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MCQs on Ocular Motility
(click the question number for the answers)

A 8 year-old girl was referred with a history of sore eyes when watching TV and reading the blackboard. Her parents complained that her eye appeared to wonder out at times. The visual acuity was 6/6 in both eyes. Alternate cover test revealed exophoria with slow recovery with the angle of deviation measuring 35 prism dioptre at distance and 10 prism dioptre at near. Following a patch test, she measured 35 prism dioptre at distance and 15 dioptre at near. (Questions 1 - 3)
1. The following are true regarding this patient:
a. the patient has intermittent exotropia of the divergence
    excess type
b. binocular single vision may be suppressed for distant
    fixation but normal with near fixation
c. patching of the eye suspend the tonic fusional
    convergence
d. a V-pattern deviation is common on upgaze
e. spontaneous resolution is common as the patient ages

2. The following treatments are appropriate:
a. tinted glasses
b. over minus glasses if refraction revealed myopia
c. orthoptic exercise
d. miotic
e. base-in prisms
3. Operation was carried out with bilateral lateral rectus
     recession. One day post-operative, the patient measured 10
     prism dioptres of consecutive esotropia. The following are true:
a. patching of the good eye should be carried out
b. prescribe prism to maintain binocular fusion
c. the eye should be explored for slipped lateral rectus
d. overcorrection of exotropia is desirable and the patient
     should be reassured
e. the esotropia will lessen with time

A 6 year-old gird was referred having moved into your area. She was previously under the care of another hospital and had squint operation for a convergent squint which was present since infancy. Her visual acuity was 6/9 in the right eye and 6/6 in the left. Cover test revealed a small right exotropia of 5 prism dioptres. The covered eye showed elevation and nystagmus was observed when either eye was covered.The nystagmus was absent when both eyes were uncovered. (Questions 4 - 6)
4. The following are true:
a. the esotropia prior to the surgery was likely to be more
    than 30 prism dioptres
b. the patient is likely to have high hypermetropia in the right
    eye
c. binocular single vision is usually better than 60 degrees of
    arc
d. asymmetrical optokinetic nystagmus is common
e. further surgery is likely to be needed.

5. True statements about elevation of the covered eye include:
a. it is caused by inferior oblique muscle overaction
b. the eye demonstrates Bielchowsky phenomenon
c. the elevation increases on adduction
d. the elevated eye usually demonstrate extortion as it
    elevates
e. the condition is usually bilateral but may be asymmetrical

6. With regard to the nystagmus:
a. it is termed manifest latent nystagmus
b. the fast phase is toward the side of the uncovered eye
c. the intensity of the nystagmus increases on abduction
d. the nystagmus has a similar waveform to congenital
    nystagmus
e. it is caused by cerebellar dysfunction

A 5 year-old child is referred the orthoptic because of strabismus. The findings include an esotropia of 20 prism dioptre in the primary position with limited abduction of the right eye. On adduction, there is narrowing of the lid fissure and upshooting ot he right. The right eye was normal. (Questions 7 - 9)
7. The following is true:
a. the child is likely to be male than female
b. the patient is likely to have a right face turn
c. the narrowing of the lid is caused by aberrant
    regeneration of the third nerve
d. amblyopia is found in 90% of patients with this condition
e. the diagnosis is type II Duane's retraction syndrome

8. The following may be associated with this condition:
a. Marcus Gunn Jaw winking
b. crocodile tears
c. glaucoma
d. cataract
e. microphthalmos

9. True statements of this condition include:
a. the strabismus is concomitant
b. surgery is useful to restore normal ocular motility
c. surgery is indicated in patient with abnormal head posture
d. resection of the muscles may worsen narrowing of the lid
e. Faden procedure can reduce the upshoot
A 24 year-old man was referred to the eye casualty because of intermittent vertical diplopia. Alternating cover test revealed a vertical phoria and when looking at a white dot through Maddox rods through both eyes he described the lines as follow:

(Questions 10 - 13)
10. The following are true if the patient had a fourth nerve palsy:
a. the patient has a right fourth nerve palsy
b. when the vertical diplopia is present, the left eye may be
    hyperdeviated
c. with the first step of the three step tests, the right eye will
    show hyperphoria
d. with the second step of the three step test, the left eye will
    show hyperphoria in left gaze
e. with the third step of the three step test, the right eye will
    show hyperphoria with right head tilt

11. The following features favours a congenital to an acquired fourth nerve palsy:
          a. absence of cyclotorsion
b. abnormal head posture
c. V pattern on upgaze
d. vertical fusional amplitude greater than 4 prism dioptre
e. absence of binocular single vision

12. The following favours a bilateral to an unilateral fourth nerve
       palsy:
          a. extorsion of more than 10 degrees

b. an abnormal head posture consists mainly of chin
    depression
c. positive Bielchowsky head tilt test to either side
d. significant hyperdeviation in the primary position
e. large V pattern

13. Surgical treatment in this patient may include:
a. right inferior oblique recession
b. right super rectus recession
c. left inferior rectus recession
d. right Harada-Ito procedure
e. Faden's procedure of the right superior oblique muscle

A 64 year-old man complains of horizontal diplopia which is worse on right gaze. (Questions 14 - 17)
14. The following are true if he had a sixth nerve palsy:
a. a right esotropia which is worse for distance than near
b. a face turn to the left
c. improved right eye movement when the left eye is closed
d. V pattern on upgaze
e. upshooting of the right eye on left gaze

15. The following muscle sequelae may occur if he had a sixth nerve palsy:
a. contraction of the right lateral rectus
b. contraction of the right medial rectus
c. inhibitional palsy of the left lateral rectus
d. overaction of the left medial rectus
e. contraction of the left lateral rectus

16. The following additional signs and the location of the lesion are
      true:

a. bilateral swollen disc - posterior fossa tumour
b. right miosis and ptosis - cavernous sinus lesion
c. fourth nerve palsy - orbital lesion
d. right facial nerve palsy and analgesia and loss of taste to
    anterior two third of the tongue - dorsal pon
e. left hemiplegia - ventral pon

17. Treatment of this patient may include:
a. injection of botulinum toxin into the right medial rectus
b. base out Fresnel prism over the right eye
c. Faden operation of the left medial rectus
d. recession of the left medial rectus and resection of the
    right lateral rectus
e. recession of the right medial rectus and resection of the left
    lateral rectus

18. True statements about microtropia include:
a. it may result from operation for congenital esotropia
b. the angle of deviation is typically between 15 and 20
    prism dioptres
c. stereopsis is usually absent
d. anisometropia is a common feature
e. a base out 4 dioptre prism can be used to detect central
    scotoma

19. Spasmus nutans:
a. usually begins at 3 years of age
b. is associated with head nodding
c. has jerky and large amplitude nystagmus
d. is rarely associated with neurological disorders
e. usually resolves spontaneously.

20. The following are true about accommodative esotropia:
a. usually begins around the age of 2 years
b. may be caused by a high AC/A ratio
c. there is usually hypermetropia of more than + 3.00 D
d. diplopia is rare
e. amblyopia is uncommon.

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