Sir,

Plateau iris is an angle appearance in which a short iris root angulates forward and centrally, and the iris surface is flat.1 It occurs most commonly in younger women and tends to be hereditary.2 The youngest previously reported patient was 22 years old.3 Rare cases of primary angle-closure in children have been reported, but none had plateau iris,4, 5, 6, 7 making this, to our knowledge, the youngest patient reported.

Case report

A 12-year-old Hispanic boy presented with transient eye discomfort both eyes (OU), while watching television in the dark. Uncorrected visual acuity was 20/20 right eye (OD) (+0.50–0.25 × 95), 20/25 OS (+1.50–0.50 × 53). Intraocular pressures were 17 mmHg OD and 15 mmHg left eye (OS). Dark room gonioscopy revealed a convex iris approach with appositional closure OU and a double hump sign. Indentation gonioscopy opened the angle 360 degrees without peripheral anterior synechiae. Optic discs and visual fields were normal. Ultrasound biomicroscopy showed an enlarged ciliary body displacing the peripheral iris forward, with loss of the ciliary sulcus (Figure 1). After laser iridotomies, the angles remained appositionally closed. A second ultrasound biomicroscopy (UBM) confirmed the gonioscopic findings (Figure 2). Argon laser peripheral iridoplasty was performed successfully to eliminate the plateau iris component of the angle closure.

Figure 1
figure 1

UBM depicting appositional angle closure before laser peripheral iridotomy with angulations of peripheral iris (white arrows) and deep appearing anterior chamber. Enlarged ciliary body observed displacing peripheral iris forward (star) with loss of ciliary sulcus. Black arrow indicates scleral spur.

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Figure 2
figure 2

UBM of the angle after peripheral iridotomy of both eyes show continued appositional angle closure (arrows). Black arrow indicates scleral spur.

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Comment

Anatomically, plateau iris is characterized by a relatively flat iris plane, large, anteriorly positioned ciliary processes, absence of the ciliary sulcus, a sharp and angulated drop-off of the peripheral iris, and narrowing or closure of the iridocorneal angle.8, 9 Plateau iris syndrome is defined by continued or inducible angle-closure in an eye with plateau iris configuration, following the elimination of pupillary block by iridotomy.5 The ciliary processes prevent the iris root from falling posteriorly. The age of presentation is determined by several factors including the extent of anterior displacement and the continued growth of the lens contributing to progressive angle crowding.10

Peripheral iridotomy eliminates pupillary block and argon laser peripheral iridoplasty addresses the residual angle closure.11 Patients with appositional angle closure may go on to develop peripheral anterior synechiae (PAS) and synechial angle closure, even years after a successful iridotomy. Patients who underwent iridotomy should not be considered cured but should undergo periodic gonioscopic examination.