Optometric examination of children - Ahalya Flashcards
what are the key stages in paediatric eye exam?
- H&S
- Visual function (VA and visions, maybe CS)
- refraction (objective + usually cyclo)
- BV status
- Colour vision
- Anterior segment and Fundus examination
what are the key things to ask in a child’s H&S?
- rfv
- if parents are worried about anything
- when did worries begin, freq, duration, anything making it worse?
- POH
- FOH
- birth history (premature? birth weight? type of delivery? maternal illnesses such as rubella?
- normal milestones?
what is an important milestone for a 10 month old baby?
touch object with finger
what is an important milestone for a 3 year old?
begins to know colours
know names and gender
important milestone for 2 year old?
use short sentences
normal va at birth?
6/120
normal va at 3years
6/12
normal va at 4 years
6/9
normal va at 5 years?
6/6
what is an electrophysiological way of testing va?
using VEPs (visually evoked potentials)
- flash VEP stimulus at birth
- pattern VEP stimulus when older
examples of preferential looking tests?
- keeler acuity cards (CITY)
- cardiff cards (CITY)
- peekaboo app
- teller acuity cards
- lea grating paddles
are the preferential looking tests using an iso-illuminant stimuli?
yes
what is spatial frequency measured in?
cycles/degree
on a preferential looking test, as the stripes become more narrow…?
the spatial frequency is higher
what age do you use preferential looking tests for?
0-24 months (0-2 years)
what distance do you use keeler acuity cards?
38cm
what do keeler acuity cards look like?
15 cards with black & white stripes on right or left side
1 blank card
4 mm hole in centre to look through
what is the range of the keeler acuity cards?
0.32 - 38 cycles/deg
with keeler acuity cards, how do you know a child can resolve it?
identify the same stimulus 2x
what is a clinically significant interocular difference with keeler acuity cards?
2 or more cards
how do teller cards and lea paddles work?
same as keeler acuity cards but diff working distance
what principle does cardiff cards work on?
vanishing optotypes
who are cardiff cards used for?
0-24 months or special needs
what do cardiff cards look like?
pictures at the top or bottom of the card (duck, house, fish, car, train, boat, dog)
do cardiff cards exhibit crowding
?
no
what are the disadvantagesof using cardiff cards?
may overestimate VA due to no crowding - amblyopic px’s will see 6/6 but may acc be 6/36
working distance for cardiff cards?
50cm or 1m depending on age
what is the VA range of cardiff cards at 1m?
1.0 - 0.1 logMAR
what is the VA range of cardiff cards at 0.5m?
1.3 - 0.5 logMAR
what is a clinically significant interocular difference using cardiff cards?
more than 2 cards
how does the peekaboo app work?
2 forced choice or 4 forced choice
px has to touch the pattern which makes a “YIPEE” sound and cartoon appearing- this Yipee sound is an example of positive feedback
which other preferential looking test is comparable to keeler acuity cards?
peekaboo app
working distance of peekaboo app?
25-50 cm
what are the tests available for 2-4 year olds?
picture naming/matching
lea symbols
kay pictures
Va tests for 0-2 years?
- preferential looking cards
- keeler acuity cards
- teller acuity cards
- lea paddles
- peekaboo app
- cardiff cards
Va tests for 3-5 years?
- letter naming/matching (keeler logMAR cards and landolt C/tumbling E)
- picture naming/matching (kay pics and lea symbols)
va tests for above 5 years old?
regular charts
what tests are available for measuring near vision?
- kay picture near test
- lea symbols near vision
- reduced snellen (landolt’s C/ tumbling E)
what age do you measure near vision?
above 2 years old
what are the 2 contrast sensitivity tests?
- cardiff CS test
- hiding heidi
how does the cardiff CS test work?
wd = 50 cm
use preferential looking or naming/matching depending on age
how does hiding heidi work?
5 contrast levels (25%, 10%, 5%, 2.5% and 1.5%)
2 cards- 1 white, 1 with heidi
use preferential looking or naming/matching depending on age
wd = variable
what are the tests to measure binocular status? (8)
- cover test
- hirschberg test
- extra ocular motility
- motor fusion
- sensory fusion
- NPC
- stereopsis
- accommodation
which binocular function test is gold standard?
cover test
when doing cover test what must you make sure is stimulated? and how do you do so ?
accommodation - use an interesting target e.g. a toy
what is normal on a cover test at near?
XOP with rapid recovery - if SLOW RECOVERY IT IS A PROBLEMO
if cover test is difficult which test do you do?
hirschberg
how do you encourage fixation when doing the hirschberg test?
flash light on and off
if you see a temporal reflex on hirschberg what does this mean?
esotropia
if you see the light is nasal on hirschberg test, what does this mean?
exotropia
if you see the light is higher up on a hirschberg test, what does this mean?
hyoptropia - but record as a HYPER deviation eg L hypo noted as R hyper (Aliya edit)
if you see the light is lower down on a hirschberg test, what does this mean?
hypertropia
what is a motor fusion test?
20D base out
on the 20 base out test what does no movement mean?
no fusion or lack of attention
on 20 base out test what does slow movement/slow recovery mean?
possible poor fusion
when do you reduce the power on a 20 BO test?
if slow to over come use 15 then 10
what is an exmaple of a sensory fusion test?
worths lights
bagolini lenses
what does NPC test for?
gross convergence ability
at what age should you be able to do NPC from?
6 months
what are some stereopsis tests you can do in a visually impaired person? and why are they good?
lang stereo, frisby
NO GLASSES NEEDED
stereopsis tests in older children
TNO
Titmus
Randot
is accommodative lag/lead objective or subjective?
objective
what do minus lenses do? (in terms of accommodation)
INDUCE ACCOM
what do positive lenses do? (in terms of accommodation?
relaxes accom
which accommodative test is a ‘clinical pearl’ in children with special needs reduced accom?
dynamic ret
if you see an accommodative lag more than +0.75DS what does this suggest?
accommodative insufficiency
usually seen in children with learning difficulties (e.g Downs)- may need bifocals
if you want to cyclo a kid, what % do you use in 3-6 months?
cyclopentolate 0.5%
if you want to cyclo a kid, what % do you use in 6-12 months with light irises?
cyclopentolate 0.5%
if you want to cyclo a kid, what % do you use in 6-12 months with dark irises?
cyclopentolate 1%
if you want to cyclo a kid, what % do you use in >12 months?
cyclopentolate 1%
do you cyclo a kid with epilepsy?
NO
advantages of cycloplegic refraction
- relaxation of accommodation
- accurate fixation not needed
- large pupil: view of fundus
disadvantages of cyclo refraction
temporary blurred vision and photophobia
when do you cyclo a kid?
- pre school children especially 1st ST
- when prescribing glasses
- unexplained poor VA
- reduced stereopsis
- presence of squint
- underactive accommodation or fluctuating accom
- FOH of squint or high hyperope
what is near mohindra retinoscopy?
- non cyclo
- occlude 1 eye
- dark room
- 50 cm
- ret as normal
- correction factor +1.25Ds
why is mohindratachnique used?
- Do not need to dilate = dark room = large pupil
- quick + easy
- not complex = easy = can track fixtion losses
what is the gold standard for identifying RG colour vision defects?
colour vision testing made easy (CVTME)
what principle does colour vision testing work on?
psuedoisochromatic principles
what does colour vision testing made easy look like?
1 demonstration plate
9 test plates
circle, star and/or square
which colour vision test has a good validity when compared to ishihara?
colour vision testing made easy
how to take IOPs in children?
tonopen
digital palpatation
For infants younger than 1, what mydriatic do you use?
0.5% tropicamide and 1 drop of 2.5% phenylephrine
