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)

if anything happens to the “good” eye = loss ofvision

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)