What is Diabetic Retinopathy: Symptoms, Stages and Treatment

These changes can blur your vision, and sometimes lead to swelling of the retina (macular edema), where fluid accumulates in the center of the retina, worsening vision in a way that cannot be corrected with glasses.

If untreated, chronic macular edema can result in irreversible damage to your sight.

Proliferative diabetic retinopathy (PDR)

PDR is the most severe stage of diabetic retinopathy. Here, the damaged blood vessels in the retina have closed off, cutting off oxygen supply to the retina. In response, the body grows new blood vessels along the surface of the retina to try to restore nourishment. However, these new vessels are fragile and can easily burst with minor activities. When they bleed, they may fill the eye with blood, creating further complications and increasing the risk of retinal detachment as they pull on the retina. What’s more, scar tissue may form around these new blood vessels, which can contract and pull on the retina, potentially causing retinal detachment.

“Sometimes you can have proliferative diabetic retinopathy and not even know it, says Olmos de Koo. “The central vision might be good, but you might have new blood vessels growing in the periphery or on the edges of the retina that haven't yet bled or tugged.”

What does diabetic retinopathy look like in the eye?

If you notice new eye floaters — tiny black specks or strands in your vision — it’s important to schedule a dilated eye exam, even if you don’t have diabetes. Only in very rare and severe cases can signs of diabetic retinopathy be visible by looking in the mirror.

A dilated eye exam allows the doctor to thoroughly inspect the retina — the light-sensitive tissue lining the inner eyewall, which contains delicate blood vessels. During the exam, your eye doctor will check for signs of retinopathy, including blood spots, fatty deposits, swelling, or the growth of new, fragile blood vessels.

Diabetic retinopathy maintenance and prevention

Even if you don’t have diabetes, adults age 50 and older should check in with their primary care provider annually to rule out a diabetes diagnosis.

“Sometimes, diabetes can creep up on you. You may feel fine and not be aware, causing damage in your eyes,” says Olmos de Koo.

For those with diabetes, prevention starts with managing blood sugar levels. It's essential to work with your primary care provider or endocrinologist to discuss medications, lifestyle changes, and dietary adjustments that can help control blood sugar.

“Even with the best ophthalmology treatments that we can provide, if the blood sugar remains high, a lot of times we’re not going to make a lot of leeway,” says Olmos de Koo.

If you have mild or moderate NPDR, immediate treatment may not be necessary, but your ophthalmologist will monitor your eyes closely. Keeping your blood sugar in check can usually halt the progression and curb vision loss, and sometimes can even restore some of your vision.

An ongoing study since 1984 has shown that maintaining lower A1c levels reduces the likelihood of developing vision-threatening retinopathy.

It’s important that patients with Type 1 diabetes have annual screenings five years after the onset of their disease. Patients with Type 2 should have a prompt examination at the time of diagnosis, and at least a yearly examination, says Rahul Khurana, M.D., an associate clinical professor in ophthalmology at the University of California San Francisco Medical Center and President of the Northern California Retina Vitreous Associates.

“Nearly 40 percent of Americans who have diabetes are not getting a dilated eye examination, and that’s a big problem,” Khurana adds. “We know that 95 percent of vision loss from diabetes can be prevented, but that can only happen if we examine patients early.”

 Monitoring blood pressure and cholesterol levels is crucial for protecting your vision. High blood pressure can exacerbate damage to the fragile blood vessels in the retina, while elevated cholesterol can lead to fatty deposits that further harm these delicate vessels. Together, these factors can accelerate the progression of diabetic retinopathy and worsen vision loss.

“Imagine a garden hose that is weak and leaking,” explains Omesh P. Gupta, M.D., an ophthalmologist and retina specialist at Wills Eye Hospital in Philadelphia. “When your blood pressure is high, it’s like turning up the faucet, so the hose starts leaking even more severely.”

Treatment options for diabetic retinopathy

To halt or even reverse diabetic retinopathy, treatment options depend on the symptoms and underlying cause of vision loss.

For diabetic macular edema (swelling of the retina that blurs vision in ways that glasses can’t correct), treatments typically involve eye injections using a small needle. There are two primary types of medications:

• Anti-vascular endothelial growth factor (VEGF): This treatment makes blood vessels less leaky and can shrink new, abnormal blood vessels.
• Steroids: These help reduce swelling in the retina.

Not only can we prevent patients from losing their vision, some patients can actually improve their vision,” says Khurana. Anti- VEGF injections are also used to prevent NPDR from progressing to more advanced stages.

For new blood vessel growth, laser treatments called pan-retinal photocoagulation (PRP) are available. This involves making thousands of tiny laser burns to shrink the abnormal blood vessels and stabilize the retina, reducing the risk of vision loss. Typically, this treatment is done in one session at an ophthalmologist’s office or eye clinic, although some patients may require additional sessions. Blurry vision is expected for about a day after the procedure.

In severe cases, such as retinal detachment or significant bleeding, retinal surgery (vitrectomy) may be necessary. This procedure clears out the blood. If there is a detachment, a bubble of silicone oil or gas can be used to hold the retina flat. Laser can be applied to any retinal tears and to perform PRP to shrink and stabilize new blood vessels.

At the University of Washington, Olmos de Koo is collaborating with primary investigator Dr. Kasra Rezaei on a study investigating oral medication as a treatment option for diabetic retinopathy. The study focuses on fenofibrate, a drug traditionally used to lower fat in the bloodstream. Another imaging study at UW is exploring non-invasive methods to analyze blood flow in the eye without the need for injected dye — an important step since diabetic retinopathy is largely caused by inadequate blood flow to the retina.