Factors influencing the outcomes of trabeculectomy, conventional canaloplasty, and mitomycin C augmented canaloplasty

Purpose: To compare the efficacy, safety, and factors influencing the outcomes of trabeculectomy (TE), conventional canaloplasty (cCP), and mitomycin C augmented canaloplasty (mCP) in glaucoma patients.

Methods: Intraocular pressure (IOP), the number of IOP-lowering eye drops, and surgery-related complications were evaluated at baseline and through 18 months postoperatively. Correlations between patients' demographic data, ophthalmic and non-ophthalmic conditions, outcomes and complications were evaluated.

Results: 171 patients were included. IOP and IOP-lowering eye drops were significantly (p < 0.001) reduced 18 months after TE, cCP, and mCP. At the 18-month follow-up, IOP and IOP-lowering eye drops were significantly lower following TE than cCP (p < 0.001, p = 0.010, respectively) and mCP (p = 0.010, p = 0.014). At the 18-month follow-up, complete success rates were significantly higher after TE compared to cCP and mCP for IOP ≤ 21, 18, and 16 mmHg (p < 0.001). Qualified success rates for IOP ≤ 16 mmHg were higher following TE than cCP and mCP (p = 0.023). In the TE group, clinical hypotony at any postoperative follow-up was positively correlated with previous intravitreal anti-vascular endothelial growth factor (VEGF)-therapy (p < 0.001), leukaemia (p = 0.002), and a spherical equivalent < -3 dioptres (p < 0.001). There were no significant correlations in the cCP and mCP groups.

Conclusion: TE, cCP, and mCP led to a significant reduction in IOP and IOP-lowering eye drops during 18 months of follow-up. At 18 months of follow-up, IOP and IOP-lowering eye drops were significantly lower following TE compared to cCP and mCP. Anti-VEGF-therapy, cystostatic therapy in leukaemia, and a spherical equivalent < -3 dioptres were significantly correlated with postoperative hypotony, macular folds, and choroidal detachment in the TE group.

Key messages: What is known • Trabeculectomy (TE) is considered the gold standard in the surgical management of glaucoma. However, TE involves extensive postoperative management and might be associated with severe surgery-related complications. What is new • In this study, intraocular pressure (IOP) and IOP-lowering eye drops were significantly lower following TE compared to conventional canaloplasty (cCP) and mitomycin C augmented canaloplasty (mCP) at a follow-up of 18 months. • In patients undergoing TE, anti-VEGF-therapy, cystostatic therapy in leukaemia, and a spherical equivalent < -3 dioptres were significantly correlated with postoperative hypotony, macular folds, and choroidal detachment.