Intravitreal dexamethasone implant versus triamcinolone acetonide for macular oedema of central retinal vein occlusion: quantifying efficacy and safety

Among the retinal vascular diseases, burden of retinal vein occlusion is most common immediately after diabetic retinopathy. Intravitreal corticosteroids are gaining popularity in managing macular edema (ME) of RVO. Our study compares efficacy and safety of intravitreal triamcinolone (IVTA) and dexamethasone implant (IVD) over 6 months.

This comparative, prospective, randomized study on 40 patients of non-ischemic central RVO with significant ME (> 330 μm) of < 3 months duration. Study was done at Army Research Hospital between Sep-2012 and May-2014 in accordance to Helsinki Declaration. IVD group (n = 20) received Ozurdex^® while IVTA group (n = 20) received triamcinolone-acetonide (4 mg/0.1 ml), followed up at day-1 and weeks 4, 8, 12, 24.

At 6 months, mean improvement in best corrected visual acuity and retinal thickness (CMT) in the IVD group was 0.43 logmar and 323 μm and in IVTA group was 0.49 logmar and 322 μm respectively. Proportion of patients achieving ≥ 15 letters was about 40% in both groups. IOP rise was significantly higher in IVTA group at 12 and 24 weeks. In IVTA group ≥ 10 mmHg IOP rise was seen in 60% of patients, 41.6% among them had > 35 mmHg and 66% needed combination treatment and failed to reach baseline line IOP at 6 months. In IVD group, 5 pts had IOP rise with all being < 26 mmHg and were easily managed with single agent with IOP reaching baseline by 6th month in all pts. Relative risk of IOP rise with IVTA is 2.4 times higher compared to IVD. Cataract progression and cataract surgeries were required at significantly higher rates in IVTA group. In IVTA group, cataract progression was seen in 35% patients, with 71.5% requiring cataract surgery at 6 months. IVD group, 10% patients had cataract progression while none required surgery at 6 months. Relative risk of cataract progression with IVTA is 3.5 times higher compared to IVD.

Intravitreal steroids are effective in managing macular edema of retinal vein occlusion, while newer formulation of sustained release dexamethasone implant is significantly safer than IVTA.