The primary treatment for most types of childhood glaucoma is surgery. PCG is usually effectively treated with angle surgery (goniotomy or trabeculotomy). Although angle surgery may be used to treat some forms of secondary pediatric glaucoma—most notably, those associated with Axenfeld-Rieger syndrome, Sturge-Weber Syndrome, and aniridia—the outcome is often less successful. The treatment of most forms of secondary childhood glaucoma (see Table 22-3) is similar to that of open-angle or secondary glaucoma 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 intervention is the treatment of choice for PCG. Goniotomy or trabeculotomy is the preferred initial procedure. In a goniotomy, an incision is made, under direct gonioscopic visualization, across the trabecular meshwork (Fig 22-6, Video 22-1).
Courtesy of Ken K. Nischal, MD.
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Figure 22-6 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.)
In trabeculotomy, an external approach is used to identify and cannulate the Schlemm canal, and then connect it with the anterior chamber through incision of the trabecular meshwork (Fig 22-7, Video 22-2).
Courtesy of Young H. Kwon, MD, PhD.
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 (Video 22-3).
Figure 22-7 Trabeculotomy. A, The trabeculotome has entered the Schlemm canal. B, The trabeculotome has been rotated into the anterior chamber.
(Courtesy of Steven M. Archer, MD.)
Illuminated microcatheter–assisted 360-degree trabeculotomy.
Courtesy of Brenda L. Bohnsack, MD, PhD.
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.
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.
When angle surgery is not successful in a child or is not indicated (as is the case in many forms of secondary glaucoma) and medical therapy is inadequate, additional surgical options include trabeculectomy with or without antifibrotic therapy (eg, mitomycin C [MMC]), tube shunt implantation, and cyclodestructive procedures.
Reported success rates for trabeculectomy 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. Long-term risk is reduced by using a fornix-based rather than a limbus-based conjunctival flap. Ab interno trabeculectomy using a mechanical device such as Trabectome (NeoMedix, Tustin, CA) has been described in the treatment of pediatric glaucoma, but its use is still evolving.
The reported success rate of tube shunt implantation surgery with Molteno (Molteno Ophthalmic Limited, Dunedin, New Zealand), Baerveldt (Johnson & Johnson Vision, Santa Ana, CA), and Ahmed (New World Medical, Rancho Cucamonga, CA) devices varies between 54% and 85%. Although most children with implanted tube shunts 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 who have undergone MMC-augmented trabeculectomy. Potential complications include shunt failure, tube erosion or migration, tube–cornea touch, cataract, restrictive strabismus, and endophthalmitis.
Laser cyclodestruction and cyclocryotherapy are generally reserved for resistant cases or those not amenable to other surgical procedures. These techniques decrease ciliary body production of aqueous humor, which results in lower IOP. Cyclocryotherapy (freezing the ciliary processes through the sclera) may be successful, but the complication rate is high. Repeated applications are often necessary, and the risk of phthisis and blindness is significant (approximately 10%). Transscleral cyclophotocoagulation with the Nd:YAG or diode laser has a lower risk of complications. The short-term success rate is approximately 50%. Patients usually require more than one treatment.
Endoscopic cyclophotocoagulation (ECP) has been used in children with glaucomas that are difficult to treat. In ECP, a microendoscope applies laser energy to the ciliary processes under direct visualization (Fig 22-8). Success rates of up to 50% have been reported. Although this is an intraocular procedure, the complication rate may be lower than that of external cyclodestructive procedures. Use of the microendoscope is advantageous in eyes with abnormal anterior segment anatomy. Some studies have shown encouraging results for patients with aphakic glaucoma.
Figure 22-8 Endoscopic view of the ciliary processes during endoscopic cyclophotocoagulation. The white structure at the bottom right of the photo is the lens.
(Courtesy of Endo Optiks, Little Silver, NJ.)
Chen TC, Chen PP, Francis BA, et al. Pediatric glaucoma surgery: a report by the American Academy of Ophthalmology. Ophthalmology. 2014;121(11):2107–2115.
Jayaram H, Scawn R, Pooley F, et al. Long-term outcomes of trabeculectomy augmented with mitomycin C undertaken within the first 2 years of life. Ophthalmology. 2015;122(11):2216–2222.
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.