What are the ddx for a fixed dilated pupil?
- Previous posterior synechiae due to iritis
- Traumatic Mydriasis (ask for hx of Trauma)
- Drops (ie. Pharma)
What are you looking for on inspection in a pupillary examination?
- Anisocoria IF FOUND CHANGE LIGHTING IN ROOM TO SEE HOW IT CHANGES + ID ABNORMAL EYE
- Ptosis
- Neck scars (LOOK CAREFULLY!)
What are the ddx for a fixed constricted pupil?
- Horner’s Syndrome– check for ptosis,
- Adie Pupil – check near light response and tendon reflexes
- Emerging CNIII palsy – check eye movements and diplopia
- Drops
How should you perform the swinging light test? What are you looking for? In what condition is it diagnostic?
Holding the pen torch up/ down to the eyes, hold it in front of each eye for 2seconds (count quickly to allow same time in front of each eye), and then swing to other eye which keeping your hand away from their eyes so as not to stimulate accommodation.
Look for paradoxical dilatation of one pupil when the light is shone in that pupil due to Relative Afferent Pupillary Defect.
If patient has fixed dilated pupil, this test can still indicate RAPD bc when light shone in dilated pupil, the other eye will dilate (rather than consensually constrict) if there is a problem with the afferent nerve.
It is diagnostic in Optic Neuritis most commonly due to MS, also B12 deficiency.
RAPD also occurs in total retinal detachment.
When examining the optic disc, what do you need to describe?
CONTOUR: should be well defined (edges)
COLOUR: should be pink
CUP: excavated part of the disc. cup:disc ratio should be <0.3
What other things should you mention as part of fundoscopy?
How blood vessels emerge from the disc, branch and go towards periphery
Describe area around disc
What are the causes of a swollen optic disc?
Papilloedema (if BILATERAL)!
Optic Neuritis
Anterior Ischaemic Ischaemic Neuropathy (either Arteritic i.e. temporal arteritis or Non-Arteritic)
Malignant HT
what is involved in the testing of visual acuity?
Snellen's chart (1 eye covered and reading with glasses) with and without a pinhole (to assess for pathology - if no sig diff found, macula degeneration for e.g. may be present). Reading acuity (using different print sizes)
What are the stages of testing visual fields?
- My face can you see it all?
- Covering 1 eye and doing tests of nasal and temporal fields superiorly and inferiorly using diff number of fingers (wiggling) CHECK SENSORY INATTENTION
- repeat for other eye
- Using white hat pin, covering one eye when can you see it? does it ever disappear?
- using red pin to test colour vision.
- repeating visual fields with red hat pin
- blind spot demarcating
What is involved in the pupil examination?
- Inspection (pref with fairly dim lights). change lights if any anisocoria observed to see how it changes
- Examine direct and consensual light reflexes in each eye (remember to get pt to focus on distant object to prevent accomodation)
- perform the swinging torch test (try not to get in pt face to stop any accommodation, also hold up light for 2 seconds, count, then swing away and to other eye. start with “normal eye”)
- accommodation reflex again start them looking into distance and then focus up close and make sure can see their eyes move.
