Zhuravlyov Andriy
Augenkompetenzzentrum Kamenz, Augen-MVZ Lausitz GmbH, Weststr. 14, 01917, Kamenz, Deutschland.
Ophthalmologe. 2018 Jul;115(7):606-612. doi: 10.1007/s00347-018-0741-x.
Several methods are available for the examination of the iridocorneal angle: gonioscopy and imaging techniques, such as ultrasound biomicroscopy, optical coherence tomography and Scheimpflug photography play an important role in the diagnostics of glaucoma. There is, however, a need for simple, easily applicable methods for screening of the narrow iridocorneal angle in routine ophthalmological practice.
To apply the diacaustic phenomenon in the examination of the iridocorneal angle, to describe the method and give its basic principles.
This article provides a review of the literature and clinical observations with photographic and video documentation. The technique is demonstrated in detail with the help of a video and which is available online.
The formation and movement of the diacaustic phenomenon in the anterior chamber are observed and documented by photography or video when a light source is moved laterally from front to back. The movement of the diacaustic line on the anterior surface of the iris and the structures of the iridocorneal angle are analyzed in relation to other optical phenomena, such as the Purkinje images 1 and 2, iris shadowing by tangential illumination at the level of the frill and the limbal crescent of light. The diacaustic test can be used to determine the depth of the anterior chamber and the width of the iridocorneal angle. The problems are briefly represented from the perspective of anatomical, physical and medical history aspects and 4 variants of the diacaustic line and 3 phases of the movement of the diacaustic light spot are described.
The diacaustic test is simple, quick and non-contact. It has potential as a screening examination of the narrow iridocorneal angle before medicinal pupil dilation. It can be integrated into the diagnostics of glaucoma for the assessment of the iridocorneal angle.
有多种方法可用于检查虹膜角膜角：房角镜检查和成像技术，如超声生物显微镜检查、光学相干断层扫描和Scheimpflug摄影术在青光眼诊断中发挥着重要作用。然而，在常规眼科实践中，需要简单、易于应用的方法来筛查窄虹膜角膜角。
将折光现象应用于虹膜角膜角检查，描述该方法并给出其基本原理。
本文提供了文献综述以及带有摄影和视频记录的临床观察。借助一段在线视频详细演示了该技术。
当光源从前向后横向移动时，通过摄影或视频观察并记录前房内折光现象的形成和移动。分析虹膜前表面折光线的移动以及虹膜角膜角的结构与其他光学现象的关系，如普尔钦耶图像1和2、在襞水平的切线照明引起的虹膜阴影以及角膜缘新月形光。折光试验可用于确定前房深度和虹膜角膜角宽度。从解剖学、物理学和病史方面简要阐述了相关问题，并描述了折光线的4种变体和折光亮点移动的3个阶段。
折光试验简单、快速且非接触式。它有潜力作为药物散瞳前窄虹膜角膜角的筛查检查。它可纳入青光眼诊断中以评估虹膜角膜角。
