strabismus in children Flashcards
what is ocular instability of infancy, when is it abnormal
- lateral ocular deviation, less than 15 degrees
- usually lasts 3 months
- if >15deg, or >3 months its abnormal
what is pseudostrabismus
when the eye actually tracks normally, but because of the skull’s shape it looks like its misaligned
strabismus - describe the light reflex test
- get child to look at a light
- if the reflection of the light off surface of cornea is symmetrical (central, slightly nasal), there is no squint
- if the reflection in one eye is too medial, they have an exotropia in that eye
- if the reflection in one eye is too lateral, they have an esotropia in that eye
strabismus - management
- at GP level
- what’s actually done
if its ocular instability, review at 3 months then refer
otherwise refer to ophthalmology
what’s actually done - patching the eye. atropine penalisation. correct refractive error
strabismus - cover test
- what defect does it test for, in which eye
manifest squint ie a tropia, in the uncovered eye
strabismus - uncover test
- what defect does it detect, in which eye
latent squint ie a phoria, in the uncovered eye
strabismus - cover test
- technique, interpretation
- get child to fix both eyes on an object
- cover the eye that you think is normal
- watch the uncovered eye. if it moves to refocus on the object, it’s a confirmed tropia (manifest squint) in the uncovered eye
strabismus - uncover test
- technique, interpretation
- cover one eye for at least 5 seconds
- get child to focus on an object using the other eye
- take the cover off
- if the newly uncovered eye has to wander into fixation position, its a confirmed phoria (latent squint) in the uncovered eye
strabismus - light reflex test
- what defect can it detect
a manifest squint ie a -tropia
3 main causes of amblyopia
strabismus
anisometropia
visual deprivation (eg media opacity, ptosis)
