Abstract
Purpose: :
To study the outcomes of surgical revision of leaking blebs after trabeculectomy.
Methods: :
Retrospective, non-comparative case series of 27 eyes with bleb leaks after trabeculectomy that underwent bleb revision. Primary outcomes analyzed were bleb survival as judged by IOP control after successful bleb revision and recurrence of bleb leak. Two different criteria of success to assess bleb survival over time were tested. Complete success (CS) was defined as IOP of 21 mm Hg or less without medication. Qualified success (QS) was defined as IOP of 21 mm Hg or less with or without one or more topical glaucoma medications. Time of failure was defined as the date when a recurrent and/or persistent bleb leak was noted or when IOP was uncontrolled by medication and an intervention was warranted. Kaplan-Meier survival curves were used to estimate bleb survival. Cox regression analysis was performed to determine if risk factors for bleb revision failure could be identified.
Results: :
12 patients had complete success whereas 6 patients had qualified success. Eighteen out of 27 (70.3%) patients had at least qualified success at their last follow up visit. All patients had a mean IOP at initial presentation that rose from 6.4 ± 5.4 mm Hg to 14.0 ± 5.6 mm Hg at the last visit (p<0.00000003). Patients with at least QS had a mean IOP at initial presentation that rose from 6.1 ± 4.8 mm Hg to 12.7± 3.1 at the last visit (p < 0.00001). All patients had mean Va at initial presentation that improved from 0.60 ± 0.56 to 0.45 ± 0.48 at the last visit (p < 0.05) . (approx 20/80 to 20/60). Patients with at least QS had mean Va at initial presentation that improved from 0.62 ± 0.61 mm Hg to 0.45 ± 0.49 mm Hg at the last visit (p < 0.02). (approx 20/80 to 20/60) Six (22.2%) patients had a decrease in vision. Complications included recurrent bleb leaks seen in 5 patients between 8 days and 2 years postoperatively. Two patients had bleb leaks at post-op month 1 and post-op day 10 and were treated conservatively with IOP lowering gtts and the other with cautery and IOP lowering drops. Both of these patients had resolution of their leaks. None of the variables studied by Cox regression analysis were associated risk factors for bleb revision failure.Kaplan-Meier analysis showed that the probability of complete and qualified success at 24 months was 51.6% and 33.3%, respectively. At 60 months the probability of complete and qualified success dropped further to 16.7% and 34.4%.
Conclusions: :
Bleb revision can offer a definitive solution for bleb leaks and be a safe and successful procedure. Few recurrence of leaks were seen in this study.
Keywords: outflow: trabecular meshwork