This section describes efficacy 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.
4.1 In a systematic review and meta-analysis of 1,498 eyes, comparing canaloplasty with trabeculectomy, there was no statistically significant difference between groups for complete success rates (maximum postoperative intraocular pressure [IOP] of 18 mmHg without medication) and qualified success rates (maximum IOP of 18 mmHg with or without medication) after the procedure. In a case series of 224 patients who had canaloplasty, the complete success rates at 1-, 2- and 3‑year follow‑up were 44% (64/144), 38% (30/80) and 31% (9/29) respectively, and the qualified success rates were 75% (108/44), 74% (59/80) and 59% (17/29) respectively.
4.2 In the systematic review and meta-analysis of 1,498 eyes, the mean IOP reduction was 9.94 mmHg (95% confidence interval [CI] 8.42 to 11.45) and was statistically significantly lower in the canaloplasty group (mean difference between groups −3.61, 95% CI −5.53 to −1.69 mmHg) at 1‑year follow‑up. In a review of 914 eyes treated by canaloplasty alone (n=777 eyes) or with phacoemulsification (n=137 eyes), the mean IOP reduction (after a maximum of 36 months' follow‑up) ranged from 29% to 66% with canaloplasty alone and from 42% to 46% with canaloplasty plus phacoemulsification. In the case series of 224 patients, there was a statistically significant decrease in mean IOP (±standard deviation [SD]) from 29.4±7.9 mmHg before surgery to 16.8±4.2 mmHg at 1 year, 17.1±4.7 mmHg at 2 years and 16.9±3.1 mmHg at 42 months (p<0.0001).
4.3 In the systematic review and meta-analysis of 1,498 eyes, the mean reduction in antiglaucoma medication use was 2.11 (95% CI 1.80 to 2.42) 1 year after canaloplasty, and there was no statistically significant difference in medication reduction between groups (mean difference −0.37, 95% CI −0.83 to 0.08). In the review of 914 eyes, mean medication use reduction (after a maximum of 36 months' follow‑up) ranged from 25% to 100% with canaloplasty alone and from 66% to 86% with canaloplasty plus phacoemulsification. In a randomised controlled trial of 59 patients comparing phaco-canaloplasty (n=29) with phaco-non-penetrating deep sclerectomy (n=30), there was a statistically significant decrease in the mean (±SD) number of medications used in both groups, from 2.64±0.68 before surgery to 0.27±0.67 at 1 year in the phaco-canaloplasty group and from 2.89±0.94 to 0.55±0.94 in the phaco-non-penetrating deep sclerectomy group (p<0.05 for the difference within groups, no statistically significant difference between groups).
4.4 In a retrospective comparative study of 327 patients who had canaloplasty (n=175) or trabeculectomy (n=152), which collected self-reported questionnaire data 2 years after surgery, the mean score (±SD) for satisfaction with results of surgery (ranging from 0, totally discontented, to 10, totally contented) was statistically significantly higher in the canaloplasty group (8.09±2.71) compared with the trabeculectomy group (7.46±2.61, p=0.034). In the same study, there were statistically significantly fewer revision surgeries reported in the canaloplasty group (mean number of revision surgeries per patient 0.12±0.43) compared with the trabeculectomy group (0.67±1.14, p<0.001). Also, patients were statistically significantly more likely to have a positive mood after canaloplasty (2.30±0.83) compared with trabeculectomy (1.96±0.87, p=0.009), stress caused by surgery or follow‑ups and treatments was statistically significantly lower with canaloplasty (4.18±0.86 and 4.36±0.80 respectively) compared with trabeculectomy (3.59±1.12 and 3.40±1.20 respectively; p<0.001), and nonvisual and visual ocular symptoms were statistically significantly lower in the canaloplasty group (p<0.05).
4.5 The specialist advisers listed the following key efficacy outcomes: intraocular pressure reduction and reduced use of glaucoma medication.