Diabetic edema drug treatments show promise

CHICAGO — Several medical therapeutic strategies for diabetic macular edema (DME) have shown promising early results in studies, said Alan Ruby, MD.

Dr. Ruby reviewed the results of studies of periocular, intravitreal and sustained-release drug delivery for DME here during Retina Subspecialty Day.

Sub-Tenon's injection of steroids is a low risk therapy for DME, Dr. Ruby said. In a study of 21 patients with diffuse DME, the mean visual acuity improved from 20/75 to 20/50, he said. At the 9-month follow-up point, none of the patients required reinjection.

Sub-Tenon's Kenalog (triamcinolone acetate, Bristol-Myers Squibb) "does appear to be efficacious in reducing macular edema as assessed by optical coherence tomography," Dr. Ruby said.

When injected intravitreally, Kenalog remains in the vitreous cavity for 3 to 6 months, and results are often achieved in 1 week, Dr. Ruby said. Intravitreal administration provides therapeutic levels of the drug rapidly, he said, but complications, while rare, can be serious.

Dr. Ruby also discussed two implants that provide sustained release of steroids.

Retisert (fluocinolone acetonide, Bausch & Lomb) may require patients to use IOP-lowering drugs and can cause cataracts, he said. The device, recently FDA approved, has a high cost and a high rate of complications, he said.

Posurdex (dexamethasone, Oculex/Allergan) is a long-term implant, an extended-release pellet made of a biodegradable polymer called PLGA. It is easy to insert in the office, and improvement of visual acuity was seen in 36% of patients in a recent study, he said.

For all of these therapies, Dr. Ruby said, further studies are warranted.