Functional Testing Flashcards
what 4 things do you need to record with a tropia
direction, size, timing, and which eye
what 2 things do you need to record with a phoria
direction and size
how do you measure a misalignment
alternating cover test- fusion is broken at all times during the test
when do you stop measuring a misalignment
when the eye stops moving; prism = size of deviation
what does prism do
bends rays of light toward the base and shift the image to the apex
what are 3 additional tests used to strabismus
hirschberg, krimsky, and bruckner
what is a normal result for hirschberg
the light reflexes are centered in each pupil
what if the reflex is 1mm away from the center; how much misalignment is that
22 prism diopters
how is krimsky different from hirschberg
krimsky measures misalignment for light reflex with prism
what setting is the ophthalmoscope set at for Bruckners
+1.0m (green number in window)
how far away do you sit from patient during Bruckner’s
1m (focal length of +1 lens)
what 3 things are you looking for during Bruckner’s
difference in brightness, clarity, and pupil size
what would be abnormal in a Bruckner’s
a lighter pupil, dark figures or different size
why is the abnormal pupil lighter colored
the fixating eye aims its fovea at the light
what are 2 tests used only for phorias
maddox rod and modified thorington
which eye is the maddox rod placed over
the OD
why do the eyes go to their phoria positions during the maddox rod test
the images (streak and light) are so radically different that fusion is broken or disrupted
why is the OD the “deviating eye”
the light is a more natural source than the streak so the OS stays straight ahead
do you perform the modified thorington technique at distance or near
only at near
what is the most reliable test for phorias
the thorington test
what size optotypes are on the thorington card
around 20/30 at 40cm
where do you shine the light during thorington
through the center hole on the card
which eye is the fixating eye during thorington
the OS (OD has maddox rod over it)
which direction do the cylinders go if measuring a lateral phoria
horizontal
which direction do the cylinders go if you are measuring a vertical phoria
vertical
how much does the gap between optotypes equal in prism diopters
1 PD when placed at 40cm
why is the thorington test so reliable
the small optotype yields a high degree of stability in the accommodative response and it stabilizes accommodative- convergence
why is the Duane White classification scheme used
to identify and classify common anomalies of ocular misalignments
what are some typical complaints of a Duane White anomaly
asthenopia after less than 30 min of near work, words blur/jump/double when reading, eyes turn out, dislikes reading, poor school performance with 20/20 VA, covers one eye, tilts head, intermittent blur
what 2 conditions have similar complaints to a duane white anomaly that you should rule out first
hyperopia and dry eyes
what anomaly has ortho in the distance and a large Exo at near
convergence insufficiency (CI)
what anomaly has ortho in the distance and a large Eso at near
convergence excess (CE)
what anomaly has a large Exo at distance and ortho at near
divergence excess (DE)
what anomaly has Eso at distance and ortho at near
divergence insufficiency (DI)
what anomaly do you measure the amplitude at distance and then calculate deviation at near (15-age/4)
accommodative insufficiency (AI)
what 2 anomalies are the most common
convergence insufficiency and accommodative insufficiency
what anomaly is associated with intermittent XT (exotropia) at distance
divergence excess
what anomaly is ortho at distance and a small (1-6D) exophoria at near
no anomaly- “expected in normal patients”
what deviation is never expected
esophoria
