Amblyopia

According to ophthalmological test 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 ​

Amblyopia is diagnosed when the following criteria are met and a cause is identified.

Unilateral:

• Asymmetric objection to occlusion of one eye

• Unequal fixation preference behaviour

• Preferential looking difference of two or more octaves (4 card difference on Teller Acuity Cards)

• Best corrected visual acuity difference between the two eyes of two or more lines.

Bilateral:

• Best corrected visual acuity less than 20/30 in either eye in a child age 5 or older

• Best corrected visual acuity less than 20/40 in either eye in a child age 4 to less than 5 years

• Best corrected visual acuity less than 20/50 in either eye in a child age 3 and younger.

Severity of amblyopia

In randomised controlled trials, typically used definitions for severity of amblyopia are as follows:

• Mild to moderate: visual acuity of 20/40 to 20/100

• Severe: visual acuity of 20/100 or worse.