Performance And Safety Of The Minimally Invasive Micro Sclerostomy (Mims) Inferonasal Procedure In Patients With Medically Uncontrolled Or Refractory Open-Angle Glaucoma: 52-Week Open-Label Study

Minimally invasive micro sclerostomy (MIMS®) is an ab-interno, implant-free surgical intervention which aims to reduce intraocular pressure (IOP) in patients with moderate open-angle glaucoma (OAG) by creating a drainage-channel of ~100 μm at the sclera-corneal junction extending from the anterior chamber to the subconjunctival space. The device has received the CE Mark, with studies to date demonstrating IOP-lowering efficacy with minimal complications when applied through superonasal sclerostomy. This prospective, open-label study aimed to evaluate MIMS® using an inferonasal sclerostomy approach avoiding the superior scarred conjunctiva in patients with medically uncontrolled or refractory glaucoma.

The procedures were conducted at the Ophthalmologic Center after S.V. Malayan, Yerevan, Armenia, Apr 2022–Jan 2023 in patients with medically uncontrolled glaucoma (IOP >20 mmHg with maximally tolerated medications) or refractory glaucoma (IOP >20 mmHg on maximally tolerated medications or prior failed filtering surgery and who had one of the following: failed incisional glaucoma surgery, neovascular glaucoma, or any other condition in which conventional incisional surgery would likely fail).

Patients (pts) were assigned to 1 of 3 treatment arms (1:1:1). Those with medically uncontrolled OAG had 1 inferonasal sclerostomy performed by the MIMS® device in 1 study eye (Arm 1, n=35). Pts with refractory OAG were randomized to receive either 1 (Arm 2, n=21) or 2 (Arm 3, n=26) inferonasal sclerostomies performed in 1 study eye. Pts were evaluated post-operatively on Days 1, 7, 14, and Weeks 4, 12, and 24, with optional visits at Weeks 38 and 52. The primary endpoint was the proportion of patients achieving a ≥20% IOP reduction from baseline on the same or less number of medications at the 24-week visit. Secondary endpoints included mean change in IOP from baseline at Week 24 and Week 52, and incidence of adverse events.

Eighty-two eyes of 82 pts underwent the procedure. At baseline, 68/82 pts used IOP-lowering medication (mean no. of medications: 1.6). Mean ± SD baseline IOP was 25.7 ± 3.8 mmHg. At Week 24, 51/69 pts achieved a ≥20% reduction in IOP from baseline on the same or fewer number of medications: 25/33 in Arm 1, 12/15 in Arm 2 and 14/21 in Arm 3. At Week 24 (n=69) and Week 52 (n=71), mean ± SD IOP was 18.1 ± 4.6 mmHg and 19.6 ± 6.5 mmHg, corresponding to a 30% and 24% IOP reduction from baseline. On day 1 increased IOP occurred in 15/82 pts and resolved with viscoelastic removal. This occurred 10/71 pts during follow-up and resolved with medication.  1 case of early and 3 cases of late corneal edema resolved with the reduction in IOP.

In this patient population, inferonasal MIMS® reduced IOP over 52 weeks, with no intraoperative complications and minimal postoperative complications. The study suggests the inferonasal MIMS® procedure may be effective in patients with uncontrolled or refractory OAG, but longer-term data in this patient population are required to confirm the efficacy of this approach.