Depending on the severity and type of glaucoma, laser treatment may be necessary or an alternative or supplement to medications.
SLT (Selective Laser Trabeculoplasty). Laser energy is applied to the drainage tissue of the eye, starting a chemical and biological change in the tissue that can lead to better fluid drainage out of the eye. It is called “Selective” because the laser selectively affects the pigmented tissue in the eye. It is generally well tolerated, takes about 1-3 months to work, and typically lowers IOP up to 30% when used as initial therapy. The effect depends on the patient, prior laser, and medication usage. The effect typically wears off after a few years and can often be repeated. Repeat treatments may not be as effective as initial treatments. If the treatment does not work or causes a pressure spike, additional medications or surgery may become necessary. Glaucoma medications may still be necessary even with a successful laser. Since SLT (Selective Laser Trabeculoplasty) is an FDA-approved treatment, it is typically covered by Medicare and medical insurance, with co-pays according to your policy.
Iridotomy. This is typically done preventatively in patients with anatomically narrow angles, or emergently in patients with acute angle closure glaucoma. In these situations, the aqueous fluid that the eye produces behind the iris has difficulty reaching the eye’s natural drainage tissue. A laser iridotomy creates a small opening in the iris to allow for passage of this fluid to its normal destination. This is done when the benefits (treatment or prevention of glaucoma) are felt to outweigh the rare, but possible risks (bleeding, glare, pain, worsening of condition).
Glaucoma MIGS (Minimally Invasive Glaucoma Surgery)
Conventional glaucoma surgeries (trabeculectomies or glaucoma drainage implants) have the strongest pressure-lowering effect of our glaucoma treatments. There are times when lesser glaucoma surgeries may be sufficient. MIGS surgeries have been developed to try to re-establish the eyes natural drainage pathways. There are new, innovative surgeries in this category that Dr. Sheets may recommend as an option to try to avoid more extensive surgery. If MIGS surgeries are not as effective as desired, medications or conventional glaucoma surgery are still possible and may be needed.
Conventional Glaucoma Surgery
Glaucoma surgery includes laser, MIGS and conventional surgery.
There are times when the eye’s natural drainage pathway is not able to be rejuvenated and a “bypass” type surgery must be performed, creating a new pathway for fluid drainage. The two main surgeries are trabeculectomies and glaucoma drainage implants.
This surgery uses the eye’s own tissues to create a passageway filter or “trap door” that releases the fluid from inside the eye to a “bleb” that then releases the fluid back into the body. This typically sits on top of the eye, under the eyelid.
Glaucoma Drainage Implant
These surgeries are designed to accomplish the same goal as the trabeculectomy but utilizes a drainage implant that takes the fluid from inside the eye to an area more posterior. The most common types of drainage implants are Baerveldt, Ahmed, Molteno or XEN. Some devices also require a donor corneal patch graft placed over the implant to help provide cushion between the implant and the outer layer of the eye (conjunctiva).
Each device has its own risk/benefit profile, and Dr. Sheets will select the device that he thinks is best for you and explain the details.
Just like with lasers and medications, even with surgery there is no “cure” for glaucoma. More medications, lasers or surgeries may be needed later on.