BV Paeds

• 6 key stages in a paediatric eye exam


  • History
  • Visual function (vision & visual acuities and if needed contrast sensitivity)
  • Refraction
  • Binocular vision status
  • Colour vision (if appropriate)
  • Anterior segment and Fundus examination
• Examining children even before they enter the room

  1. Observe child in waiting area

  2. Notice if they have a squint

  3. Notice if they are wearing glasses

  4. Notice if they are looking through/over their glasses
• Adapting history-taking when examining children


  • Observation should continue into the examining room
  • Tailor history according to child's age
  • Introduce yourself
  • Talk to the child (if appropriate) not the parents only; this may mean you have to come to child's eye level
  • Use child's name frequently
  • Always praise the child; do not criticise
  • Think about how you may dress…is a white coat appropriate or will this intimidate a child?
  • Good to have a selection of toys to ensure practice is child friendly
• What should be included in a good history when examining children


  • Establish why child came for an eye test- is it a routine eye exam or are there worries about the child's vision?
  • If parents/carers are worried—dig into what exactly they're worried about? e.g. do they feel baby is not making eye contact or copying facial expressions?
  • When did the worries begin, frequency, duration, triggering factors…is it getting worse?
  • Past ocular history (h/o patching, squint, amblyopia, hospital visits)
  • Birth history is important (pre-term; full term, birth weight, type of delivery, maternal illness during pregnancy)
  • Also establish normal milestones
  • Medical history, medications, allergies
• Never dismiss a parent; they are with the child the most so are rarely wrong
• Key developmental milestones for an infant to 1 year


  • Able to drink from a cup?
  • Able to sit alone without support
  • Babbles
  • Displays social smile
  • Gets first tooth
  • Plays peek-a-boo
  • Pulls self to standing position
  • Rolls over by self
  • Says mama and dada, using terms appropriately
  • Understands "NO" and will stop activity in response
  • Walks while holding onto furniture or other support
• 10 months old milestone is touch object with forefinger
• 1 year old milestones


  • Understands several short words
  • Imitate sounds
• 1.5 year old milestone is speak 20 words or more
• 2 year old milestone is use short sentences
• 3 years old milestone is know name and gender and BEGINS to know colours!
• 5 years old milestone is understand abstract words
• Visual development at birth


  VA of 6/120, focus at 25cm, responds to stimuli
• Visual development at different ages


  • 2 months: stable eye contact
  • 3 months: focus at 20-40cm; fixes/follows/looks for objects
  • 5 months: eyes straight, watch and copy hand movements
  • 9 months: recognise faces
  • 3 years: VA 6/12
  • 4 years: VA 6/9
  • 5 years: VA 6/6

  
• Methods of visual acuity testing


  • Electrophysiological testing
  • Behavioural testing
• Measure monocularly where possible and observe occlusion behaviour; typically from 3 months child will object to 'good' eye being covered
• Electrophysiological testing


  • Visual Evoked Potentials (VEP)
  • Flash VEP stimulus from birth
  • Pattern VEP stimulus
• Preferential looking


  • Infants would prefer to look at a pattern than a blank stimulus
  • Iso-illuminant stimulus (equally illuminated stimuli)
  • Preferential looking principle is based on resolution tests- ability to detect and resolve a target
  • Ability to discriminate different spatial frequencies (or other metrics)
  • Spatial frequency measured in cycles/degree
  • Narrower stripes = higher spatial frequency
  • Less sensitive to amblyopic defects especially in strabismus
  • Age 0-24 months
• Keeler acuity cards


  • Working distance 38cm
  • 15 cards with black and white stripes on right or left side, 1 blank card and 4mm hole in centre
  • Range from 0.32-38 cycles per degree
• Keeler card method


  1. Usually start with low spatial frequency and move in 1 or half octave steps up (if correct response or down if incorrect response)

  2. Correctly identifies same stimulus twice meaning child can resolve that card
• Clinically significant interocular difference on Keeler cards

  Greater than/equal 2 cards
• Cardiff acuity cards


  • Vanishing optotypes
  • Pictures (duck, house, fish, car, train. boat, dog) at top or bottom
  • 3 cards for each of the 11 acuity levels
  • No crowding
  • May overestimate VA
  • 50cm or 1m depending on age
• Using Cardiff acuity cards


  1. Present cards at eye level and watch if patient fixates on the correct target and if they follow it when you slightly move with it

  2. Start with card with widest target (lowest acuity level)

  3. Observe eye movements whilst horizontally moving the card

  4. Masked to tester until eye movement is observed then flip and see where the target was

  5. 2/3 responses correct

  
• Cardiff acuity cards VA range


  • > 1.0-0.1 logMAR using at 1m (older children)
  • > 1.3-0.5 logMAR using at 50cm (younger children)
• Clinically significant interocular difference on Cardiff cards

  Greater difference than 2 cards
• Peekaboo app


  • 2 forced choice or 4 forced choice
  • Free iPad app
  • Touching pattern results in yippee sound and cartoon appearing- positive feedback
  • Working distance 25-50cm
  • VA measured 0.2-1.3logMAR
  • Results comparable to Keeler
• Recognition acuity


  Ability to detect, resolve and recognise a target
• Older children 2yrs+ are more sensitive to amblyopic defects especially in strabismus and especially crowded targets
• What to use on different aged children


  • 2 year old: usually use picture matching
  • 3 year old: use picture or letter matching
  • Child greater than 3 years: consider naming targets
• Matching cards can be supplied at home for practice before clinic visit
• Kay pictures


  • Pictures of common objects known to a child e.g. duck, house, apple
  • Single pictures or crowding in logMAR format; at 3m; 1.0-0.1logMAR
  • Single pictures in snellen format (3 or 6m); 3/3 (6/6)-3/30 (6/60)
  • Each line equivalent to 0.1 logMAR acuity
  • Test also available as an app for iPad
• Clinically significant interocular difference on Kay pictures


  • Child less than 4 years: greater than 3 pictures
  • Child greater than 4 years: greater than 1 picture

  
• Lea symbols


  • Sample principle as logMAR test
  • Single and crowded version
  • Testing distance 3m
  • Test symbols: house, circle, apple, square
• Range of VA of Lea symbols

  0.10-2.0 logMAR
• Letter matching tests


  • Sheridan-Gardiner test
  • Cambridge crowded acuity test
  • Tumbling E or Landolt's C could be used
• Sheridan-Gardiner test


  • Single letters 6m, can be performed at closer distances
  • Uses flip chart
  • No crowding
  • Linear letters with crowding available
  • 6/60-6/4
• Cambridge crowded acuity test


  • Uses Sheriden-Gardiner letters 3m or 6m
  • Identify the letter which is surrounded by 4 others
  • Crowding
• Keeler logMAR crowded test


  • Flip chart
  • 6/38 (0.80) to 6/3 (-0.30)
  • 3m
  • logMAR principles
  • Screening and uncrowded sets also available
  • Similar to Sonsken Silver (uses Sheridan Gardener letters) but more crowding as letters closer together
• Other methods of testing children


  • Bradford visual function box
  • Hundreds and thousands/visually directed reaching
• Bradford Visual function box


  • Variety of targets of different sizes: beads, bauble, balls, toys and books
  • Useful when none of the other VA tests work
  • Observation response to the target e.g. eye movement, head movement