|Articles|August 1, 2016

ABiC targets all sites of outflow resistance

Ab-interno canaloplasty (ABiC) is a minimally invasive glaucoma surgery that accesses, catheterizes, and viscodilates all sites controlling aqueous outflow. When performed alone for uncontrolled glaucoma or with cataract surgery, it can result in reduced IOP and daily medication at follow-up through 12 months.

Reviewed by Mark Gallardo, MD

El Paso, TX-Growing experience with ab-interno canaloplasty (ABiC) shows the minimally invasive glaucoma surgery (MIGS) is very safe and provides significant and sustained reduction of IOP and medication use, according to Mark Gallardo, MD.

Performed through a 1.8-mm, temporal clear-corneal incision and using an illuminated microcatheter (iTrack 250A, Ellex) that provides continual transscleral visualization, ABiC lowers IOP by restoring the natural pathway of aqueous outflow.

More: ABiC: A novel approach to ab-externo canaloplasty

Based on its outcomes and benefits, Dr. Gallardo said he now considers ABiC as a first-line option for patients with mild-to-moderate glaucoma whose IOP is uncontrolled on maximum tolerated medical therapy.

Because of its potential to reduce or eliminate medication burden, he also sees ABiC as a useful adjunct when performing cataract surgery in patients with mild-to-moderate glaucoma controlled on medications.

Related: Aqueous drainage tube provides trabeculectomy-like efficacy

Dr. Gallardo is in private practice, El Paso Eye Surgeons, El Paso, TX, and an adjunct clinical faculty member in the department of ophthalmology at University of Texas Health Science Center, San Antonio, and Texas Tech Health Sciences Center, Lubbock.

With passage of the microcatheter through the ostomy in the trabecular meshwork, ABiC uniquely accesses, catheterizes, and viscodilates all sites controlling aqueous outflow. It has been associated with an average IOP reduction of about 35%, and with follow-up available to 18 months in some patients, its benefit is largely maintained, he noted.

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“What I love most about ABiC, however, is that it is truly an atraumatic procedure,” Dr. Gallardo said.

“With the exception of the small otomy created in the trabecular meshwork, there is no disruption of tissue throughout the aqueous drainage system,” he said. “Therefore, ABiC has an excellent safety profile-no sight-threatening complications have been associated with its use, and other surgical options remain available if ABiC is not successful or fails over time.”

The idea for ABiC stems from evidence that good IOP lowering was still achieved in eyes that underwent traditional canaloplasty without placement of the tensioning suture.

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To date, I have a number of patients who had traditional canaloplasty in one eye and then ABiC in the other whose IOP and need for medication is similar in their fellow eyes,” Dr. Gallardo said.

ABiC can achieve the same outcome as traditional canaloplasty, but it is a much simpler and faster surgery because it eliminates the major incisional steps of the ab externo approach and placement of a tensioning suture, he noted.

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