Interventional procedure overview of ab interno canaloplasty for open-angle glaucoma

Need for further surgery

The before-and-after study of 89 eyes in 64 people reported that 6 people required filtering surgery for glaucoma after canaloplasty. These people had higher baseline IOP and medicine use than the cohort mean (Hughes, 2020).

The before-and-after study of 80 eyes in 73 people reported that 12 eyes required further surgery after canaloplasty. This included 9 trabeculectomies and 3 deep sclerectomies (Toneatto, 2022).

The before-and-after study of 71 eyes reported that 7 eyes required further filtering glaucoma surgery after canaloplasty (Gillman, 2021).

Loss of visual acuity

In the before-and-after study of 60 eyes in 53 people, visual acuity was improved at 24-month follow up in all eyes, with 19 people (42.2%) gaining 2 or more lines of Snellen corrected distance visual acuity. Statistically significant improvements in visual acuity were only observed in the people who had both canaloplasty and phacoemulsification (Gallardo, 2021).

In the before-and-after study of 80 eyes in 73 people, there was no statistically significant change in visual acuity observed in people who had canaloplasty alone (p=0.31). In people who had canaloplasty and phacoemulsification, there was a statistically significant change in visual acuity in from 6.8/10 (SD 2.1) before surgery to 9.1/10 (SD 2.6) at 12 months after surgery (p<0.001).

Raised IOP

The before-and-after study of 180 eyes in 130 people reported 2 cases of IOP spikes of 10 mmHg or more above baseline (Tracer, 2020).

The before-and-after study of 80 eyes in 73 people reported 1 case of an IOP spike of more than 10 mmHg above baseline (Toneatto, 2022).

The before-and-after study of 71 eyes reported 12 cases of IOP spikes over 30 mmHg (Gillman, 2021).

Hypotony

The before-and-after study of 80 eyes in 73 people reported 4 cases of mild hypotony (Toneatto, 2022).

Bleeding and hyphaema

Note, Hughes (2020), Toneatto (2022), and Gillman (2021) did not consider mild or microhyphema to be an adverse event of this procedure.

The before-and-after study of 60 eyes in 53 people reported an unspecified number of cases of microhyphema and an unspecified number of cases of intraoperative bleeding at the goniotomy site (Gallardo, 2021).

The before-and-after study of 180 eyes in 130 people reported 3 cases of hyphaema (Tracer, 2020).

The before-and-after study of 106 eyes in 71 people reported 14 cases of hyphaema (Ondrejka, 2019).

The before-and-after study of 80 eyes in 73 people reported 2 cases of moderate or severe hyphaema (Toneatto, 2022).

The before-and-after study of 71 eyes reported 1 case of a self-resolving corneal endothelial blood stain (Gillman, 2021).

Device malfunction

The before-and-after study of 106 eyes in 71 people reported 1 case of the VISCO360 device malfunctioning. The catheter detached from the handle and cannula and had to be retrieved with vitrectomy forceps. The person had no adverse sequalae (Ondrejka, 2019).

Fibrin complications

The before-and-after study of 106 eyes in 71 people reported 1 case of fibrin in pupillary plane (Ondrejka, 2019).

The before-and-after study of 71 eyes reported 1 case of a fibrin plug (Gillman, 2021).

Other complications

Single cases of the following complications were reported:

Anecdotal and theoretical adverse events

In addition to safety outcomes reported in the literature, professional experts are asked about anecdotal adverse events (events that they have heard about) and about theoretical adverse events (events that they think might possibly occur, even if they have never happened).

For this procedure, professional experts listed the following anecdotal adverse events: cyclodialysis, retinal detachment, Descement's detachment, formation of peripheral anterior synechiae, and transient refractive change. They considered that the following were theoretical adverse events: catheter entering a collector channel, subretinal space, or macular area.