procedures than with cryotherapy. The most common cyclodestructive modalities currently used are transscleral CPC with the diode laser and ECP. CPC is a noninvasive procedure performed transsclerally, whereas ECP is an intraocular procedure in which the laser energy is applied under direct visualization, thereby causing less damage to adjacent tissues. ECP is particularly useful in eyes with distorted anterior segment anatomy and in eyes with prior unsuccessful CPC or cryotherapy. CPC and ECP can be very useful for providing additional IOP lowering after glaucoma drainage device surgery.

Medical Management

Although surgical management is the mainstay of PCG care, medications are frequently required in the treatment of PCG and other childhood glaucomas. Medications can be used to lower IOP before surgery in order to reduce corneal edema and improve visualization during surgery. They may also be used after surgical procedures in order to provide additional IOP lowering. Medical therapy may be useful for forms of childhood glaucoma other than PCG, including JOAG, inflammatory, and aphakic glaucoma and other secondary glaucomas. The safety and efficacy of most FDA-approved glaucoma medications have not been studied in controlled clinical trials specifically in children, although extensive clinical experience guides most clinicians. A full discussion of glaucoma medications can be found in Chapter 7.

β-Adrenergic antagonists

β-Adrenergic antagonists, or β-blockers, decrease aqueous production in the ciliary body and are useful for controlling IOP in children. Topical β-adrenergic antagonists are considered first-line therapy for glaucoma in children. These agents must be used with caution, however, as they have considerable systemic absorption and can cause bronchospasm, bradycardia, and hypotension in susceptible children. β-Blockers should therefore be avoided in children with asthma or significant cardiac disease. To decrease the risk of bronchospasm, the clinician may consider administering the cardioselective β-blocker betaxolol. The risk of adverse effects can also be diminished by occluding the nasolacrimal drainage system for 3 minutes after administration of the medication and by prescribing timolol 0.25% or levobunolol 0.25% instead of the more commonly used 0.5%, particularly in younger children. The clinician should teach parents how to occlude the nasolacrimal drainage system. Patients with lighter irides may respond as well to timolol 0.25% or levobunolol 0.25% as they do to 0.5%.

Carbonic anhydrase inhibitors

Carbonic anhydrase inhibitors (CAIs) decrease IOP by reducing aqueous production. Topical therapy with dorzolamide or brinzolamide has a minimal risk of systemic side effects and is an excellent second-line therapy after the topical β-adrenergic antagonists. There is some concern about the use of topical dorzolamide or brinzolamide in eyes with compromised corneas or after corneal transplantation, although these contraindications are not absolute. Systemic CAIs (acetazolamide and methazolamide) provide slightly more IOP lowering than do the topical preparations, but they have numerous systemic side effects. The pediatric dosage of acetazolamide is 10–20 mg/kg/day. CAIs should not be used in patients with known serious sulfa allergies. Adverse effects include anorexia, diarrhea, weight loss, tingling of the perioral areas and fingers, hypokalemia, and metabolic acidosis; children using diuretics are particularly at risk of experiencing these effects. Because of the risk of these adverse effects and of rare but life-threatening reactions such as Stevens-Johnson syndrome and aplastic anemia, systemic CAIs are reserved for patients at high risk of vision loss due to glaucoma.