# Long-term outcomes of trabeculectomy versus canaloplasty in open-angle glaucoma – an 11-year follow-up of the TVC study cohort

## TL;DR

This study compares the long-term effectiveness and safety of two glaucoma surgeries, trabeculectomy and canaloplasty, over 11 years.

## Contribution

The study provides the first 11-year follow-up comparing trabeculectomy and canaloplasty outcomes in open-angle glaucoma patients.

## Key findings

- Trabeculectomy showed greater IOP reduction and higher complete success rates compared to canaloplasty.
- Canaloplasty had a lower complication rate but resulted in higher intraocular pressure and medication use.
- Hypotony maculopathy was the only long-term complication observed, occurring in two trabeculectomy patients.

## Abstract

To assess the long-term outcomes of the Trabeculectomy versus Canaloplasty (TVC) study cohort after 11 years. The TVC study was a prospective, single-center, randomized clinical trial comparing the 24-month surgical outcomes of trabeculectomy and canaloplasty in patients with open-angle glaucoma.

This prospective follow-up study included only patients from the original 2015 TVC cohort. Primary endpoints were complete (without glaucoma medication) and qualified success (with or without glaucoma medication), defined as intraocular pressure (IOP) ≤ 18 mmHg (Definition 1) or IOP ≤ 21 mmHg with ≥ 20% reduction from baseline (Definition 2). Secondary endpoints included changes in IOP, medication use, complications, and revision surgeries.

Mean follow-up was 11.9 ± 1.1 years for trabeculectomy (TE) and 11.0 ± 2.0 years for canaloplasty (CP) (15 TE and 13 CP patients). Complete success rates for TE vs. CP were 53.3% vs. 15.4% (Definition 1, p = 0.06) and 46.7% vs. 15.4% (Definition 2, p = 0.22). Qualified success was achieved by 73.3% vs. 69.2% (Definition 1, p = 1.0) and 66.7% vs. 76.9% (Definition 2, p = 0.69). Median IOP was 10.0 (6.0–12.0) mmHg for TE and 14.0 (11.5–17.75) mmHg for CP (p < 0.01). Mean number of compounds was 1.0 ± 1.4 in TE and 1.9 ± 1.5 in CP (p = 0.17). Revision surgeries were needed in 26.7% (TE) vs. 23.1% (CP). The only long-term complication, hypotony maculopathy, occurred in two TE patients (15.4%).

After 11 years, trabeculectomy still demonstrated greater IOP reduction and higher complete success rates but was associated with a higher complication rate. In contrast, canaloplasty offers a safe alternative when slightly higher IOPs and moderate medication use are acceptable.

The online version contains supplementary material available at 10.1186/s12886-025-04183-9.