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Flashcards in Block 12 Deck (160)
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1

Involuntary rhythmic oscillation of 1 or both eyes

Nystagmus

2

Can be a sign of visual pathway lesion or an ocular control abnormality

Nystagmus

3

Type of waveform of nystagmus: has both quick and slow components

Jerk

4

Which way is the slow phase in a jerk nystagmus

Away from the target

5

Which way is the fast fast in jerk nystagmus

Back to fixation

6

How is jerk nystagmus characterized

Direction of fast phase

7

Type of waveform of nystagmus: to and fro movements of equal velocity in each direction

Pendualr

8

Type of waveform of nystagmus: doesn’t have a fast phase

Pendular

9

Which phase of jerk nystagmus reflects the abnormality

Slow

10

Slow movement to the right with a fast corrective jerk movement to the left

Left jerk nystagmus

11

The size/extent of the movement during nystagmus is known as the

Amplitude

12

From what 2 points in nystagmus is the amplitude measured

From the start of the drift away tot he start of the corrective movement

13

Number of oscillations per unit time in nystagmus

Frequency

14

Fast frequency nystagmus is how quick

>2Hz

15

1 Hz equals

1cyc/sec
- a full rotation in 1 second

16

Frequency of a slow nystagmus is what time

<2Hz
- need a slit lamp to view

17

Where the intensity of the nystagmus diminishes and the VA improves
- may be associated with head position

Null point

18

With latent nystagmus seen with occlusion, the fast phase is towards

Uncovered eye

19

What does latent nystagmus usually indicated

A congenital condition

20

Anterior seg conditions with nystagmus (3)

Congenital cataract
Congenital glaucoma
Iridocorneal dysgenesis (didnt form properly)

21

Foveal condition associated with nystagmus

Foveal hypoplasia in albinism (flattening)

22

Optic nerve/retinal disorders associated with nystagmus

Coloboma of ON head (fissure doesn’t close)
ON hypoplasia
Toxoplasmosis

23

Do children with congenital nystagmus usually complain about issues

No

24

Nystagmus from motor coordination

Less VA loss (better VA)

25

Nystagmus from sensory issues

More VA loss (worse VA)

26

Do you allow patients to use their preferred head position when doing VAs?

Yes bc this will allow you to asses true functional vision

27

When doing monocular VAs, you may have to use a high plus lens to blur instead of occlude because

You need to allow fusion so that the jerk nystagmus intensity doesn’t increase

28

When refracting pts with nystagmus, do you use the phoropter

No, need to see the nystagmus
- use trial lenses or a lens bar

29

CT may be difficult in patients with nystagmus. What can you use to determine if the reflexes appear symmetrical

Hirschberg/krimsky
Bruckner

30

Do you use occluder in Pts with nystagmus during CT and VA

No, use a high plus lens (+2 - +5)