2020–2021 BCSC Basic and Clinical Science Course™
10 Glaucoma
Chapter 9: Primary Angle Closure
Pathogenesis and Pathophysiology
Plateau Iris and Iris-Induced Angle Closure
In plateau iris and iris-induced angle closure, the peripheral iris is the cause of the iridotrabecular apposition. Iris-induced angle closure can be the direct result of developmental anomalies such as anterior cleavage abnormalities, in which the iris insertion into the scleral spur or meshwork is more anterior; a thick peripheral iris, which on dilation “rolls” into the trabecular meshwork; and/or anteriorly displaced ciliary processes (see Fig 1-9), which may secondarily rotate the peripheral iris forward (plateau iris) into the trabecular meshwork (see the section Plateau Iris later in this chapter). Though it was thought that iris-induced angle closure occurs in aniridia due to rotation of the rudimentary iris leaflets into the angle, new evidence suggests that this phenomenon occurs as a result of intraocular surgery rather than spontaneously.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.