Adult Ophthalmic Studies

Patient Leaflets Team

  • Reference Number: HEY-793/2016
  • Departments: Neurophysiology


This leaflet has been produced to give you general information about your 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 staff on arrival in the department or by telephoning the department beforehand.

What are ophthalmic studies?

These are tests measuring electrical responses from various parts of your eye, including the optic nerve, retina and macula and your brain to a variety of visual stimulus. These studies can help the doctors see how the different parts of your eye are functioning.

Why do I need ophthalmic studies?

Your doctor has requested we perform ophthalmic studies because you have reported some symptoms that raise the possibility of a problem affecting your visual pathway. There are many conditions that can cause these problems. This examination may help your doctor to understand what is causing your current symptoms.

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 you experience these symptoms, please inform the staff attending you.
  • If you have the threads (see below) in your eyes you may feel very mild discomfort and have some slight reddening of the eyes afterwards.

How do I prepare for ophthalmic studies?

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 you during/following this examination.

  • Under no circumstances should you drive home following this procedure or for the rest of the day, therefore it would be advisable for someone to accompany you home.
  • Please ensure your hair is freshly clean and dry with no spray/gel etc on it.
  • Please refrain from wearing eye makeup/mascara etc.
  • If you wear 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 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 you may have on the day of the testing, for example glaucoma.
  • You may wish to bring some sunglasses to wear on your way home due to your pupils being dilated.
  • Continue taking any medication as normal.

What will happen?

  • On your arrival in the department we will obtain your consent for the procedure before the test begins.
  • The clinical physiologist performing the test will introduce themselves, explain the test to you and will be happy to answer any questions you may have.
  • The clinical physiologist will first check your visual acuity.
  • Your head will be measured and some small metal discs applied to your scalp with some special paste. You will then 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.
  • Following the test some further testing will be done. This involves placing a fine thread across your eyeball and asking you to watch the same screen with both of your eyes together. This will be explained to you on the day in more detail and drops can be placed into your eyes if needed so you will not feel the fine threads. This extra testing will take about 30 minutes.
  • The final testing can take about 50 minutes and involves the threads staying in your eyes and some drops being placed into your eyes to dilate your pupils Please inform us if you suffer with glaucoma. You will then sit in front of a machine and place your chin on a rest into a dome which will flash and light up and you will be asked to try to keep your eyes open when the flash occurs. This may be repeated many times. Following this you will sit in the dark for 30 minutes to allow your pupils to dilate fully before some more flashes of light will be shown to you at different intensities. You will not be left on your own at any time.
  • Towards the end you will be asked to sit in the light for about 10 minutes after which you will be shown the final few flashes of light.

What happens afterwards?

  • The electrodes will be removed and your head cleaned with warm water. You may wish to bring a brush or comb with you to tidy your 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 you for ophthalmic studies. This usually takes up to two weeks.

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 or 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 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.

QR code to open leaflet