Outcomes of ab interno trabeculectomy with the trabectome after failed trabeculectomy

Abstract

Aim: To evaluate outcomes of ab interno trabeculectomy (AIT) with the trabectome following failed trabeculectomy.

Methods: Prospective study of AITs and phaco-AITs after a failed trabeculectomy. The indication for AIT was intraocular pressure (IOP) above target on maximally tolerated therapy, and for phaco-AIT a visually significant cataract and need to lower IOP or glaucoma medications. Outcomes included IOP, medications, complications, secondary procedures and success, defined as IOP of less than 21 mm Hg and a greater than 20% reduction from baseline without further surgery. Exclusion criteria were trabeculectomy less than 3 months prior to AIT or follow-up under 1 year.

Results: Seventy-three eyes of 73 patients with 1 year follow-up were identified. At 1 year, mean IOP in AIT significantly decreased by 28% from 23.7±5.5 mm Hg, and medications from 2.8±1.2 to 2±1.3 (n=58). In phaco-AIT, the mean IOP decreased 19% from 20±5.9 mm Hg and medications from 2.5±1.5 to 1.6±1.4 (n=15). Transient hypotony occurred in 7%, and further surgery was necessary in 18%. For AIT and phaco-AIT, the 1-year cumulative probability of success was 81% and 87%, respectively.

Conclusions: Both AIT and phaco-AIT showed a reduction in IOP and medication use after 1 year, suggesting that AIT with or without cataract surgery is a safe and effective option following failed trabeculectomy.

Keywords: Glaucoma; Treatment Surgery.

Figure 1

Trabectome Study Group Database. Cases analysed after accounting for exclusion criteria (AIT, ab interno trabeculectomy; phaco-AIT, phacoemulsification cataract surgery combined with AIT; IOP, intraocular pressure).

Figure 2

Preoperative and postoperative intraocular pressure (IOP) measurements (top) and change in glaucoma medications (bottom) over time in ab interno trabeculectomy (AIT) (left) and phaco-AIT (right).

Figure 3

Relative decrease of intraocular pressure (IOP) (top) and number of topical glaucoma medications (bottom graph) in patients with mild to moderate (gray) and advanced (black). Patients with advanced visual field loss had a larger IOP decrease on average. Bottom: table with means and SDs (all p>0.05).

Figure 4

Kaplan–Meier survival plots for ab interno trabeculectomy (AIT) (left) and phacoemulsification cataract surgery combined with AIT (phaco-AIT) (right) with success defined as a final intraocular pressure of less than 21 mm Hg and a greater than 20% reduction from baseline without further surgery.

Figure 5

Scattergrams for ab interno trabeculectomy (AIT) (left) and phacoemulsification cataract surgery combined with AIT (phaco-AIT) (right) demonstrating intraocular pressure (IOP) change from preoperative baseline to final measurement at 12 months.