Plateau Iris: A Review

PURPOSE: To review the concept of plateau iris and summarize the recent evidence on its diagnosis and management. METHODS: This is a narrative review on the plateau iris. A literature review was conducted in PubMed, Google Scholar, and Scopus databases using keywords: angle-closure glaucoma, glaucoma, nonpupillary block glaucoma, plateau iris, and plateau iris management. RESULTS: This review defined the current knowledge about plateau iris. First of all, the anatomy and epidemiology were discussed. Then, we outlined the available evidence on the diagnosis of plateau iris and its differential diagnosis. Conclusively, the treatment options were mentioned. CONCLUSIONS: Plateau iris is a condition in which nonpupillary block mechanisms are responsible for intraocular pressure elevation and angle closure attack when a patent peripheral iridotomy has removed the relative pupillary block. An anteriorly positioned ciliary body causes mechanical obstruction of trabecular meshwork in these patients. It is usually seen in younger patients with angle closure and is diagnosed by gonioscopic examination and imaging modalities such as Ultrasound biomicroscopy. Despite the known mechanism of plateau iris, there is no consensus over treatment. Low-dose pilocarpine and Argon laser peripheral iridoplasty are nonsurgical treatments for these patients, but their effects are short-term. Cataract extraction with/without endocyclophotocoagulation (ECP), endocycloplasty, excisional goniotomy, and transscleral cyclophotocoagulation are alternative treatments. Patients should be examined periodically for further progression or recurrence of plateau iris. In cases of glaucoma unresponsive to conventional medical treatments, surgical treatments such as trabeculectomy and drainage devices should be considered.