Orthoptics and paediatrics Flashcards
what is orthoptics
manage defects of binocular vision and abnormalities of eye movements
why might you be referred to orthoptics
squint amblyopia refractive error ptosis nystagmus anisocoria diplopia stroke TED
examinations in orthoptics
visual acuity cover test convergence ocular movements binocular single vision measure deviation
what is amblyopia
impairment of vision without any clinically detectable abnormality of eye or visual pathway
define ametropic
(category of amblyopia)
bilateral uncorrected refractive error
define strabismic
(category of amblyopia)
squinting eye is “suppressed”
define anisometropic
(category of amblyopia)
unequal refractive error
what is stimulus deprivation
(category of amblyopia)
congenital cataract/ptosis
management of amblyopia
occlusion therapy
- total (patch)
- partial (atropine 1%)
what is the purpose of a cover test
detects a: manifest squint (tropia) underlying latent squint (phoria)
how do you carry out a cover test
cover test - confirms eye with squint
cover/uncover test - confirms eye with latent squint
alternate cover - finds maximum deviation
in esotropia or esophoria, the eye is convergent/divergent and you see inward/outward movement
convergent
outward
in exotropia or exophoria, the eye is convergent/divergent and you see inward/outward movement
divergent
inward
in hypertropia or hyperphoria, the eye is higher/lower
higher
hypotropia/phoria is lower
what is a latent squint called
phoria
features of phoria (latent squint)
symmetric corneal reflections
binocular vision
underlying deviation in BOTH eyes
ie when both eyes are open and working together, the eyes will be straight and no squint will be seen
what is a manifest squint called
tropia
features of tropia (manifest squint)
asymmetric corneal reflections
no / poor binocular vision
present constantly
squint only in one eye at a time
how do you assess ocular motility
use an occluder and a pen torch and carry out a cover test in the 9 positions of gaze (to test each EOM)
most convergent/divergent squints are corrected by glasses
convergent
a baby with an absent red reflex should be referred immediately, true or false
true
causes of amblyopia
squint
refractive errors
obstruction to visual axis (cataract, ptosis)
causes of squints
congenital hypermetropia CN palsies muscle pathology Orbital problems eg #
in which types of squints is there overaccomodation and overconvergence?
hypermetropia
esotropia
management of hypermetropia and esotropia
glasses
this reduces accomodative drive and aligns eyes to restore binocular vision
what are different types of squint surgery
recession
resection
causes of abnormal red reflex in children (yellow reflex, absent reflex, opacities)
retinoblastoma
coloboma
cataract
retinal detachment / dysplasia
what is a coloboma
gap in ocular tissue
causes of paediatric cataracts
genetic
infection
causes of sticky eyes in infancy
chlamydial conjunctivitis
blocked nasolacrimal duct
features of chlamydial conjunctivitis
sticky and red eye in first 10 days of life
features of nasolacrimal duct obstruction
sticky and white uninflamed eye from 2 months
delayed fluroscein dye disappearance
esotropia is often associated with hypermetropia, true or false
true
