Argon Laser Trabeculoplasty (ALT) -- for open-angle glaucoma. This laser treats the trabecular meshwork of the eye, increasing the drainage outflow, thereby lowering the intraocular pressure. After treatment in many cases, medication will still be needed. Usually, half the trabecular meshwork is treated first. If necessary, the other half can be treated as a separate procedure. This method decreases the risk of increased pressure following surgery. Argon laser trabeculoplasty (ALT) has successfully lowered IOP (intraocular eye pressure) in up to 75 percent of patients treated. This type of laser can be performed only two to three times in each eye over a lifetime.
Selective Laser Trabeculoplasty (SLT) -- for open-angle glaucoma. SLT is a newer laser that uses very low levels of energy. It is termed "selective" since it leaves portions of the trabecular meshwork intact. For this reason, it is believed that the SLT, unlike other types of laser surgery, may be safely repeated. Some physicians have reported that a second repeat SLT treatment or SLT after prior ALT is effective at lowering IOP (intraocular eye pressure).
Laser Peripheral Iridotomy (LPI) -- for angle-closure glaucoma. This procedure is used to make an opening through the iris, allowing aqueous fluid to flow from behind the iris directly into the anterior chamber of the eye. This allows the fluid to bypass its normal route. LPI is the preferred method for managing a wide variety of angle-closure glaucoma conditions that have some degree of pupillary blockage. This laser is most often used to treat an anatomically narrow angle and prevent angle-closure glaucoma attacks.
Microtrabeculectomies (Miniaturized versions of trabeculectomy)
Using tiny, microscopic-sized tubes that can be inserted into the eye and drain fluid from inside the eye to underneath the outer membrane of the eye (the conjunctiva) like XEN Gel Stent.
Trabecular Surgery (Trabecular bypass operations)
Most of the restriction to fluid drainage from the eye rests in the trabecular meshwork. Several operations have been devised using tiny equipment and devices to cut through the trabecular meshwork without damaging any other tissues in the ocular drainage pathway. Using a special contact lens on the eye, a tiny device is inserted into the eye through a tiny incision into the trabecular meshwork under high power microscopic control. The trabecular meshwork can either be destroyed or bypassed using a tiny snorkel-like device (the iStent).
Suprachoroidal Shunts (Totally internal or suprachoroidal shunts)
Using tiny tubes with very small internal openings, the front of the eye is connected to the suprachoroidal space between the retina and the wall of the eye (Cypass or Glaukos shunts) to augment the drainage of fluid from the eye. This operation has relatively few serious complications and lowers pressures enough to be useful even in moderately severe glaucoma.
New Laser Procedures (Milder, gentler versions of laser photocoagulation)
Previously, laser cyclophotocoagulation was reserved for advanced glaucoma that could not be controlled despite trabeculectomy or tube shunts. The procedures were designed to reduce the fluid-forming capacity of the eye by targeting the delicate tissue (ciliary body) that makes the fluid. They sometimes produced severe inflammation that could reduce vision. Two recent additions to the laser treatment procedures have proven useful even before the glaucoma is far advanced. These are endocyclophotocoagulation and micropulse cyclophotocoagulation.