What is Proliferative Diabetic Retinopathy?
Proliferative diabetic retinopathy (PDR) is the advanced stage of diabetic retinopathy in which the retina begins to grow new, abnormal blood vessels. This process is called neovascularisation. These new vessels are weak and fragile, and they tend to leak blood into the vitreous (the clear gel that fills the eye), a complication known as vitreous haemorrhage.
Understanding Proliferative Diabetic Retinopathy
Think of the retina as the light-sensitive wallpaper at the back of your eye, supplied by a dense network of tiny blood vessels. In diabetes, sustained high blood sugar damages these small vessels. Over time, some of them close off, leaving parts of the retina starved of oxygen. The retina responds by releasing growth factors that try to build new blood vessels to restore the oxygen supply. But these new vessels are fragile and grow in the wrong places, tending to leak, bleed, and form scar tissue.
This process is what defines proliferative diabetic retinopathy. Because bleeding into the vitreous and traction on the retina can happen suddenly, proliferative diabetic retinopathy can cause rapid, severe vision loss in a previously comfortable eye. The good news is that with modern proliferative diabetic retinopathy treatment, including laser, injections, and surgery where needed, most cases can be controlled and useful vision preserved.
Proliferative diabetic retinopathy is particularly relevant in India, which has one of the largest diabetic populations in the world. Many people with long-standing diabetes are unaware that their eyes could be affected until vision is already reduced. This is why annual diabetic eye screening is so important, and why early diagnosis of proliferative diabetic retinopathy can make such a significant difference to long-term eye health.
What are the Symptoms of Proliferative Diabetic Retinopathy?
Proliferative diabetic retinopathy symptoms may not be noticeable in the early phase, which is why regular eye screening is essential for all diabetic patients. As the condition progresses, proliferative diabetic retinopathy symptoms can appear suddenly and significantly, particularly when a vitreous haemorrhage occurs.
Proliferative Diabetic Retinopathy Symptoms to Watch For
Symptom | Description |
Sudden floaters | Dark spots, strings, or cobweb like shapes drifting across your vision, often caused by bleeding from new vessels |
Sudden vision loss | A sudden and significant drop in vision, usually due to vitreous haemorrhage |
Blurred vision | Persistent blurring that does not improve with corrective lenses |
Dark or empty areas in vision | Parts of your visual field may appear blocked or missing |
Difficulty seeing at night | Reduced ability to see in dim or low light conditions |
Fluctuating vision | Vision that changes from day to day, often linked to blood sugar fluctuations |
Distorted vision | Straight lines may appear bent or wavy if the macula is affected |
When Should You See a Doctor?
Please visit an eye specialist urgently if you have diabetes and notice:
• A sudden shower of new floaters, cobwebs, or dark spots in your vision
• A sudden drop in vision in one or both eyes
• A dark curtain or shadow appearing over part of your vision
• Sudden flashes of light, particularly alongside floaters
• Persistent blurring that does not improve with glasses
• Distorted or wavy appearance of straight lines
• You have had diabetes for more than five years and have not had a dilated retinal examination in the past year
Sudden vision changes in a person with diabetes should always be treated as potentially serious. The sooner proliferative diabetic retinopathy treatment begins, the better the chance of preserving vision.
What are the Types of Diabetic Retinopathy?
Diabetic retinopathy is broadly classified into two main types, with the disease progressing through several stages. Understanding the different types of diabetic retinopathy helps explain where proliferative diabetic retinopathy fits in the overall picture and guides the approach to proliferative diabetic retinopathy treatment.
The Main Types of Diabetic Retinopathy
- Non Proliferative Diabetic Retinopathy (NPDR) Non proliferative diabetic retinopathy is the earlier stage of diabetic eye disease. In NPDR, the existing blood vessels in the retina become damaged, but no new abnormal vessels have yet formed.
Mild NPDR: Small areas of balloon-like swelling (microaneurysms) appear in the retinal blood vessels.
Moderate NPDR: Some retinal blood vessels become blocked, and small bleeds (dot and blot haemorrhages) may occur.
Severe NPDR: A larger number of blood vessels are blocked, depriving significant areas of the retina of blood supply. The retina sends signals to the body requesting new blood vessel growth.
- Proliferative Diabetic Retinopathy (PDR) Proliferative diabetic retinopathy is the advanced stage that follows severe NPDR. At this point, neovascularisation has begun, meaning new, abnormal blood vessels are actively growing on the retinal surface or the optic disc. These vessels can lead to vitreous haemorrhage, formation of fibrous scar tissue, and tractional retinal detachment. PDR represents the most sight threatening form of diabetic retinopathy and requires urgent specialist care.
- High Risk PDR Within proliferative diabetic retinopathy, a subcategory called “high risk PDR” is identified when neovascularisation is present on or near the optic disc, or when there is active bleeding from new vessels. High risk PDR carries the greatest danger of severe vision loss and demands immediate proliferative diabetic retinopathy treatment.
What Causes Proliferative Diabetic Retinopathy?
Proliferative diabetic retinopathy is caused by long term damage to the small blood vessels of the retina due to sustained high blood sugar levels. Understanding the proliferative diabetic retinopathy causes is the first step in preventing or delaying the condition through good diabetes control.
Primary Cause
Chronic hyperglycaemia (high blood sugar): Persistently elevated blood glucose damages the walls of the retinal capillaries, causing them to weaken, leak, and eventually close off. When enough vessels are blocked, the retina becomes ischaemic (deprived of oxygen), triggering neovascularisation. This is the fundamental mechanism behind proliferative diabetic retinopathy.
Risk Factors for Proliferative Diabetic Retinopathy
Duration of diabetes: The longer a person has diabetes, the higher the risk. Patients who have had diabetes for 15 years or more are at significantly greater risk of developing proliferative diabetic retinopathy.
Poor blood sugar control: Consistently high HbA1c levels increase the likelihood of progression to PDR.
High blood pressure (hypertension): Uncontrolled blood pressure adds further stress to already weakened retinal blood vessels.
High cholesterol (dyslipidaemia): Elevated blood lipids can worsen retinal vascular damage.
Kidney disease (diabetic nephropathy): The presence of kidney complications often indicates more widespread vascular damage, including in the eyes.
Pregnancy: Pregnant women with pre existing diabetes may experience a worsening of diabetic retinopathy.
Smoking: Tobacco use compounds vascular damage and raises the risk of progression.
Anaemia: Low haemoglobin levels reduce the oxygen carrying capacity of the blood, contributing to retinal ischaemia.
How Do Doctors Diagnose Proliferative Diabetic Retinopathy?
Diagnosing proliferative diabetic retinopathy requires a thorough examination of the back of the eye, often with specialised imaging. Because proliferative diabetic retinopathy can exist without noticeable symptoms in its early phase, regular diabetic eye screening is the most reliable way to detect the condition in time.
The examination usually begins with a visual acuity test to measure how clearly each eye sees. Eye drops are then used to dilate the pupils, giving the ophthalmologist a full view of the retina. A slit lamp with a special lens is used to examine the retina in detail and identify neovascularisation, haemorrhages, and any signs of retinal detachment.
Additional tests are often used in proliferative diabetic retinopathy diagnosis. Optical coherence tomography (OCT) provides detailed cross-sectional images of the retina and is particularly useful for assessing diabetic macular oedema. Fundus fluorescein angiography (FFA), where a fluorescent dye is injected into a vein and photographs are taken as it circulates through the retina, highlights areas of leakage and non-perfusion, helping the doctor plan laser treatment. Ultra-wide field retinal imaging can also show the peripheral retina in detail, which is valuable in proliferative diabetic retinopathy.
What Does Proliferative Diabetic Retinopathy Treatment Look Like?
Proliferative diabetic retinopathy treatment focuses on stopping the growth of abnormal blood vessels, managing complications, and preserving as much vision as possible. Proliferative diabetic retinopathy treatment must be combined with good blood sugar control and management of associated conditions such as hypertension and cholesterol.
In many cases, proliferative diabetic retinopathy treatment is a step-by-step process rather than a single intervention, and the best outcomes are often achieved by combining multiple approaches tailored to the individual patient.
Proliferative Diabetic Retinopathy Treatment Options
- Pan Retinal Photocoagulation (PRP) Laser Treatment Pan retinal photocoagulation is the standard laser treatment for proliferative diabetic retinopathy. During this procedure, multiple laser burns are applied to the peripheral (outer) areas of the retina. This reduces the oxygen demand of the damaged retina, which in turn slows or stops the release of growth factors that drive neovascularisation. PRP is typically delivered over two to three sessions and has been proven to significantly reduce the risk of severe vision loss in PDR. PRP may cause some reduction in peripheral and night vision, but this is generally considered acceptable given the protection it offers to central vision.
- Anti VEGF Intravitreal Injections Anti VEGF (vascular endothelial growth factor) injections are increasingly used in the treatment of proliferative diabetic retinopathy. These medications work by blocking the signals that drive abnormal blood vessel growth. Commonly used agents include ranibizumab, aflibercept, and bevacizumab. Injections are given directly into the vitreous cavity of the eye under local anaesthesia. Anti VEGF therapy can cause rapid regression of new vessels and is often used alongside PRP laser treatment. It is also effective for treating diabetic macular oedema, which frequently accompanies PDR.
- Vitrectomy Surgery Vitrectomy is a surgical procedure indicated for advanced complications of proliferative diabetic retinopathy, including non clearing vitreous haemorrhage (when bleeding into the vitreous does not resolve on its own within a few weeks), tractional retinal detachment (when scar tissue pulls the retina away from the back of the eye, especially if the macula is threatened or involved), and combined tractional and rhegmatogenous retinal detachment (a more complex situation requiring urgent surgical intervention). During vitrectomy, the vitreous gel and any blood or scar tissue are carefully removed. The retina is then flattened and stabilised, often with the help of laser treatment applied during the surgery.
- Combined Treatment Approaches In many cases, the best outcomes for proliferative diabetic retinopathy are achieved by combining multiple treatments. Anti VEGF injections may be given before vitrectomy surgery to reduce bleeding and make the procedure safer. PRP laser may be combined with anti VEGF therapy for more comprehensive management. Your retina specialist will design a proliferative diabetic retinopathy treatment plan tailored to the specific findings in your eyes.
- Management of Diabetic Macular Oedema Diabetic macular oedema (DMO) can occur alongside proliferative diabetic retinopathy and is a common cause of vision loss in diabetic patients. Treatment for DMO includes anti VEGF intravitreal injections (the primary treatment), intravitreal steroid implants in selected cases, and focal or grid laser photocoagulation.
- Systemic Health Management Effective proliferative diabetic retinopathy treatment is not limited to the eyes. Controlling the underlying systemic factors is equally important, including blood sugar control (maintaining HbA1c levels within the target range recommended by your physician), blood pressure management (keeping blood pressure below 140/90 mmHg or as advised by your doctor), cholesterol management (treating dyslipidaemia with appropriate medications), and regular medical reviews (coordinating care between your ophthalmologist, diabetologist, and general physician).
Proliferative Diabetic Retinopathy in the Indian Context
India has one of the largest populations of people with diabetes in the world, and diabetic retinopathy, including proliferative diabetic retinopathy, is a growing public health concern. Studies suggest that a significant proportion of people with long-standing diabetes in India will develop some form of retinopathy, and many will progress to proliferative diabetic retinopathy if not monitored regularly.
Several factors contribute to this burden: long durations of diabetes before diagnosis, variable access to diabetes care, lower rates of regular eye screening, and a higher prevalence of associated conditions such as hypertension and kidney disease. Many patients only present to an ophthalmologist after they have already developed vitreous haemorrhage or advanced retinal changes.
Vasan Eye Care, with 150+ centres across India as part of ASG Enterprises, has made diabetic eye screening and proliferative diabetic retinopathy treatment accessible across the country, including in smaller cities and semi-urban areas where specialised retinal care was previously difficult to obtain.
Lifestyle and Self-Care for Diabetic Patients
Alongside medical and surgical proliferative diabetic retinopathy treatment, daily lifestyle choices play a critical role in protecting the eyes:
• Follow your diabetes medication regimen strictly and never skip doses
• Monitor your blood sugar at home as advised by your physician
• Eat a balanced, low-glycaemic-index diet with plenty of vegetables, whole grains, and lean proteins
• Limit refined sugars, fried foods, and highly processed snacks
• Maintain a healthy weight through regular physical activity
• Control blood pressure and cholesterol as directed by your doctor
• Do not smoke and limit alcohol intake
• Attend all scheduled eye and diabetes follow-up appointments, even when you feel well
• Report any new visual symptoms promptly, rather than waiting for the next routine check
These measures complement proliferative diabetic retinopathy treatment and significantly improve long-term outcomes.
Proliferative Diabetic Retinopathy Care at Vasan Eye Care
Proliferative diabetic retinopathy is one of the conditions our retina team at Vasan Eye Care sees and treats on a regular basis. Our specialists are trained in the full range of diagnostic and treatment options, from screening through to complex vitreoretinal surgery.
When you visit us for a retinal assessment, here is what you can expect:
• A detailed dilated retinal examination, supported by OCT and FFA where needed
• A clear explanation of the stage of your diabetic retinopathy and what it means for your vision
• An individualised proliferative diabetic retinopathy treatment plan combining laser, injections, and surgery as appropriate
• Access to intravitreal anti-VEGF injections and PRP laser at our equipped centres
• Advanced vitrectomy surgery for vitreous haemorrhage and tractional retinal detachment
• Coordinated care with your diabetologist and general physician to optimise systemic health
• Regular long-term follow-up to protect the retina and detect any new changes early
Our 500+ eye care experts, 5,000+ dedicated care staff, and 150+ centres across India, as part of ASG Enterprises, make specialist retinal care accessible wherever you are.
Glossary of Terms Related to Proliferative Diabetic Retinopathy
| Term | Meaning |
| Proliferative Diabetic Retinopathy (PDR) | The advanced stage of diabetic retinopathy marked by the growth of new, abnormal blood vessels on the retina |
| Neovascularisation | The formation of new, abnormal blood vessels, typically in response to oxygen deprivation in the retina |
| Vitreous Haemorrhage | Bleeding into the vitreous gel of the eye, often from fragile new blood vessels in PDR |
| Retinal Detachment | Separation of the retina from the underlying tissue at the back of the eye |
| Tractional Retinal Detachment | A type of retinal detachment caused by scar tissue pulling the retina away from its normal position |
| Diabetic Macular Oedema (DMO) | Swelling of the macula due to fluid leakage from damaged blood vessels in diabetic eye disease |
| Pan Retinal Photocoagulation (PRP) | A laser treatment that targets the peripheral retina to reduce the drive for abnormal blood vessel growth |
| Anti VEGF | Medications that block vascular endothelial growth factor, a protein that promotes abnormal blood vessel growth |
| Vitrectomy | A surgical procedure to remove the vitreous gel, blood, or scar tissue from inside the eye |
| Ischaemia | A condition where tissue does not receive enough blood and oxygen |
| HbA1c | A blood test that measures average blood sugar levels over the past two to three months |
| Microaneurysm | A small, balloon like swelling in a tiny retinal blood vessel, often the earliest sign of diabetic retinopathy |
| Fundus Fluorescein Angiography (FFA) | A diagnostic imaging test using fluorescent dye to photograph blood flow in the retina |
| Optical Coherence Tomography (OCT) | A non invasive imaging technique that produces detailed cross sectional images of the retina |
Related Eye Conditions
Understanding conditions related to proliferative diabetic retinopathy can help you stay informed about your overall eye and metabolic health:
Non Proliferative Diabetic Retinopathy (NPDR): The earlier stage of diabetic retinopathy, where blood vessel damage is present but neovascularisation has not yet begun.
Diabetic Macular Oedema (DMO): Swelling of the macula caused by fluid leakage from damaged retinal blood vessels, often occurring alongside diabetic retinopathy.
Retinal Detachment: Separation of the retina from its underlying tissue, which can occur as a complication of proliferative diabetic retinopathy.
Vitreous Haemorrhage: Bleeding into the vitreous cavity, frequently caused by ruptured new blood vessels in PDR.
Neovascular Glaucoma: A serious form of glaucoma that can develop when abnormal blood vessels grow on the iris, sometimes as a complication of advanced PDR.
Diabetic Nephropathy: Kidney disease caused by diabetes, often found alongside diabetic retinopathy as both are microvascular complications.
References
Proliferative Diabetic Retinopathy. National Center for Biotechnology Information (NCBI), StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK563247/
Diabetic Retinopathy. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/8591-diabetic-retinopathy
Diabetic Retinopathy: What You Should Know. American Academy of Ophthalmology. https://www.aao.org/eye-health/diseases/diabetic-retinopathy
Diabetic Retinopathy. World Health Organization (WHO). https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment
Early Treatment Diabetic Retinopathy Study (ETDRS). National Center for Biotechnology Information (NCBI), PubMed. https://pubmed.ncbi.nlm.nih.gov/2062515/
Disclaimer: This content is for informational purposes only and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified ophthalmologist for concerns about your eye health.
For appointments, call 1800 571 2222 or visit your nearest Vasan Eye Care centre.
Frequently Asked Questions (FAQs)
Proliferative diabetic retinopathy is the most advanced stage of diabetic retinopathy. It occurs when damaged retinal blood vessels become so blocked that the retina is deprived of oxygen. In response, the eye grows new, abnormal blood vessels (neovascularisation) on the retinal surface. These fragile vessels are prone to bleeding and can lead to serious complications such as vitreous haemorrhage and retinal detachment.
PDR is a very serious condition and is considered sight threatening. Without timely proliferative diabetic retinopathy treatment, the condition can lead to severe and permanent vision loss or even blindness. It is one of the leading causes of preventable blindness in adults with diabetes. Early detection through regular eye screening and prompt treatment can significantly reduce this risk.
The damage caused by proliferative diabetic retinopathy cannot be fully reversed. However, treatment can stop or slow the progression of the disease. Laser therapy, anti VEGF injections, and vitrectomy surgery can control neovascularisation, clear vitreous haemorrhage, and repair retinal detachment. Good blood sugar and blood pressure control also help prevent further deterioration. The earlier proliferative diabetic retinopathy treatment begins, the better the chances of preserving useful vision.
Non proliferative diabetic retinopathy (NPDR) is the earlier stage in which the existing retinal blood vessels are damaged but no new abnormal vessels have grown. NPDR may involve microaneurysms, retinal haemorrhages, and cotton wool spots. Proliferative diabetic retinopathy (PDR) is the advanced stage where neovascularisation has begun. The presence of new abnormal blood vessels is what distinguishes PDR from NPDR. PDR carries a significantly higher risk of severe vision loss.
The main treatments for proliferative diabetic retinopathy include pan retinal photocoagulation (PRP) laser, anti VEGF intravitreal injections, and vitrectomy surgery. PRP laser reduces the oxygen demand of the retina to stop neovascularisation. Anti VEGF injections block the growth factors responsible for new vessel formation. Vitrectomy is performed when there is non clearing vitreous haemorrhage or retinal detachment. Often, a combination of these treatments provides the best results.
Yes, if left untreated, proliferative diabetic retinopathy can cause blindness. Severe vitreous haemorrhage can block light from reaching the retina, and tractional retinal detachment can permanently damage the retinal tissue. However, with timely and appropriate proliferative diabetic retinopathy treatment, the risk of blindness from PDR can be greatly reduced. This is why regular diabetic eye screening is so important.
Diabetic patients can take several steps to protect their eyes from diabetic eye disease, including proliferative diabetic retinopathy. Maintain good blood sugar control (target HbA1c as advised by your doctor), keep blood pressure and cholesterol within healthy ranges, attend annual dilated eye examinations even if vision seems normal, do not smoke, report any sudden changes in vision to your eye doctor immediately, and follow your prescribed treatment plan for diabetes and any related conditions.
All patients with diabetes should have a comprehensive dilated eye examination at least once a year. If diabetic retinopathy has already been diagnosed, your ophthalmologist may recommend more frequent examinations, such as every three to six months, depending on the severity. Pregnant women with diabetes should have an eye examination in the first trimester and be monitored throughout pregnancy.
