24-Month Evaluation Of Endothelial Cell Density And Loss Following Ab-Interno Canaloplasty

To evaluate endothelial cell density and IOP reduction over 24 months in glaucoma patients having undergone ab-interno canaloplasty using the iTrack (Nova Eye Medical Inc., Fremont, USA) combined with cataract surgery.

Prospective, multi-center registry study in the USA.

Patients undergoing ab-interno canaloplasty combined with cataract surgery were recruited. Specular microscopy was performed preoperatively and at 6, 12 and 24 months postoperatively. Standard metrics for glaucoma surgery follow-up were also measured including visual acuity, intraocular pressure, visual fields, optic nerve OCT and glaucoma medication use. Endothelial cell density and loss were analyzed at each time point. Results from patients undergoing ab-interno canaloplasty combined with cataract surgery were compared with results from age matched controls who underwent cataract surgery only.

Seventy-seven eyes of 46 patients (mean age: 74.7±6.8) were followed up for 24 months. Mean endothelial cell density was 2304±362mm² preoperatively and 2230±356 mm² 12 months following ab-interno canaloplasty combined with cataract surgery (-3.2%±-9%) (p=0.2). 8% per cent of eyes showed an endothelial cell loss above 10%; 88% of eyes lost less than 10%; 4% of the eyes showed a gain. In Samuelson et al (2019) FDA controlled pivotal trial of iStent postoperative endothelial cell loss in patients undergoing cataract surgery alone was -12.3%±-12.7%. Mean IOP (mmHg) was 17.8±7.3.4 preoperatively and it reduced to 14.8±2.9 12 months postoperatively (p<0.001).

Ab-interno canaloplasty performed in conjunction with cataract surgery causes minimal and non-statistically significant change in endothelial cell density and significant decrease in IOP up to 24 months postoperatively.