• Reference Number: HEY-429/2023
• Departments: Ophthalmology Department
• Last Updated: 1 August 2023

Introduction

This leaflet has been produced to give you general information.  Most of your questions should have been answered by this leaflet.  It is not intended to replace the discussion between you and the healthcare team, but may act as a starting point for discussion.  If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.

What is a Branch Retinal Vein Occlusion?

If one of the veins taking blood away from the eye gets blocked it is called a branch retinal vein occlusion (BRVO). The blockage of the vein means that blood cannot drain out of the retina (film at the back of eye where the image forms).

This leads to reduced vision due to:

• Build-up of blood and other fluid causing the retina to get ‘waterlogged’. Waterlogging and the lack of oxygen damages the light receptors at the central retina (the macula), causing the central vision to be blurry.

• Damage to the other healthy small capillaries resulting in shut down of circulation (macular ischaemia) at the centre of the eye causing permanent visual loss.

• 20 – 30% of patients with a BRVO develop abnormal new blood vessels on the surface of the retina itself. These abnormal vessels can bleed leading to further loss of vision.

What causes it?

A BRVO is more common in people as they get older, especially over the age of 60.

There are some conditions that we know can make it more likely to happen such as:

• High blood pressure
• Diabetes
• High cholesterol
• Smoking
• Glaucoma
• Inflammatory diseases of the eye

The doctor who sees you will organise some tests to see if a cause can be found in your case, although a cause may not be found.

Why do I need treatment?

Each case of retinal vein occlusion is unique. Generally 50% of patients with mild occlusion may get better without treatment so the doctor may advise a period of observation in these cases. However, 10 to 40% of patients with severe disease may recover some vision without treatment. Severe cases often get worse and lose central vision if left untreated for several months. This is due to development of irreversible scarring.

If you develop ‘abnormal new blood vessels’ then delaying treatment results in severe loss of vision due to bleeding.

What treatment is available?

Some patients cannot be treated as they suffer severe damage to the blood supply at the back of the eye resulting in a permanent loss of vision.

You may however be offered treatment in the following situations.

1. If you develop new blood vessels on the retina, as mentioned above, then you may need laser treatment to the part of the retina drained by the blocked vein, called sectoral pan retinal photocoagulation. This laser treatment protects the eye against a sudden further decrease in vision due to bleeding into the vitreous gel of the eye. This form of laser treatment has no effect on central vision. For further information see Pan Retinal Photocoagulation Laser Treatment leaflet.
2. If you develop waterlogging of the central part of the eye (macular oedema), then you may be offered:

• • Macular laser treatment – this is targeted laser to the central part of retina. Laser treatment creates a burn on the macular area of the retina which dries up the fluid within the waterlogged area. This is only an option if the vision is within a certain range, if there is not too much bleeding and if the vein occlusion has occurred within the last year.
  • Injections of various NICE approved drugs into the eye (intravitreal Injection) of which there are two main types:

• • •  Steroid implant – Ozurdex is the trade name of the drug dexamethasone, a type of steroid. The Ozurdex implant is injected into the eye and slowly releases the drug as it dissolves (biodegrades).  The implant is usually invisible to the patient. The drug reduces waterlogging of the macular by reducing inflammation associated with the vein occlusion. Ozurdex is licensed for use in vein occlusion patients and has been extensively studied in research clinical trials. The effect of Ozurdex implant lasts for 4-6 months so the implant must be repeated regularly over a 2-3 year period as a minimum.
    • Anti-VEGF Agents; Lucentis (Ranibizumab), Eylea (Aflibercept) and Avastin (Bevacizumab).  These drugs block the action of a molecule VEGF in the eye which make blood vessels leaky in vein occlusion and so cause waterlogging of the macula. VEGF production increases in the eye after a vein occlusion. Lucentis and Eylea are licensed for use in vein occlusion patients and have been extensively studied in research clinic trials. The effect of Lucentis and Eylea is temporary so they must be given repeatedly over a year or more.

Patients receive 4 injections, 1 injection every month, as an automatic loading dose. Patients get eye scan and vision test every visit and this information is used to decide about the spacing between further injections after the loading dose.

Patients who do not respond to one injection / treatment may be suitable to try alternative treatments.

Avastin (Bevacizumab) has been shown to have effects similar to Lucentis but is not licensed for use in the eye.   

Your doctor will discuss which treatment option may be best for your particular circumstances.

Will the treatment help?

Laser Treatment ­– In research trials, patients treated with laser have double the chance of getting a significant increase in vision, compared to those who were not treated.

Injection treatment – Regardless of the drug used, in research trial, injection treatment had double the chance of gaining 3 lines (15 letters) of vision compared to those not treated. Once the vision had improved, this improvement lasted for 1 to 3 months. Your own results may vary.

Are There any complications and Risks?

Macular Laser treatment

The main side effects of macular laser are it may need repeating, it may not work, rarely it can cause a blind spot in the centre of your vision causing your vision to be much worse and occasionally laser treatment can cause you to develop abnormal blood vessels growing at the site of the laser burn in future years. For more information see the patient information leaflet “Laser Treatment for Macular Oedema”

Injection treatment

Regardless of the drug is used, each injection procedure carries a small risk (1 in 1000 patients) of serious complication including infection inside the eyeball (endophthalmitis) which can potentially result in total loss of vision if not treated promptly (see Information for Patients Under-Going Intravitreal Injections leaflet).

Patients who receive Ozurdex implant are 6 times more likely to develop cataract as a result of using this treatment, however this can treated with cataract surgery. There is also a risk of glaucoma i.e. raised pressure in the eye (about 25% patient patients needed eye drops for the pressure in their eye after 6 months and a very small number, less than 1%, needed surgery to reduce the pressure in the eye).

There are no proven risks to your general health with these injection treatments.

None of the injection treatments have been tested on pregnant women and therefore should be used with caution in women of child bearing age.

How do I come prepared for treatment?

Please read the information leaflet.  Share the information it contains with your partner and family (if you wish) so that they can be of help and support.  There may be information they need to know, especially if they are taking care of you following this examination.

Please eat and drink as usual on the day of the treatment. Please bring your usual diabetic medications with you, especially insulin, if the timing of your visit coincides with your usual medication times. It would be sensible to bring a snack in case of any delays, although this is unlikely to happen.

Please do not drive to your appointment as you will be having dilating drops in your eye/s under-going treatment and should not drive for up to 6 hours afterwards as your vision will be blurred.

The treatments are all done as day case/ out-patient procedures and you will not be staying in hospital over-night.

What will happen?

When you attend for an injection appointment please report to the main reception desk in the Eye Hospital. You will be directed to the correct waiting area. This will be in the Eye Clinic for Laser and Lucentis/Eylea injections and will be in the day case area on the 1st Floor for Ozurdex injections.

A nurse will check your details with you and you have dilating drops administered in the eye/s to be treated. You will also have a vision test and an eye scan if you are having Lucentis injection treatment.

Laser treatment (see additional leaflet on laser treatment for macular oedema):

This is performed in the eye clinic and for many patients is a one off treatment although some require a repeat treatment.

The pupil is dilated and then anaesthetic drops are used to numb the eye. You will be asked to place your chin onto a rest, similar to the one that you will have been used to being examined on in clinic. A contact lens is then placed on the eye to focus the laser and the laser is shone repeatedly into the eye. Each shot of the laser is seen as a burst of bright light. The treatment will take 15-30 minutes and, although this is dazzling, there is no pain.

You will be able to go home the same day although your vision will be dazzled in this eye for several hours.

Injection treatment (Ozurdex or Lucentis or Eylea)

The treatment would be performed in theatre or in a clean room in the eye clinic.

The pupil is dilated and your eye will be numbed using local anaesthetic drops or a local anaesthetic injection. The injection is performed with you reclining on a couch, the eyelids are cleaned and cleaning solution is used in the eye and a sheet placed over the eyes/forehead. The injection is given from the side so that you will not be able to see the procedure, although you may be aware of pressure on or around the eye. You will be able to go home the same day.

Can everyone have the injections?

No, for some patients the risks of treatment will outweigh the benefits and for others the eye may be too badly affected to make treatment worthwhile.

Other patients who will not be suitable for treatment are: patients who have advanced glaucoma, who have had a reaction to Dexamethasone, Lucentis or Eylea or Avastin before; patients with a current eye infection should not receive treatment until the infection has cleared.

None of the injection treatments have been tested on pregnant women and therefore should be used with caution in women of child bearing age.

What happens afterwards?

Immediately after the injection, your eye may feel slightly sore/ watery and may be blood shot but this is normal and these symptoms will soon wear off. Your vision will be blurred until the effect of the dilating drops has worn off.

You will be given instructions about what to do if you think there is a more serious problem with your eye after the injection. You will also be given emergency contact telephone numbers before you leave the department.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Ophthalmology Department on (01482) 608788

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

• you must be able to give your consent
• you must be given enough information to enable you to make a decision
• you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.