Preserflo Microshunt - 1000 Eyes: 6-Year Interim Results After Implantation In Patients With Open-Angle Glaucoma - A Retrospective Monocentric Observation

The PreserFlo Microshunt (Santen) is a glaucoma implant for subconjunctival drainage from an external approach. The surgical procedure is a microinvasive bleb surgeries (MIBS) for the treatment of patients with open-angle glaucoma. The implantation of the device can be performed as a stand-alone procedure or in combination with cataract surgery.
To evaluate the postoperative 6-year safety data, we analyzed our patient collective according to the “New guide on surgical innovation for glaucoma” of the European Glaucoma Society (EGS).

The surgical procedure (“MicroInvasive Bleb Surgery” (MIBS)) was performed exclusively by two surgeons from Breyer Kaymak Klabe Augenchirurgie Düsseldorf, Germany. All evaluated follow-up observations were also performed in our practice.

The Preserflo Microshunt has been implanted in 970 eyes of 651 patients as a stand-alone procedure or in combination with cataract surgery. Intraocular pressure (IOP), the number of pressure-lowering medications, visual acuity, visual field defects and endothelial cell density were monitored regularly. In addition, all complications occurring during and after the surgery as well as postoperative interventions were recorded.

Main complications: Up to one week after the procedure, microhyphaemata (<0.5 mm) occurred in 11% and visible hyphaemata (>0.5 mm) in 2% of the observed eyes. In only 4% of our patients a clinically significant hypotonic IOP of <6 mmHg was measured up to max. 3 months after surgery. More than 50% of them developed a visible cataract after 1 to 2 years.

Postoperative interventions: Due to the use of a lower local dose of 0.02% MMC during surgery in our first patients, we observed a relatively high bleb revision rate of 31% in the first year, and postoperative re-treatment rate with MMC of 46%. The use of 0.04% MMC during surgery reduced these rates to 6% and 15%, respectively.

The PreserFlo MicroShunt is an effective and safe minimally invasive surgical method for lowering intraocular pressure. The number of complications is significantly lower compared to trabeculectomy.