Retinal neovascularisation is a condition where abnormal, fragile blood vessels grow in areas of the retina where they shouldn’t exist. These new vessels develop as the body’s attempt to compensate for damaged or blocked blood circulation, but instead of solving the problem, they often make it worse by leaking fluid and blood, which can lead to serious vision problems if left untreated.

How Treatment Can Help Preserve Your Sight

The main goal of treating retinal neovascularisation is to stop the abnormal blood vessels from growing, prevent them from leaking, and preserve as much vision as possible. Treatment approaches focus on addressing the underlying cause of the condition—such as diabetes, blocked blood vessels, or age-related changes—while also directly targeting the new vessel growth. Because these fragile vessels can cause rapid damage, early intervention is crucial to protect your eyesight.^[1]

Treatment strategies vary depending on what caused the neovascularisation in the first place and how far the condition has progressed. For instance, someone with diabetic retinopathy will need different care than someone with age-related macular degeneration. Your eye specialist will consider factors like the stage of your disease, the location and extent of the abnormal vessels, your overall health, and how well your remaining vision functions when creating a treatment plan.^[2]

Modern medicine offers several established treatment options that have been tested and approved by medical societies worldwide. At the same time, researchers continue to explore new therapies through clinical trials, seeking better ways to manage this sight-threatening condition. Regular, comprehensive eye examinations with pupil dilation remain essential, as they allow your ophthalmologist to detect neovascularisation early and begin treatment before irreversible damage occurs.^[3]

Standard Treatments That Eye Doctors Use Today

Injections Into the Eye

The most common and effective standard treatment for retinal neovascularisation involves injections directly into the eye. These are called intravitreal injections, meaning the medicine is delivered into the vitreous—the clear, gel-like substance that fills the back of your eye. While the idea of an eye injection might sound frightening, these procedures are performed with numbing medication and have become routine in eye care clinics.^[2]

The medications used in these injections are called anti-VEGF drugs. VEGF stands for vascular endothelial growth factor, which is a protein that promotes the growth of new blood vessels. In healthy situations, VEGF helps the body heal wounds and build normal blood vessels. However, when retinal tissue becomes starved of oxygen—a condition called ischemia—it releases too much VEGF, triggering the growth of abnormal, leaky vessels.^[4]

Anti-VEGF medications work by blocking this protein, either slowing down the formation of abnormal blood vessels or preventing existing ones from leaking fluid into the retina. Several anti-VEGF drugs are currently available and widely used, including bevacizumab (Avastin), ranibizumab (Lucentis), aflibercept (Eylea), brolucizumab (Beovu), and faricimab (Vabysmo). Each has slightly different characteristics, but all share the same basic mechanism of inhibiting new vessel growth.^[5]

These injections typically need to be repeated over time. Your eye doctor will determine the schedule based on how your eye responds to treatment. Some people may need injections every month initially, while others may space them out to every few months once the condition stabilizes. Regular monitoring with imaging tests helps your doctor decide when the next injection is needed.^[6]

Laser Treatment

Laser therapy has been used for decades to treat retinal neovascularisation and remains an important treatment option. The most common technique is called pan-retinal photocoagulation, often shortened to PRP. This procedure involves using a laser to create small burns in the peripheral parts of the retina—the areas away from the center of your vision.^[2]

The laser treatment works by destroying the oxygen-starved areas of the retina that are releasing VEGF and other signals that promote abnormal blood vessel growth. By eliminating these ischemic regions, the stimulus for neovascularisation is reduced or removed altogether. PRP is particularly effective for diabetic retinopathy and retinal vein occlusions, where large areas of the peripheral retina have lost their normal blood supply.^[7]

Another laser technique is photodynamic therapy, which combines light with light-sensitive medications. In this approach, a special drug is injected into your bloodstream, and when it reaches the abnormal blood vessels in your eye, a cool laser is used to activate it. This activation causes the medication to close off the damaged vessels without harming surrounding tissue. Photodynamic therapy has been used especially for wet age-related macular degeneration.^[5]

A third laser approach uses a thermal laser, which applies heat directly to burn and seal leaky blood vessels. This prevents further growth and stops bleeding. The choice of laser technique depends on the type and location of neovascularisation, as well as how advanced the condition is.^[5]

Surgical Procedures

When neovascularisation has caused complications such as bleeding into the vitreous cavity, retinal detachment, or significant scarring, surgery may become necessary. The most common surgical procedure is called a vitrectomy, which involves removing part or all of the vitreous gel from the back of the eye.^[5]

During a vitrectomy, the surgeon makes tiny incisions in the eye and uses specialized instruments to remove blood, scar tissue, and the gel itself. This clears the visual path and allows the surgeon to address any underlying problems, such as reattaching a detached retina or removing fibrous membranes that are pulling on the retina. The vitreous is replaced with a clear solution that maintains the eye’s normal shape and pressure.^[5]

Vitrectomy is typically performed for advanced cases of diabetic retinopathy where extensive scarring has developed, or when there has been severe bleeding that doesn’t clear on its own. The procedure is done under local or general anesthesia, and recovery can take several weeks. During this time, you may need to maintain certain head positions and avoid strenuous activities to allow proper healing.^[5]

Another surgical technique called pneumatic retinopexy may be used for certain types of retinal detachment associated with neovascularisation. In this procedure, a gas bubble is injected into the vitreous cavity. The bubble rises and presses against the detached retina, sealing any breaks until the retina reattaches naturally. Additional techniques like freezing therapy (cryotherapy) or laser photocoagulation may be combined with this approach.^[5]

Side Effects of Standard Treatments

Like all medical interventions, treatments for retinal neovascularisation can have side effects, though most are temporary and manageable. With intravitreal injections, the most common side effects include temporary eye discomfort, redness, a feeling of something in the eye, and increased floaters—small specks or clouds moving in your field of vision. Serious complications like infection or retinal detachment are rare but possible, which is why the procedure is performed under sterile conditions.^[2]

Laser treatment can cause some permanent loss of peripheral vision, since the procedure deliberately destroys parts of the outer retina. Some people also experience decreased night vision or difficulty adjusting to bright light. Rarely, the laser can accidentally damage the central retina if not performed carefully, affecting sharp central vision. These risks are balanced against the benefit of preventing more severe vision loss from uncontrolled neovascularisation.^[2]

Surgical procedures carry additional risks including bleeding, infection, cataract formation, increased eye pressure, and incomplete healing. Recovery from vitrectomy surgery requires patience, as vision may be blurry for weeks or months. Some people develop cataracts within a year or two after vitrectomy, requiring additional surgery to restore clear vision.^[5]

Experimental Treatments Being Tested in Clinical Trials

While current treatments have significantly improved outcomes for people with retinal neovascularisation, researchers continue searching for even better therapies. Clinical trials are ongoing worldwide to test new drugs, innovative delivery methods, and novel approaches that might provide longer-lasting effects, require fewer treatments, or work for people who don’t respond well to existing options.

Combining Different Anti-Growth Factors

Although blocking VEGF has proven very effective, scientists have discovered that other growth factors also play important roles in promoting abnormal blood vessel growth. One such factor is platelet-derived growth factor-B, abbreviated as PDGF-B. This protein helps recruit cells called pericytes, which stabilize new blood vessels and make them more resistant to treatment.^[4]

Clinical trials have explored combining VEGF antagonists with PDGF-B inhibitors. Early results suggest that blocking both pathways simultaneously may provide greater benefits than targeting VEGF alone, particularly for patients with wet age-related macular degeneration. By preventing pericytes from stabilizing the abnormal vessels, the combination therapy might make the vessels more vulnerable to regression.^[4]

Other molecules being investigated include angiopoietin-2, which is elevated in conditions where hypoxia drives blood vessel growth, and placental growth factor, another member of the VEGF family. Drugs that target multiple pathways at once are sometimes called “multi-targeted” therapies. The idea is that by attacking the problem from several angles, the treatment might be more effective and the disease less likely to find ways around the blockade.^[4]

Targeting Hypoxia Directly

Since lack of oxygen (hypoxia) is the fundamental problem triggering retinal neovascularisation in many cases, some researchers are exploring ways to target hypoxia-inducible factor-1 (HIF-1). This is a protein that acts like a master switch, turning on genes that promote blood vessel growth when oxygen levels drop. By directly inhibiting HIF-1, it might be possible to shut down the entire cascade of events leading to neovascularisation at its source.^[4]

Drugs that block HIF-1 are still in early stages of development and testing. The challenge is to design medications that can safely target this protein without interfering with normal healing processes or causing unwanted effects in other parts of the body. If successful, HIF-1 inhibitors could represent a fundamentally different approach to managing diseases driven by retinal ischemia.^[4]

Gene Therapy Approaches

One of the most exciting frontiers in treating retinal neovascularisation involves gene therapy—the idea of delivering genetic instructions directly into cells to produce therapeutic proteins continuously over time. This approach could potentially eliminate the need for repeated injections by creating a long-lasting or even permanent treatment effect.

Gene therapy works by packaging therapeutic genes into harmless viral vectors—modified viruses that can’t cause disease but are very efficient at delivering their genetic cargo into cells. Once injected into the eye, these vectors enter retinal cells and insert genes that produce anti-VEGF proteins or other beneficial substances. The cells then become tiny factories, continuously manufacturing the therapeutic agent.^[4]

Several gene therapy trials are testing this concept for conditions like wet age-related macular degeneration. If successful, a single injection might provide protection for years, greatly reducing the treatment burden for patients. Some approaches use engineered genes that produce versions of natural proteins found in the eye that normally prevent excessive blood vessel growth. By restoring the balance between pro-angiogenic and anti-angiogenic factors, gene therapy aims to achieve long-term control of neovascularisation.^[4]

Longer-Acting Drug Formulations

Even without gene therapy, pharmaceutical companies are developing new formulations of existing anti-VEGF drugs designed to last longer in the eye. These might involve creating drug molecules with modified structures that break down more slowly, packaging drugs into slow-release implants, or developing biologic molecules with enhanced properties.

Some trials are testing port delivery systems—tiny reservoirs implanted into the eye that slowly release medication over months. Patients would need refills periodically but far less frequently than current injection schedules. These delivery systems could significantly improve quality of life for people who require ongoing treatment, reducing clinic visits and the cumulative risks associated with repeated procedures.

Immunotherapy and Inflammation Control

Inflammation often accompanies neovascularisation, contributing to blood vessel leakage and tissue damage. Corticosteroid medications, which are powerful anti-inflammatory drugs, have been used in eye disease for many years, sometimes delivered through injections or implants. Researchers continue to refine these approaches and explore new anti-inflammatory agents specifically tailored for retinal conditions.^[10]

Some experimental therapies aim to modulate the immune system’s response to retinal damage more precisely, potentially reducing harmful inflammation while preserving protective immune functions. These immunomodulatory approaches are being tested in various stages of clinical trials.

Understanding Clinical Trial Phases

When reading about experimental treatments, you’ll often see references to different trial phases. Phase I trials are the first step, involving small numbers of participants to test whether a new treatment is safe and to identify appropriate doses. These trials primarily focus on safety rather than effectiveness.^[2]

Phase II trials expand to larger groups and begin evaluating whether the treatment actually works—does it slow neovascularisation, improve vision, or provide other benefits? Phase II studies still closely monitor safety but place more emphasis on gathering evidence of efficacy.^[2]

Phase III trials are the largest and most rigorous, comparing the new treatment directly against current standards of care or placebo. These trials typically involve hundreds or thousands of participants at multiple locations. Successful Phase III trials provide the evidence needed for regulatory approval, allowing the treatment to become available to everyone who might benefit.^[2]

Clinical trials for retinal neovascularisation treatments are conducted in many countries, including the United States, European nations, and Poland. Eligibility requirements vary by trial but typically include having a specific form of the disease at a particular stage, meeting certain age or health criteria, and being willing to follow the trial protocol. Your eye doctor can help determine if you might be a candidate for any ongoing trials.

Most Common Treatment Methods

• Intravitreal Anti-VEGF Injections
  • Bevacizumab (Avastin) – inhibits vascular endothelial growth factor to slow abnormal blood vessel growth
  • Ranibizumab (Lucentis) – blocks VEGF protein to prevent vessels from leaking fluid
  • Aflibercept (Eylea) – binds to VEGF and related growth factors to stop neovascularisation
  • Brolucizumab (Beovu) – a smaller molecule anti-VEGF agent allowing higher doses in the same injection volume
  • Faricimab (Vabysmo) – targets both VEGF and angiopoietin-2 pathways simultaneously
• Laser Therapies
  • Pan-retinal photocoagulation (PRP) – creates laser burns in peripheral retina to reduce ischemia and VEGF production, commonly used for diabetic retinopathy and vein occlusions
  • Photodynamic therapy – combines light-sensitive medication with laser activation to close abnormal vessels
  • Thermal laser photocoagulation – uses heat to burn and seal leaky blood vessels
• Vitreoretinal Surgery
  • Vitrectomy – removes blood, scar tissue, and vitreous gel from the eye, performed for advanced diabetic retinopathy with scarring
  • Pneumatic retinopexy – injects gas bubble to reattach detached retina, often combined with laser or freezing therapy
  • Cryotherapy – freezing technique to treat retinal breaks or stabilize tissue