Examination of the Eye

Intro

• Wash hands, introduce self, check patient name and DOB/CHI, explain procedure and gain consent

Inspection (as with every other examination!!)

• General: look at the patient and their surrounding (e.g. glasses, walking aids, blind stick, a guide dog!)
• Eye
  • Pupil size and symmetry; strabismus (squint); ptosis; proptosis; sclera/conjunctiva (e.g. redness); surrounding structures (lids, nose etc for scarring, lesions, rash); pus; discharge; swelling etc

AFROES

Acuity

• Without glasses: test acuity one eye at a time using
• Snellen chart (distance vision);
  • NB record findings as distance/smallest size type e.g. 6/9.  If the patient is unable to see the largest letter, try counting fingers or reducing the distance.
• text book (close vision);
• Ishihara plates (colour vision)

Fields

• Visual inattention
  • With both the patient’s eyes open and focused on your eyes (at level, about 1m away), hold your fists out to either side (at equal distance to you and patient) and wiggle the finger of one hand.  Ask the patient to identify which side was active.
• Field testing
  • In the same position, ask the patient to cover one eye whilst you cover your ipsilateral eye (i.e. same side).
  • With the patient focused on your eye, bring a pin/your finger in from the periphery (test four corners- make sure to maintain equal distance from yourself and the patient).  Ask the patient to say when they see the pin/finger (should be similar to your own sight).
    • Test both eyes
• Blind spot test
  • In the same position, testing one eye at a time with the patient focused on yours, hold a red pin midway between your open eyes and move it peripherally/horizontally until they say it disappears.  Map out the area of the blind spot (should be similar to your own).
    • (large blind spots may be a sign of papilloedema)

Reflexes

• Accommodation: ask the patient to focus on your finger about a metre away.  Bring your finger close to the patient’s face and watch for eye convergence and pupillary constriction
• Direct and consensual light reflexes: In a dimmed room, as the patient to focus on a distant point.  Shine a light into each eye and look at the ipsilateral (direct) and contralateral (consensual) pupil for constriction
  • Afferent defect (CN2): pupils are symmetrical at rest but when light is shone in affected eye- neither eyes constrict.  When light is shone in contralateral eye, both constrict
  • Efferent defect (CNIII): pupils are asymmetrical at rest (affected eye permanently dilated throughout, whereas non-affected eye will respond to light being shone in either eye)
• Swinging light test
  • Test for relative afferent (i.e. CNII) pupillary defect by swinging light between eyes.  Both should remain constricted but will dilate when light is shone in affected eye

Ophthalmoscopy

• Preparation
  • Dim lights
  • Consider mydriatic drops (e.g. tropicamide)
• Red reflex
  • Ask the patient to focus on a distant point
  • Look at the patient’s eyes through the scope from 1m away
    • The eyes should ‘flash’/reflect red/orange
    • Loss of red reflex suggests cataract (or rarely, in children, retinoblastoma)
• Through the eye
  • With your contralateral hand on the patients forehead (for support), hold the scope in the ipsilateral hand (i.e. right eye, right hand)
  • Set the focus wheel to 10 and look at the eye from 1m away
  • Approach the eye from the side and above
  • Once the front of the eye comes into focus, move closer to the eye and turn the wheel down (keeping the front of the eye in focus)
  • Once close to the eye, rotate the wheel further- the focus will move through the eye until the retina comes into focus
    • Comment on any findings if relevant (NB In most OSCE and clinical scenarios, the slit lamp is much better at looking at the anterior segment of the eye and is generally preferred)
• Locate the following structures
  • Optic disc
    • Comment on cup size, colour, contours
  • Track the 4 retinal artery branches to look at the 4 quadrants of the eye
    • This may be made easier by asking the patient to look in a certain direction
  • Look for signs of
    • Hypertensive retinopathy e.g. silver wiring, AV nipping, cotton wool spots, papilloedema
    • Diabetic retinopathy e.g. microaneurysms; dot/blot haemorrhages, cotton wool spots, neovascularisation, fibrotic changes)
    • Drusen
    • Pigmentation
    • NB In an OSCE, the model may have a letter on the fundus for you to identify.
  • Macula
    • Ask the patient to look directly into the light (should be pink)

Extra-ocular muscles

• Check eye movements (H-test)
  • Failure to move the eye laterally (CN6 palsy)
  • Failure to move the eye inferomedially (CN4 palsy)

Strabismus

• Perform cover tests for strabismus

Finish

• Thank patient, wash hands
• Explain/record findings
• Suggest any further investigations/management

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