Minimally Invasive Micro Sclerostomy (MIMS) Procedure: A Novel Glaucoma Filtration Procedure

Précis: Intermediate-term results suggest that ab interno Minimally Invasive Micro Sclerostomy (MIMS) stent-less subconjunctival filtration procedure is a promising treatment option for patients with open-angle glaucoma (OAG). Purpose: MIMS is a novel ab interno, stent-less, subconjunctival filtration procedure. This study set to investigate the safety, performance, and efficacy of MIMS in OAG patients. Methods: Prospective, open-label, single arm clinical trial with intrasubject comparisons. Study participants were adults with OAG who were candidates for a filtration procedure. Patients were operated by a single surgeon (A.A.) in Chennai, India. Following mitomycin-C pretreatment, ab interno MIMS procedure was performed alone or combined with phacoemulsification surgery. Procedure-related complications and adverse events were assessed. Primary outcomes: patients (%) achieving an intraocular pressure (IOP) ≥5 mm Hg and ≤18 mm Hg, and an IOP reduction of >20% as compared with baseline, with or without hypotensive medications, with no need for recurrent surgery. Results: Twenty-one phacoemulsification-MIMS and 10 standalone MIMS procedures were performed. Mean age was 63.94±6.33 years. Mean duration of MIMS was 1:58±0:25 (min:s). Scleral tunnels were achieved in all cases. No device malfunctions, intraoperative complications, or serious adverse events were reported. Five (16.12%) patients presented with iris clogging 1 to 24 weeks following procedure. Two were treated with laser and 3 required trabeculectomy. Mean IOP change from baseline at 24 weeks was 47.4% (31.2 to 16.4 mm Hg, P<0.0001, n=23). The mean difference was -14.8 mm Hg (95% confidence interval: -17.6, -11.9) with no statistically significant differences between groups. Qualified success was achieved in 21 (84%), 17 (74%), and 13 (93%) after 12, 24, and 52 weeks, respectively. Complete success was achieved in 17 (68%), 13 (57%), and 8 (57%) after 12, 24, and 52 weeks, respectively. Conclusions: The interim results suggest that MIMS procedure may be a simple and effective surgical option for early OAG patients requiring target IOP in high teens although iris clogging of incision site is the major concern with this procedure.