Kiuchi Yoshiaki, Kanamoto Takashi, Nakamura Takao
Department of Ophthalmology, Otemae Hospital, Osaka, Japan.
J Glaucoma. 2009 Feb;18(2):161-4. doi: 10.1097/IJG.0b013e31817d23b5.
A plateau iris is one of the clinical forms of angle closure glaucoma. In patients with a patent iridotomy, the double hump sign detected during indentation gonioscopy has been reported to indicate the existence of a plateau iris configuration. The purpose of this study was to determine whether the double hump sign is correlated with the presence of the plateau iris syndrome regardless of the patency of the iridotomy.
Five women and 3 men without a patent iridotomy presented with narrow angles on gonioscopy and a double hump sign on indentation gonioscopy. Ultrasound biomicroscopy (UBM) imaging was performed to determine the etiology of the narrow angle and double hump sign, and to determine the appropriate treatment to prevent the progression of visual field damage. Ten patients with narrow angles and without a double hump sign were also examined by UBM to serve as a control group.
All 8 patients who showed double hump sign had a short iris root, which was inserted anterior to the ciliary face, a typical anatomic appearance of a plateau iris. On the other hand, only 1 eye of 10 eyes in control group appeared to have a plateau iris.
A double hump sign observed on indentation gonioscopy is strongly correlated with the presence of a plateau iris, and therefore a useful indicator of a plateau iris configuration regardless of the patency of a laser iridotomy. Thus, a plateau iris configuration can be detected without using a UBM in many cases.
高褶虹膜是闭角型青光眼的临床类型之一。据报道，在虹膜切开术通畅的患者中，压陷式前房角镜检查时检测到的双峰征表明存在高褶虹膜形态。本研究的目的是确定双峰征是否与高褶虹膜综合征的存在相关，而不考虑虹膜切开术是否通畅。
5名女性和3名男性未行虹膜切开术，前房角镜检查显示房角狭窄，压陷式前房角镜检查有双峰征。进行超声生物显微镜（UBM）成像，以确定房角狭窄和双峰征的病因，并确定预防视野损害进展的适当治疗方法。另外10名房角狭窄且无双峰征的患者也接受了UBM检查作为对照组。
所有8例出现双峰征的患者均有虹膜根部短，插入睫状体表面前方，这是高褶虹膜的典型解剖表现。另一方面，对照组10只眼中只有1只眼似乎有高褶虹膜。
压陷式前房角镜检查中观察到的双峰征与高褶虹膜的存在密切相关，因此，无论激光虹膜切开术是否通畅，都是高褶虹膜形态的有用指标。因此，在许多情况下，不使用UBM也可以检测到高褶虹膜形态。
