Mini-Invasive Microsclerostomy (Mims) For Glaucoma: Preliminary Data Of A Prospective Study

In the attempt of improving glaucoma surgical options, multiple micro-invasive glaucoma surgeries (MIGS) have been developed. These new technologies should be evaluated systematically and scientifically. We intend to highlight our preliminary data in a prospective study to evaluate the effectiveness and safety of the MIMS surgery.

Our study occurred in an Ophthalmology service of a private hospital with a high glaucoma volume, with different glaucoma surgical techniques available. The MIMS is a filtering glaucoma surgery, which involves creating a sclero-corneal drainage canal to lower intraocular pressure. It utilizes a micro-trephine of 240 microns to reproducibly create this drainage canal in the trabeculum, then activated with a pedal to create the canal. This surgery lasts 3 to 5 minutes. 

We performed a prospective interventional study, with national Ethics approval. Inclusion criteria were: 1) patients with  ≥ 18 years who signed informed consent; 2) primary open-angle glaucoma, pseudoexfoliative glaucoma, or pigmentary glaucoma with an indication for glaucoma surgery (defined as uncontrolled intraocular pressure (IOP) or worsening visual fields despite maximum tolerated medical therapy); chronic angle-closure glaucoma patients were included in a combined MIMS-cataract surgery; 3) healthy and mobile conjunctiva. We excluded severe systemic and other ocular pathologies. Our main outcome was complete surgical success (IOP decrease of ≥20% without medication, and without vision loss nor major complications).

Of the included patients, there was no clinical hypotony, no severe complications, nor surgical failure, 6 months after surgery. There were no severe intra-operative complications and the MIMS technique seemed fast and with a short learning curve. We obtained less iris incarceration than the previous reported study (perhaps due to a slightly more anteriorly placed micro-trephine). Endothelial cell count did not decrease significantly. The conjunctival bleb seemed flatter during time, but the IOP remained controlled. Many patients needed subconjunctival 5FU injection, and some patients needed eyedrops to maintain a qualified surgical success. 

Of the included patients, there was no clinical hypotony, no severe complications, nor surgical failure, 6 months after surgery. There were no severe intra-operative complications and the MIMS technique seemed fast and with a short learning curve. We obtained less iris incarceration than the previous reported study (perhaps due to a slightly more anteriorly placed micro-trephine). Endothelial cell count did not decrease significantly. The conjunctival bleb seemed flatter during time, but the IOP remained controlled. Many patients needed subconjunctival 5FU injection, and some patients needed eyedrops to maintain a qualified surgical success.