Lectures 4,5, Remick Flashcards
what is the center of rotation
a pivot point in the globe where motion of the EOMs is centered around
what is a 3rd nerve palsy
“down and out” and ptosis
what is a 4th nerve palsy
head tilt/turn
what is a 6th nerve palsy
looks like and eso-strabismus
what is line of sight
a line connecting the center of the eye and a point of fixation
where are saccades controlled in the brain
in the frontal lobe
where are pursuits controlled in the brain
in the occipital lobe
which test evaluates the 6 cardinal positions of each eye
the H pattern
what does the O-pattern test for
smooth pursuits (eye tracking movements)
what is end-point nystagmus
involuntary eye movements to and fro on far lateral gazes (can be normal)
what is latent nystagmus
induced by covering either eye, but absent otherwise
what is optokinetic nystagmus
induced by attempt to fixate objects rapidly moving in the visual field
what type of nystagmus is tested for during a field sobriety test
end point
what ages can amblyopia develop up to
6-8
why would a person develop amblyopia
the visual pathway doesn’t develop due to inadequate stimulation
what is the major cause of vision loss under age 45
amblyopia (about 2% of the population)
what 3 things can cause amblyopia
form deprivation, optical defocus, strabismus
what is form deprivation
physical obstructions (cataract, ptosis) the image cannot reach the retina
when does form deprivation amblyopia occur
before age 8
what are the 3 types of optical defocus
anisometropia, meridonal, and isoametropia
how much aniso myopia can be tolerated before it can become amblyopia
up to 5.00 D
how much aniso of hyperopia can be tolerated before amblyopia can occur
as little as 1.00 D
what is meridonal amblyopia
uncorrected high astigmatism (at least 1.50-2.00)
what is isoametropia amblyopia
equal but large refractive error, both eyes have reduced vision (20/40-20/50)
