Central retinal vein occlusion (CRVO) is an eye condition in which a blood clot slows or stops circulation in a large vein within the light-sensitive retinal tissue. Reduced retinal blood flow frequently triggers the growth of abnormal blood vessels. These vessels leak blood into the macula, the central part of the retina, causing it to swell, a damaging complication called macular edema. Macular edema is the most common cause of vision loss from CRVO. Retinal laser photocoagulation therapy is used to prevent further blood vessel growth but does not eliminate edema. Until now, there has not been an effective treatment for macular edema associated with CRVO.
NIH-supported investigators conducted a clinical trial comparing the safety and effectiveness of standard care observation with two different doses of a corticosteroid, namely, triamcinolone, for the treatment of CRVO. Corticosteroids are potent anti-inflammatory drugs that are being evaluated in eye diseases like diabetic retinopathy where macular edema is also a complication. After 12-months of treatment with either 1- or 4-mg triamcinolone, patients were five times more likely to experience a substantial visual improvement compared to those who did not receive the drug. Triamcinolone improved visual acuity, enabling patients to read smaller letters on a vision chart than they could before treatment. Vision improvement was similar with either dose. However, the 4-mg group had side effects of increased intraocular pressure, a risk factor for glaucoma, and more frequent cataract formation.
Public Impact Statement/Significance:
CRVO causes a significant loss of vision worldwide. The SCORE trial identified the first effective treatment to reverse vision loss associated with blockage of large veins in the eye. Based on the results of this study, the investigators recommend that clinicians administer triamcinolone in a 1-mg dose to patients with macular edema secondary to CRVO and follow these patients for up to two years in case retreatment becomes necessary. This study will dramatically change standard of care for a previously untreatable condition.
Intravitreal Corticosteriod for Macular Edema Study U10EY014351, U10EY014404, U10EY014352.
The Score Study Research Group. A randomized trial comparing the efficacy and safety of intravitreal triamcinolone with observation to treat vision loss associated with macular edema secondary to central retinal vein occlusion. Arch Ophthalmol. 2009;127(9): 1101-14. PubMed
Last Reviewed: January 2010