Panretinal Photocoagulation (PRP)

Understanding Proliferative Diabetic Retinopathy and Its Treatment Options

The eye functions much like a camera. It has two main parts: a lens, which focuses light, and a film-like layer at the back of the eye called the retina. The retina receives its nourishment through arteries that supply blood and veins that drain it.

Proliferative diabetic retinopathy (PDR) is a complication of diabetes in which abnormal new blood vessels begin to grow on the surface of the retina. At first, these vessels may not cause any symptoms. However, over time, they can spontaneously bleed, leading to sudden vision loss, and in some cases, may require surgical treatment. These vessels can also form scar tissue, which may pull the retina away from its blood supply—resulting in further vision impairment.

This condition is triggered by poor blood flow to the retina. The most affected areas are those responsible for peripheral vision. In response, these areas produce a hormone that stimulates the growth of abnormal vessels.

How Is PDR Treated?

One proven treatment is panretinal photocoagulation (PRP)—a laser procedure performed in the office. PRP targets the oxygen-starved areas of the retina to reduce the release of the hormone that promotes abnormal vessel growth. Over time—often months to years—these vessels regress.

Some patients may require more than one session for optimal results. PRP does not typically require an eye patch or shield afterward, and most patients are able to return to work the following day.

If you’re interested in learning more about PRP, please refer to our detailed guide on the procedure.

What Are the Risks?

The primary risk of PRP is a reduction in peripheral (side) vision. While this change has been confirmed in clinical studies, most patients do not notice a significant difference in daily life. Another potential side effect is a slower adjustment to darkness when moving from bright to dim environments. Again, this change is generally mild and often goes unnoticed.

Are There Alternatives?

Yes. Another treatment option involves intravitreal injections, which may be recommended depending on the specifics of your case.

What Can Patients Do to Help?

While this condition is a result of long-term, suboptimal blood sugar control, proactive management can help reduce the risk of worsening:

• Aim for a hemoglobin A1C of 7.0 or less (equivalent to an average blood sugar of 154 mg/dL).

• Maintain blood pressure below 140/90 mmHg.

It's important to understand that tightening blood sugar control won’t reverse this condition, but it can help prevent progression.

What Symptoms Should Prompt a Call to Your Eye Doctor?

Please contact your eye care provider if you experience:

• Sudden blurry vision – this may signal retinal swelling that needs attention.

• A sudden increase in floaters or dimming vision – this may indicate a retinal bleed.

These symptoms are treatable but require timely intervention.

Why Is Regular Follow-Up So Important?

• Retinal swelling, if left untreated for weeks to months, can lead to permanent vision loss.

• Abnormal vessels may be detected early, even before symptoms occur, and treatment can help preserve vision.