March 2009

 

OPHTHALMOLOGY NEWS

 

Seeing the light for cystoid macular edema


by Maxine Lipner Senior EyeWorld Contributing Editor

 

 

Laser trumps steroids in trial results

In patients with diabetic retinopathy, laser may be preferable to steroids for controlling cystoid macular edema Source: Eric N. Kegley, C.R.A., C.O.A.

For patients with diabetic macular edema, new study results suggest that it may be time to take another look at laser rather than opting for popular steroid treatment. In the study published in the September 2008 issue of Ophthalmology, results indicate that over a two-year span, for most patients, laser photocoagulation is more effective with fewer side effects than steroid treatment, according to David M. Brown, M.D., retinal surgeon, Methodist Hospital, Houston.

When steroids first came on the scene, they made a strong impression. “Probably four to five years ago people started injecting steroids into the eye,” Dr. Brown said. “It makes the macular edema go away and it looks fantastic.” Laser, which can take a while to kick in, began to fall out of favor. “It’s a delayed gratification kind of treatment,” Dr. Brown said. “So even though there was no randomized trial a lot of retinal surgeons said, ‘I’m giving up my laser and I’m going to do steroid injections.’”

While initially steroids appeared to work well, Dr. Brown saw difficulties begin to arise. “The problem was that many of us saw a lot less effect with the second or third treatment than the first,” he said. “The other problem was that almost everybody developed worse cataracts and about one third of them developed increased intraocular pressure from the steroid injections.”

Pitting steroids against laser

Concerned about such side effects, investigators opted to launch the multicenter randomized study. “The impetus here was that we know that there are certainly side effects from the steroids, and the question we had is, do you really get a benefit to make up for those side effects?” Dr. Brown said. The study included 840 eyes of 693 diabetic macular edema patients. Those included were randomized to receive either focal laser or one or four milligrams of intravitreal triamcinolone. Patients with new or persistent edema were retreated at four month intervals. While initial outcomes appeared to favor the steroids, this advantage faded away with time. “At four months out steroids were way ahead and were significantly better than laser,” Dr. Brown said. “By about a year out they were pretty equal and from 14 to 15 months on the laser was way ahead.” Those in the laser arm ultimately saw significantly better than those in the steroid arm. This difference in acuity could not be chalked up to cataract formation. “Even in patients who were pseudophakic, the laser beat the steroids,” Dr. Brown said. “It wasn’t just the cataract causing decreased visual acuity.”

These results came as a surprise to many in the retinal community. “Most people were floored because they had this treatment and they thought that it was so much better than the laser,” Dr. Brown said. That’s the problem with anecdotal results, he contends. “You remember the shot down the fairway and you don’t remember the five balls you lost in the woods,” he said.

“It’s not until you really compare everybody on a whole bell curve and get the average versus the average that you see that one can really be superior or inferior—that’s why studies are important.”

Dr. Brown sees the study as not only a victory of evidence-based medicine over anecdotal results but also as a call to revisit the laser. “The clinical take-home message is that people ought to look at laser,” he said. “It’s a pretty good treatment after all.”

Going forward Dr. Brown recognizes that it may not be an either/or proposition. “Perhaps the combination of the two would be good,” he said. “Maybe we could use steroids to decrease the edema to get the short-term effect and then laser to get the long-term effect.”

Other new treatments

New treatments in the form of Avastin (bevacizumab, Genentech, South San Francisco, Calif.) and Lucentis (ranibizumab, Genentech) have now come into play. “Avastin became available about two years ago and that also shows anatomic improvement, but it doesn’t cause the glaucoma and the cataracts,” Dr. Brown said. This also has its drawbacks, however. “Most retinal doctors are not sticking with the Avastin,” Dr. Brown said. “Very few doctors are injecting Avastin for diabetic macular edema because you’d almost have to do it monthly and that’s a pretty hard sell.” In addition, Lucentis is now in Phase III clinical trial for use in diabetic macular edema. Similar to this study, the results with Lucentis will be compared to those with the laser. “That’s going to answer the anti-VEGF versus the laser question,” Dr. Brown said.

For his own part, Dr. Brown has returned to using the laser. He was spurred in part by results here, but also by concerns over steroid side effects. “We were kind of steering that way anyway because of the 30% incidents of glaucoma and the less efficaciousness with continued treatments,” he said. “For a lot of us, steroids had kind of lost their luster.”

Overall, he hopes that a better way to treat diabetic macular edema can soon be found. “Diabetic macular edema is a terrible problem. We have to find a better answer and we’re going to,” he said. However, even if new research on Avastin and Lucentis ultimately pan out, Dr. Brown does not see these as a long-term solution. “We can’t inject every month; that’s just not practical,” he said. “Of course, some diabetic patients are retired and coming to me once a month might be their one trip out of the house, but for the working diabetic, it’s brutal”

Editors’ note: Dr. Brown has financial interests with Alcon (Fort Worth, Texas), Allergan (Irvine, Calif.), and Genentech (South San Francisco, Calif.).

Contact information

Brown: 713-524-3434, dmbmd@houtonretina.com

Seeing the light for cystoid macular edema Seeing the light for cystoid macular edema
Ophthalmology News - EyeWorld Magazine
283 110
283 110
,
2016-08-01T13:44:13Z
True, 3