Advice after your nerve block for surgery
On this page…
INtroduction
Botulinum toxin (BT) or botox is a drug that works by blocking nerve signals to muscles. It can be used in small amounts to weaken overacting eye muscles. In a squint it can therefore be used to weaken a particular muscle to help straighten the eye.
How long does Botox last for?
The injection takes about two days to start working and usually lasts up to three months. After this the effects will begin to wear off gradually.
When is it used?
- The injection may be performed prior to squint surgery to assess any risk of double vision following surgery.
- As an alternative to squint surgery if the patient is unfit for general anaesthesia, or in small squints where there is a risk of overcorrection.
- As an addition to squint surgery.
- To alleviate double vision and aid recovery in patients with eye muscle paralysis.
What is the Botox injection procedure?
Prior to the injection, the full procedure will be discussed and you will be asked to sign a consent form stating you understand the procedure and any risks or side effects that could possibly occur.
This is a good point to ask any questions you might have with the Consultant Ophthalmologist. You will have a further appointment with the Orthoptist to check your vision and the size of your squint will be re-measured to ensure there has not been any recent change.
The procedure is carried out under a local anaesthetic in adult patients, so you will be awake throughout the procedure, and under sedation in child patients. If there are any issues with this, these should be discussed with the Consultant Ophthalmologist prior to the procedure.
Anaesthetic eye drops are put in the eye to reduce any discomfort during the procedure. When you are comfortable, sticky electrodes are placed on the skin around the eye.
Wires from these electrodes are then connected to a special machine (EMG machine). This machine can detect very small levels of electrical activity from the muscles that move the eyeball. This helps the doctor to locate the correct site for the treatment. You are asked to look in the opposite direction to the injection, so you do not see the needle!
The injection of the Botox is given into the muscle identified by the EMG machine. This may sting slightly, but any discomfort will not last long. It is important to keep as still as possible at this stage.
You must not drive home afterwards, so you will need to make other arrangements. You will be asked to wait 30 minutes to 1 hour in the department before going home.
When do I return to the clinic?
The effects of the injection are usually seen a few days following the procedure. An orthoptic follow-up is made for one week after the injection. Initially following the injection a reversal of the direction of the squint might be seen. This is then followed by a gradual straightening of the eyes as the paralysis wears off.
After this initial visit you might not be seen again for two to three months until the Botox injection has worn off. At this point, if a further injection is required this can be organised.
Are there any side effects?
- There are a small proportion of patients who do not respond to treatment.
- Leakage into other surrounding tissues giving some unwanted but temporary effects such as droopy eyelids, double vision or weakness of the muscles below the eye.
- There is a small risk of the Botox entering the globe.
- Flu-like symptoms.
- Headache and nausea.
- Pain and redness at the injection site, and the eye may feel a little red and sore.
If you have any concerns after your injection, please contact the Emergency Eye Clinic by telephone on the numbers below:
| From 9am to 5pm (Monday to Friday): | 0300 373 5884 |
| From 5pm to 9am and at weekends: |
0300 614 5000 and ask for the Eye Doctor on Call |
Contact us
If you have any queries relating to this information, please contact the Ophthalmology service.
About this information
Service:
Ophthalmology
Reference:
QQ/015
Approval date:
2 August 2024
Review date:
1 July 2027
Click ‘show accessibility tools’ at the bottom of the page
Then click ‘select language’
Alternative formats
You can use the accessibility toolbar at the bottom of your screen to:
-
Change the text size
-
Adjust the font
-
Modify the colour contrast
-
Use the translate function
If you would like this information in another format, such as Braille, audio, or easy read, please speak to a member of staff.
You can also print as well as download as PDF using the “Print this page” button at the end of the page.
Staff will print a copy for you on request
Important note
This page provides general information only. It is developed by clinical staff and is reviewed regularly every 3 years for accuracy. For personal advice about your health, or if you have any concerns, please speak to your doctor.