Sickle cell retinopathy

This page contains a summary of our information on sickle cell retinpathy. To read our full information, download our factsheet.

When sickle cell disease damages the retina, it is called sickle cell retinopathy. It is caused by loss of blood supply to certain parts of the retina (known as ischaemic retina). This is because red blood cells in sickle cell disease are sticky and less flexible. They can block the tiny blood vessels that supply nutrients and oxygen to keep the retina healthy.

Sickle cell retinopathy can affect the retina in different ways. It can be divided into 2 types:

• Non proliferative sickle cell retinopathy (NPSCR) is when there are small changes in the retina. Many people do not notice any change in their vision.
• Proliferative sickle cell retinopathy (PSR) happens when new, fragile blood vessels grow and leak in the retina. This type is more likely to affect sight and can lead to further eye complications such as vitreous haemorrhage and retinal detachment.

Non-proliferative sickle cell retinopathy

Small areas of blood vessel closure in the back of the eye will cause slight changes in the retina. These changes are not noticed by the individual and the vision is not affected. No treatment is required for this. However, monitoring by an ophthalmologist every 1-2 years is advised.

Proliferative sickle cell retinopathy (PSR)

What happens?

If sickle cell reduces the blood supply to the retina, the retina releases a protein called vascular endothelial growth factor (VEGF). VEGF makes new blood vessels grow in the outer edges of your retina (peripheral retina). The new blood vessels are weak and leaky and can cause further damage to your retina and vision.

The new blood vessels form fan-shaped networks (known as sea-fan) along the surface of the retina and back of the vitreous gel inside the eye. Movement between the two surfaces can cause the new blood vessels to leak, causing bleeding into the clear gel inside the eye. This is called a vitreous haemorrhage.

The sea-fans can be small and may disappear on their own, or they can grow quickly, join together with other sea-fans and become much larger.

In about four out of 10 people with PSR, the new blood vessels block up and the sea-fan resolves on its own. In other cases, the sea-fans do not grow much bigger and do not bleed either. However, in other cases recurrent bleeding or aggressive scar tissue formation may result.

Who does it affect?

PSR is more common in people with HbSC type of sickle cell disease (this form tends to have milder symptoms) than those with HbSS (the most common and severe form of sickle cell disease).

PSR usually develops in:

• Males -between the ages of 15 and 24 years
• Females – between the ages of 20 and 39

But it can start earlier from around 8 years old in HbSC and 13 years old in HbSS.

What increases the risk of sight loss from PSR?

The following factors can increase the risk of PSR causing sight loss:

• Age – the risk increases as people get older.
• Male gender – males are more likely to experience sight loss from PSR than females.
• HbSC – people with HbSC type of sickle cell disease are more likely to experience sight loss from PSR than people who have other types.

What are the complications of PSR?

People with PSR can have sight loss from the following complications:

• Vitreous haemorrhage: where blood from new blood vessels leak into the vitreous gel. The vitreous gel is normally clear to let light pass through to the retina. If there is blood in the vitreous gel, this can block the light and cause vision to become cloudy.
• Retinal detachment: where the retina separates from the inside of the eye. This can occur due to the new blood vessels pulling on the retina (tractional retinal detachment) and/or due to a small tear occurring in the retina. A retinal detachment can cause sight loss in the affected area and needs to be treated very quickly.

Some of the other ways that sickle cell disease can affect the retina and cause reduced vision include:

• Sickle cell maculopathy: when there is a loss of blood supply to the macular area (central area of the retina). It can cause the macula area to become thin which affects how well it works to give you detailed vision. Rarely, the very centre of the macula, known as the fovea may be affected and cause reduction in vision.
• Retinal artery occlusion: when the blood vessels that brings blood and oxygen to the retina becomes blocked. This can cause a sudden loss of vision. The amount of sight lost depends on where the blockage has occurred.
• Epiretinal membrane (ERM): where a sheet of naturally occurring cells develops on or above the surface of the macula. ERM can affect vision if this sheet of cells starts to shrink, causing the retina to wrinkle up under it. This wrinkling of the retina can then cause distortion and blurring of your vision, as well as a possible reduction in your level of sight.
• Macular hole: where a small gap which develops in the centre of the macula. A macular hole affects your central vision. It can make your vision distorted, blurred and affect how well you can see detail. You may also have a blank patch in the centre of your vision.

Spotting changes at the back of the eye early can help prevent sight loss. It is important for everyone with sickle cell disease to have regular eye examinations. In addition to your routine eye examinations with the optometrist (optician), you should also have regular eye screening. This screening does not replace your regular eye examinations as it looks specifically for any changes to your eye caused by your sickle cell disease.

Everyone with sickle cell disease should have regular eye examinations as recommended by the National Institute of Clinical Excellence (NICE). Your GP or haematology team can refer you to the ophthalmology eye service.

Currently, there is no national screening for sickle cell retinopathy, but NICE recommends that eyes be evaluated by the ophthalmology team:

• every 2 or 3 years If you have no sickle cell retinopathy
• every year or more often as recommended by your ophthalmologist (eye doctor) if there are changes to your retina

Being aware of the symptoms

It is important that if you experience any injury or trauma to the eye, that you have your eyes examined urgently.

Sometimes, PSR is diagnosed because you suddenly notice signs that your eyesight has changed. These signs may include:

• Floaters: this is where you can see small dark dots, squiggly lines or cobwebs.
• A ‘dark shadow’ or a curtain moving across your vision.
• Blurred vision.
• Flashing lights in your vision which appear suddenly.

It is important that you are seen urgently if you experience any of the above symptoms. Ask for an urgent appointment with your optometrist (optician) or your eye clinic. Alternatively, attend your nearest eye casualty or contact NHS 111.

Sea-fans can disappear on their own in some people so your ophthalmologist may choose to monitor them for awhile before considering any treatment. Research is ongoing to understand which sea-fans are more likely to bleed and which ones can be monitored.

The aim of treatment is to lower the chance of any sea-fan causing vitreous haemorrhage and reduce the pulling between the vitreous and the retina. If you require treatment for PSR, your ophthalmologist will explain which option is suitable for you and the possible benefits and risks. They will also discuss any side effects of having the treatment, whether permanent or temporary. Ask your ophthalmologist any questions or concerns you might have about treatment. Once everything has been explained, you’ll be asked to sign a consent form.

The different treatments that may be offered for PSR include:

• Laser treatment
• Anti VEGF medication
• Vitrectomy

Laser treatment

Laser treatment may be used when sea-fan is present and thought to be at risk of causing a vitreous haemorrhage or retinal detachment. Applying laser to the areas around the sea-fan helps to reduce the production of proteins such as VEGF. The result is that the sea-fan may be more likely to shrink and less likely to bleed or pull on the retina.

It’s important to remember that laser treatment is used to stop your vision from getting worse. It cannot make your vision better. If you choose not have laser treatment when it is advised, you may lose much more of your sight.

Anti-VEGF treatment

Anti-VEGF medications are used commonly to reduce new blood vessel growth in several different conditions. They work by blocking the action of VEGF. VEGF is a protein produced by the retina when there is not enough oxygen or blood flow to an area. VEGF stimulates the growth of new blood vessels. Anti-VEGF medications work by helping to reduce new blood vessel growth.

In many countries, anti-VEGF treatments are used alone or together with targeted laser treatment. It is used to lower the risk of bleeding or to help clear a vitreous haemorrhage. These injections can be used in people who have had previous laser treatment or before vitrectomy surgery. They are not routinely licensed for PSR in the UK and are only used in selected PSR cases. You can ask your ophthalmologist if anti-VEGF treatment my be suitable in your situation.

Vitrectomy

The middle part of your eye ball is filled with a clear gel (called the vitreous gel). If you have a bleed from your retina into the vitreous gel, your vision will become cloudy. Often, this blood is reabsorbed by your body and your vision clears on its own over a few months. However, if the blood does not clear, you may be offered vitrectomy surgery. In this surgery, the cloudy vitreous gel is removed and replaced with a clear liquid, which usually helps to improve your vision.

Your ophthalmologist may advise you to wait for up to 3-6 months before carrying out a vitrectomy to allow time for the bleed to resolve on its own first. This can be frustrating. However, over this time, your ophthalmologist will monitor how the bleeding changes, to see if there are any new bleeds, and whether your bleeding has begun to be reabsorbed.

If your retina detaches, then vitrectomy is needed to reattach your retina and restore vision.

A vitrectomy is a specialised and complicated operation, and your ophthalmologist would only carry out this surgery when it is needed, and the benefits outweigh the risks involved. They should discuss the advantages and disadvantages of the procedure with you before scheduling the surgery.

Depending on the type of treatment you receive, you will be given specific instructions on how to care for your eyes. This may include using eye drops for a few days or weeks. There may be some restrictions on activities for a period of time.

After having treatment for PSR, your ophthalmologist will ask you to return to clinic for follow up visits to check on how your eye has responded to treatment. You will be provided with contact details for the clinic so that you are able to get in touch with them before your scheduled appointment if you have any concerns about your recovery.

With the right support, you can live confidently and independently with your condition. You may not need all this support right now, but you can access further support at any time you need.

Driving and PSR

If you drive and have had a diagnosis of PSR in both eyes you must inform the Driver and Vehicle Licensing Agency (DVLA). Your eye doctor may also advise you to inform the DVLA.

Making things easier to see

If your sight has been affected by retinopathy, there are a lot of things you can do to make the most of your remaining vision. This may mean making things bigger, using brighter lighting, or using colour to make things easier to see. Call our Helpline or go to our website for our booklet on Making the most of your sight.

You can find out tips for making the most of your sight by downloading our booklet:

Download our Making the most of your sight booklet (PDF).

Download our Making the most of your sight booklet (Word).

Support for your work or education

When you have sight changes, you may be worried about finding work or staying in your job. Our Employment team can provide specialist support and advice about employment for people with sight loss. You can contact this team via our Helpline. 

For children who have sight loss, having the right support at an early age can make a big difference. Your local authority (LA) should have at least one qualified teacher of children and young people with vision impairment (QTVI) to work with you and your child both at home and at school. A QTVI is a qualified teacher who can provide support with development, play, learning and education. At an early stage, ask your local authority to put you in contact with a QTVI. They will support you and your child as soon as a visual impairment is suspected or diagnosed. If you have difficulty getting help or need the details of the specialist teacher in your area, contact RNIB Helpline. 

Connecting with others and support for your eye condition

Sometimes, it can help to connect to people with the same eye condition. The following organisation supports people with Sickle cell disease:

The Sickle Cell Society is a national charity in the UK that supports and represents people affected by a sickle cell disorder to improve their overall quality of life.