Ocular motility

Question 1

Which muscles do the cranial nerves supply?

Answer 1

• Cranial nerve III: Superior, inferior, medial rectus and inferior oblique
• Cranial nerve IV: superior oblique
• Cranial nerve VI : Lateral rectus

Question 2

What do you look for when doing ocular motility?

Answer 2

• Corneal reflexes
- Move eyes in 9 cardinal positions, looking at reflex
- Ask px to report diplopia

Question 3

How is ocular motility recorded?

Answer 3

• SAFE
- Smooth, Accurate, Full, Extensive

• If faltered
- Under action superior rectus, R+L
- No pain

Question 4

What 3 things can affect visual field, pre-retinal disease?

Answer 4

• Cornea (SPK)
• Crystalline lens (cataract)
• Vitreous (haemorrhage)

Question 5

Describe confrontation visual fields

Answer 5

• Gross overview, fast to administer
• Detects large defects (e.g. hemianopia)
• Insensitive to small or subtle defects (glaucoma)
• Test monocular
• compares px vision to own

• Move target from non-seeing to point first detection, continue to move asking for changes in appearance

Question 6

Describe supra-threshold

Answer 6

• Most common visual field investigation in Primary care
• Dots presented above patient’s threshold
• Point seen = pass; Point missed = fail
• Some tests measure central threshold (e.g. 32dB)
• Fast to administer
• Sensitive to most defects (e.g. hemianopia, arcuate scotoma)
• May miss shallow (mild) defects
• Screening test- use for any of the Indications

Question 7

Describe threshold

Answer 7

• Measure threshold at each location
• Determine extent and depth of defect
• Indication: failed supra-threshold test
• Primary/Secondary Care: Glaucoma
• Use as basis for glaucoma referral