BEST WAY TO LEARN PAEDIATRIC REFRACTION

1. PEDIATRIC
REFRACTION
1
YASHASWEE BHATTARAI
BOPTOM 3RD YEAR
BVDUMC SCHOOL OF OPTOMETRY
yashaswee.bhattarai@yahoo.com

2. HOW IS IT DIFFERENT FROM NORMAL
REFRACTION??????
 Objective Refraction is usually used to determine
refractive status of infants and preverbal children
 Meticulously and accurately done
 Great expertise is necessary
 Should understand Emmetropization and relation
between state of BSV and refractive status of child
 Techniques must be easily understandable
 Cycloplegic Refraction is preferable due to active
accomodation in child 2

3. REFRACTIVE STATUS OF CHILDREN
FIRST YEAR OF LIFE 3-5 YEARS OLD ADOLESCENCE
•SPHERICAL REFRACTION
Healthy neonates are
hyperopic (+2.00 D)
•PREMATURE NEWBORNS
Birth weight <2500gm= -1
to -10 D (-4.00 D) mostly
myopic and can become
emmetropic as age increases
Some hyperopic (+5D)
•ASTIGMATISM
Uncommon
Sometime +1 D present
•ANISOMETROPIA
•Length of Globe
increases (5mm from
birth to 3 yrs)
•Process of
emmetropization during
1st yr of life
•SPHERICAL REFRACTION
•ASTIGMATISM
•ANISOMETROPIA
•Mostlly emmetropic
•More myopic than hyperopic
•If myopic at 5-6 yrs= >myopia
•>+1.50D hyperopic at 5-6yrs =
mild hyperopic at 13 -14 yrs
•Spherical Refraction +0.50D to
+1.00D = emmetropic at 13-14yrs
•Spherical Refraction 0.00D -
+0.50= myopic by 13-14 yrs
•NB- AS AGE INCREASES SIZE OF
EYE INCEREASES
3

4. TYPES OF PEDIATRIC REFRACTION
4
SUBJECTIVE REFRACTION WITH/WITHOUT
CYCLOPLEGIGS
OBJECTIVE REFRACTION
STATIC and NEAR
RETINOSCOPY
DYANAMIC
MANIFEST CYCLOPLEGICS
MEM BELL BOOK CHROMORETINOSCOPY

5. CHOICE OF REFRACTION FOR
DIFFERENT AGE GROUPS
INFANTS
PRE-
SCHOOL
SCHOOL
AGED 5
Mohindra Near Retinoscopy
Retinoscopy with and without cycloplegics
Photorefraction
Keratometry/Placido’s disc/Keratoscope
Retinoscopy with or without cycloplegics
Distance (by showing TV for fixation)
Dyanamic- MEM for Near
Book Retinoscopy
Subjective Refraction
Keratometry
Manifest/Cycloplegic Retinoscopy
Dynamic Retinoscopy
Subjective Refraction
FUNDUS EVALUATION IN ALL

6. CYCLOPLEGIC REFRACTION
 CYCLOPLEGICS are the drugs that paralyze the
ciliary muscles resulting in loss of
accommodation and secondarily dilatation of
Pupil
6

7. WHY CYCLOPLEGIC REFRACTION??
 To stop eye’s ability to auto focus or
accommodate in order to determine true
prescription
 When the eye contracts and relaxes the lens
changes its shape
 Cycloplegics paralyses ciliary muscles and lens
can nolonger change its shape and there is no
chance of accommodation
 In children they have the great ability to vary
their accommodation
7

8. HYPERMETROPIA
8
LATENT
Corrected by
tone of ciliary
muscle
(cycloplegic
refraction)
MANIFEST
A)FACULTATIVE
(Corrected by
accommodation)
B)ABSOLUTE (Not
corrected by
accommodation)
TOTAL
Found out by
abolishing tone
of ciliary muscle
( cycloplegics)

9. MECHANISM OF ACTION
9
Releases acetyl
cholin from
post ganglionic
nerve fibers
Parasympathetic
system
Blocks muscarine
receptors in ciliary
body
Ciliary body is
paralysed
Loss of
accommodation
Parasympathetic
supplies Sphincter
pupilary muscle
Dosent work
Pupil Dilates

10. 10
Visual
Acuity
(Near/Dist
ance)
Pupillary
Reflex and
size under
room
illumination
Manifest
Refraction
History
Medical
Allergic
Emotional
Hyperemia
in
conjunctiva
Accommodation
and Binocular
status
AC/A
Relation
Ac angle
and IOP
MEASUREMENTS TO
BE DONE BEFORE
INSTILLING
CYCLOPLEGICS

11. IDEAL CYCLOPLEGICS SHOULD HAVE
 Rapid onset
 Full Paralysis of accommodation
 Sufficient duration to allow accurate assessment of
refraction
 Rapid recovery of accommodation
 Dissociation from cycloplegic effect from mydriatic
effect
 Absence of local and systemic side effects
 Capacity of safe administration by appropriate person
11

12. CHOICE OF CYCLOPLEGICS
NAME AGE CONCENTRATI
ON
START OF EFFECT DURATION TONUS
ALLOWANCE/
RESIDUAL
ACCOMMODATION
ATROPINE 0-7
years
1%
1 drop- twice a
day-3 days
Cycloplegic=30mi
ns to 3 days
10-14days
PMT-
14Days
TA= +1.5 D
RA= 0
CYCLOPENTOLATE 7-15
years
7-12yrs=1%
12-15yr=0.5%
1 drop
15-20mins -
2nd drop
Cycloplegics= few
mins
Maximizes in 30-
60mins
24-48hrs
PMT-
2days
TA=+0.75D/0.5D
RA= +1 D
HOMATROPINE 1-15
years
1% 2% 5%
2%- Common
1 drop
repeated twice
after 10 mins )
starts in 15 mins
Maximizes in
45-90 mins
24-48 hrs
PMT- 2
days
TA= +0.75D
RA=+0.75D
TROPICAMIDE
ALL 0.5%, 1%
2 drops after
10 mins
4 drops total
Few mins
Maximizes in 30
mins
6-8 hrs TA=0/<0.5 D
RA=+1.5D
12

13. CHOICE OF CYCLOPLEGICS
 SCHOOL AGED CHILD
1% CYCLOPENTOLATE
0.5% PROPARACAINE (Aid ocular absorption)
Let child rub eyes to facilitate absorption
Children with dark iris pigmentation and
excessive body weight may require additional
drop within 5 minutes to allow cycloplegia.
13

14.  According to the patients age we select the type of drug
 Cyclopentolate is usual drug of choice although it is not as
effective as atropine in inhibiting astigmatism because
a) Reasonabely powerful
b)fast acting –produce cycloplegia within 45-90 mins and
lose effectiveness within 3-4 hrs
c)relatively safe
 Tropicamide is fast acting mydriatic but does not inhibit
accomodation sufficiently to satisfy requirement of
cycloplegic examination
 Instill the selected cycloplegic according to the dosage
 After refraction we get certain number of Refractive value
 We deduct the tonus allowance
14

15. EG#1
 For eg
If 1% attropine is instilled in a child of 1 and half
years
Retinoscopy is done at the distance of 1m
(example)
You get +5.00D = Gross Retinoscopiy value
+5.00 D – 1.00 D = +4.00 D = Net Retinoscopy
value
Tonus allowance of atropine = +1.50D
Resulting total Power = +4.00D - +1.5D =
2.50D 15

16. 16
SIDE EFFECTS
ATROPINE
•Inhibits action of sweat and salivary
gland leading to dryness
•Tachycardia
•Hallucination/Dizziness
•Ataxia
•Photophobia
•Blurring of vision
•Asthenopic symptoms
CYCLOPENTOLATE
•Less side effect
•Photophobia
•Blurring of vision
•Burning sensation
•Ataxia
•Dizziness/Confusion
•Tachycardia
HOMATROPINE
•Less severity than Atropine
but same side effects
•Its is just a derivative so
doesn't paralyze ciliary
muscles completely
TROPICAMIDE
•Only ocular side effects like
•Blurring of vision
•Photophobia
•Burning sensation

17. 17

18. ADVANTAGES OF CYCLOPLEGICS
 Used In cases of hyperopia, esotropia ,
convergence excess, accomodative spasm and
when relative findings cannot be obtained in
dry state
 Helps in accurate refraction and post operative
inflammation
 Reliving pain in uveities
 Better view of fundus
DISADVANTAGES
 Poor vision and monochromatic abberation
 Accuracy is required 18

19. RETINOSCOPY
 Objective means of obtaining Refractive error
 PRINCIPLE
19

20. NEAR RETINOSCOPY
 Not a variation of dynamic Retinoscopy
 Basically a substitute for static Retinoscopy mainly used
in infants
 Done with/without cycloplegics
 Studies showed the relative +5D underestimation of
hyperopia in the procedure done without cycloplegics
 Mohindra introduced a technique of non-cycloplegic
retinoscopy that correlates somehow with cycloplegic
findings 20

21. NEAR RETINOSCOPY DIFFERS FROM OTHER
FORM OF DYANAMIC RETINOSCOPY IN 3
WAYS
 1) It is performed in complete darkness, the
only illumination in the room is supplied by
retinoscope with child fixating at retinoscope
light
 2) It is monocular procedure i.e eye not being
examined is occluded
 3) The adjustment factor of -1.25D is
algebrically combined with the spherical
component of the gross sphero-cylindrical
lens powers
21

22. PROCEDURE
 The examing room is darkened
 Intensity of retinoscopy light is kept as minimum
 Examiner encourages the child to fixate the light by making animal sounds
 Examiner maintains the retinoscope at the distance of 50 cm from the infant
 For young infants, the best way to scope are with the infants over parents
shoulder or while the infant being fed
 Lens racks are used to neutralize the retinoscopic motion
 An adjustment value of -1.25D is algebrically added to the neutrality value
to determine the distant refractive state
 Eg- If the motion is neutral with +1.25D lens in place the infant is
emmetropic
22

23. EG#2
 Suppose we perform retinoscopy at 50cm
 Compensatory factor= +2D
 Average Lag of accommodation in infants
0.75D
 Total compensation= +2.00 – 0.75 D = +1.25
D
 Gross Retinoscopy value = +3.00 D
 Net Retinoscopy Value = +3.00- 1.25 D =
+1.75D
23

24.  Wesson and colleagues (1990) suggested caution
in substituting Mohindra retinoscopy for
cycloplegic refraction using and adjustment value
 They found significant difference between the two
techniques in both sphere and cylinder power
 Mohindra Retinoscopy is adequate for infants who
do not have esophoria or esotropia
 When either of these two exists , uncovering the
full amount of latent hyperopia is imperative. 24

25.  In 1977 extremely highly correlation between near and
cycloplegic refraction was suggested
 In study reported by Maino et al. (1984) results of
Mohindra retinoscopy were not correlating with
cycloplegic refraction
 He stated that predictive value of near refraction was
very low and concluded that it was not a good predictor
of refractive error
 It was not capable of identifying hyperopia of +3D or
more or astigmatism of >1.00 D
 Thus concluded that noncycloplegic refraction is not the
alternative of cycloplegic standard refraction 25

26. DYNAMIC
RETINOSCOPY
26

27. 27
Lead of accommodation- At distance closer than
resting point amount of accommodation is less
than that required by stimulus
Lag of accommodation- At distance beyond
resting point amount of accommodation exceeds
than that of required

28. DYNAMIC RETINOSCOPY
- Objective test to measure the refractive status of the eye
- Done at nearpoint (40cm) in order to determine how
much plus power is required to achieve neutrality
- Basically used to measure lead and lag of
accommodation
- Especially useful with young children, whom static
retinoscopy is often not feasible.
- Number of ways have been proposed for carrying out
dynamic retinoscopy.

29.  The patient is asked to fixate at nearpoint stimulus/ plane of
retinoscope
 No working distance lens power is added or substracted
 Examiner neutralizes the motion of the retinal reflex.
 the retinal reflex is neutralized by using plus lenses
 0.50D is deducted from the finding and the amount of plus
lens power that must be added is patients lag of
accomodation
 And the remaining power will be the patient refractive error.

30. MONOCULAR ESTIMATION METHOD
 MEM is differ from standard dynamic retinoscopy in two
ways:
- testing distance is not same for all patients
- is the monocular procedure.
testing distance is determined by the
- physical size
- preferred reading distance
YOUNG CHILDREN= 8-10 INCHES
Though many clinicians choose “Harmon
distance” (elbow to knuckle )as testing
distance
-The retinoscopy mirror is set at plano
- The retinoscopy light or lens should not place infront of
eye more than 2 sec

31. The specific steps of procedure are:
1.Ask the patient to sit comfortably
2.Fixation target is a white card
containing 1 and half inch hole
having letters words or pictures
according to child’s age.
3.It is printed within one and a half inch of the hole
4. The card is attached to the retinoscope with a clip
5. Retinoscope beam passes through the hole in the card
6. Examiner is seated on the stool slightly below patients eye
level so the patients eye is at moderate downgaze while
looking at the target

32. 4. The patient Should wear his habitual prescription
5. The examiner takes a position of 10-16 inches from patient
6. The retinoscopy beam is directed toward the
bridge of patient’s nose
Child is instructed to read the words aloud and examiner quickly
moves his vertical streak across the pupil
7. with movement = lag of accommodation beyond the plane
convergence
8. Examiner estimates the direction and approximate power of
the reflex
9. Lens is placed in one eye to reassess the approximate power
10. If it validates the estimate lens power is recorded and if this
does not then procedure is repeated with more appropritae
lens

33. EG #3
 With motion of moderate degree
 +0.50D lens in front of one eye
 If it neutralizes with motion +0.50D is
recorded
 If not +1.00D sphere is selected
 If neutral motion +1.00 is recorded
 If against motion 0.75D is recorded
 Normal +0.50D to +0.75D
 When lag more than +1.00 D prescribe plus
lens for near work
33

34. BOOK RETINOSCOPY
 Is the variation of dynamic retinoscopy
 Patients fixates on a near-situated,
accommodation-stimulating target
 Differ from standard dynamic retinoscopy
procedure in following way:
- where the fixation target is positioned.
- what the examiner observes &
- how these observations are interpreted

35.  The procedure consists of 3 retinoscopic
observation made at a distance of
- 15 feets
- 7 feets
- 20 inches with fixation target in each distance
 Target is placed at 20 inches for the children
who could read
 The target is book with picture so called as book
retinoscopy

36.  The goal of the procedure were to look for & record
 relative brightness of reflex, ranging from dull to
bright
 color of the reflex , ranging from dull red to white
 Speed, range, promptness, pick up & release
motion
 Meridional difference.
 Basically observes accomodative state of eye

37. INTERPRETATION
REFLEX BRIGHTNESS/
MOVEMENT
ATTENTION
INCREASED
BRIGHTNESS/ Bright
reflex
Moment when child identifies the
target
With movement Child’s eye located the target
Against Movement Settled Attention and held to target
Occilation of against to
with to against
Relaxed attention
Dull reflex Withdrew attention
37
THE REFLEX ON THE BASIS OF COLOUR ARE
Dull Red, Dull Pink , Bright Pink, White Pink and Pink

38. BELL RETINOSCOPY
 The distance between patients &the examiner is 50 cm
 Target is moving & the examiner is constant
 The ball is used for the patient attraction
 target should be interesting enough
and suspended on its handle at eye level.
 No lenses are used
 If the initial reflex shows “neutral” or “with”
motion, move the target (nt the retinoscope) towards the
patients, until against motion is seen and come back until
neutral motion is observed in each principal meridian

39.  Neutrality usually occurs when the ball is located
about 15-16 inches from the patients face (37cm to
40 cm) resulting in lag of accomodation from 0.50
to 0.75D
 If the initial reflex shows “against” motion the
patients may judge to be over accommodation
 record the distance between the target and the
patient when against motion is seen as the target is
pushing toward the patients

40. Interpretation
 If against motion seen between 15-18 inches, patient is
normal
 If “with” motion seen between 15-18 inches, patients is
normal
 If delayed shift to against motion indicates latent , need
for addition plus
 Always with indicates, needs plus for near
 Always against motion – myopia
 If astigmatic reflex – indicates astigmatism

41. 41

42. OPHTHAMOSCOPY
 Is also effective way to obtaining an objective
refractive finding
 The procedure itself is self-evident
 Simply determine the lens power to focus the
fundus.
 This will be refractive status of the patients.

43. SUBJECTIVE REFRACTION
 DONE WITH/WITHOUT CYCLOPLEGICS
43

44. THANK YOU
REFERENCE
CLINICAL PEDIATRIC OPTOMETRY
Leonardo J Press, OD, F.A.A.O
Bruce D. Moore, OD, F.A.A.O
Pediatric Optometry second edition
Jerome Rosner and Joy Rosner
Primary Care Optometry
Theodore Grosvenor, OD, Ph.D, F.A.A.O
Optometric Investigations
David. B. Henson. Msc Phd . F.A.A.O 44