Inclusion Criteria:

1. Age >= 18 years Participants <18 years old are not being included because proliferative diabetic retinopathy is so rare in this age group that the diagnosis may be questionable.
2. Diagnosis of diabetes mellitus (type 1 or type 2)

Any one of the following will be considered to be sufficient evidence that diabetes is present:

• Current regular use of insulin for the treatment of diabetes
• Current regular use of oral anti-hyperglycemia agents for the treatment of diabetes
• Documented diabetes by American Diabetes Association and/or World Health Organization criteria 4. Able and willing to provide informed consent. 5. Patient is willing and able to undergo vitrectomy within next 2 weeks and the vitrectomy can be scheduled within that time frame.  Vitreous hemorrhage causing vision impairment, presumed to be from proliferative diabetic retinopathy, for which intervention is deemed necessary.
  • Note: Prior panretinal photocoagulation is neither a requirement nor an exclusion.
  • Subhyaloid hemorrhage alone does not make an eye eligible; however, presence of subhyaloid hemorrhage in addition to the criteria above will not preclude participation provided the investigator is comfortable with either treatment regimen.  Immediate vitrectomy not required (investigator and participant are willing to wait at least 4 months to see if hemorrhage clears sufficiently with anti-vascular endothelial growth factor without having to proceed to vitrectomy).  Visual acuity letter score ≤78 (approximate Snellen equivalent 20/32) and at least light perception.  Investigators should use particular caution when considering enrollment of an eye with visual acuity letter score 69 to 78 (approximate Snellen equivalent 20/32 to 20/40) to ensure that the need for vitrectomy and its potential benefits outweigh the potential risks.

Exclusion Criteria:

• A potential participant is not eligible if any of the following exclusion criteria are present:

1. History of chronic renal failure requiring dialysis (including placement of fistula if performed in preparation for dialysis) or kidney transplant.
2. A condition that, in the opinion of the investigator, would preclude participation in the study (e.g., unstable medical status including blood pressure, cardiovascular disease, and glycemic control).
3. Initiation of intensive insulin treatment (a pump or multiple daily injections) within 4 months prior to randomization or plans to do so in the next 4 months.
4. A condition that, in the opinion of the investigator, would preclude participant undergoing elective vitrectomy surgery if indicated during the study.
5. Participation in an investigational trial within 30 days of randomization that involved treatment with any drug that has not received regulatory approval for the indication being studied.  • Note: participants cannot receive another investigational drug while participating in the study.
6. Known allergy to any component of the study drug or any drug used in the injection prep (including povidone iodine).
7. Blood pressure > 180/110 (systolic above 180 or diastolic above 110).
8. If blood pressure is brought below 180/110 by anti-hypertensive treatment, potential participant can become eligible.
9. Systemic anti-vascular endothelial growth factor or pro-vascular endothelial growth factor treatment within 4 months prior to randomization.  • These drugs cannot be used during the study.
10. For women of child-bearing potential: pregnant or lactating or intending to become pregnant within the next two years.  • Women who are potential participants should be questioned about the potential for pregnancy. Investigator judgment is used to determine when a pregnancy test is needed.
11. Potential participant is expecting to move out of the area of the clinical center to an area not covered by another clinical center during the two years. 
12. Evidence of traction detachment involving or threatening the macula.  • If the density of the hemorrhage precludes a visual assessment on clinical exam to confirm eligibility, then it is recommended that assessment be performed with ultrasound as standard care.
13. Evidence of rhegmatogenous retinal detachment.  • If the density of the hemorrhage precludes a visual assessment on clinical exam to confirm eligibility, then it is recommended that assessment be performed with ultrasound as standard care.
14. Evidence of neovascular glaucoma (iris or angle neovascularization is not an exclusion).
15. Known diabetic macular edema (DME), defined as either
16. Optical coherence tomography central subfield thickness (microns):
17. Zeiss Cirrus: ≥290 in women; ≥305 in men
18. Heidelberg Spectralis: ≥305 in women; ≥320 in men OR
19. Diabetic macular edema on clinical exam that the investigator believes currently requires treatment.
20. History of intravitreous anti-vascular endothelial growth factor treatment within 2 months prior to current vitreous hemorrhage onset or after onset.
21. History of intraocular corticosteroid treatment within 4 months prior to current vitreous hemorrhage onset or after onset.
22. History of major ocular surgery (including cataract extraction, scleral buckle, any intraocular surgery, etc.) within prior 4 months or major ocular surgery other than vitrectomy anticipated within the next 6 months following randomization.
23. History of vitrectomy.
24. History of YAG capsulotomy performed within 2 months prior to randomization.
25. Aphakia.
26. Uncontrolled glaucoma (in investigator's judgment).
27. Exam evidence of severe external ocular infection, including conjunctivitis, chalazion, or substantial blepharitis.