Selective Laser Trabeculoplasty
SLT laser is a non-incisional glaucoma procedure that helps achieve a lower eye pressure for many patients. It can be used if glaucoma eye drops are not lowering a patient’s pressure enough, or it can be used to help a patient discontinue one or more eye drops if the patient is having intolerable side effects from drops. In some patients, SLT can be used as a primary treatment before a patient is ever placed on eye drops. The procedure is performed in our surgery center, but it requires no sedation or anesthesia other than topical numbing drops. It is low risk, and for many patients it feels no different than having their eyes examined. A small contact lens is placed on the eye and pulses of laser are targeted at a portion of the eye’s drainage system called the trabecular meshwork. The laser makes microscopic changes to this tissue and ultimately results in less resistance to outflow by fluid inside the eye.
Trabeculectomy (also known as “trab” or “filter”) is a common glaucoma procedure that surgically creates a new drainage pathway for fluid to escape out of the eye. The patient’s eye is numbed with topical or local anesthetic, and mild to moderate IV sedation is typically used to insure the patient is comfortable. A portion of tissue is surgically removed and a pathway is created for aqueous fluid to drain from inside the eye to a space underneath the conjunctiva where it is absorbed.
EX-PRESS® Glaucoma Filtration Device
The EX-PRESS® shunt is a modification of the trabeculectomy procedure described above. Rather than removing tissue, a very small surgical-grade stainless steel shunt is inserted into the eye to allow fluid to flow out of the eye in a similar pathway to that of the trabeculectomy procedure.
Laser Suture Lysis
Laser suture lysis is a relatively simple procedure that is often performed in the early postoperative period after a trabeculectomy or an EX-PRESS ® surgery. During those surgeries, small stitches were placed underneath the conjunctiva to restrict the flow of fluid out of the eye. If a patient’s pressure is still felt to be too high after the surgery, a laser can be used to release these stitches without necessitating a trip back to the operating room.
The concept of a glaucoma shunt is overall similar to that of a trabeculectomy. Like a trabeculectomy, a new pathway is made for fluid to drain from inside the eye into a space underneath the conjunctiva; however, with a shunt, a piece of hardware called a glaucoma drainage device is inserted into the eye and underneath the conjunctiva to help facilitate this flow. Often, a portion of the device is then covered with donor cornea tissue which helps to decrease the possibility of the shunt eroding through the conjunctiva .
Laser iridotomy (or laser peripheral iridotomy or “LPI”) is a laser procedure which uses a laser to create a hole in the peripheral iris (the colored portion of the eye) in an effort to treat or prevent the complications of a smaller subset of glaucoma known as narrow angle glaucoma or “anatomically narrow angles”.
Laser iridoplasty is a less common procedure that can be a useful treatment for certain forms of narrow angles that do not respond well to laser iridotomy. A laser is used to change the configuration of the peripheral portion of the iris such that it is less likely to block the flow of fluid into the drainage tissue of the eye.
The iStent Trabecular Micro-Bypass Stent® is the smallest implantable medical device to date, measuring only 1 mm in its greatest dimension. In some patients with mild to moderate open angle glaucoma who are also undergoing cataract surgery, this titanium device can be inserted into Schlemm’s canal, thus bypassing the trabecular meshwork portion of the eye’s drainage system which is generally the point of greatest resistance as fluid drains out of the eye. With the trabecular meshwork bypassed, a lower eye pressure is often achieved.