Clinical Characteristics and Long-term Outcomes in Diabetic Macular Edema Patients: With or without Additional Injection Following Ranibizumab Loading

PURPOSE: To investigate the baseline characteristics in patients with diabetic macular edema (DME) during 7 years according to the need for additional treatments after intravitreal ranibizumab (RBZ) loading injections. METHODS: The medical records of 32 patients treated with intravitreal RBZ loading for DME during 7 years were reviewed. After three-consecutive monthly RBZ injections, additional treatment was decided according to the patient’s response to RBZ loading. Based on whether the patients received treatment with or without additional injections, including intravitreal antivascular endothelial factor or steroid injection, they were divided into the “no add (NA)” or “add” groups, respectively. The baseline best-corrected visual acuity (BCVA), macular volume (MV), central subfoveal thickness, and other clinical factors were analyzed, and their 7-year changes were compared between the two groups. RESULTS: The BCVA of the NA group was better than that of the add group at 2, 3, 5, and 7 years (year 2, 3, and 5; p < 0.01, respectively). Baseline MV was significantly smaller in the NA group than in the add group (10.72 ± 0.88 μm vs. 11.98 ± 1.64 μm, p = 0.008). The DME duration before treatment in the NA group was significantly shorter than in the add group (1.03 ± 0.98 years vs. 1.91 ± 1.33 years, p = 0.042). The proportion of patients with serous retinal detachment or cystic macular edema was significantly lower in the NA group than in the add group (35.3% vs. 73.3%, p = 0.042). The NA group had smaller MV until 2 years than the add group (year 1, p = 0.002; year 2, p = 0.006). CONCLUSIONS: The DME patients without additional treatments during 7 years after the initial loading treatment had shorter duration of DME and diffuse retinal thickening morphologic type with lower MV at baseline, and better long-term visual prognosis.