Guidance
5 Safety
5 Safety
This section describes safety outcomes from the published literature that the committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.
5.1 Intraocular pressure (IOP) of more than 30 mmHg after the procedure was reported in 2% to 9% of eyes in a review of 914 eyes treated by canaloplasty alone (n=777 eyes) or by canaloplasty with phacoemulsification (n=137 eyes) at a maximum of 36 months' follow‑up.
5.2 Hyphaema (greater than 1 mm layered blood) was statistically significantly more frequent in the canaloplasty group than in the trabeculectomy group at 1‑year follow‑up, in a systematic review and meta-analysis of 1,498 eyes (odds ratio [OR] 9.24, 95% confidence interval [CI] 3.09 to 27.60). The incidence of hyphaema in the canaloplasty group was 25% (304/1221). Hyphaema was reported in 23% (7/30) of patients treated by canaloplasty and in 1 patient treated by trabeculectomy within 90 days of the procedure in a randomised controlled trial (RCT) of 62 patients.
5.3 Descemet's membrane detachment was only seen in the canaloplasty group, with an incidence of 3% (37/1185) at 1‑year follow‑up in the systematic review and meta-analysis of 1,498 eyes. Descemet's membrane detachment was reported in 2% to 6% of eyes in the review of 914 eyes at a maximum of 36 months' follow‑up. Microperforation of Descemet's membrane during the procedure was reported in 7% (2/30) of patients treated by canaloplasty in the RCT of 62 patients comparing canaloplasty (n=30) with trabeculectomy (n=32). Trabeculo Descemet's membrane rupture was reported in 1 patient in each group during the procedure in an RCT of 59 patients treated by phaco-canaloplasty (n=29) or phaco-non-penetrating deep sclerectomy (n=30).
5.4 Hypotony was statistically significantly less frequent after canaloplasty than after trabeculectomy at 1‑year follow‑up, in the systematic review and meta-analysis of 1,498 eyes (OR 0.32, 95% CI 0.13 to 0.80). The incidence of hypotony in the canaloplasty group was 9% (94/1091). Flat anterior chamber was reported in 0% to 2% of eyes in the review of 914 eyes, and persistent hypotony was reported in 0% to 1% of eyes.
5.5 Central retinal artery occlusion was reported in 1 out of 36 patients in the phaco-canaloplasty group and in none of the patients in the trabeculectomy group in a retrospective comparative study of 77 patients.
5.6 Ocular decompression retinopathy was reported in a single case report 1 day after canaloplasty. It was treated with tobramycin and dexamethasone. Three months after canaloplasty, IOP remained in control at 16 mmHg and all retinal haemorrhages had completely resolved.
5.7 Choroidal effusion or detachment was statistically significantly less frequent in the canaloplasty group than in the trabeculectomy group, in the systematic review and meta-analysis of 1,498 eyes within 1 year of the procedure (OR 0.25, 95% CI 0.06 to 0.97). Choroidal detachment was reported in 7% (2/29) of patients who had phaco-canaloplasty and in none of the patients who had phaco-non-penetrating deep sclerectomy, in the RCT of 59 patients.
5.8 Cataract formation was reported in 0% to 8% of eyes in the review of 914 eyes at a maximum of 36 months' follow‑up.
5.9 Anterior synechiae during the procedure was reported in 1 patient treated by canaloplasty in the RCT of 62 patients. It was treated by surgical peripheral iridotomy.
5.10 Conjunctival leak incidence was not statistically significantly different between the canaloplasty group and the trabeculectomy group within 1‑year follow‑up, in the systematic review and meta-analysis of 1,498 eyes (OR 0.72, 95% CI 0.16 to 3.14). Conjunctival leak was reported in 10% (3/30) of patients treated by canaloplasty and in 9% (3/32) of patients treated by trabeculectomy within 90 days of the procedure in the RCT of 62 patients.
5.11 Corneal erosion was reported in 1 patient treated by canaloplasty and in 44% (14/32) of patients treated by trabeculectomy within 90 days of the procedure in the RCT of 62 patients.
5.12 Detectable conjunctival bleb was reported in 2% (17/899) of patients after canaloplasty, in the systematic review and meta-analysis of 1,498 eyes.
5.13 Cells in the anterior chamber after the procedure were reported in 2 patients who had phaco-canaloplasty and in 1 patient who had phaco-non-penetrating deep sclerectomy, in the RCT of 59 patients.
5.14 Iris incarceration was reported in 1 patient in each group in the RCT of 59 patients who had phaco-canaloplasty or phaco-non-penetrating deep sclerectomy.
5.15 Suture cheese wiring was reported in 0% to 2% of eyes in the review of 914 eyes.
5.16 In addition to safety outcomes reported in the literature, specialist advisers are asked about anecdotal adverse events (events which they have heard about) and about theoretical adverse events (events which they think might possibly occur, even if they have never done so). For this procedure, specialist advisers did not list any anecdotal adverse events or theoretical adverse events.