Overview
Also known as lazy eye, amblyopia describes a decrease in visual acuity mainly due to the brain ignoring the image from an eye in a child with a squint, with the other eye being favoured.
A child’s visual system develops until around 7-8 years. If there is visual deprivation or if the brain receives an inadequate image (such as an abnormally-aligned image from strabismus), then the development of the visual system is slowed or stopped, leading to reduced vision. If corrected early and managed appropriately, vision can be restored provided development has not been completed.
Epidemiology
- Amblyopia is the most commonly treated visual disorder in paediatric ophthalmology
- Amblyopia is more common in premature babies
- Around 1/3 of cases are due to strabismus, and 1/3 are due to anisometropia
Presentation
Patients present with unilateral decreased visual acuity in the absence of an organic lesion. Many patients may have associated strabismus or anisometropia.
Investigations
- Children should be referred to an ophthalmologist according to the NICE guidelines highlighted in Strabismus.
- Specialist investigations may include advanced visual acuity tests, fundoscopy, functional MRIs and visual evoked potentials.
Management
The underlying cause should be managed, such as squint, cataracts, or anisometropia. Eye patches may be used to ‘force’ the amblyopic eye to ‘work harder’.
Complications
- Irreversible, lifelong decreased visual acuity
Prognosis
- Earlier identification and treatment are associated with a better outcome
- Around 50% of children may have a slight decrease in visual acuity over time
