August 26, 2008 -- Several years ago, early reports of success in treating diabetic macular edema (DME) with injections of a corticosteroid led to the rise in popularity of this drug therapy. But a new National Institutes of Health-funded study proves that the most effective treatment to preserve eyesight in diabetic patients with DME is with laser therapy.
"Many of the investigators, including myself, were surprised by the results," said Dr. David Brown, ophthalmologist and retina specialist at The Methodist Hospital in Houston and local principal investigator. "We're continually researching new treatments, but sometimes the tried and true methods are still the best course. These findings substantiate the importance of laser treatment in the management of diabetic macular edema."
The multi-center study, funded by the NIH's National Eye Institute and conducted through the Diabetic Retinopathy Clinical Research Network, demonstrates that laser therapy is not only more effective than corticosteroids in the long term treatment of DME, but also has far fewer side effects. A total of 693 patients with DME participated in the randomized study at 88 sites across the United States.
Following randomized treatment (corticosteroid or laser treatment), study patients were tested to determine whether the procedure had prevented substantial vision loss. In the corticosteroid-treated group, 28 percent experienced substantial vision loss as compared to 19 percent in the laser-treated group. In addition, about one-third of the eyes treated with laser therapy showed substantial improvement in vision. The corticosteroid-treated group also experienced more side effects, such as the need for cataract surgery and increased eye pressure, which may lead to glaucoma.
The study is the first to compare the long-term benefits of both treatments and evaluate their potential side effects. Its results are published in the online edition of the journal Ophthalmology and will also appear in the September print issue of Ophthalmology.
Another study, this one done at the University of Tennessee Health Science Center, demonstrates improved outcomes for pediatric patients treated with a laser fiber versus other methods.
OmniGuide, Inc. (Cambridge, MA), maker of the laser fiber under study (the BeamPath, "the first and only flexible CO2 laser scalpel"), says the study compared its product with two other treatment options -- external surgical excision and line-of-sight CO2 laser. Thirty pediatric patients, three years old on average, underwent procedures to remove suprastomal tracheal fibromas in their windpipe. The study, led by Jerome Thompson, M.D., MBA, Chairman, Department of Otolaryngology, Head and Neck Surgery at University of Tennessee Health Science Center, compared operating-room time, hospitalization time, need for follow-up procedures, and the success rate of immediate post-operative removal of a tracheal tube.
"The pediatric suprastomal fibroma study demonstrated that the use of a flexible CO2 laser fiber improves quality of care and clinical outcomes on several levels," said Dr. Thompson. "The rate of immediate removal of the tracheal tube was four times greater in the flexible fiber group than the external excision group and two times greater than the line-of-sight CO2 laser group."
Additionally, half of the patients who underwent treatment with the fiberoptic CO2 laser carrier had already undergone external excision prior and had experienced recurrence. After then undergoing treatment with the fiberoptic CO2 laser fiber, three of the five patients had their tracheal tube removed immediately and did not experience recurrence of fibroma. Lastly, while the external excision patients are always monitored overnight in the hospital, the endoscopic procedures were performed on an outpatient basis and the children were usually sent home after three to four hours.