Steroid injections may slow progression of diabetic retinopathy

Arch Ophthalmol. 2009;127(12):1566-1571.

Intravitreal triamcinolone appears to slow the risk for progression of diabetic retinopathy compared with photocoagulation, according to a study.

Researchers in the Diabetic Retinopathy Clinical Research Network conducted a study involving 840 eyes of 693 patients who had diabetic macular edema. Eyes were randomly assigned to receive one of three treatments: photocoagulation or a 1-mg or 4-mg intravitreal injection of triamcinolone acetonide as often as every 4 months.

After 2 years, retinopathy progressed in 31% of 330 eyes treated with photocoagulation, 29% of 256 eyes treated with 1-mg doses of triamcinolone acetonide and 21% of 254 eyes treated with 4-mg doses of triamcinolone acetonide. These differences appeared to be sustained at 3 years, even though most eyes in the triamcinolone groups did not receive injections every 4 months during the second year and less than half received any injections in the third year, the researchers said.

Corticosteroids have been shown to interfere with the creation of new blood vessels, possibly by reducing the production of compounds that spur their growth, according to the researchers. However, steroids are also associated with other eye diseases such as cataract formation and glaucoma.

"Use of this intravitreal corticosteroid preparation to reduce the likelihood of progression of retinopathy is not warranted at this time because of the increased risk of glaucoma and cataract associated with intravitreal steroid use," the researchers said. "Any treatment to be used routinely to prevent proliferative diabetic retinopathy likely needs to be relatively safe because the condition already can be treated successfully and safely with panretinal photocoagulation. Nevertheless, further investigation with regard to the role of pharmacotherapy for reduction of the incidence of progression of retinopathy appears to be warranted."