Iaccarino G, Forte R, Cennamo G
Service d'Ophtalmologie, Seconda Università, Naples, Italie.
J Fr Ophtalmol. 2006 Nov;29(9):e26. doi: 10.1016/s0181-5512(06)73898-0.
Iridoschisis is a rare condition where a localized area of iris stroma is cleaved in two, with the anterior atrophic portion disintegrating into fibrils. It is frequently associated with angle closure glaucoma and with cataract.
A 70-year-old male presented with reduction of visual acuity in the left eye. Visual acuity was 20/25 OD and 20/70 OS. He had suffered acute angle-closure glaucoma in the right eye 10 years before, treated with laser iridotomy and topical antiglaucomatous therapy. Intraocular pressure was 12 mmHg OD and 46 mmHg OS. Slit lamp biomicroscopic examination revealed bilateral shallow anterior chamber, iris atrophy, and leaf degeneration of the iris stroma. A-scan and B-scan standardized echography in both eyes showed shortening of the anterior chamber, a thickened and more anteriorly located lens, the presence of a few hyperechogeneous flocculated masses floating in the vitreous, and optic disc excavation.
The mechanism by which iridoschisis causes angle closure is unclear. A pupillary block could be favored by the thickening and anteriorization of the lens and the ciliary processes. Both the presence of strings of iris stroma occluding the trabecula and pupillary block could cause an elevation in intraocular pressure.
虹膜劈裂症是一种罕见病症,其中虹膜基质的局部区域被劈成两半,前部萎缩部分分解成纤维。它常与闭角型青光眼和白内障相关。
一名70岁男性因左眼视力下降就诊。右眼视力为20/25,左眼视力为20/70。他10年前右眼曾患急性闭角型青光眼,接受过激光虹膜切开术和局部抗青光眼治疗。右眼眼压为12 mmHg,左眼眼压为46 mmHg。裂隙灯显微镜检查显示双眼前房浅、虹膜萎缩以及虹膜基质叶状变性。双眼A超和B超标准化超声检查显示前房缩短、晶状体增厚且位置前移、玻璃体中有一些高回声絮状团块漂浮以及视盘凹陷。
虹膜劈裂症导致闭角的机制尚不清楚。晶状体和睫状突的增厚及前移可能有利于瞳孔阻滞。虹膜基质条索阻塞小梁以及瞳孔阻滞均可能导致眼压升高。