Intravitreal triamcinolone for acute central retinal vein occlusion; a randomized clinical trial.

Central retinal vein occlusion (CRVO) is the most common vascular event in the eye after diabetic retinopathy. This study was conducted to evaluate the effect of intravitreal triamcinolone (IVT) on acute CRVO. In a randomized sham-controlled clinical trial, 27 eyes with recent onset (less than 2 months) CRVO were randomly assigned to two groups. The treatment group (13 eyes) received 4 mg IVT and the control group (14 eyes) received a sham subconjunctival injection. The outcomes were visual acuity (VA), occurrence of neovascularization of the iris (NVI), and central macular thickness (CMT) measured by optical coherence tomography. Examination was repeated 1, 2, 3, and 4 months after intervention. Mean (standard error) of CMT before, 2 and 4 months after injection was 565 (50), 259 (15), and 290 (53) microns in the treatment group and 629 (43), 470 (62) and 413 (59) microns in the sham group, respectively. The 2- month difference was significant (P=0.003). The difference between VA changes (0.39 logMAR) was significant only at 1 month (P=0.013). There was no meaningful difference in the occurrence of NVI between the two groups. The therapeutic effect of IVT on acute CRVO is greatest at months 1 and 2 with regard to VA and macular thickness, respectively, and decreases up to the 4th month.