Effect of Posterior Subtenon Triamcinolone Acetonide Injection on Diabetic Macular Edema Refractory to Intravitreal Bevacizumab Injection

Abstract

PurposeTo evaluate the effects of posterior subtenon triamcinolone acetonide injection on refractory diabetic macular edema (DME) after intravitreal bevacizumab (IVB) injection failure.MethodsPatients with DME and central subfield thickness (CST) >300 µm who did not respond to IVB injections were retrospectively included. Specifically, we enrolled patients who were diagnosed with refractory DME and who experienced an increase in CST after 1 to 2 IVB injections or no decrease after ≥3 consecutive IVB injections. One clinician injected 20 mg of triamcinolone acetonide into the posterior subtenon space. All patients received ophthalmic examinations at baseline and at 2, 4, and 6 months post-baseline. Examinations included Snellen visual acuity, intraocular pressure, and spectral-domain optical coherence tomography.ResultsForty eyes of 34 patients were included. The average baseline CST was 476 µm. The average CST decreased to 368 µm at 2 months, 374 µm at 4 months, and 427 µm at 6 months (p < 0.001 for all results, Wilcoxon signed-rank test). The average intraocular pressure increased from 15.50 to 16.92 mmHg at 2 months but decreased to 16.30 mmHg at 4 months and 15.65 mmHg at 6 months. Logarithm of the minimum angle of resolution visual acuity improved from 0.56 to 0.50 at 2 months (p = 0.023), 0.50 at 4 months (p = 0.083), and 0.48 at 6 months (p = 0.133, Wilcoxon signed-rank test). No complications were detected.ConclusionsPosterior subtenon triamcinolone acetonide is an effective and safe treatment for reducing CST in DME refractory to IVB.

Characteristics of diabetic macular edema patients refractory to anti-VEGF treatments and a dexamethasone implant

“…Responsive group was defined as patients who achieved CST < 300μm after 3IVBs with or without dexamethasone implant and refractory group was defined as patients who showed CST ≥ 300μm even after both treatments (Fig 1). [21, 22] We followed all the patients until 6month after initial treatments.…”

Pharmacology of Corticosteroids for Diabetic Macular Edema

“…For example, Lazic et al 69 published significant improvements in central foveal thickness and visual acuity in 16 eyes of 15 patients with refractory DME following three anti-VEGF injections who then underwent injection of DEX implant. In addition, Kim et al 71 reported on 40 eyes of 34 patients with persistent DME despite undergoing previous bevacizumab injections that received 20 mg of posterior subtenon TA. At 2 months, the mean central retinal thickness had decreased by 108 μm while the logMAR vision had improved by 0.06.…”

Corticosteroids in ophthalmology: drug delivery innovations, pharmacology, clinical applications, and future perspectives

“…The sub-Tenon injection of triamcinolone acetonide (20 mg) was found to effectively inhibit VEGF and reduce the average macular thickness from 476 µm to 368 µm after 2months treatment. No serious complications were reported [176].…”