Assessing Microshunt Implantation In Patients With Glaucoma: A Two-Centre Experience

The MicroShunt has previously shown promising results in lowering intraocular pressure (IOP) and medication use in patients with moderate-to-advanced glaucoma uncontrolled by or intolerant of topical therapy. We present our real-world results and safety analysis for the first consecutive cohort of glaucomatous eyes undergoing MicroShunt implantation at two London healthcare trusts. 12-month results are presented in this abstract.

Imperial College Healthcare NHS Trust and The Hillingdon Hospitals NHS Foundation Trust, London, United Kingdom.

Patients were identified using the audit function of Medisoft software, cross-checked with theatre records; baseline clinical characteristics and postoperative outcomes of patients with glaucoma who underwent MicroShunt implantation were evaluated. Primary outcomes included IOP reduction and reduction in glaucoma medication. Secondary outcomes included reinterventions and success rates, categorised into complete (IOP of 21 mmHg or less, with no reoperation, chronic hypotony, nor postoperative topical medication use), qualified (‘complete success’ criteria but with the use of topical medications), and strict (‘complete success’ but with a minimum 20% IOP reduction from baseline) successes. Data are presented as mean ± standard deviation.

131 eyes of 115 patients were included, with an average age of 65.8 ± 14.9 years. Mean IOP reduced by 36.3% from 23.7 ± 8.4 mmHg preoperatively to 15.1 ± 4.9 mmHg at 12 months follow-up. The mean number of glaucoma medications decreased from 3.4 ± 1.2 to 0.7 ± 1.0 at 12 months. The proportion of patients that were medication-free increased from 0.8% to 57.7% at 12 months. At 12 months, complete success was 53.8%, qualified success was 76.9%, and strict success was 46.2%. Surgical reinterventions included bleb revision (n = 13), anterior chamber washout (n = 1), and secondary glaucoma surgery (n = 7).

This retrospective analysis highlights the effectiveness of the MicroShunt in reducing IOP and medications, in a clinically heterogeneous patient population with various glaucoma diagnoses. This supports the increasing promise of the MicroShunt to be utilised as an effective glaucoma surgery option. However, prospective studies with longer follow-up are required to investigate the uncertain long-term efficacy of the MicroShunt.