The effect of posterior subtenon injection of triamcinolone acetonide for diabetic macular edema refractory to intravitreal bevacizumab injection

Abstract

AbstractPurpose To evaluate posterior subtenon injection of triamcinolone acetonide (stTA) for diabetic macular edema (DME) refractory to intravitreal bevacizumab injection.Methods Patients with DME involving fovea who revealed central foveal thickness (CFT) over than 300μm continuously and did not respond to intravitreal bevacizumab injection (IVB) were included. When CFT increased after 1 or 2 IVB or CFT did not decreased more than 50μm after 3 consecutive IVB, we classified these group of patients as DME refractory to IVB. Other diseases which can cause macular edema including macular degeneration, vein occlusion and epiretinal membrane were also excluded. 40mg TA was injected in to the posterior subtenon space by one clinician. All patients received ophthalmic examination including Snellen visual acuity, intraocular pressure (IOP), spectral domain optical coherence tomography at the time of posterior stTA injection, 2‐month, 4‐month and 6‐month follow up period.Results 41 eyes of 35 patients were included. Average CFT reduced from 474μm to 377μm at 2‐month, to 352μm at 4‐month and 401μm at 6‐month (p<0.001, p=0.001, p=0.035 respectively; paired T‐test). Average IOP were increased from 15.5mmHg to 16.9mmHg at 2‐month but it reduced to 16.2 at 4‐month and to 15.8 at 6‐month. Visual acuity in logMAR scale increased from 0.55 to 0.50 at 2‐month, to 0.49 at 4‐month and to 0.50 at 6‐month (p=0.001, p<0.001, p<0.001 respectively; paired T‐test). No complications such as glaucoma and cataract were detected.Conclusion Posterior stTA is effective treatment for DME refractory to IVB. But the effect did not continue over 6 months.