L34 - visual defects 2

Question 1

questions to ask about visual field

Answer 1

• do things look distorted?
• is there a shadow?
• does the shadow move?

Question 2

blurred vision

Answer 2

• out of focus
• no distortion or shadows
• refractive problem

Question 3

glare

Answer 3

difficulty seeing in bright light

• corneal or lens problem
• may be due to cataracts

Question 4

distortion of vision

Answer 4

• things look wavy, jumbled up
• lines not straight
• condition affecting retina

Question 5

things look pale

Answer 5

• look dark / less colour
• optic nerve disease
• affects retina

Question 6

floater

Answer 6

• smudge
• movement
• degeneration of the vitreous (bits of it liquefy)

Question 7

where is the defect if it is homonymous

Answer 7

defect of visual pathway

Question 8

where is defect it is is heteronymous

Answer 8

retinal

optic nerve

Question 9

What are the 2 formal measurements of visual fields?

Answer 9

1. Field testing by confrontation

2. Field testing by machine analyser

Question 10

field testing by confrontation

Answer 10

• doctor and patient opposite each other with opposing eyes covered
• use finger to try and compare their visual field to your visual field

Question 11

machine analyser

Answer 11

Humphrey Field Analyser

• A bowl a patient rests their chin on
• Spectacle lens to correct for their refraction
• A fixation point (dot in the middle)
• Dots of light come up at
• Patient presses button if they see light

Question 12

cataracts

Answer 12

An opacity or discoloration of the lens

*lens matures from the inside out

Question 13

blood supply to the retina

Answer 13

choroid (underneath sclera) and retinal vascular supply;y

Question 14

symptoms of cataracts

Answer 14

• gradual onset

- depend on type: blurred vision, glare, change in refraction

Question 15

where does the choroid supply

Answer 15

outer 2/3

Question 16

where does the retina vascular supply

Answer 16

inner 1/3

Question 17

signs of ARMD (age related macular degeneration)

Answer 17

• drusen
• RPE pigmentation
• RPE atrophy

Question 18

What are the symptoms of dry ARMD?

Answer 18

• gradual deterioration (early stages are often asymptomatic)
• reading vision is affected

Question 19

surgery in cataracts

Answer 19

phacoextraction with lens implant

Question 20

On fundoscopy, a paler retina with spots of red and a pronounced redness of the fovea is indicative of what condition?

Answer 20

Indicative of CRAO

Question 21

CRAO

Answer 21

central retinal artery occlusion

Question 22

causes of CRAO

Answer 22

• carotid artery disease
• heart disease
• giant cell arteritis

Question 23

Giant cell arteritis causes visual loss due to which 2 conditions?

Answer 23

CRAO or AION

not treatable, urgent treatment required

Question 24

AION

Answer 24

anterior ischaemic optic neuropathy

Question 25

What are the main conditions which affect the retina?

Answer 25

- ARMD - wet macular regeneration - macular hole / pucker - retinal detachment

Question 26

What occurs in wet ARMD?

Answer 26

- newly immature blood vessels in choroid grow towards outer retina - leak fluid within or below the retina

Question 27

glaucoma

Answer 27

damage to optic nerve related to high pressure in the eye

Question 28

VEGF stimulates the growth of what?

Answer 28

choroidal neovascular membrane

Question 29

VEGF

Answer 29

vascular endothelial growth factors

Question 30

giant cell arteritis / temporal arteritis

Answer 30

- systemic vasculitis of unknown cause - headache - malaise - visual loss

Question 31

metamorphopsia

Answer 31

visual defect that causes linear objects, such as lines on a grid, to look curvy or rounded

Question 32

how does the choroid supply the retina

Answer 32

diffusion

Question 33

Dry ARMD

Answer 33

- built up of waste products - photoreceptors lost and retinal pigment epithelium damaged - sudden deterioration may indicate wet ARMD

Question 34

drusen

Answer 34

fatty deposits in the eye

Question 35

how to treat wet ARMD

Answer 35

anti-VEGF prevent growth of choroidal neovascular membrane - visual loss can be reversed