal quadrants of the anterior chamber.AS-OCT images were obtained in the ＂anterior segment quadrant＂ mode at 0-180,45-225,90-270,and 135-315 degree meridians.UBM and ASOCT images were categorized into three dominant angle closure mechanisms：pupil block,anterior located ciliary body and thick peripheral iris roll,separately.And the same mechanism of at least two UBM/AS-OCT images of one eye was defined as the angle closure mechanism of this eye.If both eyes of one PACD patient were eligible for inclusion,the right eye was selected for analysis.The reproducibility of two examinations was evaluated by Kappa coefficients.Results Finally 40 PACD patients （40 eyes,27 right eyes and 13 left eyes） were enrolled for analysis.Based on UBM images,12 eyes （30.0%） were classified as pupil block,23 eyes （57.5%） as anterior located ciliary body and 5 eyes （12.5%） as thick peripheral iris roll.Based on AS-OCT,12 eyes （30.0%） were classified as pupil block,21 eyes （52.5%） as anterior located ciliary body and 7 eyes （17.5%） as thick peripheral iris roll.The Kappa coefficient for the classification of angle closure mechanisms was 0.870.Conclusions Criterion of angle closure mechanism categories based on AS-OCT images was established.Mechanism categories obtained from AS-OCT and UBM images showed a good reproducibility.