背景:睫状突不断产生的房水和通过引流角或通过葡萄膜巩膜途径通过小梁网流出的等量非常小(每个2-3μg/min),约占前房含量的1%;因此,可视化它的流动是具有挑战性的。
方法:一名69岁的男性患者,其眼内压(IOP)(>20mmHg)具有最大的青光眼滴眼液剂量,并出现严重的视野丧失(HumphreyFieldAnalyzer30-2:-26.32dB),已植入350mm2的房型Baerveldt管以治疗难治性开角型青光眼。IOP最终降低(<15mmHg),不需要青光眼滴眼液。
方法:手术后,在人工晶状体前表面反复形成的纤维蛋白膜。
方法:通过两轮掺钕钇铝颗粒(Nd:YAG)激光手术和处方甾体滴眼液解决了这个问题。
结果:在激光手术期间,在Baerveldt管的开口处出现了一个不寻常的和意外的纤维蛋白瓣;这个皮瓣与心跳同步移动,通过检查手腕桡动脉的脉搏来验证。纤维蛋白瓣模仿心脏瓣膜的行为,房水和杂散的纤维蛋白颗粒模仿心脏腔室中的血液。尽管Baerveldt管本身是一种人造仪器,在正常人眼中是不存在的,我们假设我们的观察显示了房水引流的基本机制。
结论:这部小说,生动的描述性观察强调了心跳作为引流泵在房水血流动力学和眼内压稳态中的重要作用,这是青光眼的治疗目标,失明的主要原因。
BACKGROUND: The amount of aqueous humor that is constantly produced by the ciliary processes and the equal amount that flows out through the trabecular meshwork via the drainage angle or through the uveoscleral route is very small (2-3 μg/min each), representing approximately 1% of the content of the anterior chamber; therefore, it is challenging to visualize its flow.
METHODS: A 69-year-old man who had high intraocular pressure (IOP) (>20 mm Hg) with the maximum glaucoma eyedrop dose and presented with severe visual field loss (Humphrey Field Analyzer 30-2: -26.32 dB) had been implanted with a 350-mm2 Baerveldt tube of the aqueous chamber type for refractory open-angle glaucoma. The IOP ultimately decreased (<15 mm Hg) with no need for glaucoma eyedrops.
METHODS: After the procedures, a fibrin membrane repeatedly formed on the anterior surface of the intraocular lens.
METHODS: This issue was resolved by two rounds of neodymium-doped yttrium aluminum granet (Nd:YAG) laser surgery and prescription steroidal eyedrops.
RESULTS: During the laser surgery, an unusual and unintended fibrin flap appeared at the opening of the Baerveldt tube; this flap moved synchronously with the heartbeat, as verified by checking the pulse at the radial artery of the wrist. The fibrin flap mimicked the behavior of a cardiac valve, and the aqueous humor and stray fibrin particles mimicked the blood in the chambers of the heart. Although the Baerveldt tube itself is an artificial instrument that is not present in normal human eyes, we hypothesize that our observation shows the fundamental mechanism of aqueous humor drainage.
CONCLUSIONS: This novel, vividly descriptive observation highlights the important role of the heartbeat as a drainage pump in aqueous humor flow dynamics and IOP homeostasis, which are treatment targets for glaucoma, the leading cause of blindness.