Gonioscopy provides important information about the mechanism of the pediatric glaucoma as well as evidence of a patient’s prior surgeries. An EUA is usually required for gonioscopic examination of younger children. A Koeppe lens allows direct visualization of the angle structures. In older children, indirect gonioscopy can be performed with a 4-mirror goniolens at the slit lamp.
The normal anterior chamber angle of an infant differs from the normal adult angle in several ways, including a less pigmented trabecular meshwork, a less prominent Schwalbe line, and a less distinct junction between the scleral spur and ciliary body band (Fig 11-10A). In PCG, the anterior chamber is deep, with a high anterior iris insertion. The angle recess is absent, and the iris root appears as a scalloped line of glistening tissue (Fig 11-10B). Although this tissue is not a true membrane, it has been referred to as the Barkan membrane and likely represents thickened and compacted trabecular meshwork (see Fig 1-11).
In eyes with JOAG, the angle usually appears normal. In patients with aniridia, gonioscopy reveals a rudimentary iris root.
Figure 11-10 Gonioscopy of the anterior chamber angle. A, Anterior chamber angle of a nonglaucomatous infant eye, as seen by direct gonioscopy with a Koeppe lens. B, Typical appearance of the anterior chamber angle of an infant with primary congenital glaucoma. Note the scalloped appearance of the peripheral iris. The anterior iris insertion obscures the scleral spur.
(Courtesy of Ken K. Nischal, MD.)
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.