Canaloplasty, MIGS Instruments Effectively Lower Intraocular Pressure

Optical Coherence Topography (OCT) image, showing a macular map. On this image, the left eye to prevent glaucoma. (Photo by: BSIP/Universal Images Group via Getty Images)
The surgical systems can preserve the sclera and conjunctiva while reducing the need for medications, according to the report.

Canaloplasty alone or in conjunction with a minimally-invasive glaucoma surgery (MIGS) surgical system can achieve statistically significant reductions in intraocular pressure (IOP) and reduce the need for medications while sparring tissue, according to a retrospective study published in the Journal of Cataract and Refractive Surgery. The study evaluated patients who had undergone MIGS with or without a surgical system designed for an ab-interno approach that preserves the sclera and conjunctiva, the report explains. 

This single-center, open-label, non-interventional study assessed 130 patients (206 eyes, mean age 75.0±7.7 years) with open-angle glaucoma (OAG) who had undergone canaloplasty between 2015 and 2018 who were evaluated for 3-year outcomes. All procedures were performed using 1 of 2 surgical systems. Procedures performed with and without cataract extraction (CE) were included. The primary outcome for patients with high baseline intraocular pressure (IOP) was a reduction in both IOP and use of hypotensive medications and for patients with lower baseline IOP, the maintenance of IOP with a reduction in hypotensive medications.

Patients had a preoperative IOP of 21.1±8.8 mm Hg, and took 2.0±0.9 hypotensive medications.

Following the procedure, medicated IOP ranged between 13.7 to 16.1 mm Hg and hypotensive medications were reduced by 59% to 61%. Visual acuity increased from 0.60 to 0.89 (P <.0001).

The primary outcome was met by 73% of patients overall, in which IOP decreased among those with high baseline IOP (mean, 21.8 vs 15.6 mmHg; P <.0001) and was maintained by those with lower baseline IOP (mean, 15.4 vs 13.9 mm Hg; P =.24). Medications were reduced in both the high (mean, 2.2 vs 0.9; P =.024) and lower (mean, 1.8 vs 0.7; P =.003) IOP cohorts.

At 36±6 months, 58% of patients were medication free and no adverse events were reported during follow-up. Stratified by primary OAG (n=123), pseudoexfoliation glaucoma (n=30), pigmentary glaucoma (n=2), and terminal glaucoma (n=25), the greatest reduction in medication use was observed among the patients with pseudoexfoliation glaucoma (mean change, -2.4) and smallest reduction was among patients with terminal glaucoma (mean change, -1.1).

Most eyes did not have complications during the procedure (64.4%). The eyes with complications had flowing erythrocytes without hyphema (24.4%) or hyphema (11.1%).

This study was limited by the fact that there was no comparator group.

The study authors report that both surgical systems were safe and effective for reducing IOP and hypotensive medication use among patients undergoing canaloplasty for OAG.


Ondrejka S, Körber N, Dhamdhere K. Long term effect of canaloplasty on iop and use of iop-lowering medications in patients with open angle glaucoma. J Cataract Refract Surg. Published online July 1, 2022. doi:10.1097/j.jcrs.0000000000001000