7.1.7 Understands the special examination needs of patients with severe visual defects

Question 1

Severe defects including

Answer 1

Homonymous hemianopia – stroke
Bitemporal hemianopia – pituitary tumour
Tunnel vision - Retinitis pigmentosa
Severe AMD

Question 2

Adaptations:

Answer 2

May need to guide patient or facilitate transfer from waiting area to test room. Offer shoulder or elbow for px to hold if they wish. Remove any potential obstacles.
Make sure at good/seeing side of patient
Might tap against wall on blindside

Question 3

Confrontation: adaptations

Answer 3

Change target size; use 15mm

Question 4

Peripheral Fields: Peripheral Fields

Answer 4

Same set up as confrontation

Same procedure but target is brought slowly from non-seeing to seeing round in an arc at about 33cm from the eye being tested

Both techniques involve target moving from non-seeing to seeing – the field plotted from seeing to non-seeing is larger

Could do FF81 for larger field to get idea of full extent
Use diamond fixation target - not spot

Amsler
Use chart no 2; diagonal lines help to fix the centre of the square in spite of a central scotoma – px fixates on where the lines would meet

Be aware that px may struggle to find the test chart.

Question 5

Coloured Targets: Adaptations

Answer 5

• Target is usually red – ideally 15mm red hatpin
• Good contrast to background – easier for px to detect
• In Chiasmal lesions due to pituitary tumours – colour desaturation occurs across the vertical midline
• Test slowly. Be aware that px may only read half the chart (e.g. homonymous hemianopia).
• Use large target during cover test, ret etc. to ensure it is seen
• Use large changes in lens power – large brackets
• Pinhole may be difficult/impossible
• Give encouragement during VFs