Long Term Effect Of Ab-Interno Canaloplasty With Or Without Cataract Extraction (Ce) On Intraocular Pressure (Iop) And Use Of Iop-Lowering Medications In Patients With Open Angle Glaucoma (Oag)

Microinvasive glaucoma surgeries (MIGS) are undertaken with the goal of lowering IOP and/or need of IOP-lowering medications. Canaloplasty is a non-filtering MIGS to restore the natural aqueous outflow by addressing key points of resistance in pathway, including trabecular meshwork, Schlemm's canal and collector channels. Traditional canaloplasty procedures involved an invasive ab-externo approach requiring full thickness scleral incisions, while recent advances in canaloplasty using OMNI® or VISCO360® devices (Sight Sciences, Inc., USA) allow for an ab-interno approach that preserves the sclera and conjunctiva. Here we assess the long-term safety and effectiveness of canaloplasty in eyes with OAG.

This single-center, consecutive, open-label, non-interventional retrospective surgical case series evaluated the safety and effectiveness of canaloplasty using either the VISCO360 or OMNI Surgical Systems in OAG. The study was conducted at Surgical center (Augencentrum Köln, Köln, Germany) between December 2015 and May 2018. This study evaluated data from 206 eyes from 130 patients at 36±6 months of follow-up after canaloplasty. 

Canaloplasty was performed using the VISCO360® or OMNI® surgical system as a stand-alone procedure in 22 eyes and concomitantly with cataract extraction (CE) in 184 eyes with chronic OAG insufficiently controlled or intolerant to IOP-lowering medications. The number of hypotensive medications and IOP were recorded at baseline, Day 1, Week 1, Month 1, Month 3, and every three months thereafter, with the last follow-up visit at 36±6 months post-surgery. Patients were stratified by baseline IOP (Group 1, IOP >18 mmHg; Group 2, IOP ≤18 mmHg). Treatment success in Group 1 was defined as a reduction in IOP and the use of IOP-lowering medications; Group 2 success was defined as maintenance of a lower IOP and a reduction in medication use.

In 206 eyes of 130 patients, preoperative mean IOP was 21.1±8.8 mmHg, with an average 2.0±0.9 hypotensive medications. Postoperative mean medicated IOP ranged from 13.7±7.3 to 16.1 ± 5.1 mmHg, with an average postoperative IOP of 15.3±3.0 mmHg. The average medication burden at last follow-up was reduced to a mean 0.9 and 0.7 in Groups 1 and 2, respectively (59% to 61% reduction). The primary success endpoint was met by 73% of patients, with a mean IOP reduction in Group 1 (131 eyes; 21.8 to 15.6 mmHg, p < 0.0001), and a maintenance of IOP control in Group 2 (76 eyes; 15.4 to 13.9 mmHg, p = 0.24). Medications decreased from 2.2±0.9 to 0.9±1.1 in Group 1 (P = .024) and from 1.8±0.8 to 0.7±1.0 in Group 2 (P = 0.003).

The results show that canaloplasty performed using VISCO360 or OMNI is a safe, tissue-preserving and effective MIGS option that allows surgeons to perform multiple procedures (canaloplasty and CE) using a clear corneal incision or perform a standalone procedure in phakic or pseudophakic eyes. Both devices successfully and consistently performed canaloplasty and achieved statistically significant and clinically meaningful reductions in IOP and use of medications in adult patients with OAG. Ongoing data collection is expected to better describe the persistence of these real-world outcomes, and further studies are warranted to confirm the persistence of benefit of this intervention in patients with OAG.