Short- And Long-Term Safety Profile Of Preserflotm Microshunt In Patients With Open-Angle Glaucoma: Up To 5 Years Interim Results Of A Retrospective Monocentric Observation

The PreserFlo Microshunt (Santen) is a glaucoma implant for subconjunctival drainage from an external approach. The surgical procedure is one of the new microinvasive bleb surgeries (MIBS) that developed the last decade for patients with open-angel-glaucoma (OAG).
To evaluate the postoperative 5-year safety data, we analyzed our patient population according to the "New guide on surgical innovation for glaucoma" of the European Glaucoma Society. 

Treatment and follow-up examinations were performed at Breyer Kaymak Klabe Augenchirurgie Düsseldorf, Germany.

The Preserflo Microshunt was implanted as a standalone procedure in 708 eyes of 473. We have currently analyzed the first 72 eyes with a follow-up of 5 years. During surgery, mitomycin C (MMC) -soaked sponges with MMC concentrations of 0.02% were applied under the sub-tenon layer for 2 minutes. We regularly monitored intraocular pressure (IOP), the number of postoperative medications, visual acuity, visual field defects as well as complications and postoperative interventions.

Microhyphaema occurred in 21% and visible hyphaema in 8% of the observed eyes up to one week after the surgery. Only 3% of our patients had clinical hypotony with an IOP <6 mmHg up to 3 months. Choroidal detachment was observed in 12% of eyes 1 week and in 2% up to 3 months after surgery. 3% of the eyes still had a flat anterior chamber after 1 week. More than 60% of phakic eyes developed a visible cataract after 1 to 2 years.

Due to the use of a low local dose of 0.02% MMC during surgery in our first patients, we observed a high frequency of bleb revision of 34% and 54% required a postoperative treatment with MMC. The use of 0.04% MMC during surgery reduces these rates by a factor of around 3.5 and 2 respectively.

The PreserFlo MicroShunt shows a very effective reduction of intraocular pressure. The number of complications is significantly lower compared to trabeculectomy. After 2 years no more complications were observed.