Neuro-ophthalmology

Question 1

internuclear ophthalmoplegia is what?

Answer 1

a disorder of conjugate lateral gaze in which the affected eye shows impairment of adduction
When an attempt is made to gaze contralaterally (relative to the affected eye), the affected eye adducts minimally, if at all. The contralateral eye abducts, however with nystagmus. Additionally, the divergence of the eyes leads to horizontal diplopia. That is, if the right eye is affected the patient will “see double” when looking to the left, seeing two images side-by-side. Convergence is generally preserved.

Question 2

The conjugate gaze is ….

Answer 2

`` the motion of both eyes in the same direction at the same time, and conjugate gaze palsy refers to an impairment of this function.

The conjugate gaze is controlled by four different mechanisms:
saccadic system
pursuit system
optokinetic system
vestibulo-ocular reflex system (VOR system)

Question 3

the saccadic system allows for

Answer 3

voluntary direction of the gaze

Question 4

the pursuit system allows

Answer 4

the subject to follow a moving object

Question 5

the optokinetic system does what?

Answer 5

restores gaze despite movements of the outside world

Question 6

vestibulo-ocular reflex system (VOR system) does whta?

Answer 6

corrects for the movements of the head to preserve the stable visual image of the world