Different treatments may be recommended for different types of glaucoma. These are laser treatments or surgery in the operating room. These alternative treatments become necessary when patients on eye drops fail to take their medications correctly or have problems with side effects.
ALT (Argon Laser Trabeculoplasy):
Used to treat open angle glaucoma. The laser treats the drain itself, modifying it in order to help control the IOP. With traditional ALT, tiny, evenly spaced burns are made in the trabecular meshwork (TM) with an argon laser. These burns facilitate the drainage of aqueous humor. However, scarring of the TM occurs as a result of the burns and may limit the success of the procedure and the ability to retreat the eye in the future, should it need to be repeated.
SLT (Selective Laser Trabeculoplasty):
Also used to treat open angle glaucoma. This is a cold laser that instead of generally burning tissue, selectively stimulates or changes only specific pigmented cells to activate increased fluid drainage. SLT produces an equivalent drop in pressure to ALT, but it is more gentle and does not have the associated damage to other tissues and adverse scarring effects. This means that SLT treatments may potentially be repeated.
PI (Posterior Iridotomy):
Used to treat narrow angle glaucoma. This laser creates a small hole in the iris to improve the flow of aqueous fluid to the drain. In some cases, after the laser, the angles may open back on their own. Nevertheless, the patient's response is determined by the type of narrow angle glaucoma and the basic make-up of the patient's eye.
When surgery in the operation room is needed to treat glaucoma, your ophthalmologist uses fine microsurgical instruments to create a new drainage channel for the aqueous fluid to leave the eye. Surgery is recommended if the doctor feels it is necessary to prevent further damage to the optic nerve. As with laser treatments, surgery in the operation room is typically an outpatient procedure.