Amblyopia Flashcards
What VA is considered amblyopia?
20/30 or worse
Amblyopia is caused by what kind of strabismus?
Constant unilateral strab
How long to patch a mild strab 20/50-20/80?
2 hours per day with one hour near work
How long to patch a moderate strab 20/100-20/400
6 hours per day with one hour near work
How much atropine instead of patching?
2 days a week mild
Same for moderate
Best way to test microphoria?
4BO test
Infantile or congenital amblyopia
< 6 months old
Large 30-60 prism diopters
Latent nystagmus (when cover one eye)
Worse when look in
HRAC
No double vision
Angle of deviation
4BO test
Tests for micro tropia
When patient has mild VA reduction and it can’t be seen on cover test
Outward movement and refixation with uncovered eye = no suppression
Outward movement and no refixation with other eye = suppression of non covered eye
No outward movement or refixation with other eye = suppression of covered eye
What refractive error causes the highest chance of amblyopia?
Astigmatism
Potential amblyopia refractive errors:
Hyperopia: >1D aniso, >5D OU
Myopia: > 3D aniso, >8D OU
Astigmatism: >1.5D aniso, >2.5D OU
Hirshberg testing
Normal angle .5mm nasal
Nasal displacement is exo and temporal displacement is eso
1mm deviation = 22 prism
Do contour tests have monocular cues?
Yes. Allows for guessing
Do global tests have monocular cues?
No. Good to detect strabismus
Normal steriopsis is
20 seconds of arc
