Background

Plateau iris is one of the most common angle-closure glaucomas presenting in younger patients. This condition is characterized by closing of the anterior chamber angle secondary to a large or anteriorly positioned ciliary body that mechanically alters the position of the peripheral iris in relation to the trabecular meshwork.

Pathophysiology

In plateau iris configuration, the pars plicata may be large and anteriorly positioned, mechanically positioning the peripheral iris against the trabecular meshwork. In addition, the iris root is inserted anteriorly on the ciliary face further crowding the anterior chamber angle. The iris crowding of the angle obstructs aqueous flow via the trabecular meshwork and may lead to angle-closure glaucoma.

Except in the rare younger patients (age 20-30s), some degree of pupillary block also is present. Because a component of pupillary block may exist in patients with plateau iris configuration, laser iridotomy should always be performed as the first intervention. If the angle remains capable of closure despite a patent iridotomy, the condition is termed plateau iris syndrome.

A high prevalence of plateau iris configuration and plateau iris syndrome has been reported in relatives of patients with plateau iris syndrome. An autosomal dominant inheritance pattern with incomplete penetrance has also been suggested.^[1]

Frequency

United States

The exact prevalence of plateau iris is unknown. A 2016 study found that one third of eyes with primary angle-closure glaucoma had plateau iris.^[2]In another report, it accounted for more than half of recurrent angle closure cases in young patients.^[3]The diagnosis of plateau iris should be suspected when angle closure occurs in patients who are young or myopic and when angle narrowing persists despite iridotomy.

International

A study from Singapore reported that although plateau iris represents 32% of early-to-moderate primary angle glaucoma, it accounts for 50% of severe primary angle glaucoma.^[4] Another study found that 20% of Japanese patients with primary angle closure after laser iridotomy had plateau iris based on ultrasound biomicroscopy.^[5]

Mortality/Morbidity

Plateau iris is an important cause of angle-closure glaucoma in patients younger than 50 years.

Race

Studies reported no difference in prevalence of plateau iris between whites and Asians.^{[6, 7]}

Sex

Plateau iris is seen most commonly in women.

Age

Patients with plateau iris usually are younger than those with primary angle-closure (relative pupillary block) glaucoma.

Clinical Presentation

Etter JR, Affel EL, Rhee DJ. High prevalence of plateau iris configuration in family members of patients with plateau iris syndrome. J Glaucoma. 2006 Oct. 15(5):394-8. [Medline].
Mansoori T, Sarvepally VK, Balakrishna N. Plateau Iris in Primary Angle Closure Glaucoma: An Ultrasound Biomicroscopy Study. J Glaucoma. 2016 Feb;25(2):e82-6.:[Medline].
Stieger R, Kniestedt C, Sutter F, Bachmann LM, Stuermer J. Prevalence of plateau iris syndrome in young patients with recurrent angle closure. Clin Experiment Ophthalmol. 2007 Jul. 35(5):409-13. [Medline].
Nongpiur ME, Verma S, Tun TA, Wong TT, Perera SA, Aung T. Plateau Iris and Severity of Primary Angle Closure Glaucoma. Am J Ophthalmol. 2020 Dec. 220:1-8. [Medline].
Mizoguchi T, Ozaki M, Wakiyama H, Ogino N. Plateau iris in Japanese patients with primary angle closure and primary angle closure glaucoma. Clin Ophthalmol. 2015 Jun 29;9:1159-63:[Medline].
Leeungurasatien T, Radhakrishnan S, Porco T, Huang G, Osmanovic S, Huang JY. Plateau iris in Whites versus Asians. Eye Sci. 2012 Mar. 27(1):13-8. [Medline].
Li Y, Wang YE, Huang G, Wang D, He M, Qiu M, et al. Prevalence and characteristics of plateau iris configuration among American Caucasian, American Chinese and mainland Chinese subjects. Br J Ophthalmol. 2014 Apr;98(4):474-8:[Medline].
Shukla S, Damji KF, Harasymowycz P, Chialant D, Kent JS, Chevrier R, et al. Clinical features distinguishing angle closure from pseudoplateau versus plateau iris. Br J Ophthalmol. 2008 Mar. 92(3):340-4. [Medline].
Kumar G, Bali SJ, Panda A, Sobti A, Dada T. Prevalence of plateau iris configuration in primary angle closure glaucoma using ultrasound biomicroscopy in the Indian population. Indian J Ophthalmol. 2012 May-Jun. 60(3):175-8. [Medline]. [Full Text].
Mochizuki H, Takenaka J, Sugimoto Y, Takamatsu M, Kiuchi Y. Comparison of the prevalence of plateau iris configurations between angle-closure glaucoma and open-angle glaucoma using ultrasound biomicroscopy. J Glaucoma. 2011 Jun-Jul. 20(5):315-8. [Medline].
Diniz Filho A, Cronemberger S, Ferreira DM, Mérula RV, Calixto N. Plateau iris configuration in eyes with narrow-angle: an ultrasound biomicroscopic study. Arq Bras Oftalmol. 2010 Mar-Apr. 73(2):155-60. [Medline].
Shabana N, Aquino MC, See J, Ce Z, Tan AM, Nolan WP. Quantitative evaluation of anterior chamber parameters using anterior segment optical coherence tomography in primary angle closure mechanisms. Clin Experiment Ophthalmol. 2012 Nov. 40(8):792-801. [Medline].
Ramakrishnan R, Mitra A, Abdul Kader M, Das S. To Study the Efficacy of Laser Peripheral Iridoplasty in the Treatment of Eyes With Primary Angle Closure and Plateau Iris Syndrome, Unresponsive to Laser Peripheral Iridotomy, Using Anterior-Segment OCT as a Tool. J Glaucoma. 2016 May;25(5):440-6:[Medline].
Crowell EL, Chuang AZ, Bell NP, Blieden LS, Feldman RM. Using Anterior Segment Optical Coherence Tomography (ASOCT) Parameters to Determine Pupillary Block Versus Plateau Iris Configuration. J Glaucoma. 2020 Nov. 29 (11):1036-1042. [Medline].
Triolo G, Barboni P, Savini G, De Gaetano F, Monaco G, David A, et al. The Use of Anterior-Segment Optical-Coherence Tomography for the Assessment of the Iridocorneal Angle and Its Alterations: Update and Current Evidence. J Clin Med. 2021 Jan 11. 10 (2):[Medline].
Ritch R, Tham CC, Lam DS. Argon laser peripheral iridoplasty (ALPI): an update. Surv Ophthalmol. 2007 May-Jun. 52(3):279-88. [Medline].
Liu J, Lamba T, Belyea DA. Peripheral laser iridoplasty opens angle in plateau iris by thinning the cross-sectional tissues. Clin Ophthalmol. 2013. 7:1895-7. [Medline].
Espana EM, Ioannidis A, Tello C, Liebmann JM, Foster P, Ritch R. Urrets-Zavalia syndrome as a complication of argon laser peripheral iridoplasty. Br J Ophthalmol. 2007 Apr. 91(4):427-9. [Medline].
Francis BA1, Pouw A, Jenkins D, Babic K, Vakili G, Tan J, et al. Endoscopic Cycloplasty (ECPL) and Lens Extraction in the Treatment of Severe Plateau Iris Syndrome. J Glaucoma. 2016 Mar;25(3):e128-33.:[Medline].
Hollander DA, Pennesi ME, Alvarado JA. Management of plateau iris syndrome with cataract extraction and endoscopic cyclophotocoagulation. Exp Eye Res. 2017 May. 158:190-194. [Medline].
Lu M, Chuang AZ, Feldman RM. Comparing the Effect of Lens Extraction with Endocycloplasty to Lens Extraction Alone in Eyes with Plateau Iris Configuration: Pilot Study. J Glaucoma. 2021 Jan 13. [Medline].
Kumar RS, Baskaran M, Chew PT, Friedman DS, Handa S, Lavanya R, et al. Prevalence of plateau iris in primary angle closure suspects an ultrasound biomicroscopy study. Ophthalmology. 2008 Mar. 115(3):430-4. [Medline].
Rao A. Clear lens extraction in plateau iris with bilateral acute angle closure in young. J Glaucoma. 2013 Dec. 22(9):e31-2. [Medline].
Azuara-Blanco A, Spaeth GL, Araujo SV, Augsburger JJ, Terebuh AK. Plateau iris syndrome associated with multiple ciliary body cysts. Report of three cases. Arch Ophthalmol. 1996 Jun. 114(6):666-8. [Medline].
Barkana Y, Shihadeh W, Oliveira C, Tello C, Liebmann JM, Ritch R. Angle closure in highly myopic eyes. Ophthalmology. 2006 Feb. 113(2):247-54. [Medline].
Crowston JG, Medeiros FA, Mosaed S, Weinreb RN. Argon laser iridoplasty in the treatment of plateau-like iris configuration as result of numerous ciliary body cysts. Am J Ophthalmol. 2005 Feb. 139(2):381-3. [Medline].
Leung CK, Chan WM, Ko CY, Chui SI, Woo J, Tsang MK, et al. Visualization of anterior chamber angle dynamics using optical coherence tomography. Ophthalmology. 2005 Jun. 112(6):980-4. [Medline].
Liebmann JM, Ritch R. Laser surgery for angle closure glaucoma. Semin Ophthalmol. 2002 Jun. 17(2):84-91. [Medline].
Liebmann JM, Ritch R. Ultrasound biomicroscopy of the anterior segment. J Am Optom Assoc. 1996 Aug. 67(8):469-79. [Medline].
Pavlin CJ, Foster FS. Plateau iris syndrome: changes in angle opening associated with dark, light, and pilocarpine administration. Am J Ophthalmol. 1999 Sep. 128(3):288-91. [Medline].
Pavlin CJ, Ritch R, Foster FS. Ultrasound biomicroscopy in plateau iris syndrome. Am J Ophthalmol. 1992 Apr 15. 113(4):390-5. [Medline].
Polikoff LA, Chanis RA, Toor A, Ramos-Esteban JC, Fahim MM, Gagliuso DJ, et al. The effect of laser iridotomy on the anterior segment anatomy of patients with plateau iris configuration. J Glaucoma. 2005 Apr. 14(2):109-13. [Medline].
Rao A. Clear Lens Extraction in Plateau Iris With Bilateral Acute Angle Closure in Young. J Glaucoma. 2012 Jun 4. [Medline].
Ritch R. Plateau iris is caused by abnormally positioned ciliary processes. J Glaucoma. 1992. 1:23-26.
Ritch R, Chang BM, Liebmann JM. Angle closure in younger patients. Ophthalmology. 2003 Oct. 110(10):1880-9. [Medline].
Ritch R, Liebmann JM. Argon laser peripheral iridoplasty. Ophthalmic Surg Lasers. 1996 Apr. 27(4):289-300. [Medline].
Ritch R, Shields MB, Krupin T. Angle-closure glaucoma: clinical types. The Glaucomas. 1996. 827-9.
Ritch R, Tham CC, Lam DS. Long-term success of argon laser peripheral iridoplasty in the management of plateau iris syndrome. Ophthalmology. 2004 Jan. 111(1):104-8. [Medline].
Tello C, Rothman R, Ishikawa H. Differential diagnosis of the angle-closure glaucomas. Ophthalmol Clin Nor Am. 2000. 13:443-53.
Wand M, Grant WM, Simmons RJ, Hutchinson BT. Plateau iris syndrome. Trans Sect Ophthalmol Am Acad Ophthalmol Otolaryngol. 1977 Jan-Feb. 83(1):122-30. [Medline].
Wand M, Pavlin CJ, Foster FS. Plateau iris syndrome: ultrasound biomicroscopic and histologic study. Ophthalmic Surg. 1993 Feb. 24(2):129-31. [Medline].

Media Gallery

Ultrasound biomicroscopy. (A) In plateau iris, the anterior position of the ciliary body holds the peripheral iris against the trabecular meshwork. (B) The angle is obstructed further in the dark as the peripheral iris thickens with physiologic pupillary dilation.
Ultrasound biomicroscopy, plateau iris syndrome. (A) Appositional anterior chamber angle in dark condition prior to laser iridotomy. (B) After laser iridotomy, the angle remains occludable. (C) After peripheral laser iridoplasty, the peripheral iris is thinned, opening the angle and significantly reducing the risk of closure.

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Author

Jim C Wang (王崇安), MD Vitreo-Retinal and Cornea/Anterior Segment Subspecialist, Department of Ophthalmology, Kaiser Permanente Fontana Medical Center

Jim C Wang (王崇安), MD is a member of the following medical societies: American Academy of Ophthalmology, American Society of Retina Specialists, American Society of Cataract and Refractive Surgery

Disclosure: Nothing to disclose.

Coauthor(s)

Robert Ritch, MD, FACS, FARVO Shelley and Steven Einhorn Distinguished Chair in Ophthalmology, Professor of Ophthalmology, Surgeon Director Emeritus, New York Eye and Ear Infirmary of Mount Sinai

Robert Ritch, MD, FACS, FARVO is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, American Medical Association, American Ophthalmological Society, Chinese American Medical Society, International College of Surgeons, New York Academy of Medicine, New York Academy of Sciences

Disclosure: Received none from Sensimed for board membership; Received none from iSonic Medical for board membership; Received consulting fee from Aeon Astron for consulting; Received honoraria from Pfizer for speaking and teaching; Received honoraria from Allergan for speaking and teaching; Received honoraria from Ministry of Health of Kuwait for speaking and teaching; Received honoraria from Aeon Astron for speaking and teaching; Received royalty from Ocular Instruments for other.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Martin B Wax, MD Professor, Department of Ophthalmology, University of Texas Southwestern Medical School; Vice President, Research and Development, Head, Ophthalmology Discovery Research and Preclinical Sciences, Alcon Laboratories, Inc

Martin B Wax, MD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, Society for Neuroscience

Disclosure: Nothing to disclose.

Chief Editor

Hampton Roy, Sr, MD † Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences

Hampton Roy, Sr, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, Pan-American Association of Ophthalmology

Disclosure: Nothing to disclose.

Additional Contributors

Bradford Shingleton, MD Assistant Clinical Professor of Ophthalmology, Harvard Medical School; Consulting Staff, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary

Bradford Shingleton, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Ophthalmology

Disclosure: Nothing to disclose.

Paul S Lee, MD Clinical Assistant Professor, Department of Ophthalmology, Icahn School of Medicine at Mount Sinai; Chief of Ophthalmology, James J Peters Veterans Affairs Medical Center; Associate Adjunct Surgeon, New York Eye and Ear Infirmary

Paul S Lee, MD is a member of the following medical societies: American Academy of Ophthalmology, American Society of Cataract and Refractive Surgery

Disclosure: Nothing to disclose.

Acknowledgements

Celso Tello, MD Clinical Assistant Professor, Department of Ophthalmology, New York Eye and Ear Infirmary

Celso Tello, MD is a member of the following medical societies: American Academy of Ophthalmology, American Medical Association, and New York Academy of Sciences

Disclosure: Nothing to disclose.