Comparison of 2-Year Outcomes between Intravitreal Ranibizumab and Intravitreal Aflibercept for Diabetic Macular Edema with "Treat-and-Extend" Regimen-Its Usefulness and Problems

Background: To compare the effectiveness of intravitreal ranibizumab (IVR) and intravitreal aflibercept (IVA) performed with the treat-and-extend (TAE) regimen on eyes with diabetic macular edema (DME).

Patients and methods: This is a retrospective study of 125 eyes of 125 treatment-naïve DME patients who received anti-VEGF injections at three consecutive monthly intervals as the loading phase. The changes in the best-corrected visual acuity (BCVA), central retinal thickness (CRT), diabetic retinopathy severity scale (DRSS), and total injection numbers were compared between the two anti-VEGF agents.

Results: Among 125 eyes, 26 eyes completed the treatment with the TAE regimen for 24 months (20.8%). Thirteen eyes of 13 patients (mean age, 70.9 ± 6.0 years) received intravitreal injections of 0.5 mg ranibizumab, and 13 eyes of 13 patients (65.9 ± 8.6 years) received 2 mg aflibercept. No significant differences were detected in the baseline demographics. At 24 months, BCVA was significantly improved in both groups; from 0.31 ± 0.19 to 0.10 ± 0.12 logMAR units for IVR and 0.41 ± 0.19 to 0.16 ± 0.28 logMAR units for IVA (p = 1.29 × 10^-9). CRT was significantly reduced in both groups; 440.9 ± 69.3 to 307.5 ± 66.4 μm for IVR and 473.9 ± 71.5 to 317.8 ± 71.2 μm for IVA (p = 3.55 × 10^-9). No significant differences were detected in the improvements of BCVA, CRT in both groups, and the total injection numbers for 24 months (11.0 ± 1.2 for the IVA group and 12.0 ± 1.0 the IVR group). DRSS was significantly improved in both groups (p = 0.0004 for IVR and p = 0.009 for IVA).

Conclusion: No significant differences were detected in the improvements of BCVA or CRT and injection numbers between the IVR and IVA groups treated with the TAE regimen. These results indicate that the results of the treatment with both agents with the TAE regimen were equally effective, but only 20.8% of patients completed 24 months of continuous treatment with the TAE regimen. Synopsis: There are no significant differences regarding effectiveness between the IVR and IVA groups treated with the TAE regimen for DME eyes.

Keywords: aflibercept; diabetic macular edema; ranibizumab; treat-and-extend regimen.