The treatment of encapsulated trabeculectomy blebs in an out-patient setting using a needling technique and subconjunctival 5-fluorouracil injection

Abstract

Purpose. Encapsulation of the trabeculectomy bleb is a common cause of drainage failure in the early post-operative period. The primary management of bleb encapsulation has previously been to restart medical therapy, but recent advances in the technique of needle manipulation and the introduction of adjunctive 5-fluorouracil (5-FU) have increased the popularity of early surgical bleb management. By reporting the results of bleb needling in a series of patients, we aim to illustrate its safety and efficacy. Methods. We have reviewed a series of 32 eyes in which needling and 5-FU injection was performed for bleb encapsulation, and analysed the results over a follow-up period of 10.7 ± 2.9 months. Results. In 14 (43.7%) cases, primary needling was performed; in the other 18, needling was performed after conservative treatment had proved inadequate. The mean intraocular pressure (IOP) of the group decreased from 29.2 ± 10.5 mmHg prior to needling to 15.9 ± 4.0 mmHg at the most recent attendance (paired t-test p = 1.3 X 10-7), with all eyes having a final IOP measurement of 22 mmHg or less. Twenty-three (71.9%) of the cases maintained a target IOP of 18 mmHg or less without additional treatment; 5 (15.6%) were qualified successes with an untreated IOP between 19 and 21 mmHg. The remaining 4 (12.5%) patients, whose IOPs ranged between 20 and 22 mmHg with one hypotensive agent, were considered needling failures. Choroidal detachment complicated the procedure in 2 cases; in each this resolved with conservative management and without long-term visual consequence. Conclusion. This technique is recommended as a safe and effective method of treating bleb encapsulation.