EYE SQUINTS (STRABISMUS)

A squint occurs when the eyes look in different directions (the medical term for a squint is strabismus). Squints tend to affect children and are fairly common, affecting 1 in 20 young children, but can generally be effectively treated. Occasionally adults can re-develop squints that were treated during their childhood, so it is essential to see your doctor as soon as possible should you develop a squint.

Types of squint

There are different forms of squint and they are named according to the direction the eye is looking. These include:

• Esotropia: when the eye turns inwards.
• Exotropia: when the eye turns outwards.
• Hypertropia: when the eye turns upwards.
• Hypotropia: when the eye turns downwards.

Squints can be either constant or intermittent, with constant squints present all the time while intermittent squints appear only some of the time.

What causes a squint?

There are various possible causes of a squint, including:

• Congenital squint: it is possible for babies to be born with a squint. However, it is not known why some babies develop squints and others do not, but there is evidence to suggest that squints run in families.
• Refractive errors: refractive errors occur when the eye cannot focus light rays that come into the eye properly. Examples of refractive errors include short-sightedness (myopia), long-sightedness (hyperopia) and astigmatism.
• Genetic conditions, including Noonan syndrome.
• Neurological conditions.
• Childhood illnesses and infections.
• Eye problems.
• Being born prematurely can amplify the danger of developing a squint.

Symptoms of a squint

A squint prevents you from seeing clearly because the eyes are not functioning together, which causes:

• Blurred vision.
• The eyes to look in different directions.
• Double vision.
• An increased risk of lazy eye (known as amblyopia).

Children with a squint may carry out actions such as:

• Looking at things with one eye closed.
• Tilt their head to look at things.

How is a squint diagnosed?

Routine eye tests are offered to newborn babies and young children on the NHS. A squint may be detected during a routine eye test or you may notice that your child has symptoms of a squint. If this is the case arrange to see your GP as soon as possible. If your GP thinks your child may have a squint they will refer them to an orthoptist (a specialist in assessing problems related to the eye). If a child is diagnosed with a squint they will be cared for by a team of professionals.

Treatment for a squint

It is important that squints are detected and seen to as quickly as possible to prevent a child developing lazy eye. Squints can be treated with various methods, including:

• Wearing glasses: glasses are the most common treatment and are used to correct sight by treating refractive errors.
• Using an eye patch (this is for children with a lazy eye, with the ‘good’ eye covered to make the lazy eye work harder).
• Botox injections: Botox makes the muscles around the eye temporarily weaker, which cause the eyes to realign.
• Eye exercises: exercises are designed to encourage the eyes to work as a couple.
• Surgery: surgery is usually a last resort and is used when other treatments have been ineffective. Surgery is used to re-align the eyes and encourage them to work together.