Care Needed

Attendees of the 5th World Glaucoma Congress were given a glimpse of the first consensus statement on childhood glaucoma. Publication is expected soon. This first consensus statement defines childhood glaucoma somewhat differently than the way we define it in adults, according to Allen Beck MD, professor of ophthalmology at Emory University. While childhood glaucoma is defined as intraocular pressure (IOP)-related damage to the eye, the optic nerve is not the only factor. The disc appearance is important as are fields.

Elevated IOP can affect various ocular structures in infancy, and in turn, interpretation of IOP can be influenced by various factors. Also, physicians need to consider other possible indicators of glaucoma, such as ocular enlargement, Haab striae and increased cup-to-disc ratio. The statement classifies childhood glaucoma as primary or secondary, but secondary glaucoma is sub-classified according to whether the condition is acquired after birth or is present at birth (non-acquired). Terms such as developmental, congenital or infantile glaucoma lack clear definition and are falling out of favour as terms, he said.

In children, other conditions can mimic glaucoma, so extra care is needed for the diagnosis. The statement includes "categories of definitions for glaucoma, and we have criteria that include both optic nerve changes and the effects of ocular stretching such as progressive myopia,” he said. The statement also addresses glaucoma which develops after cataract surgery. Surgical treatment is controversial, and a survey was performed of paediatric glaucoma surgeons worldwide to determine common practices, said Peng T Khaw MD, PhD, professor of glaucoma and ocular healing, UCL Institute of Ophthalmology, and consultant ophthalmic surgeon at Moorfields Eye Hospital, London UK.

Survey results were based on feedback from 78 surgeons. Results showed that, for primary congenital glaucoma, goniotomy is performed by 28.6 per cent of surgeons, and 27.3 per cent perform trabeculectomy with metal trabeculotome. "There are 360 degree trabeculectomies as well, with 13 per cent saying they do this”, Prof Khaw said. The statement confirms that surgery is critical in managing childhood glaucoma, but there was a strong sense that “glaucoma surgery should be performed by a trained surgeon in centres where there is sufficient volume to ensure surgical expertise and skill, and safe anaesthesia,” he said.

"A longer-term surgical strategy, including the choice of procedures, should be based on training, experience, logistics and the surgeon’s preference. The first chance for surgery is often the best chance, and it is important to choose the most appropriate operation," he said. Glaucoma surgery in children has a higher failure and complication rate than in adults. However, among consensus experts, angle surgery is the preferred option for primary congenital glaucoma. The exact choice should be dictated by corneal clarity and the surgeon’s experience and preference. The results for non-primary congenital glaucoma cases are not as good, he said. “There was consensus that trabeculectomy done by an experienced paediatric surgeon can be associated with satisfactory and good outcomes in appropriate cases," Prof Khaw said. As for long-term IOP control, aqueous drainage devices were often deemed the most effective, especially in cases refractory to other surgical treatments. The statement notes that cyclophotocoagulation has limited long-term success.

“Other glaucoma procedures have not been widely adopted because of the technical challenges in buphthalmic eyes, or because they are yet to be proven efficacious or safe in children," he said. Visual development needs to be evaluated as children undergo treatment, and how treatment and repetitive surgery on the problem eye may affect the other eye. "With childhood glaucoma, one needs to carefully consider the risks and benefits of each intervention," he said.

John Brookes FRCOphth from the Moorfields Eye Hospital addressed the management of primary congenital glaucoma and juvenile open-angle glaucoma. Primary congenital glaucoma is the most common non-syndromic glaucoma in infancy, he said. It occurs worldwide though the incidence is higher in consanguineous populations. A family history is reported in 10 to 40 per cent of cases. The actual pathogenesis of primary congenital glaucoma is still uncertain but thought to be isolated trabeculodysgenesis.

The consensus group considers primary congenital glaucoma a surgical condition. First line surgery should usually be angle surgery (goniotomy or trabeculectomy), and there are high rates of success reported for both of these types of surgery. Some experts prefer combined trabeculectomytrabeculotomy as an initial procedure, however there are no prospective comparisons in the medical literature to support this. If an angle surgery fails, the statement suggests the next procedure of choice be either trabeculectomy or a glaucoma drainage device.

Juvenile open-angle glaucoma is discussed too. It is rare but usually presents after four years of age with a normal angle appearance and no signs of other ocular anomalies or systemic disease. Evidence is weak for the best interventions for this but experts concurred that depending on age, medical therapy be the first-line treatment, although surgery is often required, Dr Brookes said. The consensus report will have more details on these and other topics once it is published.