Paediatric Visual Evoked Potentials (PRVEP)

Patient Leaflets Team

  • Reference Number: HEY-788/2016
  • Departments: Neurophysiology


This leaflet has been produced to give you general information about your child’s procedure.  Most of your questions should be answered by this leaflet.  It is not intended to replace the discussion between you and your doctor, 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 caring for you.

What is a PRVEP?

A Pattern Reverse Visual Evoked Potential is a test of the pathway between your eye and your brain (the optic nerve). The test provides a way of assessing how well the nerve is working.

Why does my child need a PRVEP?

Your child’s doctor has requested we perform a PRVEP because your child or you have reported some symptoms that raise the possibility of a problem affecting their nerves. There are many conditions that can cause these problems. Their symptoms may not necessarily affect their eyes or their vision.

How do I prepare my child for the PRVEP?

Please read this 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 your child during/following this examination.

  • Please ensure your child’s hair is freshly clean and dry with no spray/gel etc on it.
  • If your child wears glasses please bring them with you. Contact lenses cannot be worn for some of the testing so glasses are needed if you have them.
  • Please do not bring any other children with you as we are unable to accommodate them unless you bring someone to supervise them in our waiting area.
  • Please inform us of any eye conditions your child may have on the day of the testing.
  • Give your child any medication as normal unless otherwise directed by your doctor.
  • Please bring a list of any current medication they are taking.

What will happen?

The tests we will be doing are dependent on the age and co-operation of your child on the day of the examination and they may have one or all of the following examinations:

  • On your arrival in the department we will obtain your consent for the procedure before the investigation begins.
  • The Clinical Physiologist performing the PRVEP will introduce themselves, explain the test to you and your child and will be happy to answer any questions you may have.
  • The Clinical Physiologist will first check your child’s visual acuity where possible.
  • If old enough, your child will be asked to sit on a chair and the Clinical Physiologist will measure their head and mark some points on it with a soft pencil.
  • A patch will be placed over your child’s eyes, one eye at a time and a light flashed in front of their non-patched eye continually for a minute or so at a time. This may be repeated at different intensities of light and may take about 20 minutes.
  • Your child may be asked to look at the centre of a screen that has moving black and white squares on it. Each eye will be tested separately. This test is totally painless and there are no after effects. The test can take up to 45 minutes.
  • Sometimes following the test it may be necessary to do some further testing which involves placing a fine thread across your child’s eyeballs and asking them to watch the same screen with both of their eyes together. This will be explained to your child on the day in more detail and drops can be placed into your child’s eyes if needed, so they will not feel the fine threads. This extra testing will take about 30 minutes.

What happens afterwards?

  • The electrodes will be removed and your child’s head cleaned with warm water. You may wish to bring a brush or comb with you to tidy their hair. Any residue of paste can be removed by shampooing the hair.
  • Once you have left the department the recording will be reviewed by the Clinical Physiologist and then by a member of the medical team who will send a report to the doctor who referred your child for the PRVEP. This usually takes up to two weeks.

Can there be any complications or risks?

  • Very occasionally people may experience a slight local reaction at the electrode site. This may cause reddening and soreness. These symptoms resolve quickly on removal of the electrodes. If your child experiences these symptoms please inform the staff attending to them.
  • If your child has to have the threads in their eyes (please see below) they may feel very mild discomfort and have some slight reddening of the eyes afterwards. Their vision will not be affected however.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Neurophysiology Department on tel: 01482 675339/675388.

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 your child, 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 your child. 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 child’s condition, the alternatives available for your child, 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 your child

We collect and use your child’s information to provide your child with care and treatment. As part of your child’s care, information about your child will be shared between members of a healthcare team, some of whom you may not meet. Your child’s 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 your child 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 child’s doctor, or the person caring for your child.

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 your child. For further information visit the following page: Confidential Information about You.

If you need information about your child’s (or a child you care for) health and wellbeing and their 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.

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