Early and Late Switch from Ranibizumab to an Intravitreal Dexamethasone Implant in Patients with Diabetic Macular Edema in the Event of a Poor Anatomical Response

Background and ObjectivePatients with diabetic macular edema may not have optimal outcomes even with monthly ranibizumab intravitreal injections. A corticosteroid implant might be considered in such patients. The objective of this study was to compare the outcomes of switching from ranibizumab to an intravitreal dexamethasone implant after three or six consecutive monthly injections of ranibizumab.MethodsPatients with treatment-naive diabetic macular edema who showed a poor anatomical response to three or six consecutive intravitreal ranibizumab injections and received an intravitreal dexamethasone implant were enrolled in this retrospective study. Patients were divided into two groups as early- and late-switch groups. The early-switch group consisted of the patients who initially received three consecutive monthly ranibizumab injections and the late-switch group consisted of the patients who initially received six consecutive monthly ranibizumab injections and switched to a dexamethasone implant because of a poor anatomical response. Best corrected visual acuity and central retinal thickness at the baseline and 3, 6, 9, and 12 months in the study population were recorded.ResultsSixty-eight eyes of 68 patients were included. The early-switch group consisted of 34 eyes and the late-switch group consisted of 34 eyes. The mean change in best corrected visual acuity was similar between the two groups at 3, 9, and 12 months; however, it was significantly better in the early-switch group than the late-switch group at 6 months. The change in central retinal thickness was similar between the two groups at 3, 9, and 12 months; however, it was significantly better in the early-switch group than the late-switch group at 6 months.ConclusionsAlthough both early switching and late switching are similar in terms of providing functional and morphological improvement, early switching appeared better for ensuring patient well-being in the early period and improving patient adherence.