Neovascularization of the Disc: A Guide for Patients
Understanding Neovascularization of the Disc
The optic disc is a circular area at the back of your eye where the optic nerve enters the retina. In NVD, fragile new blood vessels grow at or within one disc diameter of this structure. These new vessels are abnormal. They are thin, weak, and prone to breaking open and bleeding inside the eye.
NVD is the feature that separates proliferative diabetic retinopathy from the earlier, nonproliferative stages. When a retina specialist identifies NVD, it means the disease has progressed to a point that requires prompt treatment to prevent severe vision loss.
Diabetes damages the tiny blood vessels in the retina over time. As these vessels close off, large areas of the retina lose their blood supply. This oxygen-starved retinal tissue is called ischemic retina. In response, the ischemic retina releases a protein called vascular endothelial growth factor (VEGF). VEGF signals the body to grow new blood vessels to restore oxygen delivery.
However, these new blood vessels are not normal. They first appear as fine tufts of bare vessels on the surface of the retina or the optic nerve head. These vessels tend to grow along the back surface of the vitreous (the clear gel filling the eye). Because they are fragile, they can bleed into the vitreous, causing a vitreous hemorrhage that clouds vision.
Not all cases of NVD carry the same level of danger. Retina specialists classify certain findings as high-risk proliferative diabetic retinopathy. This classification applies when any of the following are present:
- NVD covering more than one quarter of the disc area
- Any amount of NVD combined with vitreous or preretinal hemorrhage (bleeding in front of the retina)
- Neovascularization elsewhere (NVE) covering more than half the disc area, combined with hemorrhage
Without intervention, nearly 25% of eyes with high-risk PDR experience severe vision loss within two years, and that number rises to 44% after four years (PMC, 2024).
Who Is Affected and Risk Factors
The longer a person has diabetes, the greater the chance of developing diabetic retinopathy and eventually NVD. After 20 years of living with diabetes, approximately 99% of people with type 1 diabetes and 60% of people with type 2 diabetes show some degree of retinopathy (PMC, 2024). In 2021, an estimated 9.60 million people in the United States, representing 26.43% of those with diabetes, had diabetic retinopathy (Rein et al., 2023). Of these, 1.84 million people (5.06% of those with diabetes) had vision-threatening diabetic retinopathy (Rein et al., 2023).
Uncontrolled blood glucose levels are a primary driver of diabetic retinopathy progression. A higher glycosylated hemoglobin (HbA1c), a measure of average blood sugar over two to three months, is closely linked to the development and worsening of NVD. Uncontrolled blood pressure also increases the risk. Keeping both blood sugar and blood pressure within recommended ranges is one of the most important steps a person with diabetes can take to protect their eyes.
Several additional factors raise the risk of progressing to high-risk proliferative diabetic retinopathy with NVD:
- History of diabetic neuropathy (nerve damage from diabetes)
- Kidney impairment related to diabetes
- Elevated triglyceride levels
- Lower hematocrit (a measure of red blood cell volume)
- Younger age at the time of diabetes diagnosis
- Increased retinal venular diameters, which can be seen during a dilated eye exam
Signs and Symptoms
One of the most concerning aspects of NVD is that it can develop without any symptoms. Proliferative diabetic retinopathy is sometimes called a visually silent disease because a person can have significant neovascularization at the optic disc and still see clearly. This is why regular dilated eye exams are critical for anyone with diabetes. Waiting for symptoms to appear before seeking care can allow the condition to progress to a dangerous stage.
When symptoms do develop, they usually indicate that a complication such as bleeding has occurred. Symptoms may include:
- Sudden appearance of many new floaters (dark spots or cobweb-like shapes drifting in your vision)
- Blurred or cloudy vision
- Dark or shadowy areas in your field of vision
- Sudden decrease in vision in one or both eyes
- Ocular pain in some cases
Small pockets of blood, called preretinal hemorrhages, may form in the space between the vitreous and the retina. These are warning signs that the new blood vessels are active and at risk of larger bleeds.
Certain symptoms require immediate attention. If you experience a sudden increase in floaters, flashes of light, a curtain or shadow moving across your vision, or sudden vision loss in one eye, see a retina specialist or go to the emergency room immediately. These signs can indicate a vitreous hemorrhage or a retinal detachment, both of which can cause permanent vision loss if not treated quickly.
Diagnosis and Testing
The primary method for detecting NVD is a comprehensive dilated eye exam. During this exam, a retina specialist places drops in your eyes to widen the pupils. This allows the specialist to view the retina and optic disc directly. NVD appears as clusters of fine, abnormal blood vessels growing on the surface of the optic disc or nearby retinal tissue.
Fluorescein angiography is an imaging test that provides detailed pictures of blood flow in the retina. A special dye is injected into a vein in your arm, and a camera takes rapid photographs as the dye travels through the retinal blood vessels. Areas of NVD light up brightly because the abnormal vessels leak dye. This test helps your retina specialist determine the extent and location of neovascularization and identify areas of ischemia.
Optical coherence tomography (OCT) uses light waves to create detailed cross-sectional images of the retina. It can reveal swelling, fluid buildup, and structural changes related to diabetic eye disease. Newer technologies, such as ultra-widefield (UWF) color fundus photography combined with widefield swept-source optical coherence tomography angiography (WF-SS-OCTA), may enhance the ability to detect and monitor high-risk proliferative diabetic retinopathy. These advanced imaging tools allow retina specialists to see a wider area of the retina and track changes in blood vessel growth over time without requiring a dye injection.
Treatment Options
Panretinal photocoagulation (PRP) has been a cornerstone of treatment for proliferative diabetic retinopathy for decades. During PRP, a retina specialist uses a laser to create hundreds of tiny burns in the peripheral (outer) retina. This reduces the amount of ischemic retinal tissue, which in turn decreases the release of VEGF. With less VEGF driving their growth, the abnormal new blood vessels can shrink and become less active. PRP does not improve vision, but it is highly effective at preventing further vision loss.
Anti-VEGF injections (injections of medication that blocks vascular endothelial growth factor) have become a primary treatment for NVD and proliferative diabetic retinopathy. These medications are injected directly into the vitreous cavity of the eye. They work by blocking the VEGF protein that drives abnormal blood vessel growth. Several anti-VEGF medications are used for this purpose:
- Eylea (aflibercept), typically given every 4 to 8 weeks after an initial loading phase
- Eylea HD (high-dose aflibercept), a higher-dose version approved by the FDA in 2023 for diabetic macular edema, offering extended dosing intervals of every 8 to 16 weeks after loading
- Lucentis (ranibizumab), typically given every 4 weeks
- Avastin (bevacizumab), which is FDA-approved for cancer treatment and used off-label for eye conditions, typically given every 4 to 6 weeks
- Vabysmo (faricimab), a bispecific antibody given every 4 to 16 weeks
Avastin (bevacizumab), used off-label for eye conditions, has shown the ability to cause rapid regression of new blood vessels, sometimes within 48 hours to 3 weeks after injection. The DRCR Retina Network Protocol S study demonstrated that Lucentis (ranibizumab) was noninferior to PRP in managing patients with proliferative diabetic retinopathy, meaning it performed comparably well in preserving vision.
In many cases, retina specialists use a combination of anti-VEGF injections followed by PRP laser treatment. This approach may provide stable and sustained protective effects. The anti-VEGF injection rapidly reduces active neovascularization, while PRP provides longer-term control by reducing the ischemic stimulus.
When complications such as a non-clearing vitreous hemorrhage or a tractional retinal detachment (where scar tissue pulls the retina away from the back of the eye) occur, a procedure called vitrectomy (surgery to remove the vitreous gel from inside the eye) may be necessary. Early vitrectomy may improve outcomes in select cases, particularly when bleeding obscures the retina specialist's view or when the retina is being pulled out of position.
What to Expect
An intravitreal injection (injection into the eye) takes only a few minutes. Your retina specialist will numb the eye with anesthetic drops and clean the area around the eye. The injection itself uses a very fine needle. Most patients feel pressure rather than sharp pain, though some discomfort is normal. You may notice floaters or a slight blur in your vision afterward, which usually resolves within a day or two.
Anti-VEGF treatment for NVD typically involves a series of injections. The frequency depends on how your eye responds. Your retina specialist will monitor you closely with regular exams and imaging to determine when additional injections are needed.
Panretinal photocoagulation is usually performed in the office over one or more sessions. Your retina specialist will use numbing drops and a special contact lens on your eye to direct the laser. You may see bright flashes of light during the procedure and feel mild discomfort. After PRP, your peripheral vision and night vision may be somewhat reduced. This is a known trade-off of the treatment, as it sacrifices some side vision to protect the central vision needed for reading, driving, and recognizing faces.
NVD and proliferative diabetic retinopathy require ongoing monitoring, even after successful treatment. New blood vessels can regrow if the underlying diabetes-related damage continues. Your retina specialist will schedule follow-up visits at regular intervals to check for any recurrence and to assess whether additional treatment is needed. The frequency of these visits varies but may range from every few weeks during active treatment to every few months once the condition is stable.
Living With NVD and Proliferative Diabetic Retinopathy
Controlling your diabetes is the foundation of protecting your vision when you have NVD. Work with your primary care doctor or endocrinologist to keep your HbA1c, blood pressure, and cholesterol levels within recommended ranges. Studies consistently show that better blood sugar control slows the progression of diabetic retinopathy and reduces the risk of complications like vitreous hemorrhage.
In addition to medical management, certain lifestyle choices can help support your overall health and potentially slow retinopathy progression:
- Follow a balanced diet that supports stable blood sugar levels
- Engage in regular physical activity as recommended by your doctor
- Avoid smoking, which worsens blood vessel damage
- Keep all scheduled eye and medical appointments
- Take all prescribed medications consistently
Living with a serious eye condition can be stressful. It is normal to feel worried about your vision. Reaching out to diabetes education programs, vision rehabilitation services, or support groups can provide practical tools and emotional support. If vision loss has affected your daily activities, a low vision specialist can recommend devices and strategies to help you maintain independence.
When to See a Retina Specialist
Because NVD can develop without symptoms, every person with diabetes should have a dilated eye exam at least once a year, or more often if recommended by their eye care provider. If you have been diagnosed with any stage of diabetic retinopathy, your retina specialist may recommend more frequent visits. Early detection of NVD before complications arise offers the best chance of preserving vision.
Contact a retina specialist or go to the emergency room immediately if you experience any of the following:
- A sudden shower of new floaters
- Flashes of light in your vision
- A dark curtain or shadow spreading across part of your vision
- Sudden, significant vision loss in one or both eyes
These symptoms may indicate a vitreous hemorrhage or retinal detachment, both of which require urgent evaluation and treatment to prevent permanent vision damage.
Questions and Answers
Anti-VEGF injections can cause the abnormal blood vessels to shrink significantly, and in many cases they regress substantially. However, the underlying condition, diabetic retinopathy caused by diabetes, is a chronic disease that requires ongoing management. Treatment aims to control the growth of new vessels and prevent vision-threatening complications rather than eliminate the disease entirely. Continued monitoring and treatment adjustments are part of long-term care.
The frequency of anti-VEGF injections varies from person to person. Most treatment plans begin with injections given every four to eight weeks during an initial phase. Over time, your retina specialist may extend the interval between injections based on how well the neovascularization responds. Some patients eventually need fewer injections, while others require ongoing treatment at regular intervals to keep the abnormal vessels inactive. Your retina specialist will tailor the schedule to your specific needs.
Both panretinal photocoagulation and anti-VEGF injections are effective treatments for proliferative diabetic retinopathy with NVD. The DRCR Retina Network Protocol S study showed that Lucentis (ranibizumab) performed comparably to PRP for managing PDR (DRCR Retina Network). Many retina specialists now use a combination of both approaches, starting with anti-VEGF injections to quickly reduce active neovascularization and then applying laser treatment for longer-term stability. The best approach depends on factors such as the severity of your condition, the presence of complications, and your ability to attend regular follow-up visits.
Untreated NVD can lead to serious, vision-threatening complications. The fragile new blood vessels can rupture and bleed into the vitreous, causing a vitreous hemorrhage that severely blurs vision. Over time, scar tissue can form along these vessels and contract, pulling the retina away from the back of the eye in what is called a tractional retinal detachment. Without intervention, nearly 25% of eyes with high-risk PDR experience severe vision loss within two years (PMC, 2024). Prompt treatment greatly reduces the risk of these outcomes.
While there is no guaranteed way to prevent NVD, strong control of blood sugar, blood pressure, and cholesterol levels significantly reduces the risk of developing proliferative diabetic retinopathy. Regular dilated eye exams allow early detection of diabetic changes before they progress to the proliferative stage. If earlier stages of retinopathy are found, your retina specialist can monitor you more closely and begin treatment at the earliest sign of progression. Early intervention and consistent diabetes management offer the best protection for your vision.