Specialists who perform this surgery
Mr Jonathan Durnian
Mr Ian Marsh
Strabismus (or what is often colloquially known as squint) is where the two eyes do not look in the same direction. The eyes can be turned out, turned in, turned up or down in relation to each other. This problem is often apparent when a person with a squint looks at you. They fix you with one eye and the other looks in another direction. It is not an uncommon problem – 4% of the adult population suffer some degree of squint - and can often be fixed with either glasses or an operation.
Strabismus can either occur as a child or adult
There are three type of childhood strabismus.
Congenital or early onset strabismus can present either at or close to birth. In this condition the eye tend to point inwards towards the nose. The child will often use each eye in turn making it difficult to decide which eye is turning. The vision in each eye develops normally but the child will usually not have 3D vision. The usual treatment of this condition is surgery to realign the eyes before the child’s peer’s notice or comment about the squint. This can be from aged 2 upwards. Spectacles can be given to improve vision but often do not change the alignment of the eyes.
Partially or fully accommodative convergent squint – This type of squint tends to occur around the age of 3. The child may require patching or drops to improve vision as usually only one eye is misaligned and amblyopic (lazy eye). The child is also provided with spectacles, which may either totally or partially correct the eye position when they are worn. If the squint is totally corrected with glasses then no further surgery or treatment is needed apart from patching/occlusion. If there is still a significant angle of turn even with spectacles then surgery to correct the angle of turn with glasses is necessary. The child will always have a squint without specs even with an operation. Surgery again is performed before their peers comment upon the squint.
Divergent squints where the eyes look outwards are less common and usually have normal 3D vision and no amblyopia. There is not usually a need for spectacles and only 30% of patients require surgery. Surgery is usually deferred until visual maturity (over the age of 8yrs)
Vertical squints are uncommon and surgery to eliminate the deviation is offered where the deviation is noticeable. Rarely squints in children are associated with a neurological problem. Prior to any surgery, treatment of the underlying cause is vital.
Some squints that develop in adults are due to nerve problems. The cranial nerves which cause the six eye muscles to work can be damaged either by tumour, trauma, pressure and medical problems such as blood pressure and diabetes. Treatment of the underlying cause is vital in these situations although often a residual squint remains requiring intervention. These types of squint are often associated with the symptom of double vision (diplopia). Diplopia can also be associated with other adult deviations not associated with an underlying cause.
The majority of adult squints are secondary to a previous childhood squint, as the reflexes required to maintain parallel eyes rely upon good vision in each eye and ability to appreciate the eyes pointing in the same direction. Often children with squint do not develop these reflexes or are maybe born without them.
Adult who have had squints as a child may develop a turn as they enter their middle years the eyes either diverge or converge in relation to each other. These individuals are often told that there is nothing to be done and squint surgery is only for children. THIS IS NOT CORRECT. They are often told that surgery to correct their squint is cosmetic. THIS ADVICE IS ALSO INCORRECT.
There is plenty of evidence available in academic papers that show surgery in these individuals improve not only eye position but also psychosocial functioning. People change the way they interact with others and become more confident and outgoing.
Most squints are managed in conjunction with an Orthoptist (a Profession Allied to Medicine who specialize in assessment and treatment of strabismus)
In children the vast majority of treatment is aimed at improving visual function, eliminating amblyopia and provision of spectacles. The Ophthalmologist becomes involved in the surgical intervention.
Adult squints may require investigation with blood tests and scans along with an appointment with a neuro-ophthalmologist.
The treatment of adult squints consequent upon a childhood operation will require an assessment with the Orthoptist. Some patients may have the risk of diplopia and may need treatment with Botulinum Toxin (Botox – a substance to temporarily weaken a muscle) to temporarily realign the visual axes to assess whether the patient will be able to live with the diplopia. Most adult patients require surgery to straighten the eyes. Adjustable sutures can be offered to fine tune the eye position after surgery.
Strabismus Treatment in 1 Penny Lane, Spire Hospital Liverpool
1 Penny Lane has two Consultant Ophthalmologists who specialize in the treatment of strabismus. Orthoptic assessment is also available.