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

Abstract

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. Retrospective, observational cohort study. 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 December2015. 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. Primary outcome measures included IOP, attainment of target IOP, and number of glaucoma medications used at different time points pre- and post-operatively. 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. 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.