Amblyopia

What's going on?

This is what is known as 'lazy eye'. The brain relies on visual input in the first five years of life to lay down the visual pathways for normal vision. If the brain is deprived of normal focused vision in one or both eyes in early life, it ignores that eye and vision does not develop to its full potential. This is irreversible after approximately five to eight years of age (depending on type), but if the problem is alleviated, vision may be restored to its full potential.

Many adults have a long-standing lazy eye, in which vision may vary from 6/9 to counting fingers.

If I examine the patient what will I find?

By definition the findings will be normal. However, the patient may have a squint.

What if I've diagnosed it?

Amblyopia is a diagnosis of exclusion. Adults with unexplained visual loss from childhood with no evidence of any pathology will have amblyopia. If the patient is not certain that the vision has been poor from childhood or they feel that there has been a further deterioration in vision, they should be assessed by the ophthalmology service routinely. When there is a concern about a child's vision in one or both eyes they should be referred soon via letter for formal assessment and potential treatment.

What will the hospital do?

Organic pathology will be excluded and a full orthoptic assessment carried out to look for a squint. In children, spectacles may be prescribed, and occlusion (patching) treatment may be started on a full- or part-time basis to encourage use of the lazy eye. Subsequently, squint surgery may be considered.

What do I need to do?

If the child is prescribed spectacles or patching, it is vital that the parents are advised about the importance of compliance. Saying that it is difficult to make an uncooperative child wear spectacles or a patch is an understatement.

Problems that may arise, and how to deal with them

Patching treatment can be difficult because children don't like it, and lack of compliance can hamper progress. It is important to emphasise the window of opportunity in childhood to restore vision, and the need for regular follow-up.