Around eyes (scarring, lesions, pus, discharge, swelling)
Acuity
Ask the patient to cover one eye with their palm to test each eye in turn.
Distant vision (visual acuity)
Test with Snellen chart (the result is recorded as distance/smallest font size read, e.g. 6/9)
If the patient wears glasses, do this with glasses on (corrected visual acuity) and off (uncorrected visual acuity)
A standard Snellen chart is read from 6 metres away but there are smaller versions which may be used at closer distances (e.g. 1 or 3 metres) – adjust the final acuity to ‘1/…’ or ‘3/…’ respectively
If the patient gets more than two letters wrong, the previous line should be recorded as their acuity. If they get two letters wrong, record acuity as the font size of this line but note ‘-2’ in brackets, e.g. 6/9 (-2); and if they get one letter wrong, note ‘-1’ e.g. 6/9 (-1).
Near vision
Read a line of a letter / magazine
Colour vision
‘I would also like to test colour vision using Ishihara plates.’
Sit the patient 1 metre directly in front of you with both your eyes at the same level.
Visual inattention
While the patient keeps both eyes open and focussed on you, hold out your hands in each of their outer visual fields
Ask them to point at the hand(s) which you are opening/closing. (Inattention to one side = contralateral parietal lesion.)
Visual fields
Ask the patient to cover one eye with their palm and close your eye on the same side (without using your palm if you can)
Ask them to stay focussed on your open eye
Select a white visual fields pin and bring it in from the periphery, keeping it at mid-distance between you and the patient
Ask them to tell you when they can see it. Move in a diagonal direction into each of the four quadrants.
Test both eyes individually, comparing their fields with yours
Pathology:
Mononuclear field loss = intra-ocular pathology or ipsilateral optic nerve lesion
Bitemporal hemianopia = optic chiasm compression
Left/right homonymous hemianopia = contralateral optic tract/radiation lesion, or occipital cortex if macular sparing is present
Blind spots
Offer to test blind spots:
Ask the patient to cover one eye with their palm and close your eye on the same side (without using your palm if you can)
Ask them to stay focussed on your open eye
Hold a red pin mid-distance between you
Check they can see it as red in the middle (central scotoma = optic nerve lesion)
Now move the pin horizontally towards the periphery in each direction and to tell you when it disappears
Map each of their blind spots against your own (large blind spot = papilloedema)
Visual field defects
Reflexes
Accommodation
Ask the patient to focus on a distant object, then hold your finger close to their face and ask them to focus on it
Pupils should constrict and eyes should converge
Direct and consensual papillary reflexes
In a dimmed room, ask the patient to hold an open hand between their eyes and focus on a distant point in the room
Shine the light at each pupil in turn from about 45°
Observe for direct and consensual papillary constriction
Defects:
Afferent defect (i.e. pupils are symmetrical but when light is shone in affected eye, neither pupil constricts) = CN2 (optic nerve) lesion
Efferent defect (affected pupil is persistently dilated, whilst other is reactive to light being shone in either eye) = CN3 lesion
Swinging light test
Swing the light between the two eyes – the pupil size should stay the same regardless of which eye the light is shone in
If pupils become more dilated when the light is shone in one eye, then that eye is less sensitive to light and, hence, there is a relative afferent pupillary defect in that eye (partial optic nerve lesion on that side)
Ophthalmology
Ask the patient to remove glasses if present; consider preparing pupils with mydriatic drops (e.g. tropicamide); and use a darkened room
Ask the patient to focus on a point in the distance until you tell them otherwise
Red reflexes: look through ophthalmoscope at patient’s pupil from 1 metre away (lost in: cataract, retinoblastoma, vitreous haemorrhage)
Hold the patient’s right shoulder with your left hand and the ophthalmoscope in your right to examine the right eye (and vice versa for the left). First focus the ophthalmoscope to your vision by looking through it at a point in the distance and adjusting the focus wheel. Now look in the patient’s eye and adjust the wheel to focus the ophthalmoscope on their retina. When their retina is in focus, look at:
Optic disc
Visualised by aiming the ophthalmoscope slightly nasally. Check the 3Cs:
Cup – normal cup to disc ratio is 0.3 or less, i.e. the cup occupies 3/10 of the diameter of the entire disc (enlarged = glaucoma)
Colour (grey/pale = optic atrophy)
Contours (swelling = papilloedema)
Four quadrants
Follow the blood vessels out from the optic disc in each direction to visualise each of the four quadrants. Observe for:
Diabetic retinopathy signs (dot and blot haemorrhages, cotton wool spots, neovascularisation, retinal fibrosis)
Other characteristic appearances, e.g. drusen (macular degeneration), peripheral pigmentation (retinitis pigmentosa)
Macula
Visualise by asking the patient to focus on the light of the ophthalmoscope. Should be pink (dark = macular degeneration).
Learn more here…
Learn about the findings of conditions you may see on fundoscopy and see examples here!
Eye anatomy
Retina anatomy
Extra-ocular muscles
Ask if the patient has any double vision and to tell you if they experience any during the test.
H-test: ask patient to keep their head still (you may need to hold a finger on their forehead) and, with both eyes open, to follow your finger. Make an ‘H’ shape.
Pause when they are looking laterally (nystagmus = cerebellar pathology)
If there is complex ophthalmoplegia, ask them to look straight up while counting down from 20 (fatigability suggests myasthenia gravis)
For blind spot assessment I think the patient needs to cover one eye and the doctor need to cover the opposite eye. I don’t think it is possible to assess for the blind spot with the patient having both his / her eyes open
For blind spot assessment I think the patient needs to cover one eye and the doctor need to cover the opposite eye. I don’t think it is possible to assess for the blind spot with the patient having both his / her eyes open