Eye

Question 1

What can causes diplopia, unilateral ptosis, drooping of one eyelid, fixed pupil, eye in the out position, and normal visual acuity?

Answer 1

Aneurysm of the posterior communicating artery - CN III courses bw PCA and superior cerebellar arteries.
Ipsilateral

Question 2

MC site of berry/saccular aneurysm

Answer 2

acomm and ACA

Causes subarachnoid hemorrhage

Question 3

Contralateral upper extremity and facial hemiparesis, sensory deficits

Answer 3

rupture of MCA

Question 4

Bitemporal hemianopsia (compressed optic chiasm), contralateral lower extremity hemiparesis, sensory deficits

Answer 4

anterior communicating artery aneurysm

Question 5

constricted pupil

Answer 5

miosis

Question 6

dilated pupil

Answer 6

mydriasis

Question 7

MS patient with diplopia. Images are horizontal on lateral gaze. Dec adduction bilaterally during lateral conjugate gaze. Most likely location of a demyelinating plaque causing the diplopia?

Answer 7

medial longitudinal fasciculus (allows for crosstalk bw CN6 and CN 3 nuclei to coordinate horiz gaze) located in the dorsal pons

this patient has internuclear ophthalmoplegia

Question 8

Left homonymous hemianopia (cant seen on left in both eyes) is due to lesion where?

Answer 8

RIGHT optic tract (just posterior to the optic chiasm) (pg 489 FA)
Note this is CONTRALATERAL to side of visual defect

Question 9

Left hemianopia with macular sparing (normal visual acuity) is due to what?

Answer 9

PCA infarct (occipital lobe) (pg 489 FA)

Question 10

central scotopa (ie blind in one eye in the center) is due to what?

Answer 10

macular degeneration (pg 489 FA)

Question 11

Left upper quadrantic anopia (ie pie in the sky) is due to lesion where?

Answer 11

Meyer loop (right temporal lesion, MCA) - outer tract (pg 489 FA)

Question 12

Left lower quadrantic anopia is due to lesion where?

Answer 12

right parietal lesion, MCA - inner tract (pg 489 FA)

Question 13

Glaucoma damages what cells in the eye, which can result in blindness and no bilateral constriction in response to light?

Answer 13

retinal ganglion cells

Question 14

Timolol and other nonselective BB work by diminishing the secretion of aqueous humor by targeting what structure?

Answer 14

Ciliary epithelium
(Acetazolamide, a carbonic anhydrase inhibitor also uses this mechanism)

Question 15

Prostaglandin F2a (e lantaoprost, travoprost) and cholinomimetics (pilocarpine, carbachol) decrease intraocular pressure how?

Answer 15

Increase outflow of aqueous humor

Question 16

Elevating or depressing the eye from the abducted position tests what EOM and nerve?

Answer 16

Superior and inferior rectus (CN III)
Note: CN III innervates the SKELETAL mm of the levator palpebrae superioris as well. Sympathetics innervate the SMOOTH mm of the levator and can also cause ptosis

Question 17

Elevating or depressing the eye from the adducted position tests what EOM and nerve?

Answer 17

Inferior (CN III) and superior oblique (CN IV)

Question 18

How does central retinal artery occlusion present?

Answer 18

sudden onset, painless and permanent monocular blindness.

CHERRY RED macula and pale retina

Question 19

How does diabetic retinopathy present?

Answer 19

Blurry vision, black spots, floaters, “cotton wool spots”, dec peripheral vision.
Neovascularization and flame-shaped hemorrhage seen
This is a microangiopathy. Cotton wool spots can be seen with hypertensive retinopathy as well

Question 20

How does amaurosis fugax present?

Answer 20

Painless, transient, monocular vision loss - small embolus of OPHTHALMIC artery
Doesn’t last for more than a few sec
Key feature of peripheral vascular disease

Question 21

What mediates direct and consensual pupillary light reflex?

Where is this located?

Answer 21

Edinger-Westphal nuclei –> CN III

Upper MIDBRAIN

Question 22

Nerves responsible for afferent and efferent Pupillary light reflex ?

Answer 22

Afferent - CN II

Efferent - CN III (also causes ptosis, down and out)

Question 23

Grey subretinal membrane and subretinal hemorrhage is sign of wet age related macular degeneration. Treatment?

Answer 23

Stop smoking
VEGF inhibitor (ranibizumab, bevacizumab)

Question 24

Lesion of what nerve results in vertical diplopia? (eg walking downstairs or up close reading)

Answer 24

Trochlear nerve. Superior oblique mm

Note: abducens n palsy results in horizontal diplopia

Question 25

SENSORY limb of the corneal reflex is mediated by what nerve?
MOTOR component of corneal reflex is carried by what nerve?

Answer 25

CN V1

CN VII

Question 26

How can vision improve with aging?

Answer 26

Patient with Myopia: Aging –> presbyopia (diff to focus on nearby objects bc image behind retina). Presbyopia will compensate for myopia (image focuses in front of retina)

Question 27

Definition of scotoma? Patient with small yellow retinal lesions clustered in the macula would be expected to have what type of scotoma?

Answer 27

Visual defect surrounded by unimpaired field vision
Central scotoma - Macular degeneration(MD)/lesions of the macula cause central scotomas.
MD is characterized by progressive loss of central vision d/t deposition of fatty tissue (drusen) behind the retina (dry MD) and neovascularization of the retina (wet MD)
Note: arcuate scotomas occur d/t damage to part of the optic n head –> visual field defect that follow arcuate shape of the n fiber pattern

Question 28

What is the most likely cause of a funduscopic exam showing copper wiring and AV nicking?

Answer 28

Hypertensive retinopathy

Cotton wool spots can be seen as well. These spots are also seen with diabetic retinopathy