childhood require regular ophthalmic examination.

The mechanism that results in aphakic glaucoma is unclear. The anterior chamber angle usually appears open on gonioscopy; the outflow channels are compromised by some combination of abnormal development of the anterior chamber angle and perhaps susceptibility of the infant eye to surgically induced inflammation, loss of lens support, retained lens epithelial cells, or vitreous factors. The children at highest risk for glaucoma development following cataract surgery are those who have surgery during infancy, and the risk appears to be even higher in patients with microcornea or persistent fetal vasculature. Surgery before 6 weeks of age may be an independent risk factor. Contradicting earlier reports, recent studies have not confirmed a lower incidence of glaucoma in pseudophakic compared with aphakic eyes.

Acute or subacute angle closure with iris bombé is a rare form of aphakic glaucoma. Although it usually occurs soon after surgery, onset can be delayed by a year or more. The diagnosis should be apparent with a slit lamp, but examination at the slit lamp may be difficult in young children. Treatment consists of anterior vitrectomy to relieve the pupillary block, often with surgical iridectomy and goniosynechialysis.

Beck AD, Freedman SF, Lynn MJ, Bothun E, Neely DE, Lambert SR; Infant Aphakia Treatment Study Group. Glaucomarelated adverse events in the Infant Aphakia Treatment Study: 1-year results. Arch Ophthalmol. 2012;130(3):300–305.

Chak M, Rahi JS; British Congenital Cataract Interest Group. Incidence of and factors associated with glaucoma after surgery for congenital cataract: findings from the British Congenital Cataract Study. Ophthalmology. 2008;115(6):1013–1018.

Treatment

The primary treatment for most childhood glaucoma is surgery. PCG is usually effectively treated with angle surgery (goniotomy or trabeculotomy). Although angle surgery may be used in some secondary pediatric glaucomas—most notably Axenfeld-Rieger syndrome, SWS, and aniridia—the outcome is often less successful. The treatment of most secondary childhood glaucomas is similar to that of open-angle or secondary glaucomas in adults. Medical treatment often has value prior to surgery and may have long-term benefit, particularly in JOAG and some secondary childhood glaucomas.

Surgical Therapy

Surgical intervention is the treatment of choice for PCG. Angle surgery is the preferred initial procedure. In a goniotomy, an incision is made, under direct gonioscopic visualization, across the trabecular meshwork (Fig 22-5). In a trabeculotomy, an external approach is used to identify and cannulate the Schlemm canal, then connect it with the anterior chamber through incision of the trabecular meshwork (Fig 22-6). A modification of this technique uses a 6-0 polypropylene monofilament suture or illuminated microcatheter to cannulate and open the Schlemm canal for its entire 360° circumference in one surgery. If the cornea is clear, either a goniotomy or a trabeculotomy can be performed at the surgeon’s discretion. Preoperative glaucoma medications or stripping of edematous epithelium from the cornea can temporarily clear the cornea. If the view through the cornea is compromised, trabeculotomy or combined trabeculotomy-trabeculectomy can be performed.

Figure 22-5 Goniotomy needle with its tip in the trabecular meshwork. The trabecular meshwork to the left of the needle has

been incised. (Courtesy of Ken K. Nischal, MD.)

Figure 22-6 Trabeculotomy. A, The trabeculotome has entered the Schlemm canal. B, The trabeculotome has been rotated

into the anterior chamber. (Courtesy of Steven Archer, MD.)

In approximately 80% of infants with PCG presenting from 3 months to 1 year of age, IOP is controlled with 1 or 2 angle surgeries. If the first procedure is not sufficient, at least 1 additional angle surgery is usually performed before a different procedure is used.

For children in whom angle surgery is not successful or is not indicated (as is the case in many secondary glaucomas) and medical therapy is inadequate, additional surgical options include trabeculectomy with or without antifibrotic therapy (eg, mitomycin C [MMC]), glaucoma implant procedures, and cycloablative procedures.

Trabeculectomy with the use of MMC is successful in approximately 50% of children. Reported success rates vary considerably by surgical technique and type of glaucoma and decrease as the length of follow-up increases. Patients younger than 1 year and those who are aphakic are more prone to treatment failure. Although the success rate of trabeculectomy improves with the use of antifibrotics such as MMC, the long-term risk of bleb leaks and endophthalmitis also increases. Longterm risk is reduced by using a fornix-based rather than a limbus-based trabeculectomy flap. The reported success rate of glaucoma implant surgery with Molteno (Molteno Ophthalmic, Dunedin, New Zealand), Baerveldt (Abbott Medical Optics, Abbott Park, IL), and Ahmed (New World Medical, Rancho Cucamonga, CA) devices varies between 54% and 85%. Although most of these children must remain on adjunct topical medical therapy to control IOP after surgery, their blebs are thicker and are less prone to leaking and infection than those of patients undergoing MMC-augmented trabeculectomy. Potential complications include shunt failure, tube erosion and migration, tube– cornea touch, cataract, restrictive strabismus, and endophthalmitis.

Laser cycloablation and cyclocryotherapy are generally reserved for resistant cases or those not amenable to other surgical procedures. These techniques decrease ciliary body production of aqueous