occlusion therapy
Occlusion therapy treats amblyopia by patching the non-amblyopic eye, which forces use of the amblyopic eye. Occlusion of the normal eye is the most effective treatment for amblyopia, and patching has been its principal treatment since about AD 900.1,2
The regimen, full-time or part-time, depends on the patient's age and the density of the amblyopia.1 In randomized trials of children aged 3 to 7 years, 6 hours of daily patching matched full-time occlusion for severe amblyopia, and 2 hours matched 6 hours for moderate amblyopia. When an electronic monitor measured the occlusion dose, patching beyond 2 hours a day hastened the response but did not improve the outcome.2
The younger the patient, the faster the likely improvement and the greater the risk of inducing amblyopia in the normal eye, so acuity in both eyes is monitored regularly. The better the acuity at the start of occlusion, the shorter the treatment, although patients vary widely.1 Poor compliance is the single greatest barrier to improvement. If acuity has not improved after 6 months of effective occlusion, further treatment is unlikely to help.1 The sensitive period for improvement usually lasts up to 7 to 8 years in strabismic amblyopia and may extend into the teens for anisometropic amblyopia.1
More detail
In penalization, the main alternative, atropine blurs vision in the normal eye. Penalization may work best for mild to moderate amblyopia (6/24 or better), especially from anisometropic hyperopia, but patch occlusion usually produces a quicker response.1 In anisometropic amblyopia, constant occlusion could interfere with binocularity, so the child should have at least 2 hours a day of binocular vision. A significant heterophoria needs close monitoring throughout occlusion to make sure it does not break down into a strabismus.2
Sources (8)
- Kanski's Clinical Ophthalmology (2024), ch. 18
- Pickwell's Binocular Vision Anomalies, ch. 13
- American Academy of Ophthalmology. 2019. Amblyopia Preferred Practice Pattern. San Francisco: American Academy of Ophthalmology.
- Holmes, J.M. and Clarke, M.P. 2006. Amblyopia. The Lancet, 367(9519), pp.1343-1351.
- Loudon, S.E. and Simonsz, H.J. 2005. The history of the treatment of amblyopia. Strabismus, 13(2), pp.93-106.
- Pediatric Eye Disease Investigator Group. 2003. A randomized trial of patching regimens for treatment of moderate amblyopia in children. Archives of Ophthalmology, 121(5), pp.603-611.
- Repka, M.X., Beck, R.W., Holmes, J.M., Birch, E.E., Chandler, D.L., Cotter, S.A., Hertle, R.W., Kraker, R.T., Moke, P.S., Quinn, G.E. and Scheiman, M.M. 2003. A randomized trial of patching regimens for treatment of moderate amblyopia in children. Archives of Ophthalmology, 121(5), pp.603-611.
- Rutstein, R. and Daum, K. 1997. Anomalies of Binocular Vision: Diagnosis & Management. St. Louis: Mosby.
Reviewed October 2026