The prognosis depends on the age of onset, cause, severity, duration, previous treatment, adherence to treatment, and concomitant conditions.[41]American Academy of Ophthalmology. Pediatric ophthalmology/strabismus summary benchmarks - 2022. December 2022 [internet publication].
https://www.aao.org/education/summary-benchmark-detail/pediatric-ophthalmology-strabismus-summary-benchma
Amblyopia treatment is highly effective when instituted early in life. Untreated amblyopia portends a lifelong decrease in unilateral visual acuity and even increases the risk of bilateral visual impairment. Treated, visual acuity usually responds rapidly within weeks to months before tending to plateau.
Untreated amblyopia
Untreated amblyopia is unlikely to improve on its own.[90]Simons K, Preslan M. Natural history of amblyopia untreated owing to lack of compliance. Br J Ophthalmol. 1999 May;83(5):582-7.
https://bjo.bmj.com/content/83/5/582.long
http://www.ncbi.nlm.nih.gov/pubmed/10216059?tool=bestpractice.com
If the amblyopia is not treated during childhood, with some exceptions, permanent vision loss results.[1]Cruz OA, Repka MX, Hercinovic A, et al. Amblyopia preferred practice pattern. Ophthalmology. 2023 Mar;130(3):P136-78.
https://www.aaojournal.org/article/S0161-6420(22)00865-X/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/36526450?tool=bestpractice.com
[12]Rahi JS, Logan S, Borja MC, et al. Prediction of improved vision in the amblyopic eye after visual loss in the non-amblyopic eye. Lancet. 2002 Aug 24;360(9333):621-2.
http://www.ncbi.nlm.nih.gov/pubmed/12241937?tool=bestpractice.com
[13]Wilson ME. Adult amblyopia reversed by contralateral cataract formation. J Pediatr Ophthalmol Strabismus. 1992 Mar-Apr;29(2):100-2.
http://www.ncbi.nlm.nih.gov/pubmed/1588469?tool=bestpractice.com
People with unilateral vision loss due to amblyopia also have an increased risk of vision loss in the normal eye. One population-based study found that, among people with amblyopia, the incidence of vision loss in the normal eye was 1.75/1000, which was compared with the lower overall incidence of adult blindness of 0.66/1000.[98]Tommila V, Tarkkanen A. Incidence of loss of vision in the healthy eye in amblyopia. Br J Ophthalmol. 1981 Aug;65(8):575-7.
https://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1039584&blobtype=pdf
http://www.ncbi.nlm.nih.gov/pubmed/7295619?tool=bestpractice.com
More than half of the causes of vision loss in the sound eye were trauma.[98]Tommila V, Tarkkanen A. Incidence of loss of vision in the healthy eye in amblyopia. Br J Ophthalmol. 1981 Aug;65(8):575-7.
https://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1039584&blobtype=pdf
http://www.ncbi.nlm.nih.gov/pubmed/7295619?tool=bestpractice.com
Another population study found that the lifetime risk of bilateral visual impairment was 18% in people with amblyopia compared with 11% in the general population, and that people with amblyopia had bilateral visual impairment 6 months longer than the general population.[99]van Leeuwen R, Eijkemans MJ, Vingerling JR, et al. Risk of bilateral visual impairment in individuals with amblyopia: the Rotterdam study. Br J Ophthalmol. 1981 Aug;65(8):575-7.
http://www.ncbi.nlm.nih.gov/pubmed/17522151?tool=bestpractice.com
Treated amblyopia
The first amblyopia treatment study conducted by the Pediatric Eye Disease Investigator Group demonstrated that 75% of children younger than age 7 years with moderate amblyopia attain visual acuity of 20/30 or better in the amblyopic eye with treatment.[57]Pediatric Eye Disease Investigator Group. A randomized trial of atropine vs. patching for treatment of moderate amblyopia in children. Arch Ophthalmol. 2002 Mar;120(3):268-78.
http://www.ncbi.nlm.nih.gov/pubmed/11879129?tool=bestpractice.com
Visual acuity benefits are maintained in the long term.[58]Repka MX, Kraker RT, Beck RW, et al. A randomized trial of atropine vs patching for treatment of moderate amblyopia: follow-up at age 10 years. Arch Ophthalmol. 2008 Aug;126(8):1039-44.
http://www.ncbi.nlm.nih.gov/pubmed/18695096?tool=bestpractice.com
[70]Hertle RW, Scheiman MM, Beck RW, et al; Pediatric Eye Disease Investigator Group. Stability of visual acuity improvement following discontinuation of amblyopia treatment in children aged 7 to 12 years. Arch Ophthalmol. 2007 May;125(5):655-9.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2614923
http://www.ncbi.nlm.nih.gov/pubmed/17502505?tool=bestpractice.com
However, even among children with anisometropic amblyopia and visual outcome of 20/25 or better in the treated amblyopic eye, stereopsis is worse than among nonamblyopic children of the same age.[100]Wallace DK, Lazar EL, Melia M, et al; Pediatric Eye Disease Investigator Group. Stereoacuity in children with anisometropic amblyopia. J AAPOS. 2011 Oct;15(5):455-61.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3223370
http://www.ncbi.nlm.nih.gov/pubmed/22108357?tool=bestpractice.com