*Department of Ophthalmology, Glaucoma Service, Federal University of São Paulo †Glaucoma Service, Hospital Medicina dos Olhos, São Paulo, Brazil ‡Department of Ophthalmology, Glaucoma Service, Mayo Clinic, Jacksonville, FL.
J Glaucoma. 2013 Dec;22(9):e36-7. doi: 10.1097/01.ijg.0000435777.99193.08.
The purpose of the study was to report a patient with primary angle closure associated with a different nonpupillary block mechanism in which an abnormally thick peripheral iris assumes a cross-sectional shape resembling a cobblestone.
This is a case report focussing on clinical and imaging description.
Slit-lamp biomicroscopy revealed patent laser peripheral iridotomies OU. The anterior chamber was relatively deep in the center but 360 degrees narrow at the periphery, associated with an abnormally elevated iris contour OU. On dark-room gonioscopy, the angles were occludable with few areas of peripheral anterior synechiae. Anterior segment-adapted spectral domain-optical coherence tomography revealed an unusual iris profile. Despite a flat contour and normal thickness until the mid-periphery, the iris assumed a rectangular cross-sectional shape (resembling a cobblestone) with an abnormal increase in its thickness in the periphery (360 degrees OU). Ultrasound biomicroscopy imaging showed a normal ciliary sulcus and ciliary body configuration, revealing no cysts at 360 degrees. Definitive relief of appositional angle closure was achieved with laser peripheral iridoplasty OU.
This unusual anatomic condition of the peripheral iris, which has different characteristics when compared with ordinary cases of thick peripheral iris roll, may lead to angle closure and intraocular pressure elevation despite a patent iridotomy. Clinicians should be aware of this anatomic condition whenever dealing with cases of angle closure.
本研究旨在报告一例原发性闭角型青光眼患者，其非瞳孔阻滞的发病机制不同于一般情况，周边虹膜异常增厚，横切面形似鹅卵石。
这是一个病例报告，重点介绍了临床和影像学描述。
裂隙灯生物显微镜检查显示双眼激光周边虹膜切开术通畅。前房在中央较深，但在周边 360 度狭窄，伴有虹膜轮廓异常升高。暗室房角镜检查显示，房角可闭，周边有少量粘连。眼前节自适应谱域光学相干断层扫描显示虹膜异常形态。尽管虹膜轮廓平坦，厚度正常，直到中周缘，但虹膜呈矩形横切面（类似鹅卵石），周边厚度异常增加（双眼 360 度）。超声生物显微镜成像显示睫状沟和睫状体形态正常，360 度无囊肿。双眼激光周边虹膜成形术可有效缓解房角贴附性关闭。
这种周边虹膜的异常解剖结构与普通厚周边虹膜卷的情况不同，即使虹膜切开术通畅，也可能导致房角关闭和眼压升高。临床医生在处理房角关闭病例时应注意这种解剖结构。
