This information aims to answer some of the questions you may have about squint surgery. The information does not cover everything as every patient and squint is different. Your surgeon will discuss your particular case with you. Please ask the clinical staff about anything you want to be made clear.
What are the aims of surgery?
- To improve the alignment of the eyes, to make the squint smaller in size.
- In some patients, to reduce or try to eliminate double vision or to protect or restore binocular vision.
- Occasionally to improve head posture.
What happens before the day of surgery?
A pre-assessment is performed in the weeks leading up to the operation date.
What happens on the day of surgery?
Squint surgery is nearly always a day case procedure. Squint surgery is a common eye operation. It involves weakening or strengthening or altering the action of one or more of the extraocular muscles which move the eye. The muscles may be recessed (to weaken), resected (to strengthen), their insertions moved (to alter their action) or less commonly altered in some other way (advanced, plicated, tucked, belly sutured permanently to the globe etc).
The muscles are sutured into their new positions. The operation is carried out under general anaesthetic. The operation usually takes up to 60 minutes depending on the number of muscles that need surgery. Parents can go down to the operating theatre with your child and stay until he/she is asleep but cannot come in to watch the surgery. Remember to discuss which eye(s) is/are being operated on and why.
What are the success rates?
Overall about 90% patients/parents perceive some improvement in the squint after surgery. However, there is some unpredictability in the procedure, so that the squint may not be completely corrected by the operation. Many patients require more than one operation in their lifetime. If the squint returns it may be in the same or in the opposite direction and may occur at any time. The operation does not change visual acuity or refractive error. More patching may be needed after the operation.
Does the surgery cure the need for glasses or a lazy eye?
No, the operation does not aim to change the vision or need for glasses.
What are the risks of the operation?
Parents can be informed that squint surgery is generally a safe procedure. However, as with any operation, complications can and do occur. Generally these are relatively minor but on rare occasions they may be serious.
Under and overcorrection
The original squint may still be present (undercorrection) or the squint direction may change over (overcorrection). Occasionally a different type of squint may occur. Some patients may require another operation.
Double vision after surgery is normal and often settles in days or weeks. Some patients may continue to experience double vision on side gaze. Permanent primary position diplopia is very rare in children.
Mild allergy to postop drops: itching/irritation/ redness/puffiness of the eyelids. It usually settles quickly when the drops are stopped. Infection or abscess around the stitches. Cyst or granuloma related to the wound or sutures: occasionally needs further surgery.
Can take up to 3 months to resolve, occasionally the eye remains discoloured (red, yellowish) permanently, particularly with repeated operations.
Most of the scarring of the conjunctiva not noticeable by three months, but occasionally visible scars will remain, especially with repeat operations.
Lost or slipped muscle
Muscle may slip back from new position during the operation or shortly after, limiting eye movements. May require further surgery and not always possible to correct. The risk of slipped muscle requiring further surgery is about 1 in 1,000.
If suture passed too deep or thin sclera: may require antibiotic treatment and laser/cryo treatment. Can affect sight (via endophthalmitis, vitreous haemorrhage, retinal detachment). Risk is up to 2%.
Infection is a rare complication but the risk increases if drops are not instilled as directed and treatment not sought promptly. Significant infection is extremely rare but in the worst cases can cause loss of vision in the eye (endophthalmitis, orbital cellulitis).
Loss of Vision
Very rare, loss of vision in the eye being operated can occur. Risk of serious damage to the eye or vision is approximately 1 in 30,000.
Anterior segment ischaemia
The blood circulation to the front of the eye can rarely be reduced following surgery, producing a dilated pupil and blurred vision. This usually only occurs in patients who have had multiple surgeries. The risk is about 1 in 13,000 cases.
Unpredictable reactions occur in around 1 in 20,000 cases and death in around 1 in 100,000.
What will it be like after the operation?
Eye(s) will be swollen, red and sore and the vision may be blurry. Start the drops that evening, and painkillers suitable for age of the child, such as paracetamol and ibuprofen suspension, can be taken. The pain usually wears off within a few days. The redness and mild discomfort can last for up to 3 months particularly with repeat squint operations.
Care after the operation
- Use the eye drops as directed
- Attend your follow up appointment(s) to ensure the eye is healing well
- Use cooled boiled water and a clean tissue or cotton wool to clean any stickiness from the eyes
- Don’t rub the eye(s)
- No swimming for 4 weeks
- Continue using glasses if have them
- Your child will need a few days to one week off nursery or school.