Clinical Studies:


Summarized by Mrinali Gupta, MD (Retina Associates of Orange County)

Citation:  Wells JA, Glassman AR, Ayala AR, et al. Two-year results from a comparative effectiveness randomized clinical trial. Ophthalmology 2016; 123: 1351-1359.

Key Points

  • Protocol T is a randomized, controlled clinical trial that compared aflibercept, bevacizumab, and ranibizumab for diabetic macular edema (DME)
  • From months 0 through 6, eyes were treated at baseline and then monthly thereafter unless criteria to hold treatment were met. From months 6 – 12, eyes were evaluated monthly and treated unless there had been no improvement nor worsening in vision and imaging in response to the past 2 injections, and treatment was re-initiated if there was worsening. From months 12 through 24, eyes were evaluated and treated q4-16 weeks based on protocol criteria.
  • At 2 years, there was no difference between aflibercept, ranibizumab, and bevacizumab for DME in eyes with baseline vision 20/32-20/40 (similar to one year results). In eyes with baseline vision worse than 20/50, visual outcomes at 2 years were better for aflibercept relative to bevacizumab (similar to one-year results), but there was no significant difference in visual outcomes for aflibercept versus ranibizumab.
  • At 2 years, APTC rates were higher for ranibizumab (12%) as compared to aflibercept (5%) or bevacizumab (8%)
  • Objective

    To compare outcomes for aflibercept versus bevacizumab versus ranibizumab for diabetic macular edema


    Multicenter, randomized, controlled clinical trial


    24 Months



(if the non-study eye needed treatment during the study period, the same medication was used)

Treatment schedule


Laser (focal, grid, or both) performed at or after 24 months based on protocol-defined criteria. Other treatment for DME allowed if the study eye met criteria for treatment failure.

VA/OCT technicians were masked; study coordinators/investigators were not masked; participants masked until 1-year results were published, and at that point, the participant could be switched therapies per investigator/protocol chair decision


Study population


Visual acuity end-points

Anatomic outcomes

Systemic adverse events