Intravitreal Dexamethasone Implant versus Intravitreal Ranibizumab Injection for Treatment of Non-Proliferative Diabetic Macular Edema: A Prospective, Randomized and Blinded Trial

In the working age population, Diabetic Macular Edema (DME) is the most common cause of visual loss.The present study is aimed to assess the safety and efficacy of intravitreal injection of Ranibizumab (IVR) versus intravitreal Dexamethasone implant (IVD) in patients with DME in a tertiary care centre upto 4 months.This is a comparative, prospective, randomized study that was done on 140 patients with macular edema confirmed on optical coherence tomography (OCT). IVD group received Ozurdex® (Allergan, Inc, Ireland) while the IVR group received Lucentis® (Novartis, Basel, Switzerland); the groups were followed up at day-1 and weeks 4, 8, 12, 16. Patients were divided into Group A, in which patients were given 3 doses (monthly) of IVR 0.3 mg in 0.05 ml (n=70). Group B patients were given a single dose of IVD implant 0.7 mg (n=70).The mean number of injections given was 1 Ozurdex® per patient vs. 3 Lucentis® per patient. The maximum reduction in central macular thickness (CMT) with IVD was 167.8 μm and 138.8μm in the 2nd and 3rd months, respectively, with IVR. The mean best-corrected visual acuity (BCVA) in the 4th month was 0.34 logMAR and 0.33 logMAR, in IVD and IVR groups, respectively, with consistent improvement. Patients with 0-5 letters, 6-10 letters and 10-15 letters, and >15 letters visibility in IVD group were 9.5, 20.6, 4.8, 6.4%, and 20.4, 18.8, 20.3 20.3% in IVR groups, respectively. The maximum intraocular pressure (IOP) rise with IVD was found to be 16 mmHg in 2 patients (3.17%). IOP rise >10 mmHg was observed in 14/63 patients (22.22%); the majority of patients indicated a high rise at 2nd month with all returning to baseline by 4th month. No reports of infectious endophthalmitis or new cataracts were detected in either of the treated groups.Both intravitreal Ranibizumab injection and Dexamethasone implants were found to be safe and effective in lowering CMT and improving BCVA at the 4-month follow up in patients with DME. Since there was no recurrence of CMT in the Dexamethasone implant group, we suggest that early administration before the 4th month may indicate superior efficacy over the ranibizumab injection. Further randomized trials in a large sample size with a longer period follow- up would be performed to justify the obtained results in the present study.