[Efficacy of early injection of intravitreal triamcinolone acetonide (IVTA) versus delayed injection for macular edema resulting from retinal vein occlusion]

Abstract

Purpose: To assess the efficacy of early injection of intravitreal triamcinolone acetonide (IVTA) versus delayed injection for macular edema from retinal vein occlusion.

Methods: This was a retrospective monocentric study. Forty-four patients received an IVTA (4 mg) for macular edema resulting from central retinal vein or branch retinal vein occlusion. The patients were assigned to two groups: group 1 consisted of patients who received an IVTA less than 6 weeks after the diagnosis of macular edema, while group 2 consisted of patients who received the injection more than 6 weeks after. All patients underwent a comprehensive ophthalmological examination before the injection and 1, 3, and 6 months after. Each visit included best-corrected visual acuity measurement (BCVA), slit lamp examination, intraocular pressure measurement, fundus examination and central macular thickness (CMT) measurement by OCT.

Results: The two groups were comparable in terms of age, sex-ratio, and the percentage of branch retinal vein occlusion (54 and 61% in groups 1 and 2, respectively). In group 1, the BCVA (logMAR) was 0.87 before the IVTA and significantly improved at 1 and 3 months (0.46 and 0.48, respectively; P<0.05) before worsening at the 6-month visit (0.62; P>0.05). The mean CMT was also significantly improved (from 567 μm before the injection to 276, 307, and 386 μm at the 1-, 3-, and 6-month visits, respectively) (P<0.05 at 1 and 3 months). In group 2, there were no significant differences in visual acuity at any time point (0.86 before the IVTA, 0.76, 0.76, and 0.78 at the 1-, 3-, and 6-month visits; P>0.05). The CMT was reduced after the injection from 552 μm to 294, 446, and 456 μm at the 1-, 3-, and 6-month visits, respectively (P<0.05 at 1 month).

Conclusion: Patients with macular edema due to retinal vein occlusions, who received a single intravitreal injection of triamcinolone acetate less than 6 months after the diagnosis, displayed both anatomical and functional improvement, whereas patients injected more than 6 weeks after the diagnosis of macular edema showed a CMT reduction but with less improvement in visual acuity. The difference observed at 1 month disappeared after 6 months.