Although intraocular pressure is only one of the risk factors (albeit a major one) of glaucoma, lowering it via pharmaceuticals or surgery is currently the mainstay of glaucoma treatment.
ARGON LASER TRABECULOPLASTY
A trabeculoplasty is a modification of the trabecular meshwork. Laser trabeculoplasty (LTP) is the application of a laser beam to burn areas of the trabecular meshwork, located near the base of the iris, to increase fluid outflow. LTP is used in the treatment of various open-angle glaucomas. The two types of laser trabeculoplasty are argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT). As its name suggests, argon laser trabeculoplasty uses an argon laser to create tiny burns on the trabecular meshwork. Selective laser trabeculoplasty is newer technology that uses a Nd:YAG laser to target specific cells within the trabecular meshwork and create less thermal damage than ALT.
LASER PERIPHERAL IRIDOTOMY
A Laser peripheral iridotomy (PI) is performed almost exclusively for patients with narrow angles, narrow angle glaucoma, or acute angle closure glaucoma. Aqueous fluid is made in the ciliary body of the eye, which is anatomically situated behind the iris. The aqueous fluid primarily escapes the eye by flowing between the lens and iris of the eye, and then drains via the trabecular meshwork, which is located in the angle of the eye (where the front clear cornea meets the iris, essentially). If the flow of aqueous fluid to the drainage angle (trabecular meshwork) is obstructed by a forwardly bowed iris, the patient is said to have narrow angles. This condition may predispose one to an acute episode of angle closure glaucoma. If the angles are never acutely closed, but glaucoma is still present, the patient is diagnosed with narrow angle glaucoma.
Laser peripheral iridotomy involves creating a tiny opening in the peripheral iris, allowing aqueous fluid to flow from behind the iris directly to the anterior chamber of the eye. This typically results in resolution of the forwardly bowed iris and thereby an opening up of the angle of the eye. The narrow or closed angle thus becomes an open angle!
The laser peripheral iridotomy procedure is usually completed in the office or as a brief outpatient procedure. Prior to the procedure, the pupil is often constricted with an eye drop medication known as pilocarpine. The procedure itself is completed with the patient seated at the laser, and requires no sedation. Usually, a lens is placed on the eye after topical anesthetic drops are applied to better control the laser beam. The entire procedure only takes a few minutes. The lens is then removed from the eye, and vision will quickly return to normal. After the procedure, your eye surgeon may recommend anti-inflammatory eye drop medications for the next few days. A post-op visit will be scheduled.