Long-Term Outcomes from an Intraoperative Bleb Needling Procedure Augmented with Continuous Infusion

Abstract

Purpose: To investigate long-term outcomes of a modified bleb needling technique performed in the operating room in controlling intraocular pressure (IOP) and to report risk factors for procedure failure.

Design: Retrospective, observational cohort study.

Participants: One hundred six eyes of 98 consecutive patients undergoing intraoperative bleb needling with a continuous infusion of balanced salt solution at the Wilmer Eye Institute, Johns Hopkins Hospital, in the setting of a failed trabeculectomy or express shunt, between May 2011 and December 2015.

Methods: Postoperative data were collected between May 2011 and August 2019. Success was defined as achieving a previously determined target IOP regardless of (qualified success) or without (complete success) glaucoma medications. Patients who underwent additional glaucoma surgery were censored in the survival analysis.

Main outcome measures: Primary outcome measures included IOP, attainment of target IOP, and number of glaucoma medications used at different time points pre- and post-operatively.

Results: Needling was performed in 106 eyes at an average of 4.3 years from the time of trabeculectomy (standard deviation [SD], 6.5 years) and an average baseline IOP of 20.7 mmHg (SD, 7.2 mmHg). Further glaucoma surgery was required for 33 eyes. We observed a 70% qualified success rate with a mean IOP lowering of 25% (95% confidence interval [CI], 13.8%-36.4%) at 1 year after surgery and a 52% qualified success rate and 44.3% reduction in IOP (95% CI, 34.9%-53.6%) at 5 years after surgery. Nearly half and a third of the eyes did not require medications after 1 and 5 years, respectively. The average medication reduction was 0.8 at year 1 (95% CI, 0.5-1.1) and 0.4 at year 5 (95% CI, -0.2 to 1.0). Postoperative complications were uncommon. Poorer outcomes were not associated with the age of the bleb but were more likely in Black patients.

Conclusions: Reductions in IOP were maintained in most patients over the long term using a modified bleb needling technique, despite an average time from trabeculectomy of over 4 years. No significant adverse events were observed. Bleb needling may defer or avoid more invasive procedures such as tube-shunts or repeat trabeculectomy.