LE3

Question 1

1. In III nerve palsy, the eye is:

A. Adducted, depressed
B. Abducted, depressed
C. Abducted, elevated
D. Adducted, elevated

Answer 1

B. Abducted, depressed

In III nerve palsy, the lateral rectus and superior oblique muscles are unopposed, resulting in the eye being abducted and depressed

Question 2

2. An aneurysm in which location may cause isolated III nerve palsy?

A. Anterior communicating artery
B. Middle cerebral artery
C. Posterior communicating artery
D. Posterior cerebral artery

Answer 2

C. Posterior communicating artery

An aneurysm in the posterior communicating artery can compress the oculomotor nerve, leading to isolated III nerve palsy.

Question 3

3. In question no. 2, the pupil will be:

A. Fixed, dilated
B. Constricted
C. Normally reactive
D. Teardrop-shaped

Answer 3

A. Fixed, dilated

A compressive lesion, such as an aneurysm, typically affects the parasympathetic fibers of the III nerve, leading to a fixed, dilated pupil.

Question 4

4. Actions of the superior oblique muscle are:

A. Elevation, adduction, intorsion
B. Depression, adduction, extorsion
C. Depression, abduction, intorsion
D. Elevation, abduction, intorsion

Answer 4

C. Depression, abduction, intorsion

The superior oblique muscle primarily depresses, abducts, and intorts the eye.

Question 5

5. The agonist muscle of the right lateral rectus is:

A. Left medial rectus
B. Left lateral rectus
C. Right medial rectus
D. Left superior oblique

Answer 5

A. Left medial rectus

The left medial rectus works as the yoke muscle of the right lateral rectus, coordinating horizontal eye movements.

Question 6

6. Yoke or agonist muscles receive approximately similar innervation according to:

A. Sherrington’s law
B. Müller’s law
C. Hering’s law
D. Murphy’s law

Answer 6

C. Hering’s law

Hering’s law states that yoke muscles receive equal innervation for conjugate eye movements.

Question 7

7. Optic neuritis may be an initial manifestation of:

A. Multiple myeloma
B. Subacute sclerosing panencephalitis
C. Systemic lupus erythematosus
D. Multiple sclerosis

Answer 7

D. Multiple sclerosis

Optic neuritis can be an initial presentation of multiple sclerosis.

Question 8

8. By itself, which of the following is NOT a cause of Marcus Gunn pupil?

A. Dense cataract
B. Total retinal detachment
C. Optic atrophy
D. Retrobulbar optic neuritis

Answer 8

A. Dense cataract

A dense cataract does not affect the afferent visual pathway and therefore does not cause a Marcus Gunn pupil.

Question 9

9. Which of the following is a strengthening procedure?

A. Resection
B. Recession
C. Tenotomy
D. Faden procedure

Answer 9

A. Resection

Resection is a surgical procedure that strengthens a muscle by shortening it.

Question 10

10. Which of the following visual field defects is due to a temporal optic radiation lesion?

A. Homonymous hemianopsia
B. Bitemporal hemianopsia
C. “Pie in the sky” visual field defect
D. Inferior quadrantanopia

Answer 10

C. “Pie in the sky” visual field defect

A lesion in the temporal optic radiation affects the superior visual field, resulting in a “pie in the sky” defect.

Question 11

11. A patient with superior oblique palsy primarily presents with which of the following?

A. Hypertropia
B. Esotropia
C. Exotropia
D. Hypotropia

Answer 11

A. Hypertropia

Superior oblique palsy typically causes hypertropia, where the affected eye is higher than the unaffected eye.

Question 12

12. A 40-year-old male consulted for blurring of vision in the right eye. He also experienced pain around the right eye on eye movement. On examination, the visual acuity was counting fingers up to 1 foot. Intraocular pressure was normal, and funduscopy was normal. There was a Marcus Gunn pupil. What is the most likely diagnosis?

A. Papillitis
B. Papilledema
C. Retrobulbar optic neuritis
D. Central retinal artery occlusion

Answer 12

C. Retrobulbar optic neuritis

The combination of pain on eye movement, decreased visual acuity, and a Marcus Gunn pupil with a normal fundus suggests retrobulbar optic neuritis.

Question 13

13. A 1-year-old boy is brought to you by his parents, who noted that he was “duling” (cross-eyed). On examination, the corneal light reflexes were centered in both eyes. Visual acuity was grossly normal. What is the diagnosis?

A. Esophoria
B. Exophoria
C. Esotropia
D. Pseudoesotropia

Answer 13

D. Pseudoesotropia
Pseudoesotropia is suggested when the corneal light reflexes are centered and visual acuity is normal, but the eyes appear crossed due to facial features.

Question 14

14. All of the following muscles arise from the annulus of Zinn EXCEPT:

A. Superior rectus
B. Inferior oblique
C. Superior oblique
D. Inferior rectus

Answer 14

B. Inferior oblique
The inferior oblique muscle arises from the maxillary bone, not from the annulus of Zinn.

Question 15

15. The surgical management of congenital esotropia is:

A. Medial rectus recession
B. Medial rectus resection
C. Lateral rectus recession
D. Lateral rectus tenotomy

Answer 15

A. Medial rectus recession
Medial rectus recession is the preferred surgical management for congenital esotropia to weaken the overactive medial rectus muscles.

Question 16

16. Which lenses are used to correct astigmatism?

A. Concave lenses
B. Convex lenses
C. Cylindrical lenses
D. Spherical lenses

Answer 16

C. Cylindrical lenses
Cylindrical lenses are used to correct astigmatism by compensating for the irregular curvature of the cornea or lens.

Question 17

17. Which of the following is true about concave lenses?

A. They converge light rays
B. They magnify
C. They diverge light rays
D. They correct hyperopia

Answer 17

C. They diverge light rays
Concave lenses diverge light rays and are used to correct myopia (nearsightedness).

Question 18

18. A +2.00 spherical lens has a focal length of:

A. 1 meter
B. 0.5 meter
C. 0.33 meter
D. 2 meters

Answer 18

B. 0.5 meter
The focal length of a +2.00 diopter lens is calculated as 1 divided by the lens power in diopters (1/2.00 = 0.5 meters).

Question 19

19. A complete CN III palsy has all the following features EXCEPT:

A. Dilated pupil
B. Ptosis
C. Divergent strabismus
D. Esotropia

Answer 19

D. Esotropia
A complete CN III palsy causes divergent strabismus (the eye is turned outward), not esotropia.

Question 20

20. Which one of the following four patients would you emergently evaluate and refer? An acquired…

A. CN IV palsy
B. CN III palsy, pupil dilated
C. CN III palsy, pupil spared
D. CN VI palsy

Answer 20

B. CN III palsy, pupil dilated
A CN III palsy with a dilated pupil is an emergency, often indicating compression from an aneurysm or other serious condition, requiring immediate evaluation.

Question 21

21. A lesion in the right optic tract typically produces what type of visual field defect?

A. Bitemporal hemianopsia
B. Macular sparing
C. Right homonymous hemianopsia
D. Left homonymous hemianopsia

Answer 21

D. Left homonymous hemianopsia
A lesion in the right optic tract causes a loss of vision in the left visual field of both eyes, known as left homonymous hemianopsia.

Question 22

22. What action is appropriate for a patient you discover to have bilateral papilledema?

A. Make a neurology appointment in the next two weeks
B. Neurology referral ASAP
C. Obtain head CT scan with attention to the orbits
D. Obtain disc photos and re-evaluate in a week

Answer 22

B. Neurology referral ASAP

Rationale: Bilateral papilledema is an alarming sign that indicates increased intracranial pressure, which can be caused by serious conditions such as a brain tumor, intracranial hemorrhage, or pseudotumor cerebri. This requires urgent evaluation, as delayed diagnosis and treatment can lead to permanent vision loss or other neurological complications. Therefore, an immediate referral to neurology (or neuro-ophthalmology) for further workup is essential. Other options, such as re-evaluating in a week or scheduling a delayed neurology appointment, would not address the urgency of the situation.

Question 23

23. Unilateral optic disc swelling is usually associated with all of the following EXCEPT:

A. RAPD (relative afferent pupillary defect)
B. Bitemporal hemianopsia
C. Central scotoma
D. Decreased visual acuity

Answer 23

B. Bitemporal hemianopsia
Unilateral optic disc swelling is not associated with bitemporal hemianopsia, which typically occurs with lesions at the optic chiasm.

Question 24

24. What is the major complaint of a patient with left VI nerve palsy?

A. Vertical diplopia, greatest on downgaze
B. Horizontal diplopia, greatest on gaze right
C. Pain on attempted gaze right
D. Horizontal diplopia, greatest on gaze left

Answer 24

D. Horizontal diplopia, greatest on gaze left
In left VI nerve palsy, the lateral rectus muscle of the left eye is weakened, causing horizontal diplopia, which is worse when looking to the left.

Question 25

25. What contributes most to the refractive power of the eye? A. Cornea B. Lens C. Aqueous humor D. Vitreous humor

Answer 25

A. Cornea The cornea provides the majority of the eye's refractive power due to its curvature and air interface.

Question 26

26. Which of the following is true of a myopic eye? A. Cornea is less steep B. Corrected by convex lenses C. Shorter than normal D. Longer than normal

Answer 26

D. Longer than normal In myopia, the eye is longer than normal, causing light to focus in front of the retina.

Question 27

27. Patients with myasthenia gravis may have one of the following EXCEPT: A. Ptosis B. Diplopia C. Relative afferent pupillary defect D. Difficulty swallowing

Answer 27

C. Relative afferent pupillary defect Myasthenia gravis affects the muscles controlling eye movement and eyelids, but it does not cause a relative afferent pupillary defect, which is associated with optic nerve pathology.

Question 28

28. Occlusion treatment for amblyopia: A. Patch the eye with poorer vision B. Patch the eye with better vision C. Patch eyes alternately D. Patch any eye

Answer 28

B. Patch the eye with better vision Occlusion treatment involves patching the stronger eye to force the weaker eye to work harder, thus improving vision in the weaker eye.

Question 29

29. The corneal light reflex is noted to be about 2 mm temporally off the center of one eye. The patient has: A. Esotropia B. Exotropia C. Hypertropia D. Hyperopia

Answer 29

B. Exotropia A temporally displaced corneal light reflex indicates exotropia, where the eye turns outward.

Question 30

30. The law of reciprocal innervation (Sherrington's law) states that: A. When one muscle contracts, its agonist contracts B. When one muscle contracts, its agonist relaxes C. When one muscle contracts, its antagonist contracts D. When one muscle contracts, its antagonist relaxes

Answer 30

D. When one muscle contracts, its antagonist relaxes Sherrington's law of reciprocal innervation states that when a muscle contracts, its antagonist relaxes to allow smooth movement.

Question 31

31. In right lateral rectus palsy, there is: A. Diplopia greatest on left gaze B. Diplopia lessened by turning head to left C. Diplopia greatest on right gaze D. Diplopia lessened by tilting head to right

Answer 31

C. Diplopia greatest on right gaze In right lateral rectus palsy, diplopia is greatest on right gaze due to the weakness of the right lateral rectus muscle, which is responsible for abducting the eye.

Question 32

32. On examining a patient, pointing a penlight to the left eye reveals constriction of the left pupil. Swinging the penlight to the right eye, the right pupil is noted to dilate. What does this indicate? A. This is a normal finding B. Vision of the left eye is probably poor C. There is probably optic neuropathy of the right eye D. There is probably optic neuropathy of the left eye

Answer 32

C. There is probably optic neuropathy of the right eye A relative afferent pupillary defect (RAPD) is indicated when the right pupil dilates upon shining light in the right eye. This suggests optic nerve dysfunction in the right eye.

Question 33

33. Which cranial nerve arises from the dorsal aspect of the brainstem? A. CN III B. CN IV C. CN V D. CN VI

Answer 33

B. CN IV The trochlear nerve (CN IV) arises from the dorsal aspect of the brainstem.

Question 34

34. Which cranial nerve is adjacent to the posterior communicating artery? A. CN II B. CN IV C. CN V D. CN VI

Answer 34

A. CN II The optic nerve (CN II) is adjacent to the posterior communicating artery, making it susceptible to compression from aneurysms in this region.

Question 35

35. What is true of a hyperopic eye? A. Cornea is more steep B. Corrected by concave lenses C. Shorter than normal D. Longer than normal

Answer 35

C. Shorter than normal A hyperopic (farsighted) eye is shorter than normal, causing light to focus behind the retina.

Question 36

36. "Pie on the floor" visual field defect is characteristic of which of the following? A. Temporal optic radiations B. Parietal optic radiations C. Main radiation lesion D. Anterior visual cortex lesion

Answer 36

B. Parietal optic radiations A lesion in the parietal optic radiations causes a "pie on the floor" visual field defect (inferior quadrantanopia).

Question 37

37. Which of the following is true about LASIK? A. Never has complications B. Always results in 20/20 vision C. Makes the cornea more steep D. Makes the cornea less steep

Answer 37

D. Makes the cornea less steep LASIK reshapes the cornea by making it less steep, which corrects refractive errors like myopia.

Question 38

38. A child is seen to have the right eye turned inward. On covering the left eye, the right eye takes up fixation (looks straight ahead). On uncovering the left eye, the right eye turns inward while the left eye takes up fixation (looks straight ahead). What is the most appropriate diagnosis? A. Alternating esotropia, right eye preference B. Left monocular esotropia C. Left esophoria D. Alternating esotropia, left eye preference

Answer 38

A. Alternating esotropia, right eye preference Alternating esotropia is indicated when fixation alternates between the eyes, but there is a slight preference for the right eye in this case.

Question 39

39. Which of the following is true about retinal detachment? A. Higher risk of retinal detachment in hyperopia B. Higher risk in myopia C. Higher risk in astigmatics D. Risk not related to refractive error

Answer 39

B. Higher risk in myopia Myopic (nearsighted) individuals have a higher risk of retinal detachment due to the elongation of the eye, which can lead to retinal thinning and detachment.

Question 40

40. Which is the most commonly involved muscle causing hypertropia? A. Superior rectus B. Inferior rectus C. Superior oblique D. Inferior oblique

Answer 40

C. Superior oblique The superior oblique muscle is most commonly involved in causing hypertropia when it's weak or paralyzed, leading to vertical misalignment of the eyes.

Question 41

41. Which of the following eyes is hyperopic? A. Aphakic eye (eye with no lens) B. Longer than normal eye C. Eye where the image is focused in front of the retina D. Eye with steep cornea

Answer 41

A. Aphakic eye (eye with no lens) An aphakic eye is hyperopic because, without the lens, the eye cannot focus light properly, leading to far-sightedness.

Question 42

42. Which of the following is present if strabismus develops in older children or adults? A. Diplopia B. Suppression C. Amblyopia D. Diminished light sensitivity

Answer 42

A. Diplopia Strabismus that develops in older children or adults often results in diplopia (double vision) because the brain cannot suppress the image from one eye as effectively as in younger patients.

Question 43

43. Conductive keratoplasty is a treatment for: A. Hyperopia B. Astigmatism C. Myopia D. Glaucoma

Answer 43

A. Hyperopia Conductive keratoplasty is a treatment used to correct mild to moderate hyperopia (farsightedness).

Question 44

44. In right homonymous hemianopsia: A. Patient has blurred temporal visual fields B. Patient has blurred vision in the right eye alone C. Patient has blurred right temporal and blurred left nasal visual fields D. The visual field defect is represented by shading the left half of each eye

Answer 44

C. Patient has blurred right temporal and blurred left nasal visual fields Right homonymous hemianopsia results in a loss of the right visual field of both eyes, affecting the right temporal field and the left nasal field.

Question 45

45. A lesion at the optic chiasm, for example due to a pituitary tumor, will cause: A. Homonymous hemianopsia B. Bitemporal hemianopsia C. Binasal hemianopsia D. "Pie in the sky" visual field defect

Answer 45

B. Bitemporal hemianopsia A lesion at the optic chiasm, such as from a pituitary tumor, results in bitemporal hemianopsia, where the temporal visual fields of both eyes are lost.

Question 46

46. Sudden, severe headache; stiff neck; loss of consciousness, and preretinal hemorrhages indicate: A. Subarachnoid hemorrhage B. Subdural hemorrhage C. Occlusion of the posterior cerebral artery D. Occlusion of the basilar artery

Answer 46

A. Subarachnoid hemorrhage Sudden severe headache, stiff neck, loss of consciousness, and preretinal hemorrhages are classic signs of subarachnoid hemorrhage.

Question 47

47. Diplopia when fatigued may indicate: A. VI nerve palsy B. Aneurysm C. Myasthenia gravis D. Error of refraction

Answer 47

C. Myasthenia gravis Diplopia when fatigued is a characteristic symptom of myasthenia gravis, as muscle weakness worsens with exertion.

Question 48

48. Which is NOT true of disorders of the retrochiasmal visual pathways? A. Homonymous B. Partial lesions are incongruous C. The more posterior the lesion, the more incongruous D. There may be associated neurologic symptoms and signs

Answer 48

C. The more posterior the lesion, the more incongruous This statement is incorrect; the more posterior the lesion, the more congruous the visual field defects tend to be.

Question 49

49. In heterophoria or latent strabismus: A. Strabismus is present under normal binocular viewing conditions B. Strabismus is present when one eye is covered C. No movement with cover/uncover test D. Associated with amblyopia

Answer 49

B. Strabismus is present when one eye is covered In heterophoria (latent strabismus), strabismus manifests when binocular fusion is disrupted, such as when one eye is covered.

Question 50

50. In hypertropia: A. One eye is elevated B. There may be an associated accommodative esotropia C. There is a weakness in the elevators of the eye D. The eyeball is longer than normal

Answer 50

A. One eye is elevated Hypertropia is a condition where one eye is abnormally elevated compared to the other.