Ab externo canaloplasty for primary open-angle glaucoma

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 out of 144), 38% (30 out of 80) and 31% (9 out of 29) respectively, and the qualified success rates were 75% (108 out of 144), 74% (59 out of 80) and 59% (17 out of 29) respectively.

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).

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).

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).

The specialist advisers listed the following key efficacy outcomes: intraocular pressure reduction and reduced use of glaucoma medication.