Canaloplasty 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. Canaloplasty is also suitable for the following:
Make your incision large, i.e., 5×5 mm for a good exposure until you gain familiarity with the procedure.
Use high magnification on your microscope during cut-down of the deep flap in order to recognize the surgical anatomical landmarks, such as the scleral spur.
Good exposure of the Schlemm’s canal ostia is crucial. Schwalbe’s Line Detachment: Once Schlemm’s canal is exposed use only a blunt instrument (spatula) or Weck-cell sponge to detach Schwalbe’s Line (SL). Sudden egress of aqueous humor may be observed during the proper detachment.
After lowering IOP via paracentesis, dissect the sides with gentle upward strokes while holding the bottom of the deep flap with your forceps on the same side as where you are applying the upward strokes.
Check the flow through the Trabeculo-Descemetic Window and follow the 3-second rule – add balanced salt solution (BSS) to the anterior chamber to bring the IOP to the high teens; dry the scleral bed. Within three seconds the whole bed should be filled with aqueous humor.
Perforations may occur, but can easily be addressed while continuing with Canaloplasty. There is no need to convert to Trabeculectomy. Opening of Schlemm’s Canal Ostia: Use a Grieshaber or 30 gauge introducer cannula by placing it on top of the trabecular meshwork, parallel with the scleral spur, coaxial to Schlemm’s Canal ostium.
Activate the lubricious coating by dipping the working length of the microcatheter into BSS. Prime the catheter with Healon and insert into an ostium while Healon is still oozing from the tip of catheter. This will be enough for gentle, atraumatic catheterization. Full Circumferential Catheterization: Generally speaking, the iTrack™ microcatheter passes through 360 degrees very readily; however, it may become stuck at times, most commonly in the ostium of a super collector channel. The easiest way to address an obstruction is to remove the iTrack™ and re-enter counter-clockwise.
Use a slipknot to control and adjust the tension. Tighten until you see dimpling or folds in the trabecular meshwork. Ensure watertight closure to restore natural physiological outflow without creating a filtering bleb.
Refill the Anterior Chamber with BSS and bring IOP to at least 20mmHg; by doing so there will be less hyphema at day 1 as the flow of aqueous will be forced out through the newly opened Collector Channels.
Take the patient off anti-glaucoma medication and follow standard post-cataract regimen with antibiotics and anti-inflammatory therapy.