Objective: To evaluate the short-term efficacy of ranibizumab therapy in terms of visual function and retinal thickness in patients with diabetic macular edema (DME) who failed to respond to treatment with repeated bevacizumab injections. Additionally, parameters affecting outcomes after switching were investigated.

Materials and Methods: The present study was a multicenter, retrospective study of 70 eyes with DME non-responding to bevacizumab. All patients were initially treated with at least three consecutive injections of bevacizumab then switched to at least one injection of ranibizumab. A monthly follow-up after the first ranibizumab injection to the last injection within six months was monitored. Primary outcomes included mean change in best-corrected visual acuity (BCVA) and central subfield thickness (CSFT) changes from baseline. Exploratory outcomes included parameters affecting prognosis after switching.

Results: Seventy eyes with DME were included in the present study. The mean change of BCVA (logMAR) was 0.075±0.375 (95% CI 0.014 to 0.164, p=0.098). The mean change of CSFT was 58.85±110.37 μm (95% CI 32.54 to 85.17, p<0.001). Forty-two percent of patients had BCVA improvement and 75.71% had CSFT improvement after switching to ranibizumab. Factors associated with BCVA and CSFT improvement were baseline BCVA, baseline CSFT, and older than 50 years old.

Conclusion: Switching to ranibizumab therapy in DME patients unresponsive to repeated bevacizumab injection provides better anatomical outcomes than visual acuity improvement. This will help ophthalmologists better understand the benefits on switching therapy to ranibizumab in terms of visual function and retinal thickness in patients with DME in the real-world setting.

Keywords: Diabetes, macular edema; Anti-vascular endothelial growth factor (VEGF); Intravitreal injection; Non-responder; Persistent diabetic macular edema

DOI: 10.35755/jmedassocthai.2022.04.13285

Received 13 December 2021 | Revised 9 February 2022 | Accepted 14 February 2022