Evaluation of efficacy dexamethasone intravitreal implant compared to treatment with anti-VEGF in the treatment of diabetic macular edema

Abstract

Objective: The study compares the effectiveness of an intravitreal slow-release dexamethasone implant respect to an intravitreal injection of a anti-VEGF, ranibizumab, in the treatment of diabetic macular edema (DME).

Design: we used a non randomized retrospective study to compare the effectiveness of two treatment approaches to DMESubjects: 50 patients were investigated, 30 of whom underwent injections of ranibizumab and 20 of whom  underwent dexamethasone implantation.Methods: When patients were injected with the anti-VEGF ranibizumab, they were monitored every three months.Dexamethasone implant was administered only once in 6 months, different  to ranibizumab which was administered monthly .Main Outcome Measures:  these were carried out by measuring the improvements in ETDRS (visual acuity scores) and CMT (central macular thickness) after one month, three months, and six months (T1, T3, T6). intraocular pressure were performed.Results: Data evidenced that the slow-release dexamethasone implant is more efficacious than the intravitreal injection of the anti-VEGF, ranibizumab, in terms of improvement of visual acuity and central macular thickness.Dexamethasone implant at T3 produced an improvement of visual acuity which was significantly better respect to injections of ranibizumab, with a mean ETDRS gain of nearly 8,5  letters, compared to only 4 letters gained in the case of ranibizumab injected patients. This significance, however, is lost by T6, (p=0.516), where those treated with dexamethasone had lost 6 of the eight letters gained, while those with ranibizumab had lost 4 letters. As such, the overall gain at the T6 checkpoint was only 2.5 letters for dexamethasone implant and 2 for ranibizumab.Conclusion: The study highlighted a better initial efficacy of the dexamethasone implant due to its superior performance at 3 and 6 month evaluation points.