Entrance Tests Flashcards
What test measures phoria objectively? Which way does prism go when neutralizing? Which way does prism go when correcting?
Cover Test. Important to control for accommodation. Start with UCT to see if there is phoria or tropia, look at uncovered eye. Measure magnitude of deviation with ACT.
Direction of prism goes toward movement of eye.
EXO= BI, ESO= BO, HYPO= BU, HYPER= BD
What does the EOM test?
……SR IO IO SR
LR I———I MR I———I LR
IR SO SO IR
Which cranial nerves innervate the extraocular muscles?
LR- 6
SO- 4
Everything else- 3
What kind of conditions can affect peripheral vision?
Glaucoma, retinal detachment, vascular occlusions within the eye, stroke, certain brain tumors. Dermatochalasis can affect superior VF.
What is the pathway of the pupillary light reflex? What does it test?
Light –> photoreceptors, nasal retina crosses at optic chiasm (CNII) to contralateral pretectal nucleus. temporal retinal fibers do not cross and go to ipsilateral pretectal nucleus in midbrain. –> information is relayed to both ipsilateral and contralateral preganglionic parasympathetic nucleus called Edinger-Westphal nucleus (that’s why light reflex is CONSENSUAL) –> efferent parasympathetic preganglionic fibers travel on CN III and synapse with ipsilateral ciliary ganglion –> short ciliary nerve –> postganglionic fiber synapse on pupillary sphincter (which constricts)
Used to assess brain stem function.
What are some causes of RAPD?
Any condition affecting the optic nerve, unilateral ischemic retinal diseases