No benefit of adjunctive beta irradiation in control of IOP, study shows

LEEDS, England — Beta irradiation failed to induce any additional lowering of intraocular pressure as an adjunct to trabeculectomy in a study here. The study authors suggest that the sample size of their study was not large enough for adjunctive irradiation’s effect to be shown in the study’s low-risk patient population.

Sixty-one eyes of 61 white patients with poorly controlled primary or secondary open-angle glaucoma underwent routine trabeculectomy with fornix-based conjunctival incision. The patients, who were considered to be at a low risk of filtering surgery failure, were randomly assigned to receive either beta irradiation (750 cGy applied directly over the sclerostomy site on completion of the conjunctival suturing) or an identical, but inactive, applicator.

Intraocular pressure (IOP) control to 21 mm Hg or less without the need for additional medication was achieved in 86% of the control eyes and 90% of the irradiated eyes at 12 months postop. Qualified IOP control success, measured as achieving an IOP of 21 mm Hg or less but needing additional medication to maintain control levels, was achieved in 95% of the control eyes and 100% of the irradiated eyes at 12 months postop.

The researchers suggest further studies to determine if adding beta irradiation to standard trabeculectomy may have a benefit to patients at high risk for filtration failure.

The study is published in the February issue of Ophthalmology.