January is Glaucoma Awareness Month to provide education about prevention and treatment of glaucoma. About 4 million people in the United States have glaucoma, but it is estimated that half of those people are unaware that they have glaucoma.
Glaucoma is a condition of the eye in which the pressure inside the eye is too high, causing damage to the delicate optic nerve fibers at the back of the eye. Vision gradually begins to fail, with loss of peripheral vision at first and, if not discovered in time, blindness can result.
In 1996, a new laser procedure for open angle glaucoma was first described. Known as “selective laser trabeculoplasty” (SLT), this laser uses lower-energy laser to selectively treat pigmented cells within the drain of the eye.
Studies have shown that this selective laser procedure achieves its effect without causing structural damage to the trabecular meshwork of the eye, unlike argon laser, which creates several burns in the trabecular meshwork (argon laser was the laser most frequently used to treat open angle glaucoma prior to the development of the selective laser).
Selective laser trabeculoplasty has been shown to be effective in open angle glaucoma, even in patients who have had previous argon laser treatment.
The success rate of this procedure is comparable to the success rate of argon laser trabeculoplasty, but studies have shown that the lowering of pressure is almost immediate, unlike the four to six week delay in effect which occurs with argon laser. As with argon laser, the procedure takes approximately four to five minutes, and most patients experience no pain or minimal discomfort. Potential complications are few: mild discomfort and inflammation of the eye, and rare (almost always temporary) elevation of pressure can occur.
This laser has been available in many parts of the world for three or four years. It was approved by the FDA for use in the United States in the spring of 2001.
Because it achieves its effect by targeting pigmented cells within the trabecular meshwork, and because it does not cause any structural damage within the trabecular meshwork (unlike argon laser), it is theorized that selective laser trabeculoplasty may be repeatable. This is important, because unfortunately the effect from laser tends to wear off over time.
What are the drawbacks of the selective laser trabeculoplasty? There are a few to consider.
First of all, there is only four or five years of clinical experience with this type of laser surgery. Second, for many glaucoma patients it gives only a modest reduction in pressure, and medications will still be needed. (However it is likely that should the laser succeed, medication use will be delayed or at least reduced in a given patient). And third, the laser effect may wear off over time.
Complications must always be considered, but in all of the studies that have been published to date, selective laser trabeculoplasty appears to be very unlikely to lead to serious complications. Cost must also be a consideration, but unlike glaucoma medications, laser surgery is covered by insurance. For most patients the co-pay will be approximately the same cost as a bottle or two of glaucoma medication.
This treatment is available in the Carolina Eye Associates Pinehurst, Fayetteville, Laurinburg, and Sanford locations. If you have open angle glaucoma, SLT may be offered as a treatment option.
Messner is a glaucoma specialist at Carolina Eye Associates
