Size Matters: Ab Interno Canaloplasty Revision with Suture Trabeculotomy

Area of Science:

• Ophthalmology
• Glaucoma Surgery
• Minimally Invasive Glaucoma Surgery (MIGS)

Background:

• Failed ab interno canaloplasty requires revision strategies for effective intraocular pressure (IOP) management in open-angle glaucoma (OAG).
• Micro-invasive suture trabeculotomy (MIST) is a potential revision technique, but its efficacy after prior canaloplasty is not well-established.

Purpose of the Study:

• To evaluate the 24-month efficacy of revising failed ab interno canaloplasty with micro-invasive suture trabeculotomy (MIST) in OAG patients.
• To assess the impact on intraocular pressure (IOP), medication use, and need for secondary interventions.

Main Methods:

• Retrospective analysis of 23 eyes with OAG undergoing MIST revision after failed canaloplasty.
• Primary outcome: proportion of eyes achieving IOP ≤ 18 mm Hg or ≥20% reduction without secondary intervention (SI) at 12 months.
• Secondary outcomes: IOP, number of glaucoma medications (NGM), best corrected visual acuity (BCVA), and SI evaluated over 24 months.

Main Results:

• Complete success was achieved in 36.4% of eyes at 12 months, maintained in 27.3% at 24 months.
• Mean IOP significantly reduced from 23.1 mm Hg at baseline to 14.3 mm Hg at 24 months (27.3% reduction).
• No significant decrease in NGM or BCVA was observed; however, 47.8% of eyes required SI during follow-up.

Conclusions:

• Ab interno trabeculotomy revision following failed canaloplasty demonstrated limited effectiveness in achieving sustained IOP control in OAG.
• The small suture gauge used in initial canaloplasty may have contributed to suboptimal outcomes.
• Further research is warranted to refine surgical techniques and improve outcomes for revision glaucoma surgery.