Canaloplasty for primary open-angle glaucoma: long-term outcome.

Background/aims: To study the safety and effectiveness of 360° viscodilation and tensioning of Schlemm canal (canaloplasty) in black African patients with primary open-angle glaucoma (POAG).

Methods: Sixty randomly selected eyes of 60 consecutive patients with POAG were included in this prospective study. Canaloplasty comprised 360° catheterisation of Schlemm's canal by means of a flexible microcatheter with distension of the canal by a tensioning 10-0 polypropylene suture.

Results: The mean preoperative intraocular pressure pressure (IOP) was 45.0 ± 12.1 mm Hg. The mean follow-up time was 30.6 ± 8.4 months. The mean IOP at 12 months was 15.4 ± 5.2 mm Hg (n=54), at 24 months 16.3 ± 4.2 mm Hg (n = 51) and at 36 months 13.3 ± 1.7 mm Hg (n=49). For IOP ≤ 21 mm Hg, complete success rate was 77.5% and qualified success rate was 81.6% at 36 months. Cox regression analysis showed that preoperative IOP (HR = 1.003, 95% CI = 0.927 to 1.085; p = 0.94), age (HR = 1.000, CI = 0.938 to 1.067; p = 0.98) and sex (HR = 3.005, CI=0.329 to 27.448; p=0.33) were all not significant predictors of IOP reduction to ≤ 21 mm Hg. Complication rate was low (Descemet's detachment n=2, elevated IOP n = 1, false passage of the catheter n = 2).

Conclusion: Canaloplasty produced a sustained long-term reduction of IOP in black Africans with POAG independent of preoperative IOP. As a bleb-independent procedure, canaloplasty may be a true alternative to classic filtering surgery, in particular in patients with enhanced wound healing and scar formation.