Novel Aqueous Humor Microshunt Implanted Alone or Combined With Phacoemulsification: 3-Year Follow-up

Saturday, April 18, 2015: 3:26 PM
Room 1B (San Diego Convention Center)
Juan F. Batlle Sr, MD
Rachel Alburquerque, MD
Adalgisa Corona, MD
Leonard Pinchuk, PhD, DSc
Yasushi P. Kato, PhD
Esdras A. Arrieta, MD
Paul F. Palmberg, MD, PhD
Richard K. Parrish II, MD
Bruce A. Weber, BS, MBA
Jean-Marie A. Parel, PhD, FARVO

A feasibility study to evaluate the safety and efficacy of a micro-lumen aqueous drainage device made of poly(styrene-block-isobutylene-block-styrene) (SIBS), the InnFocus MicroShunt, used intraoperatively with mitomycin C (MMC), alone or in combination with phacoemulsification and intraocular lens (IOL) implantation.

Prospective nonrandomized study of 23 eyes in 23 primary trabeculectomy-stage patients who failed maximum tolerated glaucoma medication.   Patients received a MicroShunt with intraoperative MMC (0.4 mg/mL, 3 minutes) either as an alone procedure or in combination with cataract surgery.  A MicroShunt is implanted ab externo through a 3 mm-long needle tract in the sclera, draining aqueous humor from the anterior chamber to under the conjunctiva and Tenon's capsule.  Main outcome measures include success rate (IOP ≤ 21 mmHg and ≥ 20% reduction in IOP from baseline), IOP, visual fields, visual acuity, medication use, and adverse events with 3 years follow-up.

The MicroShunt was implanted in 14 eyes alone and 9 eyes combined with cataract surgery.  At 3 years (n=22),  the qualified success rate (with or without glaucoma medication) was 95%; the complete success rate (with glaucoma medication) was 73%; the mean IOP was reduced from 23.8 ± 5.3 to 10.7 ± 3.5 mmHg (55%); mean glaucoma medications was reduced from 2.4 ± 0.9 to 0.5 ± 0.9, respectively. The most common complications were immediate postoperative transient hypotony (13%, 3/23) and transient choroidal effusion (8.7%, 2/23), all spontaneously resolved without sequelae.  There were no sight-threatening long-term adverse events.

The InnFocus MicroShunt trans-scleral aqueous drainage tube implanted with MMC is a safe standalone as well as combined procedure with cataract surgery.  Mean IOP reductions of >50% to approximately 10mmHg are achieved and sustained for 3 years. Results are comparable to trabeculectomy with MMC without the need for scleral dissection.