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

Background/Aims To study the safety and effectiveness of 360 degrees 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 degrees 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 mmHg. The mean follow-up time was 30.6 +/- 8.4 months. The mean IOP at 12 months was 15.4 +/- 5.2 mmHg (n=54), at 24 months 16.3 +/- 4.2 mmHg (n=51) and at 36 months 13.3 +/- 1.7 mmHg (n=49). For IOP <= 21 mmHg, 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 mmHg. 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.