Intravitreal implant treats macular edema due to retinal vein occlusion

November 1, 2010

A dexamethasone intravitreal implant is a notable new therapeutic option for eyes with macular edema secondary to branch retinal vein occlusion or central retinal vein occlusion and may reduce the risk of vision loss as well as improve both the speed and incidence of visual improvement, according to one expert.

In two identical masked, randomized, 6-month clinical trials, patients were assigned to either a sham procedure or treatment with a 0.35- or 0.7-mg dexamethasone implant.

The results showed that a single treatment with either dose of the implant produced significantly greater mean improvements from baseline best-corrected visual acuity (BCVA) than did the sham procedure at days 30 to 90 (p < 0.001). This trend was evident throughout the study period (p ≤ 0.006).

Treated and untreated eyes entering the open-label phase of the study were followed for an additional 6 months. The response to a second dexamethasone implant during this period was similar.

"This is a very exciting treatment because it can be given as an intravitreal injection and then has a long duration," said lead investigator Dr. Haller, ophthalmologist-in-chief, Wills Eye Institute, and professor and chairwoman, Department of Ophthalmology, Thomas Jefferson University, Philadelphia.

"The implant slowly delivers dexamethasone, one of the most highly potent steroids, over a 6-month period," she added. "That's a revolutionary approach to treating venous occlusive disease."

The findings add momentum to a shift in the approach to management of retinal vein occlusion (RVO), she commented. Until recently, treatment options were extremely limited, and the preferred approach often was to postpone treatment to the later stages of disease.

Other treatments being investigated include laser photocoagulation, the anti-vascular endothelial growth factor therapy ranibizumab (Lucentis, Genentech), and triamcinolone acetonide.