Purpose: To evaluate the visual and morphologic outcomes of intravitreal ranibizumab (IVR) in eyes with diabetic macular edema (DME) based on the morphologic pattern on optical coherence tomography.
Methods: A prospective and consecutive series of 55 eyes with DME was classified according to OCT features: diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD). Patients received three consecutive monthly injections of IVR and as needed thereafter. The primary outcome was the number of treatments undertaken by DME type over 12 months. Best-corrected visual acuity, retinal thickness, and microstructural changes were also evaluated.
Results: The eyes were classified as DRT (n = 23), CME (16), or SRD (16). The mean number of injections over 12 months was significantly different among the groups: DRT (3.69), CME (5.33), and SRD (5.09; P = 0.028). Best-corrected visual acuity of SRD (20/60) was significantly worse than that of the other types (DRT = 20/38; CME = 20/43; P = 0.015) after 12 months.
Conclusion: Vision gains and retinal anatomy improvement were maintained in all three types during the first year of IVR administration. Especially, DRT maintained a good response to ranibizumab in a fewer number of injections. Disruption of the photoreceptor integrity at the baseline was correlated with poorer visual outcome and occurred more frequently in SRD.