Clinical Studies:

DRCR Protocol I

Summarized by Tamara Lee Lenis, MD, PhD (Weill Cornell Medicine Department of Ophthalmology)


Early vitrectomy for severe vitreous hemorrhage in diabetic retinopathy. Two-year results of a randomized trial. Diabetic Retinopathy Vitrectomy Study report 2. The Diabetic Retinopathy Vitrectomy Study Research Group. Arch Ophthalmol. 1985 Nov;103(11):1644-52.

*Elman MJ, Ayala A, Bressler NM, Browning D, Flaxel CJ, Glassman AR, et al.; Diabetic Retinopathy Clinical Research Network. Intravitreal Ranibizumab for diabetic macular edema with prompt versus deferred laser treatment: 5-year randomized trial results. Ophthalmology. 2015 Feb;122(2):375–81.

*NOTE: This summary focuses on the year 1 report from 2010. However, the results from the 5 year report are also included in this summary, denoted by “*NOTE” followed by text in italics.

Other reports (not summarized here):

Elman MJ, Bressler NM, Qin H, et al. Expanded 2-year follow-up of ranibizumab plus prompt or deferred laser or triamcinolone plus prompt laser for diabetic macular edema. Ophthalmology. 2011 Apr;118(4):609-14.

Elman MJ, Qin H, Glassman AR, et al. Intravitreal Ranibizumab for Diabetic Macular Edema with Prompt versus Deferred Laser Treatment Three-Year Randomized Trial Results. Ophthalmology 2012 Nov;119(11):2312-2318.

Key Points

  • The Protocol I was a multicenter randomized clinical trial that compared intravitreal sham injection + prompt laser vs. intravitreal ranibizumab 0.5 mg + prompt laser vs. intravitreal ranibizumab + deferred (after 6 months) laser vs. intravitreal triamcinolone 4 mg + prompt laser for diabetic macular edema.
  • At one year, compared with the sham/prompt focal laser and the triamcinolone/prompt focal laser group, the intravitreal ranibizumab with prompt or deferred laser focal groups showed better visual acuity scores from baseline.
  • *NOTE: A 2-year extension study randomized patients who made it to the 3 year time point to ranibizumab every 4 weeks and prompt or deferred (after 6 months) laser.
    • Of those that completed the 5-year total follow up, the ranibizumab/deferred laser group showed equivalent mean change in visual acuity scores from baseline than the ranibizumab/prompt laser group.
    • The proportion of eyes with ≥10 and ≥15 letters of improvement was greater in the ranibizumab/deferred laser group compared with the ranibizumab/prompt laser group.
  • Objective

    To study the efficacy of prompt laser alone vs. ranibizumab 0.5mg + prompt laser vs. ranibizumab 0.5mg + deferred laser vs. triamcinolone vs. deferred laser in the treatment of diabetic macular edema (DME). The main outcome was best corrected visual acuity (BCVA) and safety and one year (with subsequent analyses at 2-5 years).


    Phase 3 randomized, multicenter clinical trial

  • Duration

    1 year with extension studies



RESULTS (1 year)

Study population

Visual acuity end-points

Anatomic end-points:

Number of injections

Adverse events at 1 year