TRABECULECTOMY COMBINED WITH BETA-IRRADIATION FOR CONGENITAL GLAUCOMA

Sixty-six eyes with congenital glaucoma were subjected to trabeculectomy between July 1975 and June 1989 are presented. Thirty-one were treated with beta-irradiation at the time of surgery with a strontium-90 applicator; 35 were not treated with beta-irradiation. The usual dose was 750 rad. Analysis was limited to three years because of the shorter follow-up of the irradiated eyes. Failure in the two groups was compared statistically. When failure was categorised as IOP > 21 mm Hg, beta-irradiation was found to be significantly protective with an adjusted risk ratio of 0.31 (95% confidence interval 0.11-0.90, p < 0.05). Failure categorised as the need for additional medical treatment or further surgery showed significant protection with an adjusted risk ratio of 0.33 (confidence interval 0.12-0.94, p < 0.05). Multiple regression models were used for the analysis of intraocular pressure; beta-irradiation was associated with a significantly lower IOP at six months, one year, and three years (p < 0.05). Other factors identified as being associated with a reduced failure rate or lower IOP were: no previous topical glaucoma medications: age over seven years; lack of previous surgery involving the conjunctiva. The results indicate that beta-irradiation may have a beneficial effect on the prognosis of trabeculectomy in children with congenital glaucoma. However, because of the retrospective and observational nature of the study, the results must be regarded as tentative.