Lazy Eye Research Project with University Hospital Southampton NHS Foundation Trust

The effect of circadian rhythm on the efficacy of occlusion therapy: How can a patching protocol be amended to improve outcomes for patients with amblyopia (lazy eye)?

Amblyopia (lazy eye) is a visual development condition that affects 1-5% of the population.  It arises secondary to ocular pathology during the critical period of visual development – commonly refractive error or strabismus.  It is characterised by reduced visual acuity in one or both eyes.  Once underlying pathology is managed effectively (for example through correction of refractive error with glasses) visual acuity may improve.  The improvement of visual acuity following correction of refractive error continues for the first 18 weeks of full time glasses wear and is termed refractive adaptation.  Further to management of the primary ocular pathology no specific treatment for bilateral and symmetrical amblyopia exists, however, visual acuity typically improves over the time period of refractive adaptation.

If left untreated after a period of refractive adaptation the unilateral condition persists.  Pharmacologic penalisation of the sound eye using atropine eye drop has the same visual acuity outcomes as part time total occlusion therapy, in which an eye patch is used to cover the sound eye for a prescribed time period per day.  Occlusion therapy remains the preferred treatment in the UK and Europe.