Canaloplasty is a surgical procedure used in the treatment of glaucoma. In this non-penetrating surgery, a suture is spun along the inner drainage channel of the eye (Schlemm's canal) using a fiber optic microcatheter. The yarn is then knotted with a little tension to dilate the canal again, thus restoring the natural flow of the aqueous humor.
To open the Schlemm's canal, a viscoelastic polymer is injected and is absorbed within a few days. Then, the end of the microcatheter is inserted and navigated along the channel with a flashing light at the end. Once the line is complete, the suture is threaded and tied. This technique dilates and rectifies the Schlemm's canal and trabeculum pathways, and thus restores the evacuation of the aqueous humor and lowers the IOP.
The purpose of trabeculectomy is to create a passage from the anterior chamber of the eye to the outside of the eye to evacuate the aqueous humor. At the beginning of the procedure, an incision is made through the conjunctiva. Then, the surgeon creates a flap in the sclera (the wall of the eye). Below the scleral flap, a hole is drilled to the anterior chamber. However, the aqueous humor can evacuate from the anterior chamber and pass through the scleral flap, and go under the conjunctiva where it will be resorbed by blood vessels.
The iris is grasped through the tunnel and a small piece is excised with scissors (iridectomy) to ensure that the iris does not obstruct the tunnel. The scleral flap is then closed with stitches to prevent the IOP from descending to zero at the end of the operation (before scarring is formed). Finally the conjunctiva is closed with stitches, so that a liquid bubble can form there, acting as a filter. This filtering bubble is normally found on the upper part of the eye and is covered by the eyelid. The fluid that accumulates is slowly absorbed by the blood vessels of the sclera and conjunctiva.
GOLD MICRO SHUNT
The Gold Micro Shunt is a 24-carat gold micro plate that contains 20 channels. This plate is inserted to create a bridge between the anterior chamber of the eye and its supra-ciliary region. Once inserted and placed in position, the shunt creates a new passage to evacuate the aqueous humor by connecting these two spaces. The aqueous humor is evacuated through the channels and along the surface of the shunt, thus reducing the IOP.
It is the difference in pressure between the anterior chamber and the supra-ciliary space that allows a flow of aqueous humor through the micro-channels. The Gold Micro Shunt is the first implant that uses the natural pressure differential in the eye to reduce IOP.
In conjunction with the implementation of the Gold Micro Shunt, laser is also used. At the time of surgery, 10 of the 20 shunt channels are closed. These channels can be opened or closed with a laser. This gives the possibility to reduce or increase IOP according to the needs.
The iStent is one of the smallest implants available for glaucoma surgery, it mesures 1.0 mm by 0.5 mm. This device has the shape of a miniature snorkel. One end is inserted into the anterior chamber and the other end into the Schlemm's canal, allowing the aqueous humor to bypass the obstructed trabeculum lanes. The iStent is implanted through a corneal incision measuring 1.7 mm, and usually, no suture is required. It is held in place by three protrusions located on the part inserted in the Schlemm's canal.
The procedure using Express Shunt is a variant of trabeculectomy. Instead of perforating the sclera and cutting off part of the iris, the surgeon inserts a tiny tube-shaped implant (the shunt) under the flap of the sclera, towards the anterior chamber, that will serve as the escape route for the fluid. Thanks to the Shunt, we can control the evacuation of the aqueous humor towards the filtration bubble in a more efficient way.
The procedure of the trabectome surgery uses a heating instrument and a slight suction to remove a portion of the trabeculum. The trabectome is inserted through the cornea, the trabeculum and into the Schlemm's canal, and then guided along the trabecular meshwork. This procedure facilitates the evacuation of aqueous humor by increasing access to evacuation routes.
Deep sclerectomy is a variant of trabeculectomy. Instead of perforating the sclera to the anterior chamber, the surgeon leaves a thin layer of sclera. This allows the aqueous humor to escape through the sclera layer as through a coffee filter. Some surgeons insert a micro collagen implant into this scleral space to prevent tissue scarring. The advantage of this operation is that it avoids low pressure drops and intraocular bleeding which restores visual function quickly. The disadvantage, however, is that sometimes the IOP is not reduced enough.
THE ADVANTAGES OF SURGERY AT BELLEVUE CLINIC
The Bellevue Clinic provides state-of-the-art glaucoma surgery services to its patients. Our modern facilities, cutting-edge equipment and experienced staff ensure effective, professional and personalized care.
*We also operate patients NON-RESIDENTS of Canada.