Outcomes of 360° suture trabeculotomy after unsuccessful canaloplasty

Background Canaloplasty is a well-established non-penetrating glaucoma surgery. Unsuccessful outcomes can be enhanced by micro-invasive 360 degrees suture trabeculotomy (360 degrees trabeculotomy), analyzed in this study. Methods This retrospective study included twenty eyes of 19 patients, mean age 59.7 +/- 17.2 years, with primary open-angle glaucoma (POWG n = 14), pseudoexfoliation glaucoma (PEX n = 3), juvenile glaucoma (n = 2) and aphakic glaucoma (n = 1), who underwent micro-invasive 360 degrees trabeculotomy after unsuccessful (intraocular pressure (IOP) >21 mmHg under maximum glaucoma eye drop therapy (Meds)) canaloplasty. IOPs, Meds, complications and failure rates (IOP >21 mmHg at two consecutive follow-ups) were evaluated. Complete success (no Meds) and qualified success (with Meds) rates for IOP levels <= 21 mmHg and <= 18 mmHg at the last follow-up were evaluated. Results IOPs and Meds were significantly reduced from before to 1 week (10.3 +/- 3.1 days) after 360 degrees trabeculotomy (IOP, 28.3 +/- 6.0 mmHg to 15.8 +/- 4.5 mmHg; p < 0.001; Meds, 3.1 +/- 1.2 to 1.0 +/- 1.2; p < 0.001). IOPs (p = 0.37) and Meds (p = 0.33) did not decrease further from 1 week until the last follow-up (18.3 +/- 8.2 months (IOP, 14.4 +/- 3.8 mmHg; Meds, 1.5 +/- 1.3)). Complete and qualified success was 25% (5/20) and 70% (14/20) for IOP <= 21 mmHg, as well as 25% (5/20) and 60% (12/20) for IOP <= 18 mmHg. Four eyes had postoperative hyphema, which resolved after a mean period of 4.0 +/- 2.2 days. Five failures occurred after a mean of 40.6 +/- 51.9 days after 360 degrees trabeculotomy. All failures underwent trabeculectomy. Eyes that needed early (<= 3 months post canaloplasty) 360 degrees trabeculotomy showed higher IOPs before (p < 0.001) and lower (p = 0.03) IOPs 2 months post 360 degrees trabeculotomy than eyes with late (>3 months) 360 degrees trabeculotomy surgery. Conclusions 360 degrees trabeculotomy is a safe, micro-invasive, simple and successful method to enhance failed canaloplasty.