Further Surgical Options in Children

Introduction and Indications

The pediatric glaucomas encompass a wide range of disorders with variations in epidemiology, pathophysiology, and anatomical considerations which affect the selection and prognosis of available treatment modalities. Angle surgery such as trabeculotomy or goniotomy typically offers the best initial treatment option, particularly in infants with developmental glaucoma, with 75–90% success and low complication rates. These procedures address the main site of pathology in infantile glaucoma. We typically recommend treating the angle in its entirety in these cases before moving on to other surgical options.

A considerable minority of patients requires intervention beyond angle surgery. Long-term follow-up for infantile glaucoma reveals that failure of initial angle surgery may occur years later. In India and the Middle East, infantile glaucoma may present at a more severe stage, and initial failure rates of angle surgery are higher. In children with secondary glaucomas, such as Sturge–Weber, aphakia, aniridia, and anterior segment dysgenesis, alternative treatment is more likely to be necessary. Patients with chronic synechial angle closure following congenital cataract surgery should not undergo angle surgery. The choice of surgical treatment depends on underlying diagnosis, urgency of intraocular pressure lowering, potential vision, follow-up concerns, and access to tertiary care and medical supplies (see Chapter 34 ).

Presently, surgical options for refractory pediatric glaucomas include: (1) glaucoma drainage device implantation (preferred); (2) filtering surgery (less desirable); and (3) cyclodestructive procedures (least desirable).

Anesthetic Considerations and the Exam Under Anesthesia

In all but the oldest, most cooperative children, general anesthesia will be required for the procedures in this chapter. General anesthesia in infants and young children carries a small but significant risk, including death. A complete preoperative systemic evaluation is essential. Children with some secondary glaucomas are predisposed to anesthetic complications, such as cardiac issues in homocystinuria, and tracheomalacia in Rubinstein–Taybi patients. Appropriate consent and equipment should be obtained for any anticipated procedures, as uncertainty may exist preoperatively as to which, if any, procedures will be performed. Discussion with the parents while the child is under anesthesia should be attempted when unexpected findings warrant intervention.

In these refractory cases, a primary diagnosis has often previously been made. Complete ocular examination is performed with attention to diagnosing progression of glaucoma, as well as factors that might impact surgical decision-making. Intraocular pressure readings should be taken immediately after induction of general anesthesia, to avoid artificial reduction in pressure by anesthetics. Alternatively, midazolam or ketamine may be used for sedation as they may not affect intraocular pressure. Pachymetry, axial length, corneal diameter, anterior segment exam, to include breaks in Descemet's membrane and corneal edema, optic nerve exam and photography may be helpful.

Filtering Surgery

Trabeculectomy is currently the most widely performed glaucoma filtration procedure for glaucoma in adults; however, this procedure has become less popular for infants and children due to high failure rates and long-term infection risk. The technique of trabeculectomy is covered in detail elsewhere in these volumes (see Chapter 77 ).

Special considerations apply to trabeculectomy in young children. A limbus-based conjunctival flap is commonly used in young children, probably because of decreased risk of early wound leak and less potential for the child to disrupt the wound. Postoperative interventions typically require general anesthesia. Both steroids and antifibrotic agents are used intraoperatively and postoperatively to inhibit healing; however, administration of eyedrops may be less reliable. Serial 5-fluorouracil (5-FU) injections have been replaced mainly by intraoperative mitomycin C (MMC). Examination may be limited in the clinic, and children may present with complications at a later stage than adults.

The following studies highlight important features of filtration surgery for refractory pediatric glaucomas ( Table 121-2 ).