Diabetic Retinopathy

Introduction

If you live with diabetes, you have probably been told that your eyes need to be checked regularly. Diabetic retinopathy is the reason. It is the most common eye complication of diabetes, and over time it affects a large share of people who have lived with type 1 or type 2 diabetes for many years.

The phrase itself can sound frightening. Many patients first hear it during a routine eye check, often without any change in their vision, and worry that blindness is around the corner. The reality is more hopeful. Diabetic retinopathy is a slow, staged disease. With the screening, treatments, and blood sugar control available today, most people who are diagnosed early can keep useful vision for life.

This guide is written for people who already have diabetes and have either been diagnosed with diabetic retinopathy, told they have early signs, or are entering regular screening. It explains what is happening inside the eye, the stages of the disease, how decisions about treatment are made, and what long-term care looks like. It also covers diabetic macular oedema, the most common cause of vision change in diabetic eye disease, and the place of laser, injections, and surgery in modern care.

What Is Diabetic Retinopathy?

The retina depends on a dense network of very small blood vessels to keep it supplied with oxygen and nutrients. Over years, high blood sugar damages the walls of these vessels. They may:

• Leak fluid or blood into the surrounding retina
• Close off, leaving parts of the retina without enough blood supply
• Trigger the growth of new, fragile blood vessels that bleed easily and pull on the retina

Each of these changes can affect vision in a different way. The macula, the small central area of the retina responsible for sharp central vision — reading, recognising faces, driving — is especially vulnerable to swelling from leaking vessels. This is called diabetic macular oedema, or DME.

Diabetic retinopathy can affect anyone with diabetes, whether type 1, type 2, or gestational diabetes during pregnancy. The risk grows with the number of years a person has had diabetes and with how well blood sugar, blood pressure, and cholesterol have been controlled over that time.

Stages and Types of Diabetic Retinopathy

Eye specialists describe diabetic retinopathy in stages. The stage determines how often you are followed, when treatment begins, and what kind of treatment is offered. The main framework is widely used by societies such as the American Academy of Ophthalmology (AAO) and the International Council of Ophthalmology (ICO).

Non-proliferative Diabetic Retinopathy (NPDR)

NPDR is the earlier stage. The blood vessels in the retina are damaged but no new abnormal vessels have started to grow yet. It is divided into mild, moderate, and severe NPDR based on the number and pattern of changes the doctor sees on examination and imaging.

• Mild NPDR. Small balloon-like swellings of capillaries (microaneurysms) appear. Vision is usually normal.
• Moderate NPDR. More extensive changes including small haemorrhages and areas where blood flow is reduced.
• Severe NPDR. Widespread changes that signal a high risk of progressing to the next stage within the next year if not addressed.

Proliferative Diabetic Retinopathy (PDR)

PDR is the more advanced stage. In response to areas of the retina that are not getting enough blood, the eye begins to grow new blood vessels (this is what “proliferative” refers to). These new vessels are fragile and abnormal. They can bleed into the gel inside the eye (vitreous haemorrhage), form scar tissue that pulls on the retina, and in serious cases lead to retinal detachment or a form of glaucoma. PDR is the stage most associated with sudden, serious vision loss and usually requires treatment.

Diabetic Macular Oedema (DME)

Causes and Risk Factors

The root cause of diabetic retinopathy is long-standing exposure of the retinal blood vessels to high blood sugar. But several other factors influence how fast it develops and how severe it becomes.

• Duration of diabetes. The longer a person has lived with diabetes, the higher the risk. After 20 years of diabetes, the majority of people show some retinal changes.
• Blood sugar control. Higher long-term blood sugar, measured by HbA1c, accelerates damage. Stable, lower-range control slows it.
• Blood pressure. Untreated or poorly controlled high blood pressure adds stress to retinal vessels.
• Cholesterol and blood fats. Elevated cholesterol contributes to vessel damage and to fatty deposits in the retina.
• Kidney disease. Diabetic kidney disease often appears alongside diabetic retinopathy; they share the same small-vessel mechanism.
• Pregnancy. Retinopathy can progress more quickly during pregnancy in women with pre-existing diabetes, which is why extra eye checks are typically advised.
• Smoking. Smoking damages blood vessels throughout the body, including in the eye.
• Type of diabetes and age at onset. Type 1 diabetes diagnosed in childhood carries a high lifetime risk simply because of the years involved.

Genetics plays a part too — some people develop retinopathy after relatively few years of diabetes, while others go decades with stable eyes. Doctors cannot fully predict who will progress quickly, which is why regular screening matters for everyone with diabetes.

Signs and Symptoms

One of the most important things to understand about diabetic retinopathy is that it is usually silent in its early stages. The retina has no pain fibres, and early damage often does not affect vision until the macula is involved or until bleeding occurs. People are often surprised to learn at a routine eye exam that they already have moderate disease.

As the condition progresses, possible symptoms include:

• Blurred or fluctuating vision, sometimes changing from day to day with blood sugar swings
• Dark spots, strings, or “floaters” drifting across the field of vision
• A reddish haze or dark shadow, which can indicate bleeding into the eye
• Difficulty reading or seeing fine detail when DME affects the central retina
• Difficulty seeing in low light or at night
• Empty or dark areas in the field of vision
• Sudden, painless loss of vision in part or all of one eye, which can signal vitreous haemorrhage or retinal detachment and needs urgent assessment

For a reader already in regular eye care, the relevance of these symptoms is mostly about recognising change between appointments. New floaters, a sudden shadow, or a sudden drop in vision should be reported to an eye specialist promptly rather than waiting for the next scheduled visit.

How Diabetic Retinopathy Is Diagnosed

Diagnosis is based on a detailed eye examination by an ophthalmologist or trained eye-care professional, supported by imaging of the retina.

Dilated Eye Examination

Drops are used to widen the pupil so the doctor can look through the lens at the back of the eye. With special lenses and a slit-lamp microscope, the specialist can see microaneurysms, haemorrhages, abnormal new vessels, and signs of swelling. Pupils stay dilated for several hours, so vision is blurred and sensitive to light for the rest of the day.

Retinal Photography

Wide-field colour photographs of the retina document its appearance and allow comparison over time. In many diabetes screening programmes, a trained reader reviews these photos to identify people who need a specialist appointment.

Optical Coherence Tomography (OCT)

OCT is a quick, painless scan that produces detailed cross-section images of the retina. It is the standard test for diagnosing and monitoring diabetic macular oedema, because it shows fluid in the retinal layers that the doctor cannot easily judge by eye alone. OCT is typically repeated at each visit when DME is being treated.

Fluorescein Angiography

A dye is injected into a vein in the arm, and a special camera photographs the retina as the dye flows through its blood vessels. This shows areas of leakage, blockage, and abnormal new vessel growth in detail. Fluorescein angiography is used selectively, often before laser treatment or in complicated cases.

OCT Angiography

A newer, non-injection scan that maps the retinal blood vessels using OCT technology. It is increasingly used to assess areas of poor blood flow without the need for dye.

Screening Frequency

Once diabetes is diagnosed, regular screening becomes part of ongoing care. The American Diabetes Association and other major societies generally recommend:

• An eye examination at or shortly after the diagnosis of type 2 diabetes
• An examination within five years of diagnosis for type 1 diabetes, then yearly
• Annual examinations thereafter for most people, with more frequent checks if retinopathy is present or progressing
• Eye assessment before pregnancy where possible, and during each trimester for women with pre-existing diabetes

If retinopathy has been found, the eye specialist sets a personalised follow-up schedule, which may be every few months for active disease.

Treatment of Diabetic Retinopathy

Treatment depends on the stage of retinopathy, whether DME is present, and the overall health of the person. The aim is to stop progression, treat sight-threatening complications, and preserve as much vision as possible. Modern care has shifted significantly over the past decade, with anti-VEGF injections becoming central to treatment of DME and many cases of proliferative disease.

Managing Mild to Moderate NPDR

In mild and moderate NPDR without macular oedema, eye-specific treatment is usually not needed. The focus is on:

• Regular monitoring — typically every 6 to 12 months
• Optimising blood sugar (HbA1c targets agreed with the diabetes team)
• Controlling blood pressure and cholesterol
• Reviewing kidney function
• Stopping smoking

Tight metabolic control at this stage has been shown in major long-term studies to slow progression substantially.

Anti-VEGF Injections

VEGF, or vascular endothelial growth factor, is a protein that drives the growth of abnormal blood vessels and increases leakiness in damaged ones. Anti-VEGF drugs block this protein. They are given as injections into the vitreous (the gel inside the eye), under local anaesthetic, in the clinic. The injection itself takes seconds and most people describe pressure rather than pain.

Anti-VEGF therapy is now widely used for:

• Diabetic macular oedema affecting the centre of vision, where it is considered first-line by current AAO guidance
• Many cases of proliferative diabetic retinopathy, where it can reduce abnormal vessels and stabilise the retina

Laser was the mainstay of diabetic eye treatment for decades and remains important. There are two main types:

• Focal or grid laser. Tiny laser burns are applied to specific leaking vessels or areas of swelling near the macula. It is used in some cases of DME, particularly where the swelling is not directly at the centre of the macula.
• Panretinal photocoagulation (PRP). A scatter of laser burns is applied to the peripheral retina to reduce the drive for abnormal new vessels in proliferative disease. PRP can stabilise PDR very effectively. It does cause some loss of peripheral and night vision in exchange for protecting central sight, which the specialist will explain in detail.

Laser is usually done in clinic under local anaesthetic eye drops. Several sessions may be needed.

Vitrectomy Surgery

Doctors may consider vitrectomy when:

• There is significant bleeding into the vitreous that has not cleared on its own
• Scar tissue is pulling on the retina or causing tractional retinal detachment
• DME has not responded to injections and laser

Recovery from vitrectomy takes several weeks. If a gas bubble is used, the surgeon may ask the patient to keep their head in a particular position for a period afterwards. Air travel is restricted while gas is in the eye.

The Role of Medical Control

Eye-specific treatments work best when blood sugar, blood pressure, and cholesterol are also well controlled. Eye specialists routinely communicate with the diabetes care team, because injections and laser can stabilise an eye, but the underlying small-vessel disease is driven by metabolic factors. This shared care model — ophthalmology with endocrinology or the primary diabetes team — is the foundation of long-term vision preservation.

Living with Diabetic Retinopathy

Many people with diabetic retinopathy continue to live full lives, work, drive (where vision standards allow), and enjoy their usual activities. The key shift after diagnosis is treating the eyes as a part of overall diabetes care rather than as a separate issue that flares up only when vision changes.

Day-to-Day Vision

Vision can fluctuate, especially when blood sugar is changing or after treatments. After an injection, vision in the treated eye may be hazy for a day or two and small floaters from the injection are common. After laser, light sensitivity and some blurring are usual for a short period. The specialist will explain what to expect after each treatment.

Driving and Work

Local driving regulations set vision standards. After certain treatments — particularly extensive PRP laser — peripheral vision or night vision may be reduced, which can affect driving eligibility. Ask the eye specialist for a clear opinion on driving safety based on your specific vision and any recent treatment.

Emotional Wellbeing

Worry about vision is one of the most distressing parts of a diabetic retinopathy diagnosis. Anxiety, low mood, and a sense of loss of control are common, particularly around the time of treatment decisions or after a bleed. Talking with the care team about feelings as well as findings is reasonable; many diabetes clinics have access to psychology or counselling support, and patient groups can be a useful source of shared experience.

Low Vision Support

When vision has been affected despite treatment, low-vision services can make a significant difference. These may include magnifiers, lighting adjustments, screen-reader technology, large-print materials, and training in daily skills. Referral is typically made through the eye specialist when vision drops below certain levels.

Monitoring and Long-term Follow-up

Diabetic retinopathy is a long-term condition, and follow-up is shaped by where the disease is and how it is behaving.

• No retinopathy or minimal changes: annual eye screening is standard.
• Mild to moderate NPDR without DME: review every 6 to 12 months.
• Severe NPDR or treated PDR: closer review, often every 2 to 4 months in active phases.
• Active DME on injections: typically monthly initially, then spaced out as the swelling settles.

At each visit, the team usually checks vision, takes retinal photographs and OCT scans, and reviews diabetes control with the patient. The plan is then adjusted — sometimes injections continue, sometimes they are paused, sometimes laser is added.

Pregnancy is a specific situation where the schedule changes. Women with diabetes who become pregnant are usually seen by the eye specialist early in pregnancy and at intervals through it, because retinopathy can progress faster in pregnancy and may need treatment.

Complications

When diabetic retinopathy progresses, several complications can affect vision:

• Vitreous haemorrhage. Bleeding into the gel inside the eye, often from fragile new vessels. It can cause sudden floaters, shadows, or loss of vision. Some clear on their own; others need vitrectomy.
• Tractional retinal detachment. Scar tissue can contract and pull the retina away from the back of the eye. This is a serious cause of vision loss and usually requires surgery.
• Neovascular glaucoma. Abnormal new vessels can grow on the iris and block fluid drainage from the eye, causing a painful rise in eye pressure. It needs prompt treatment.
• Persistent macular oedema. Some DME does not fully resolve despite injections and laser, and may leave reduced central vision.

Most of these complications can be managed if caught early, which is why prompt reporting of new symptoms between appointments matters.

Prevention and Slowing Progression

Diabetic retinopathy cannot always be prevented entirely, but the rate at which it appears and progresses is strongly influenced by daily care.

Blood Sugar Control

Long-term studies in both type 1 and type 2 diabetes have shown that tighter blood sugar control reduces the risk of developing retinopathy and slows progression once it has appeared. HbA1c targets are individualised by the diabetes team; the eye specialist supports this by tracking the retina over time.

Blood Pressure

Treating high blood pressure protects the small vessels of the retina as well as the kidneys and the brain. People with diabetes and retinopathy are often advised to keep blood pressure within a specific target range.

Cholesterol and Lipids

Statins and other lipid-lowering medications are commonly part of diabetes care. Beyond their effect on heart disease, they may have a modest protective effect on the retina.

Stopping Smoking

Smoking accelerates damage to blood vessels everywhere in the body. Stopping is one of the most impactful changes a person with diabetic retinopathy can make.

Keeping Appointments

Diabetic Retinopathy in Children and Young People

Diabetic retinopathy is uncommon in children even when type 1 diabetes was diagnosed in early childhood, because it usually takes years of exposure to high blood sugar for changes to appear. For this reason, eye screening in children with diabetes typically begins around puberty or after several years of diabetes, rather than at the moment of diagnosis. The exact timing depends on age at diagnosis and the recommendations of the paediatric diabetes team.

When retinopathy does develop in adolescents and young adults, it can sometimes progress more quickly than in older adults, particularly through puberty and during pregnancy. Tight, but safe, blood sugar control during these years has long-term protective value. Parents of children with diabetes can support this by:

• Keeping regular diabetes clinic appointments
• Following the paediatric team’s schedule for the first eye examination
• Reporting any changes in vision the child describes, including blurring after periods of high blood sugar
• Encouraging healthy lifestyle habits early, including not starting smoking

Young women with diabetes planning a pregnancy benefit from an eye check before conception, because pre-pregnancy stabilisation reduces the risk of progression during pregnancy.

When to Seek Urgent Eye Care

Most diabetic retinopathy review is planned. There are a few situations where waiting for the next appointment is not appropriate. Contact your eye specialist promptly — or seek urgent eye care — if you notice:

• A sudden shower of new floaters in one eye
• A dark curtain or shadow moving across the vision
• Sudden, painless loss of vision in part or all of one eye
• A sudden change from clear to very blurred central vision
• A painful, red eye with reduced vision (which can indicate neovascular glaucoma)

Acting quickly on these symptoms can be the difference between a treatable problem and permanent vision loss.

Frequently Asked Questions

Can diabetic retinopathy be cured?

Diabetic retinopathy is generally not described as “cured” in the way an infection is cured. The underlying small-vessel damage caused by diabetes is long-term. However, the disease can often be stabilised so that vision is preserved for years or decades, and active complications such as macular oedema or new vessel growth can be treated effectively in many people.

If my vision is fine, do I still need eye checks?

Yes. Early and even moderate diabetic retinopathy usually causes no symptoms. Regular dilated examinations and retinal imaging are how disease is found at the stage where it responds best to treatment or careful monitoring. This is why diabetes care guidelines build annual eye checks into routine care.

Will I need injections forever?

Not necessarily. Some people need ongoing anti-VEGF injections for several years; others are able to stop after the eye stabilises. The eye specialist adjusts the schedule based on OCT findings and vision. Discussing the expected pattern of treatment with your specialist before starting injections can help set realistic expectations.

Does laser treatment cause vision loss?

Panretinal photocoagulation deliberately treats the outer retina to stop the drive for abnormal new vessels in proliferative disease. It can cause some loss of peripheral vision and night vision, but the trade-off is protection of central sight from much more serious complications. Focal laser for macular oedema is more localised and generally has less impact on vision. The specialist will explain the specific trade-offs in your case.

Can good blood sugar control reverse diabetic retinopathy?

Good blood sugar control is one of the most powerful tools to slow progression, but it does not reliably reverse damage that has already occurred. Interestingly, when blood sugar drops rapidly after a long period of being high, retinopathy can briefly worsen before stabilising — which is why diabetes teams often aim for steady, gradual improvement and may arrange closer eye monitoring during major changes in control.

Is diabetic retinopathy linked to other diabetes complications?

Yes. The same small-vessel damage process affects the kidneys (diabetic nephropathy) and the nerves (diabetic neuropathy). People with retinopathy are more likely to have, or to develop, these other complications, which is one reason eye findings prompt a wider review of diabetes care.

Can I exercise normally?

Most people with diabetic retinopathy can and should remain physically active. In advanced or active proliferative disease, very high-impact or strenuous activities that sharply raise blood pressure may temporarily increase the risk of bleeding into the eye, and the eye specialist may suggest modifying these for a period. Walking, swimming, and moderate aerobic exercise are generally encouraged unless specifically advised otherwise.

Will diabetic retinopathy affect my pregnancy plans?

Pregnancy can accelerate diabetic retinopathy, particularly when blood sugar control is brought down rapidly in early pregnancy. Women with diabetes are usually advised to have an eye assessment before conception where possible and follow-up checks during pregnancy. With good planning and monitoring, most pregnancies in women with diabetic retinopathy go well.

Conclusion

Diabetic retinopathy is one of the more serious long-term consequences of diabetes, but it is also one of the most studied and treatable. The combination of regular screening, modern treatments such as anti-VEGF injections and laser, surgical options when needed, and consistent control of blood sugar, blood pressure, and cholesterol means that severe vision loss from diabetes is now largely preventable for people who stay engaged with their care.

If you have been told you have diabetic retinopathy — at any stage — the most useful next step is usually a clear conversation with your eye specialist about your stage, your treatment plan, and your follow-up schedule, and a parallel conversation with your diabetes team about how blood sugar, blood pressure, and lifestyle factors fit into protecting your vision over the years ahead.