Intravitreal Triamcinolone for Acute Central Retinal Vein Occlusion; a Randomized Clinical Trial

Purpose: Central retinal vein occlusion (CRVO) is the most common vascular event in the eye afterdiabetic retinopathy. This study was conducted to evaluate the effect of intravitreal triamcinolone(IVT) on acute CRVO.Materials Methods: In a randomized sham-controlled clinical trial, 27 eyes with recent onset (lessthan 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. Themain outcome measures were visual acuity (VA), occurrence of neovascularization of the iris (NVI),and central macular thickness (CMT) measured by optical coherence tomography. Examinationwas repeated 1, 2, 3, and 4 months after intervention.Results: The mean (standard error) CMT before, 2 and 4 months after injection was 565(50),259(15), and 290(53) μ in the treatment group and 629(43), 470(62) and 413(59) μ in the shamgroup, respectively. The 2- month difference was significant (P=0.003). The difference between VAchanges (0.39 logMAR) was significant only at 1 month (P=0.013). There was no meaningfuldifference in the occurrence of NVI between the two groups.Conclusion: The therapeutic effect of IVT on acute CRVO is greatest at months 1 and 2 withregard to VA and macular thickness, respectively, and decreases up to the 4th month.