Amblyopia

• reduction in best corrected visual acuity caused by abnormal visual dev during critical period

• VA less than expected for age with Rx

• VA less than 6/9 without anomalities

1. NOT a reduction in VA due to uncorrected Rx

2. NOT a reduction in VA due to pathology

3. NOT visual impairment- VI happens in both eyes

4. NOT suppression - SUP occurs durng binocular viewing conditions

Light deprivation (LD) - light doesnt reach retina ( media opacity/ptosis)

Form deprivation- light reaches retina but image out of focus ( less severe than LD)

Developmental - change to ret and eye ( VA + emmetropisation) ( birth to 3-5yrs)

Critical period - dev of bino vision ( birth to 7yrs)

“one eye is not developing as quickly as the other and so the childs vision will remain weaker in that eye unless we fix it. The important thing to know is that a child’s vision develops the most in the early years, especially up until around the age of 7. After that, it becomes much harder to improve the weaker eye.“

If anything happens to the “good” eye = loss of vision

career restrictions: grp 2 driving license ( lorry/bus), pilot, forces, police

onset - observed by fam member

fam hx of strabismus, high Rx, anisometropia, amblyopia

any previous treatment

GH and birth history

VA: distance and near, @3m or less, note if with AHP or not

CS: hiding heidi CS test

CT: px need to see target

BSV: prism fusion 20 base out + stereopsis + 4 bas out ( microtropia)

Rx: cyclo Rx, full time wear, review in 6 or 12 weeks

1. patching - cover good eye, px is forced to use amblyopic eye

   • patches can be reused

   • might cause hypersensitivity if placed on face

   • part time wear more compliant: improve by positive attitude from friends and fam/rewards/headbands to keep specs on

2. Cycloplegia

   • atropine drops to good eye - long lasting

   • reduces accom, have to use amblypic for near

at least every 3 months

greater occlusion hrs = more often

younger children = more often

• risk of latent developing into manifest

• can lead to intractable dip ( diplopia without suppression)