Beta radiation as an adjunct to low-risk trabeculectomy. Randomized controlled clinical trial of beta irradiation as an adjunct to trabeculectomy in open-angle glaucoma. Effect of beta radiation on success of glaucoma drainage surgery in South Africa: randomised controlled trial.
To assess a single dose of intraoperative beta radiation used to enhance the success rate of trabeculectomy in a population of low-risk glaucoma patients in whom antimetabolites might not be indicated.
                A prospective randomized trial of 65 eyes was designed, with 31 eyes receiving 750 rads of intraoperative beta radiation (group 1), and 34 eyes receiving no supplementation (group 2).
                Mean follow-up time was 24 months. Mean postoperative intraocular pressure was 12.2 mmHg in group 1, and 13.7 mmHg in group 2 (P = 0.16). Mean decrease in intraocular pressure was 10.3 mmHg in group 1, and 9.3 mmHg in group 2 (P = 0.49). The two groups were not significantly different in terms of surgical complications.
                For this population of low-risk patients, there was no significant difference in outcome after applications of a single intraoperative dose of beta radiation. To assess the effect of a single intraoperative application of 750 cGy of beta irradiation on the outcome of trabeculectomy for uncontrolled open-angle glaucoma.
                A prospective, randomized, double-blind, placebo-controlled clinical trial.
                Sixty-one eyes of 61 Caucasian patients at low risk of filtering surgery failure, with poorly controlled primary or secondary open-angle glaucoma undergoing routine trabeculectomy.
                Patients were randomly assigned to control or beta irradiation groups. All patients underwent standard trabeculectomy with fornix-based conjunctival incision. Eyes assigned to beta irradiation received 750 cGy of beta irradiation directly over the sclerostomy site on completion of conjunctival suturing. An identical but inactive applicator was applied to control eyes, delivering no radiation. Both operator and patient remained masked to the assignment for the 12-month follow-up period.
                The main outcome measure was intraocular pressure (IOP) control. Complete success of IOP control was defined as an IOP less than 21 mmHg at 12 months without need for additional medication. Qualified success was defined as an IOP less than 21 mmHg at 12 months where additional medication was required.
                Complete success of IOP control was achieved in 19 (86%) control eyes and 35 (90%) irradiated eyes (P = 1.0). Qualified success of IOP control was achieved in 21 (95%) control eyes and 39 (100%) irradiated eyes at 12 months follow-up (P = 1.0)
                We experienced a very high success rate of filtration surgery in this select population without adjunctive irradiation. Our sample size was too small to show any improvement in success with use of beta irradiation in this group. Other studies would have to be done to determine whether it may have measurable benefit in cases with a high risk of filtration failure. To evaluate whether beta radiation may offer a practical method of improving surgical success for glaucoma drainage surgery in South Africa.
                Double blind, randomised controlled trial.
                Three public hospitals in South Africa.
                450 black Africans with primary glaucoma.
                Trabeculectomy with 1000 cGy beta radiation or standard trabeculectomy without beta radiation (placebo).
                Primary outcome measure was surgical failure within 12 months (intraocular pressure > 21 mm Hg while receiving no treatment for ocular hypotension). Secondary outcomes were visual acuity, surgical reintervention for cataract, and intraoperative and postoperative complications.
                320 people were recruited. beta radiation was given to 164; 20 (6%) were not seen again after surgery. One year after surgery the estimated risk of surgical failure was 30% (95% confidence interval 22% to 38%) in the placebo arm compared with 5% (2% to 10%) in the radiation arm. The radiation group experienced a higher incidence of operable cataract (18 participants) than the placebo group (five participants; P = 0.01). At two years the estimated risks with placebo and beta radiation were, respectively, 2.8% (0.9% to 8.3%) and 16.7% (10.0% to 27.3%).
                beta radiation substantially reduced the risk of surgical failure after glaucoma surgery. Some evidence was, however, found of an increased risk for cataract surgery (a known complication of trabeculectomy) in the beta radiation arm during the two years after surgery.
                ISRCTN62430622 [controlled-trials.com].
Trabeculectomy with beta irradiation has a lower risk of surgical failure compared to trabeculectomy alone. A trial of beta irradiation versus anti-metabolite is warranted.