Overview of the Ab Interno Canaloplasty Procedure

Overview of the Procedure
  • Following cataract surgery, inject Miostat into the anterior chamber, followed by a dispersive viscoelastic. Create a sideport incision for inserting the iTrack™ microcatheter approximately 1 1/2 clock hours away from the 3-o’clock (right eye) or 9-o’clock (left eye) position. Next, insert the primed iTrack™ microcatheter into the anterior chamber.
  • Entering at the temporal location, create a small horizontal incision approximately 1-mm wide in the trabecular meshwork.
  • Using MST retina forceps, feed the iTrack™ microcatheter into Schlemm’s canal and align it flush to the trabecular meshwork. As the tip of the iTrack™ is advanced 360° to the initial incision site, follow its progress by observing the position of the red light.
  • Slowly withdraw the iTrack™ microcatheter while steadily injecting viscoelastic. Once this step is complete, remove all dispersive viscoelastic from the anterior chamber.
  • Unlike with traditional Canaloplasty, a tensioning suture is not placed into Schlemm’s canal during viscodilation.

Clinical Tips: ABiC

Clinical Tips
  • Creating the Otomy: To create the otomy, use a 27-gauge needle on a 3 mL syringe. Start high in the anterior of the trabecular meshwork and pull downward to approximately the middle of the trabecular meshwork, inserting the tip of the needle in the trabecular meshwork with the bevel facing toward the ceiling. When creating the otomy heme reflux can occur, and it may be necessary to refill the anterior chamber with OVD for better visualization. A whitish scleral color should help to identify Schlemm’s canal. Note: it is important that the otomy be situated central to the anterior of the trabecular meshwork. If the otomoy is too posterior in the trabecular meshwork, it will be impossible to stent because of the close proximity to the sclera.
  • It is recommended to use Miostat for all patients who undergo combined ABiC and phacoemulsification to avoid the angle’s narrowing after dilation.

Patient Selection: ABiC

ABiC™ is indicated for the reduction of elevated IOP in patients with open-angle glaucoma, including those with ocular surface disease and individuals who cannot tolerate anti-glaucoma medications. ABiC™ is also suitable for the following:

Patient Selection
  • Pigmentary Glaucoma (PG)
  • Pseudoexfoliation Glaucoma (PXF)
  • Ocular Hypertension
  • Post-SLT eyes
  • Eyes that have received a single session of low-powered ALT
  • Patients with previous failed trabeculectomy or tube surgery
  • OAG with narrow but not occludable angles after laser iridectomy
  • (Note: Once a surgeon has gained the necessary experience, ABiC™ can also be performed on patients who have previously undergone trabeculectomy or tube surgery.)
ABiC™ is contraindicated for the following:
  • Neovascular Glaucoma
  • Multiple Argon Laser Trabeculoplasty (ALT): Patients who have undergone more than one ALT procedure
  • Chronic Uveitis
  • OAG with narrow angle (Note: unless canaloplasty and phacoemulsification are scheduled at the same time)
  • Narrow inlet with plateau iris