Injection in the Treatment of Strabismus
What is the effect of Botulinum Toxin (botox)?
Botox is injected into a muscle and results in paralysis of the muscle.
How long has it been used?
Moorfields has been using Botox treatment since the early 1980s.
Will it affect my general health?
Botox treatment is considered safe with no broader health risks such as botulism (food poisoning) or special risk to pregnant women of mothers who are breastfeeding – although some mothers/mothers-to-be may prefer to delay treatment.
Who will I see when I attend the clinic?
You will first be examined by an Orthoptist and then see a doctor, who will discuss the treatment options with you. If treatment is recommended and you would like to proceed with it, you will be asked to read and sign a consent form. Patients are normally treated on the same day. You should expect to be in the clinic for up to 3 hours.
What is the treatment procedure?
You will be given local anaesthetic drops to numb the eye. These drops are very effective in taking away the surface sensation of the eye but you should note that there may still be some discomfort when the injection is given (especially if there is scar) tissue around the muscle from previous surgery).
Wires connecting the muscle to a speaker helps direct the injection accurately, by detecting the electrical signal and activity of the muscle; the patient can also hear this. Usually, only one muscle will be injected although more than one is possible.
What happens after the injection?
After the injection you can choose to wear a pad over the eye or wear your own glasses to protect the eye for 2 hours whilst it is still numb from the drops. There may be an aching sensation in the eye which should subside quickly and medication may help, if not.
When should I expect to see an effect from the treatment?
The effects should be noticeable within the 2 days following the injection.
How long does the effect last?
This can vary but it usually lasts for weeks and occasionally months, before it will wear off. To begin with, you may notice a temporary reversal of the squint, followed by gradual straightening of the eyes as the paralysis wears off.
What are the possible side effects?
- Temporary reversal of the direction of squint
- Temporary double vision – you should not drive whilst you have double vision. It is very important that you discuss this with the doctor before treatment if this is of particular concern to you.
- Temporary drooping of the eyelid on the injected side. This usually resolves after a few weeks.
- Slight bruising of the surface of the eye.
All these will improve without treatment.
When do I return to the clinic?
1-2 weeks after treatment and a repeat injection may be needed if the first injection did not have the desired effect. Speak to your consultant about the treatment and make sure you understand the details before going ahead and signing consent.