Eye Investigations + Visual Defects Flashcards Preview

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Flashcards in Eye Investigations + Visual Defects Deck (32)
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1

What are investigations for the eye

Fluorescein Angiography
Optical Coherence tomography
ERG
EOG
VEP
Open slit lamp
Fundoscopy

2

What is fluorescein angiography

Retina impermeable to fluorescein
Choroid vessels are so look white
If there is leak in the retina will be able to detect

3

When do you use

Neovascular macular degeneration suspected
GCA

4

What does optical coherence tamography do

Scans the macula
See different layers of retina
Useful for macular and disc pathology

5

What is your blind spot

Optic nerve
No photoreceptor cells

6

What does ERG do

Measures AP's in retina and function

7

What does EOG

Measures function of retinal pigment epithelium and photoreceptors

8

What does VEP do

Records optic nerve function

9

When is it useful

MS

10

What does reduced amplitude suggest

Ischaemia
Neuropathy

11

What does latency suggest

Optic neuritis

12

How do you investigate retinal pathology

Visual acuity / field
Fundoscopy
Fluorescein angiography
Optic coherence tomography
Electrophysiology - EOG / ERG

13

What is myopia

Short sightedness

14

How does this occur

Light focuses in front of retina in VH as eye is too long

15

What do you want to stop this happening

Bend rays of light less so focus on retina (use concave lens)
No accommodation

16

What are the symptoms of short sightedness

Close objects are clear but distant = hazy
May have headache
Divergent squint

17

How do you Rx

Biconcave lenses (minus lens)
Glasses
Laser eye surgery

18

What should you do if presents with divergent squint

Test for refractive error

19

What is long sightedness

Hypermetropia

20

What happens

Light focuses past retina as eye is too short
Distant objects will focus past but can accommodate
Can focus on far away objects as accommodate but as move closes the power is used up

21

Symptoms

Close up = hazy
Eye strain
Convergent squint

22

How do you Rx

Biconvex lens
Laser eye

23

What does convergent squint require

Immediate treatment to preserve vision and prevent a lazy eye

24

Wha is astigmatism

Non spherical curvature of cornea or lens so everything is hazy

25

How do you treat

Special glasses
Laser eye surgery

26

What is presbyopia

Long sightedness of old age as lens less mobile so can't change shape

27

How do you treat

Biconvex glasses

28

What are causes of squint (strabismus) and what happens

Concomitant - imbalance of extra-ocular muscles = most common and occur in childhood
Paralytic = rare
Leads to diplopia
Brain copes by reducing signal from less dominant eye leading to a lazy eye

29

How do you Dx

Examination
Refer ophthalmology
Eye movement
Fundoscopy to rule out retinoblastoma
Visual acuity
Corneal light reflexion test
Cover test

30

How do you Rx

Eye patches over good eye to prevent ambylopia and encourage use of the squint eye
Refer 2 for surgery