November 10, 2006

Laser Treatment Doesn’t Prevent Age-Related Macular Degeneration

Picture viewed by as it might be viewed by a person with age-related macular degeneration A scene as it might be viewed by a person with age-related macular degeneration. NIH’s National Eye Institute.

Age-related macular degeneration (AMD) is the leading cause of vision loss in the United States for people over the age of 60. Low-intensity laser treatment was thought by many to help slow or prevent the loss of vision from AMD, but the studies looking into it were inconclusive. A major trial has now found that the laser treatment is ineffective in preventing complications of AMD or loss of vision.

Yellowish deposits under the retina called drusen are the first sign of early AMD. Eyes with large drusen are at increased risk of progressing to advanced AMD, with an accompanying loss of vision. Low-intensity laser treatment reduces the extent of drusen. However, the studies evaluating the impact of laser treatment on vision were small, and their results inconsistent.

The Complications of Age-Related Macular Degeneration Prevention Trial (CAPT) was designed to assess the safety and effectiveness of laser treatment in preventing vision loss among people with large drusen in both eyes. The study, which was supported by grants from NIH’s National Eye Institute (NEI), enrolled over 1,000 participants over the age of 50 (average age of 71) who had ten or more large drusen and a visual acuity of 20/40 or better in each eye. One eye of each participant was treated and the other was observed throughout the five years of the trial.

In the November 2006 issue of the journal Ophthalmology, the researchers report that they found no difference in vision or in progression to advanced AMD between treated and untreated eyes. After five years, 20.5% of the treated eyes and 20.5% of the untreated eyes had lost three or more lines of visual acuity on a standard eye chart. Likewise, 20% of treated and untreated eyes progressed to advanced AMD. Changes in visual acuity were strongly associated with the development of advanced AMD, but had no relation to the treatment.

NEI director Dr. Paul A. Sieving said, “This is an important study because after 35 years of inconsistent results from preventive laser treatment trials, we now know that this approach does not seem to stop vision loss from AMD. Doctors using this technique should reconsider its use in patients with good vision, such as those studied in this trial.”

Sieving added, “At present, the only established way to decrease the risk of vision loss in people with large drusen (early AMD) is to take daily supplements of vitamins and minerals as used in the NEI-supported Age-Related Eye Disease Study (AREDS).”

AREDS found that people at risk of developing advanced AMD could reduce their risk of progressing to advanced AMD by 25% and their risk of moderate vision loss by 19% with high-dose antioxidant vitamins and minerals (vitamins C and E, beta-carotene, zinc and copper). NEI has just launched a new nationwide study called AREDS2 to see if a modified combination of vitamins, minerals, and fish oil can further slow the progression of vision loss from AMD.

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