Examining children Flashcards
What are the key stages in a paediatric eye test:
- History
- Visual function (Vision & Visual Acuities and if needed contrast sensitivity)
- Refraction - retinoscopy under cycloplegia and subjective refraction
- Binocular vision status – cover test, ocular motility
- Colour Vision (if appropriate)
- Anterior segment and Fundus examination
Examining infants and children:
Observe child in the waiting area….
- Do you notice a squint for example
- Is the child wearing glasses
- Are they looking through/over their glasses
History taking in paediatrics dos and donts:
- Your observation should continue into the examining room
- Tailor history according to child’ age
- Introduce yourself to parent and child
- Talk to the child (if appropriate) not the parents, this may mean that you have to come to the child’s eye level!
- Use the child’s name frequently
- Always praise the child, don’t criticise
- Good to have a selection of toys and ensure the practice is child friendly
What to include in history for paediatrics
- Establish why the child has come for an eye test?
- If they (parents/carers) are worried what is it they are specifically worried about
- When did the worries begin, frequency, duration, triggering factors, are they getting worse?
- Past ocular history
- Family history is important
- Birth history is also important
- Also establish normal milestones
- Medical history, Medications, Allergies
- Tailor your questions to children where appropriate
- Use child friendly language where appropriate
Reasons for coming in for eye test child:
- Routine eye exam
- Or are there worries about the child’s vision
- E.G. family history of squint
- Baby not making eye contact
Examples of past ocular history child eye test:
- Patching
- Squint
- Amblyopia
- Hospital visits
- Surgery
Examples of family history child eye test:
- Patching
- Squint
- Amblyopia
- Hospital visits
Examples of birth history child eye test:
- Pre-term
- Full term
- Birth weight
- Type of delivery
- Maternal illness during pregnancy
Examples of key developmental milestones for infant to 1 year old:
- 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 on to furniture or other support
Important milestones newborn to 3 year olds:
- Understand several short words- 1 year
- Imitate sounds- 1 year
- Speak 20 words or more- 1.5 years
- Use short sentences- 2 years
- Know name and gender- 3 years
- Understand abstract words- 5 years
- Touch object with forefinger- 10 months
- Begin to knows colours- 3 years
Visual development - what acuity can children see:
- Birth: VA of 6/120, focus at 25cm, responds to stimuli
- 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 visual acuity 6/12
- 4 years visual acuity 6/9
- 5 years visual acuity 6/6
Types of visual acuity testing:
- Electrophysiological testing = objective method of measuring VA
- Behavioural testing = subjective method of measuring VA
Is visual acuity testing in children binocular or monocular and when do you start observing VA:
- Monocularly
- Observe behaviour when child occluded
- Usually from 3 months
- Child will object to ‘good’ eye being covered
Types of electrophysiological testing:
- Flash VEP stimulus- from birth
- Pattern VEP stimulus
When would you use electrophysiological testing:
- In hospitals
- When you cant get a reading of what child can see
What does flash VEP involve:
Sitting child in front of screen or bowl and show them flashing light
What does pattern VEP involve:
Show them pattern – checkerboard which keeps flashing or moving
What does electrophysiological testing involve:
- Looking at signals that go to brain from these patterns
- So when child is looking at flashing light or checkerboard pattern, there are visual signals going to the occipital cortex
- And the flash VEP can look at those signals
- So there are electrodes placed over occipital cortex on head
- And can see latency of responses and whether responses are delayed
- Child doesn’t have good VA if delayed
Testing visual acuity in children - preferential looking:
- Fantz et al, 1962
- ‘Infants would prefer to look at a pattern than a blank stimulus’
- Iso-illuminant stimuli i.e pattern has same luminance as grey blob
- Behavioural test
- Principle based on resolution tests = ability to detect and resolve a target ( use black and white target )
- Ability to discriminate different spatial frequencies (or other metrics)
- 1 black and 1 white line = 1 cycle
- Measure how many cycles you get per cm and convert how many cycles you get per degree – depends on distance your sitting from test
Which px’s is preferential looking not good for:
- Less sensitive to amblyopic defects especially in strabismus
- Because it’s a resolution test and resolution tests are easier to do
What is spatial frequency:
Black and white target measured in cycles/degree
What does narrower stripes mean:
Higher spatial frequency = harder to see
What age do you do preferential looking VA:
0 - 24 months
Examples of preferential looking tests:
- Teller Acuity Cards
- Keeler acuity cards (City Sight)
- Lea Grating paddles
- Cardiff acuity cards (Vanishing optotypes) (City Sight)
- Peekaboo App
Keeler acuity cards:
- Working Distance: 38cm
- Usually 15 cards with black-&-white stripes on right or left side, 1 blank card
- 4mm hole in centre
- Range 0.32 to 38 cycles per degree
- Usually start with low spatial frequency/poor VA i.e broader black and white stripes and move in 1 or half octave steps up (if correct response or down if incorrect response) i.e 1 card or skip a card
- Correctly identifies the same stimulus twice means the child can resolve that card
- Clinically significant interocular difference: Greater than/equal 2 cards (McDonald et al, 1986)
Summary of keeler acuity cards method:
- Look through hole
- Present card to px
- Trying to see if px is looking at stripes or not
Working distance for keeler acuity cards:
38cm
Cardiff acuity cards:
- Vanishing optotypes
- Also used in special needs patients – stroke, dementia
- Pictures (duck, house, fish, car, train, boat dog) at top or bottom
- No crowding – if present letter, theres nothing surrounding that letter but if line of letters or letter in box = crowding
- If someone has amblyopic defect, if show them non crowded target, they may still be able to read 6/9 but if crowded, 6/36
- May overestimate VA if have a test that measures non crowded VA
Method of cardiff acuity cards:
- 50cm or 1m depending on age
- 3 cards for each of the 11 acuity levels
- Present cards at eye level and watch eye movements
- Start with card with widest target (lowest acuity level)
- Observe eye movements
- Masked to tester
- 2 out of 3 responses correct – go to next lower acuity
- Clinically significant interocular difference: Greater than 2 cards (Adoh and Woodhouse, 1994)
Which VA range to use in cardiff acuity cards:
- 1.0- 0.1 LogMAR using at 1m (older children)
- 1.3-0.5 LogMAR using at 50cm (younger children)
Working distance for cardiff acuity cards:
50cm or 1m depending on age
Peekaboo App:
- 2 forced choice or 4 forced choice, Livingstone et al; 2019
- Free Ipad App , currently (August 2022) unavailable
- Touching the pattern results in a yippee sound and a cartoon appearing, positive feedback, four or two choices
- Results comparable to Keeler
Working distance for peekaboo app:
25 - 50 cm
What VA is measure for peekaboo app:
VA measured 0.2-1.3 LogMAR
How to test VA for older children 2 years and above:
- Recognition acuity: Ability to detect, resolve and recognise a target
- More sensitive to amblyopic defects especially in strabismus especially crowded targets
- 2 years: usually use picture matching
- 3 years: can use picture and or letter matching
- Greater than 3 years can consider naming pictures or letters
- 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 (3m)
- Single pictures in Snellen format (3 or 6 metres)
- Each line equivalent to 0.1 LogMAR acuity
- Tests also available as an app for iPad
- Clinically significant interocular difference (Crowded) :Greater than 3 pictures (less than 4 years); Greater 1 than picture (above 4 years)
What VA is used for kay pictures:
- 1.0 – 0.1 LogMAR
- 3/3 (6/6) – 3/30 (6/60)
Lea symbols:
- Same principles as LogMAR test
- Single and Crowded version of letters
- Test distance 3m
- Test symbols: Simple shapes familiar to small children which blur equally: Square, House, Circle and Apple
Working distance for lea symbols:
3m
What VA is used for lea symbols:
0.10-2.0 LogMAR
Letter matching tests - types of 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 Sheridan-Gardiner letters 3m or 6m
- Identify the letter in centre which is surrounded by four 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 Sherdian Gardener letters) but more crowding as letters closer together
- Clinically significant interocular difference: 0.1 LogMAR; Sonsken Silver is 0.125 LogMAR
What distance is keeler logMAR crowded test done at:
3m
What VA’s are used for keeler logMAR crowded test:
6/38 (0.80) to 6/3 (-0.30)
Other methods of testing VA on children:
- Bradford Visual Function Box
- Hundreds and thousands/Visually directed reaching
Bradford Visual Function Box test:
- 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,
Hundreds and thousands/Visually directed reaching test:
- Usually over 6 months
- Small cake decorations (100s & 1000s) held in the palm of the hand
- Nine months: may prod the decorations
- One year: may attempt to pick up. VA roughly 6/60 @25 cm
- Rarely used
What tests to use on birth to 2 years for VA:
- Keeler Acuity Cards
- Peekaboo App
- Cardiff Cards
What tests to use on 2 - 4 years for VA:
- Picture naming/matching
- Lea symbols
- Kay pictures
What tests to use on 3 - 5 years for VA:
- Letter naming/matching
- Sheridan-Gardiner
- Sonksen-Silver
- Cambridge Crowding Cards
- Keeler LogMAR acuity cards
- Landolt C/Tumbling E
- Can also use picture naming and matching so Kay pictures and Lea symbols
- Remember crowded cards better
- Above 5 years regular charts
How to measure near vision for 2 years onwards:
- Kay Picture Near Test
- Lea Symbols Near vision
- Reduced Snellen (Landolt’s C/ Tumbling E)
What is the kay picture near test:
- Age: 2 years onwards
- Working distance: 33cm
- Crowded & Uncrowded
- See what child can read
What is the lea symbols near vision test:
- Age: 2 years onwards
- Working distance: 40cm
- 6/120 – 6/3
What age is reduced Snellen (Landolt’s C/ Tumbling E) used for:
2 years onwards
What are the two tests to measure contrast sensitivity on children:
- Cardiff Contrast Sensitivity Test
- Hiding Heidi
Cardiff Contrast Sensitivity Test:
- Same vanishing optotypes as the Cardiff Acuity
- Three cards at each contrast level from 46% to 1% in twelve steps.
- Testing distance usually 50cm
- Use PLT or matching/naming depending on age
- 12 months onwards but probably use from younger
- Get px to point where symbol is or is symbol is up or down
What distance is cardiff contrast sensitivity done at:
50cm
Hiding Heidi test:
- Five contrast levels: 25%, 10%, 5%, 2.5%, and 1.25%
- Two cards: White and one with ‘Heidi’ – ask px to point to where Heidi is
- Use PLT or matching/naming depending on age
- 0 months onwards
- Variable working distance infant/examiner dependent
Tests on children to test binocular function:
- Cover test
- Hirschberg test
- Extra Ocular Motility
- Motor fusion
- Sensory Fusion
- Near point of convergence
- Stereopsis
- Accommodation
Cover test on children:
- Very useful test- Gold standard .
- Accommodation needs to be simulated so use an interesting target, e.g. a toy with some detail, sticker etc = can ask questions about the target to stimulate interest
- Can use palm/thumb to occlude child’s eye rather than occluder
What is it common and normal to have on cover test for children:
EXOP at near
Hirschberg Test on children:
- Useful if cover test is difficult
- Can flash light on and off to encourage fixation
- Temporal reflex = esotropia.
- Nasal reflex=exotropia.
- Higher reflex suggests hypotropia
EOM test on children:
- Needs interesting target, could use flashing lights, auditory stimulus may be useful.
- In very small children may need to move child rather than target as may not understand
Motor fusion 20D BO test:
- BO prism is held before either eye in turn with child fixating suitable target.
- Eye behind prism should adduct rapidly to restore fusion and abduct again on removal
- Speed of the fusion movement helps establish binocularity
- Start with 20Δ BO then reduce to 15Δ BO to 10Δ BO if slow to overcome
Abnormal responses of 20D BO test:
- No movement
- Either no fusion or lack of attention
- Slow to overcome the prism/slow recovery
- Possibly poor fusion
- Prism fusion range (full) can be attempted in school going children
What test do you use for sensory fusion in children:
- Worth 4 dot test / Worth’s lights
- Bagolini lenses /glasses
Worth 4 dot test / Worth’s lights:
- Four lights, usually round but can be different shapes
- 2 green
- 1 red
- 1 white
- View through red and green goggles
- Red filter before RE / green filter before LE
Why test sensory fusion in children:
- Normal Retinal Correspondence.
- Diplopia (Exotropia and Esotropia)
- Suppression
- ARC
Bagolini lenses:
- Spot light seen by both eyes
- Striations oriented in different directions for each eye
- Striated lenses positioned at 45 & 135 degrees
- Streaks of light seen separately by either eye
Near Point of Convergence in children:
- Gross convergence ability
- Use an interesting target such as a toy or a sticker
- Move target towards child until one eye turns out/eyes converge till nose
Normal values for near point of convergence in children:
- Dependant on age
- Children/ younger adults <6cms
- Break 5cms recovery 7cms
What age can you measure near point convergence:
Should be able to do from about 6 months
Measuring stereopsis on children:
- Based on age & test
- For example 40” of arc for adults > 9 years old 60” for adults with TNO
Examples of stereopsis test to use on children:
- Lang’s two pencil test
- Lang stereo-test- good for young children
- Frisby test
- TNO
- Titmus test
- Randot test
Lang strereotest:
- Random dot
- No glasses required
- Lang 1 (cat, car, star)
- At 40 cm: 1200” to 550”
- Lang 2 (elephant, car, star, moon)
- At 40 cm: 600” – 200”
- Good screening test
What distance is lang stereotest done:
40cm
Frisby stereo test:
- No glasses
- 4 squares of shapes per sheet
- 3 thicknesses of sheet: 6mm, 3mm and 1mm
- Disparity 875” to 20”
- Viewing distance: 30 cm – 80cm
- One square contains a central circle
- Observe behaviour or ask question about circles
- Turn around sheet ask again
- Responses seen in infants as young as 6 months
What distance is frisby stereotest done:
30 cm – 80cm
Langs 2 pen test:
- Patient and examiner each hold a pen vertically
- Patient brings points of pens into contact
- Cover one of patients eyes
- Repeat test
In langs 2 pen test what does it mean if accuracy poorer when using only one eye:
Indicates presence of stereopsis under binocularly conditions
In langs 2 pen test what does it mean if theres an equal monocular and binocular response:
Absence of stereopsis
Why is langs 2 pen test useful clinical tool:
- Qualitative test
- Tests low grade BSV
- GROSS (Coarse) stereopsis
What stereopsis tests to do in older children:
- TNO
- Titmus test
- Randot test
Ways of measuring accommodation in children:
- Accommodative amplitude or range
- Near point
- Minus lenses
- Accommodative facility
- Flipper lenses
- Accommodative lag or lead
Measuring accommodation in children using dynamic retinoscopy:
- Objective technique
- Lag (under accommodation is normal approx. +0.75DS)
- Lead (overaccommodation tends to be abnormal)
- Spec Rx should be worn
What are the two methods of dynamic ret:
- MEM method (neutralise with lenses)
- Or move backwards/forwards until neutral reflex obtained and then work out depending on target distance/ accommodative demand
Who is dynamic ret useful for:
Very useful in children with special needs who often have poor accommodative facility/reduced accommodation and need bifocals
Normal value for dynamic ret:
0.75D
Why is cycloplegic refraction gold standard:
Accommodation controlled, large pupil
Which cyclopentolate drops to use in children:
- > 12months – use Cyclopentolate 1%
- 6 - 12months with Light irides – use Cyclopentolate 0.5%
- 6 – 12months with dark irides – use Cyclopentolate 1%
- 3- 6 Months – use Cyclopentolate 0.5%
- Do not use Cyclopentolate in children with a history of epilepsy
How many drops of cyclopentolate to use:
- If there is no sign of mydriasis in 10 mins a second drop can be instilled
- If needed Proxymetacaine 0.5% can be used before instilling cyclopentolate to improve tolerance and the cycloplegic effect.
Advantages and disadvantages of cycloplegic refraction:
Advantages
* Relaxation of accommodation: better estimation of refractive error
* Accurate fixation not needed
* Large pupil: view of fundus
Disadvantages
* Temporary blurred vision and photophobia
When to do a cycloplegic refraction:
- Pre school children especially first sight test
- When prescribing glasses
- Unexplained poor VA
- Reduced stereopsis
- Presence/suspicion of squint e.g. Esophoria, Esotropia
- Underactive accommodation or accommodation appear to fluctuate
- Family history of high hypermetropia or squint.
Near Mohindra Retinoscopy:
- Non cycloplegic
- Occlude one eye
- Room should be completely dark
- Use a 50cm working distance
- Ret as normal, neutralise all meridians
- Original study suggests correction factor of +1.25DS
- Saunders and Westall (1992) suggest +1.00DS over 24 months and +0.75DS if younger
- Repeat on other eye.
- Observe pupil, quality of reflex and co-operation, may need Cyclo
Colour Vision testing in children:
- Not possible in infants
- Colour Vision Testing Made Easy: Gold standard for identifying RG colour vision defects
- Pseudoisochromatic principles
- Generally 3 years and above
- One demonstration plate and 9 test plates: circle, star, and/or square
- Good validity when compared to Ishihara
Anterior segment eye exam in children:
-Red reflex; pupil reflex
- Burton lamp
- Portable slit lamp if available
- 20D lens with magnification
- Regular slit lamp- child in parent’s lap: older child
- IOP (if needed)
* Tonopen
* Digital palpation
Fundus exam in children - which drops to use:
- Dilated is better
- For infants younger than age 1: 0.5% tropicamide and one drop of 2.5% phenylephrine. If cycloplegic refraction also then 0.5% cyclopentolate
- Above 1 year; 1.0% tropicamide or 1.0% cyclopentolate
- Indirect ophthalmoscope
