Squint Surgery

Surgery for turned eyes aims to improve the alignment of the eyes, that is make the eyes "look straight".

Why operate on turned eyes?

Surgery for turned eyes aims to improve the alignment of the eyes, that is make the eyes "look straight".

The benefits of surgery for squint are:

  • Improved appearance (often)
  • Increased peripheral (side) vision (often)
  • Improved depth perception (sometimes)

Alternatives to surgery may include:

  • Glasses
  • Exercises (occasionally)
  • Do nothing (i.e. leaving the squint alone)

These alternatives should have been discussed and tried (if appropriate) before undertaking squint surgery. If you feel you do not understand the place of alternative treatment please ask.

When not to operate on turned eyes.

  • If you are unwilling to accept the risks associated with squint surgery outlined below.
  • If you do not understand why the operation is being done or do not understand the risks involved.
  • If the chance of improving the alignment of the eyes is low.
  • If your child is longsighted and glasses work well to control the turned eyes.

Risks of surgery for turned eyes.

There are risks that are related to the general anaesthesia required and risks specific to the eye surgery.

General anaesthesia risks

  • The risks related to the general anaesthesia should be discussed with the anaesthetist on the day of surgery. The anaesthetic plan is designed to minimise risk and distress.
  • The risk of serious harm occurring to your child during the course of an elective general anaesthetic is extremely low (of the order of 1 in 200,000).
  • Transient problems, e.g. sore throat, bruise at IV site, contribution to nausea and vomiting, getting upset, etc are more common.
  • If your child has another significant medical problem these risks may change. The significance of general conditions should be discussed with your child's anaesthetist.
  • The operation may not produce the desired effect (that is the eyes are not well aligned). The magnitude of this risk varies with the age of the child and the type of squint that is present. In virtually all cases this problem can be treated by undertaking another squint operation. This is the most common risk of squint surgery. An estimate of the size of this risk will be given for your child as part of the process of consent for surgery. In about 1 in 500 - 1,000 cases this problem occurs because the stitch(es) used to reattach the muscles to the eye loosen.
  • Infections are uncommon. About 1 in 150 children experience a mild surface infection (conjunctivitis) that will require topical antibiotic eye drops to settle. More serious infection at the site of the surgery, in the socket or in the eye itself is very rare.
  • Loss of sight following a squint operation is extremely rare occurring in 1 in 20,000 cases.
  • Problems with wound healing occur occasionally (1 in 100's). This may be evident as a pink lump (granuloma) or white strand of tissue (prolapsed connective tissue). These problems usually settle without any specific treatment. Rarely an operation is required to remove the lump. Rarely there may be a small visible scar or cyst at the site of the operation.
  • Double vision is common after operations for turned eyes. In most children this is quite transient. Occasionally in older children (over 10 -12 years old) the double vision is more persistent. It is extremely rare for this to be a major problem. In theory further surgery may be required if the double vision does not settle.

How is the surgery actually done?

Once your child is asleep the skin around the eyes and the surface of the eye is cleaned with disinfectant (Betadine). The eyelids are then held apart with a small clamp and the eye rotated so that the muscle that is to be operated on is accessible. The tissue (conjunctiva) over the white of the eye is then cut open with scissors to expose the muscle and then the muscle is either weakened or strengthened. The muscle is reattached to the eye wall with a suture (thread). The opening in the conjunctiva may or may not be sutured. This process is repeated for each muscle that is operated on.

What do I tell my child before an operation?

Most children do not need a detailed explanation of what is involved in an operation but need to have questions answered honestly, for example: "Yes, your eyes will be a bit sore after the operation." Children want to know they will not be left alone and that you will be there when they wake up. It is a good idea to tell your child that s/he will meet several different people during their visit to hospital (receptionists, nurses, orderlies, anaesthetist and surgical assistant). Being positive about the visit to hospital and operation will help your child.

What to do before you leave home on the day of the operation.

  • Make sure you understand the fasting instructions and know what time you have been asked to come to hospital.
  • Dress your child in loose clothing (does not need to be pyjamas).
  • Bring a favourite toy or books etc to comfort your child.
  • Pack a towel and container in case your child vomits on the way home.
  • Make sure you have a supply of paracetamol appropriate for your child.

Arrival in hospital

After completing admission paper work your child will be assessed by nursing staff and then seen by the anaesthetist. In general the order of operating list is from youngest to oldest child. If your child is having their operation later in the list it is still vital to arrive on time to see the anaesthetist before the start of list so that s/he is able to start the list on time and prevent disruptions during the list. As there is always some waiting involved bringing some toys or books to keep your child amused is a very good idea.

Going off to sleep

In general one parent will be able to go with your child into the anaesthetic room or operating theatre. Children can be anaesthetised ("put to sleep") with either gas (given by mask) or by an injection. Please discuss these different methods of going to sleep with the anaesthetist during the pre-operative assessment. Your child will go to sleep quite suddenly and it is not uncommon to feel a bit helpless and distressed by this. If you feel faint sit down on the floor. We won't be upset and may not catch you if you faint while standing!


Once your child is asleep you will be accompanied out of the anaesthetic room to the waiting room. If you go for a walk while your child is being operated on please return to the designated waiting area at the time suggested so that I can speak to you as soon as the operation is completed. Most squint operations take between 30 to 70 minutes.

What to expect immediately after squint surgery.

  • You will see your child first in the recovery ward. This is an area near the operating theatre where your child is closely monitored by a recovery nurse while they wake up from the anaesthetic. It is common for children to be connected a monitor to measure pulse rate and oxygen saturation in the blood. Some extra oxygen may also be given by mask at this time. Once your child is more fully awake they will go back to the ward.
  • Most children are "grumpy" when they first wake up after squint surgery. The child may cry, scream and thrash around. This almost always settles in 10-30 minutes. This occurs because there is some pain (not severe) and the child is confused, hungry and often disorientated because of reluctance to open the eyes. After this initial period of being unsettled most children go to sleep and are much more comfortable when they next wake up. If your child is particularly upset an additional dose of pain relief (often codeine) will be given at this time.
  • Vomiting may occur after any operation but is more of a problem following squint surgery, especially for children over 5 years of age. The anaesthetist will do a number of things during the operation to reduce the risk of this. The intravenous line will be left in place until you leave the hospital in case extra medication is needed to control vomiting.

What will the eyes look like after squint surgery?

Most often no patch is required. There may be slightly blood stained tears for a few minutes after the operation and a little dried blood on the eyelids. This can be washed off with saline or cool boiled water. The eyes will be blood-shot and appear "bruised" over the muscle(s) that were operated on and this will increase over the fist two days after the operation. The redness will go over 1 - 2 weeks though there may be a persisting pink area on the white of the eye for weeks to months after a squint operation, especially if a muscle was tightened (resected). The eyes may appear much better aligned as soon as they are opened after the operation. Often there will be noticeable variation in the alignment with the eyes moving in and out a bit as the brain "learns" to control the eyes following the surgery. This variation usually settles in days to a week or so.

Going home

Your will stay in hospital until both you and the nursing staff are happy for your child to be discharged. This is generally two to three hours after the operation is finished. If you live more than two hours drive from hospital it is recommended you stay closer to the hospital for the first night.

Eating after squint surgery.

Young children (less than 2 years old) are often keen to drink immediately after waking. Once the recovery room nursing staff or ward staff are satisfied your child is sufficiently "awake" you will be able to offer your child a drink. In older children small volumes of drinks and then solid food should be offered once your child is awake. Most older children will only eat small amounts of food during the afternoon and evening after the operation. Over feeding soon after the operation may increase the chance of vomiting in older children.

Pain relief after squint surgery.

Most children will only require paracetamol for pain relief. For children younger than one year often no pain relief is needed after leaving hospital. Pain relief should be given if a younger child will not settle with soothing and feeding and in an older child if you believe there is pain. Codeine can be given if the pain is severe in older children. This may increase the risk of vomiting slightly. For children having surgery on one eye only an injection of local anaesthetic may be given to lessen pain after the operation. Following such an injection the vision will be poor in that eye for several hours and a patch will be placed over the eye.

What will the vision be like after the operation?

Often there is some blurring of vision for a few days after surgery. Younger children will not notice this. Double vision (diplopia) is common after squint surgery. It is usually quite transient. A small number of older children (usually over 10 to 12 years of age) will experience more troublesome double vision. Light sensitivity (photophobia) is common after squint surgery. Older children will benefit from sunglasses and younger children should be kept out of direct sunlight for a few days if this seems to be a problem.\

What care is needed after the operation?

  • Eye drops are occasionally prescribed following squint surgery.
  • Pain relief and eating after the operation are discussed above.
  • The only activity that your child should avoid for about two weeks after the operation is swimming. Chlorine can be quite irritating during this time.
  • Care should be taken with hair washing as soap and shampoo can also cause significant discomfort.
  • It is common for the eye(s) to be a little sticky after sleeping for a few days following the surgery. This does not mean that there is an infection. This discharge can be cleaned away with boiled water that has been allowed to cool and a cotton ball or clean face washer.
  • Your child can return to normal activities as soon as s/he feels up it. It is common for children to have a quiet day or so after any operation.

Potential problems to look out for after a squint operation.

  • The eyes seem to be in an entirely unexpected position, that is way out of alignment in the opposite direction to that seen prior to the surgery.
  • Copious green or yellow-grey discharge from the eye(s).
  • Persistent bleeding that soaks several tissues.
  • Persistent severe pain that is not relieved by paracetamol.
  • Marked reduction in vision in one or both eyes.

If any of these problems occur please contact your ophthalmologist or hospital medical staff promptly.

Post-operative visits after squint surgery.

The first post-operative visit is generally the next working day after the surgery and the second approximately one month later.

When will we know if the operation has been a success?

The best time to judge longer term success is at one month for convergent squints and six months after surgery for divergent squints. Unfortunately no matter how successful an operation has been for a turned eye there is always a small chance of the eye turning again at some time after the surgery, even many years later.