Efficacy of Ab Interno Revision for Trabeculectomy Bleb Failure Using a Minimally Invasive Approach: A Prospective Study

Abstract

Précis: Ab interno bleb revision using the Grover and Fellman spatula offers potential benefits in improved intraocular pressure control and spares the conjunctiva for enhanced bleb management. Purpose: This study aimed to evaluate the safety and effectiveness of Ab-Interno Bleb Revision (AIBR) for treating failed trabeculectomy blebs. Methods: This noncomparative case series enrolled glaucoma patients with failed trabeculectomy blebs who underwent AIBR and were followed up for 1 year. Eligible patients received subconjunctival Mitomycin C 0.1 mL of 0.2 mg/mL (20 μg) 5 days before the AIBR, performed using the Grover and Fellman spatula. The primary outcome measures were intraocular pressure (IOP) and the usage of IOP-lowering medications 1 year after the procedure. Secondary outcomes included the procedure’s failure rate and complications. Complete success was defined as achieving an IOP between 5 and 21 mm Hg without medication, while qualified success required additional medical treatment. Results: The study comprised 23 eyes from 23 patients, having a mean age of 59.66±14.93 years. Preoperatively, the mean IOP was 23.54±10.7 mm Hg, and the mean antiglaucoma medication requirement was 3.99±0.65, both significantly reduced to 15.7±6.9 mm Hg (P=0.009) and 1.26±1.2 (P <0.001) at 1 year, respectively. Overall, 19 eyes (82.6%) achieved success (complete success: 39.2%, qualified success: 43.4%), while in 4 (17.4%) patients, the procedure failed (IOP >21 mm Hg). 5 patients had transient hyphema, but there were no sight-threatening complications such as hypotony or choroidal detachment. Conclusions: Ab-Interno Bleb Revision (AIBR) is a safe, effective, and minimally invasive intervention for managing failed trabeculectomy blebs. By eliminating the need to reopen the conjunctiva, this technique offers a promising alternative for the treatment of this challenging condition.