Articles

An ab externo minimally invasive aqueous shunt comprised of a novel biomaterial

Author(s):

Leonard Pinchuk

Isabelle Riss

Abstract:

The PRESERFLOTM MicroShunt, formerly called the InnFocus MicroShunt® (MicroShunt) is a minimally invasive, ab externo glaucoma drainage device used to shunt aqueous humor from the anterior chamber of the eye to a filtration bleb formed under the conjunctiva and Tenon’s capsule. The invention of a new biomaterial called poly(styrene-block-isobutylene-block-styrene), or SIBS, was the enabling factor that led to the success of this product. SIBS is ultrastable with virtually no foreign-body reaction in the body, which results in minimal inflammation and fibrous capsule formation in the eye. The 70 μm lumen is designed to obtain low intraocular pressures without chronic hypotony.
This article summarizes the latest implant techniques and five sets of clinical studies, performed outside of the United States, which concluded that:
1. Mitomycin C (MMC) was required;
2. MMC should be widely applied under the conjunctiva/Tenon’s flap;
3. MMC concentration of 0.4 mg/ml was more effective than 0.2 mg/ml (P = 0.027);
4. when 0.4 mg/ml MMC was used, the MicroShunt was effective in lowering the average intraocular pressure (IOP) from baseline by 40-55% for at least five years, with a mean IOP below 13 mmHg;
5. mean numbers of glaucoma medications were significantly reduced from baseline and sustained for at least five years; and
6. adverse events were generally transient with no long-term, sight-threatening adverse events.

New Concepts in Glaucoma Surgery Series: Volume 1, pp. 181-192 #13
Edited by: John R. Samples and Iqbal Ike K. Ahmed
© Kugler Publications, Amsterdam, The Netherlands

Buy this article