Diabetic macular edema (DME) affects around 750,000 people in the United States and is one of the leading causes of vision loss.

Macular edema occurs when fluid and protein deposits collect on or under the central area of the retina. This causes the central part of the eye to thicken and swell, which can lead to distorted vision.

Typically, doctors prescribe one of three treatments for this condition: Eylea (afibercept), Avastin (bevacizumab), or Lucentis (ranizumab).

Both Lucentis and Eylea are approved for treating DME, while Avastin is used off-label because it works similarly to Lucentis but is significantly less expensive.

Comparing the three treatments

The National Institutes of Health National Eye Institute sponsored a study comparing the three drugs, seeking to find evidence for which treatment is the most effective. There were 660 people diagnosed with DME in the study who were each randomly assigned to one of the three medications. Eylea, Avastin, and Lucentis all produced significant improvements for most people with DME; however, Eylea showed evidence for the most improvement in the study participants that had vision 20/40 or worse. For those with vision 20/40 or better, each of the medications worked generally equally well.

Approximately three-quarters of people with DME have 20/40 vision or better (51 percent of the participants in the study had 20/40 vision or better). For these people, treating with Lucentis still makes sense as it is just as effective as the other medications and costs significantly less. But for the other quarter of those with DME who have vision worse than 20/40, there is evidence that Eylea may be the best way to treat this complication.

For more on diabetic eye complications:

Summer and Sunglasses: Protect your Eyes
Cataracts and Glaucoma: The Other Diabetic Eye Complications
Eye Drug for Diabetics Receives FDA Breakthrough Therapy Designation