Children in the orthoptic department
A squint is a condition in which the eyes are not straight. In most cases, one eye appears to look straight ahead, while the other eye turns inwards, outwards, upwards or downwards.
- Convergent squint - the abnormal eye looks inwards
- Divergent squint - the affected eye looks outwards towards the corner of the eye
- Vertical squint - the eye looks up or down
- any squint can be present all the time or be intermittant
Treatment is threefold
- to correct refractive error as below...many children need spectacles to place a clear image on the retina
- to correct lazy eye if present (patching etc)
- if the squint is still present with spectacles and correction (as much as can be achieved) of the lazy eye, then squint surgery is often needed
- there may be other issues that need to be addressed
|A child may need glasses if they are long-sighted (hypermetropic), short-sighted (myopic) or have astigmatism in one or both eyes. See animation||Long-sighted
when the shape of the eye is more like that of a 'rugby ball' than that of a 'football'?
Sight is blurred unless the astigmatism is corrected by glasses.
Glasses will correct the refractive error and enable a clear image to be formed on the retina. In certain types of squint, glasses may straighten the eyes and surgery for the squint is not necessary.
Visual development occurs rapidly in the early years of life and continues until approximately 7 - 8 years of age. If the back of the eye and the brain do not receive a clear focused image during this time of visual development, the child's vision will be reduced. Hence the term 'lazy eye'. Amblyopia does not affect educational achievement etc BMJ. Eye 2011. Retina is thinnner BJO 15 .
- there are not just acuity deficits
- also reduced perception of real world scenes
- fellow eye is also abnormal but less so
- when (amblyopia) acuity improves to normal, reduced perception remains although better than if vision does not improve to normal
- there are reduced saccades and pursuit movements, and slower hand eye coordination
- there are also defects in multisensory integration, with reduced hearing perception, and other motor and sensory systems similarly affected.
- Amblyopia can improve into adulthood, but is much more responsive treated early.
- There is not much evidence that new behavioural treatments help.
Amblyopia is treated by patching (occlusion) of the good eye. As a result, the weaker eye is encouraged to work harder, and visual activities such as colouring, reading, and drawing are helpful while the patch is worn.
Occlusion (sometimes called 'patching') is helpful in younger children, but is not so effective over 5y.
If a squint persists in a child who is wearing glasses and has had all necessary occlusion treatment, surgery may be considered. An animation of surgery. A word document for patients The aim of surgery may be to
- improve the cosmetic appearance by reducing the squint in size
- realign the eyes so that they are straight and can work together
These are used when there is an intermittent squint.