Visual System Disorders

Question 1

what are the 3 “vital signs” of ophthalmology?

Answer 1

1) Visual acuity
2) Pupils
3) intraocular pressure

Question 2

What is an easy way to determine if decreased vision is only a refractive error?

Answer 2

Have them read a chart with only one eye open… and then have them read the same chart with only one eye open looking through a “pinhole”… If it’s easier to read, then its a refractive problem

*because a small hole will only allow perpendicular light to travel back to the retina, thus it won’t require focusing

Question 3

What are the 5 steps involved in pupillary constriction?

Answer 3

1) retinal ganglion cells
2) pretectal nuclei
3) edinger-westfall nuclei
4) Parasympathetics via CN 3
5) Ciliary Ganglion to ciliary muscle for constriction

Question 4

Give an example of left eye relative affarent pupillary defect

Answer 4

RAPD is a optic nerve problem (afferent signal). In this case, the left eye would not constrict with direct stimulation (AND there wouldn’t be a consensual response). But if light was shined in the right eye, the left eye would constrict (be consensual response) because that is efferent, not afferent.

Question 5

How do you determine if double vision is neurologic or non-neurologic?

Answer 5

have the pt. cover one eye, if their vision is still “double” then it is a refractive problem (aka monocular diplopia = non-neurological)

if the pt. sees double ONLY with both eyes open, then it is neurological (binocular dipoplia = neurological)

Question 6

What does an increased cup:disc ratio indicate?

Answer 6

Glaucoma (increased intraocular pressure) tends to cause an increased cup size… thus the C:D ratio will increase (because normally the disc is larger than the cup)

Question 7

What does a diabetic retinopathy look like?

Answer 7

numerous microaneurisms in vessels of retina

Question 8

what should you suspect in a person with blurry vision, visual field loss, and loss of color vision?

Answer 8

optic nerve probs

Question 9

clinical characteristics of optic neuritis (3 of em)

Answer 9

1) 92% have ocular pain
2) rapid onset of central vision loss (5ish days)
3) unilateral presentation!
* 77%female, mean age 32

Question 10

What is best treatment for optic neuritis?

Answer 10

IV steroids

*oral prednisone actually increased the risk of recurrence (bad!)

Question 11

what are the outcomes of optic neuritis?

Answer 11

with IV steroids, they will recover most (if not all 70% back to 20/20) visual acuity and stays with them for a long time

Question 12

what is the risk of developing MS with optic neuritis?

Answer 12

Depends on # of other white matter lesions at the time of optic neuritis…

• 0 other lesions = 22% chance of MS @ 10 years
• 1 or more white matter lesions = 56% chance of MS @ 10 years

Question 13

Giant Cell arteritis characteristics (3 of em)

Answer 13

1) Rapid (hours to days) visual acuity loss
2) Jaw pain is very sensitive (headache, wt. loss also common)
3) extremely high erythrocyte sedimentation rate (measure of inflammation in body)

Question 14

Diagnosis and treatment of Giant cell arteritis

Answer 14

temporal artery biopsy = gold standard

9-12 mo. of steroids!

Question 15

visual field loss with pituitary tumor

Answer 15

optic chiasm compression (aka only the axons that cross) resulting in a bitemporal hemianopsia

Question 16

visual field loss with left cerebrovascular event

Answer 16

right homonymous hemianopsia (aka can’t see right field of each eye)