Ophthalmology Physiology

Question 1

What happens to the pupil reflex if you have a lesion at the optic nerve?

Answer 1

Neither pupil will constrict when light is shined into the eye with the optic nerve lesion.

Question 2

What happens to the pupil reflex if you have a lesion at the optic chiasm?

Answer 2

Both direct and consensual responses will still be present due to bilateral stimulation of the edinger westphal nucelus

Question 3

What happens to the pupil reflex if you have a lesion at the occulomotor nerve??

Answer 3

If light is shone into left eye and there is a lesion of the left occulomotor nerve then there will be no direct response but there will be a consensual response.
If light shone into left eye and lesion in right occulomotor nerve then there will be a direct response but no consensual response.

Question 4

Where is the lesion if you have a superior quadrantanopia?

Answer 4

Inferior optic radiations in the temporal lobe (Meyers loop)

Question 5

Where is the lesion if you have an inferior quadrantanopia?

Answer 5

Superior optic radiations in the parietal lobe.

PITS - parietal-inferior, temporal-superior

Question 6

Where are the lesions if you have a incongruous or congrous homonymous hemianopia and what does this mean?

Answer 6

Incongruous = asymmetrical. Lesion of the optic tract.
Congruous = Symmetrical. Lesion of optic radiation or occipital cortex.

Question 7

Where is the lesion if you have macular spearing in a homonymous hemianopia?

Answer 7

Occipital cortex

Question 8

Lesion location if you have more superior bitemporal hemianopia?

Answer 8

There is inferior chiasmal compression, commonly a pituitary tumour.

Question 9

Lesion location if you have more inferior bitemporal hemianopia?

Answer 9

Superior chiasmal compression, commonly craniopharyngioma

Question 10

Meaning of chemosis?

Answer 10

Swelling of conjunctive