Safety And Efficacy Of Three Variants Of Canaloplasty With Phacoemulsification To Treat Open-Angle Glaucoma And Cataract: Three–Year Results.

A prospective observational study to compare clinical outcomes of three types of canaloplasty using the iTrack microcatheter (Nova Eye Medical, Fremont, California): ab-externo (ABeC), ab-interno (ABiC) and minicanaloplasty (miniABeC) combined with cataract surgery in primary open-angle glaucoma (POAG) patients over 36 months.

All procedures were performed at a single centre, the Military Institute of Medicine, Warsaw, Poland by one surgeon MR.

48 POAG patients underwent one of three canaloplasty procedures: ABeC (16 eyes), ABiC (16 eyes) or miniABeC (16 eyes) combined with phacoemulsification as a part of a prospective efficacy study. miniABeC is a novel method using small scleral flaps and does not require excision of a deep scleral flap. Prior to surgery, antiglaucoma medications were washed out. Intraocular pressure (IOP), slit-lamp examination and number of medications were assessed at baseline, at day 0-1-7 and at 1-6-12-24-36 month. Successful treatment was defined as an IOP reduction ≥20% without medications.

Median pre-washout IOP(mmHg) was 17(ABeC), 18(miniABeC) and 17(ABiC) and decreased 36-month postoperatively to 15(p=0.140), 15(<0.001) and 15(<0.001) respectively. There were no statistically significant differences in median IOP between groups at 36 months (p=0.810) after operation. In patients not taking medication, a 20% reduction in IOP was observed in 56.2% in the ABiC group, 75.0% in the C group, and 68.8% in the MC group and there was no significant relationship with the group factor. There was one complete failure after miniABeC. Preoperatively, the median number of medications was 2.0(range 1–3) (ABeC), 2.0(1–3) (miniABeC) and 2.0(0–4) (ABiC); 36-month post-operatively all medications reduced significantly to 0(0–1) in all groups. 

This 36-month prospective observational trial demonstrated that the three variants of canaloplasty (ABeC, miniABeC and ABiC) significantly reduced IOP and number of medications in patients with mild to moderate POAG and with no significant complications. miniABeC demonstrates similar clinical efficacy and safety outcomes to ABeC with a less invasive procedure.