hope it will be beneficial for both clinical as well as academic purpose..

1. Pediatric refraction &spectacle power
prescription in pediatrics.
Moderator :- Presenters:-
Dr. Sanjeev Bhattarai Srijana lamichhane
Bipin koirala
IOM , MMC

2. Quote of
the
day……

3. Contents
Pediatric refraction
Introduction
Emmetropization
Refractive changes in eye with age
Near retinoscopy
Cycloplegic refraction
Dynamic retinoscopy
Amblyopia
Spectacle power prescription
Introduction
Prescription guidelines
Aphakia and prescription
Summary
References

4. Background
The human eye undergoes dramatic anatomical and physiological
development through out infancy and early childhood
Most of the growth of eye takes place in the 1st yr of life
So, one dealing with the pediatric age group should have great
expertise in determining refractive state

5. Should have knowledge of:
Normal values of refractive error with age
Emmetropization
Relationship b/w vision , refraction ,state of BSV , and age
of child

6. Background
AAO recommends the routine eye examination of a child begins
from 6 months of age becoz an average child will reach a number of
developmental milestones at this age.
Refractive error is among commonest visual problem in children
Early detection & appropriate management of refractive error helps
to achieve optimal acuity , binocularity & overall development.

7. Background
Clinicians who encounter pediatric age group must be fully aware of
impact of treatment on pediatric ocular disorder.
Inappropriate refractive correction will hamper child’s optical &
neural development as a result of which child will suffer life long.
Hence clinician must be aware about the development of optical
components of eye before appropriate refraction and correction.

8. Age groups in pediatric population:-
Age group Age
Neonate Birth – 1 months
Infant 1 months – 1 yrs
Toddlers 1- 3 yrs.
Preschool age 3- 6 yrs.
School age 6- 12 yrs.
Adolescent 12 -18 yrs.
• This subdivision of the pediatric population is based on the
developmental changes that occur from birth through childhood.

9. Emmetropization
A process operating to obtain greater frequency of emmetropia is
called as emmetropization.
Achieved by negative feed back mechanism.
Biometric components in eyes influencing emmetropization:-
1. Corneal power
2. Crystalline lens power
3. Axial length
4. AC depth

10. Estimation
Variance in refractive error Components of eye
½ of variance Axial length
¼ of variance Corneal curvature
1/20 of variance Anterior chamber
1/5 of variance Due to measurement error and variation in
lens and refractive indices

11. Contd…
During emmetropization preexisting refractive errors are eliminated.
Eg. If myopia is induced by (+ve) lens eyeball growth will stop & if
if hyperopia is induced by (-ve) lens eyeball growth will increase
Proper care must be given for spectacle prescription during critical
period.
Full correction of high refractive error may disturb emmetropization
leaving permanent refractive error.

12. Contd..
A few infants are myopic at birth.
Rate of emmetropization is generally proportional to the initial
error.
Who start off close to emmetropia or with a low amount of
hyperopia show little change.
 While those who have higher ametropia generally show greater and
faster changes.

13. Emmetropization lose approximately one-half of their spherical
equivalent refractive error in the first year.
Approximately one-third between nine and 21 months.
Approximately two-thirds of the astigmatism is lost between
nine and 21 months

14. Emmetropization fails when refractive errors are outside normal
range for age
And the risk of amblyopia and strabismus is increased
Lastly, children with low vision are less likely to fully emmetropize

15. For children with disabilities , the story of refractive development can be
quite different ( i.e. Down’s syndrome ,children with cerebal palsy )
The distribution of refractive error in the first months of life mirrors that
of typical children
Emmetropization fails in children with these conditions
So, one should be alert to the possibility of similar failure in children
with other disabilities.

16. Refractive errors and accommodative deficits are common among
children with disabilities at any age
Most children with visual impairment are reported with under
accommodation

17. Objectives of pediatric refraction
To determine the refractive status in infants and preverbal children’s
Must be appropriate for non-verbal ,uncooperative, non-
communicative children’s
Must provide important information in refractive state of eye
Must be understandable ,easily assessable and accessible
Practitioner must be competent enough to deliver a perfect
judgement

18. Challenges
As a child have a great ability to maintain a wide range of accommodation
Un-cooperative
Greater range of accommodation
Difficulty in quantifying visual status
Risk of visual deprivation
Difficulty in making a child understand wear glasses
So, cycloplegic refraction must be carried out in
every patient with or without strabismus

19. Changes in refractive error with age
Premature infants :- Mostly presented with high myopia a/w ROP
Full term newborn :- Mostly presented with hyperopia of (+1-2 D)but
refractive error might range b/w from +11 to -11 D
Preschool child :- Shift towards emmetropia / small myopia / less
hyperopia
School children :- Emmetropia / school myopia
Adolescent :- Mostly myopia

20. 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 2 D present
Anisoetropia ( 1-3 D)
•Length of Globe
increases (5mm from
birth to 3 yrs)
•Process of
emmetropization during
1st yr of life
•SPHERICAL REFRACTION
(+1-2 D)
•ASTIGMATISM 1.50 D
Anisometropia < 3 D
Mostly 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

21. Types of pediatric refraction
Objective refraction Subjective refraction
Near retinoscopy
Dynamic
retinoscopy
Static retinoscopy
Dry retinoscopy
Cycloplegic (wet
retinoscopy)
keratometry
Ophthalmoscopy
Retinoscopy
autorefraction
photorefraction

22. NEAR RETINOSCOPY

23. Near Retinoscopy
Mohindra introduced a technique of non-cycloplegic retinoscopy that
correlates somehow with cycloplegic
 Not a variation of dynamic Retinoscopy
 Basically a substitute for static Retinoscopy mainly used in infants
 Done with/without cycloplegics

24. Principles
The stimulus or fixation is the dimmed light source of the
retinoscope in a darkened room which provide ineffective
or neutral accommodative stimulus
Accommodation remains stable during this technique

25. What actually happens ??
Most patients exhibits anomalous myopia during retinoscopy
This excessive refractive power reflects a shift of
accommodation towards the patients intermediate resting
focus under reduced stimulation
To compensate for this effect, a tonus factor is applied to
the gross refraction obtained with near retinoscopy
Tonus factor is +0.75

26. In addition , taking the WD in consideration ( if 50 cm)
i.e. -2.00 D
The total adjustment factor will be :
Working distance + tonus factor = ( -2.00 D + 0.75 D)
= - 1.25 D

27. Procedures
The room light is dimmed
The child is encouraged to fixate the retinoscope light
Babies will instinctively fixate the light
Retinoscope is performed monocularly
At WD =50 cm

28. Example
Gross refraction = 4.00 D – 1.00 D × 180
Add adjustment factor = -1.25
Final net refraction = +2.75 – 1.00 × 180

29. Indications for near retinoscopy
Frequent follow-up visits
A child is anxious about instillation of drops
A child is at risk for an adverse effect to cycopentolate
Had an adverse reaction to cyclopentolate previously

30. Errors
Too much room illumination
Incorrect working distance
Variable fixation of the child

31. Static retinoscopy
Retinoscopy performed when the patient is asked to fixate the
distance target ,with the accommodation relax
streak movements
With movement : eye conjugate to a point either behind the
eye or behind the retinoscope.
Against movement : eye conjugate to a point between the eye
(patient’s) and retinoscope.
Neutrality : eye conjugate with retinoscope

32. Cycloplegic refraction

33. Cycloplegic refraction
CYCLOPLEGICS are the drugs
that paralyze the ciliary
muscles resulting in loss of
accommodation and
secondarily dilatation of Pupil

34. Principle of cycloplegic refraction
Determination of total refractive
error during temporary paralysis of
ciliary muscles as an instillation of
cycloplegic drugs which otherwise
doesn’t manifest on subjective
non-cycloplegic refraction
Total hyperopia
Latent Manifest
facultative absolute

35. Mechanism of action
Releases
acetylcholine
from post-
ganglionic
fibres
Parasympathetic
system
Blocks the
muscarine
receptors of
ciliary body
Ciliary body
is paralyzed
Loss of
accommodation
Parasympathetic
supplies
sphincter
pupillary muscle
Pupil dilates
Doesn’t
work

36. Indications
Pseudomyopia
Latent hyperopia
Young
children
Young patients
who have
symptoms but not
significant
refractive error
StrabismusInconsistent
endpoint of
refraction

37. Additional indications:-
Every nonverbal and non communicative children
Patient with high heterophoria
Accommodative esotropia ( atropine is best choice)
Accommodative asthenopia
Poor reliability b/w dry retinoscopy objective finding with
subjective finding.

38. “EVERY CHILD HAS THE RIGHT OF A
CYCLOPLEGIC REFRACTION”

39. Selection of cycloplegic drugs
Name Age Dosage Peak effect Duration of
action
Post
cycloplegic
test
Tonus
allowance
Atropine
sulphate
(1%ointment)
<5 yrs TDS for 3 days 2-3 days 10-20 days After 3weeks
of retinoscopy
1 D
Homatropine
hydrobromide
(2%)
5-8 yrs 1 dp repeated
twice after 10
mins
60-90 mins 48-72 hours After 3 days of
retinoscopy
0.5D
Cyclopentolate
hydrochloride
(1%)
8-20 yrs 1dp repeated
thrice after 15
mins
80-90 mins 6-18 hours After 3 days of
retinoscopy
0.75D
Tropicamide
( 0.5%,1%)
All 1 dp TID 20-40 mins 4-6 yrs _ _

40. Guidelines
 Atropine cycloplegic refraction is advised in the children
younger than 5 years
 Atropine cycloplegic refraction is advised in esotropic
children (accommodative type) up to 4 years
 After 5 years, cyclopentolate cycloplegic refraction is
advised up to 25-30 years
 Above 30 years, amplitude and lag of accommodation is
checked and cycloplegic refraction is advised

41. When is cycloplegia ready for refraction ??
 The completeness of the cycloplegia is determined by
assessing the residual accommodation by push up test
 The mydriasis and cycloplegia do not complete at the
same time
 The cycloplegia is completed prior to mydriasis (in
cyclopentolate)
 - when there is complete mydriasis the cycloplegia is
considered to be complete for the refraction

42. Post mydriatric treatment (PMT)
Assessment of the finding of cyclorefraction by subjective
means after the effect of cycloplegia is eliminated
Cilliary tonus should be subtracted
(Cilliary tonus being +0.50 to +0.75D in case of
cyclopentolate)

43. Example
If 1% atropine is instilled in a child of 1 and half
years
Retinoscopy is done at the distance of 1m
You get +5.00D = Gross Retinoscopiy value
Net Retinoscopy value = +5.00 D – 1.00 D = +4.00 D
Tonus allowance of atropine = +1.50D
Resulting total Power = +4.00D –( +1.00D)= 3.00D

44. contraindications
Adverse
effects
 Narrow angle
glaucoma
 Hypersensitivity
to a specific
cycloplegic drugs
 Blurred vision
 Photophobia
 Systematic side
effect except
tropicamide

45. !!!!!!!CAUTION!!!!!!
Cyclopentolate may produce
oedma , follicular conjunctivitis
& dermatitis in some pts .
Cyclopentolate may produce
exaggerated seizure in
children’s with epilepsy
Overdose of cycloplegic agent has to be avoided in children
with Down’s syndrome or those affected by cerebral palsy,
trisomy 13 and 18, and other central nervous system (CNS)
disorders becoz it produces hallucinogenic effect

46. Dynamic retinoscopy

47. Dynamic retinoscopy
Objectively determines the point that is conjugate to the retina when the
pt. is viewing a particular near target
Accommodation is active
NO WORKING DISTANCE POWER IS ADDED OR SUBSTRACTED FROM THE
FINDING

48. Goal is to determine accommodative Response
Also helps to determine the most appropriate near prescription with
testing conditions.
Techniques to perform dynamic retinoscopy include
Interposing additional lenses into line of sight to
achieve neutrality
Moving retinoscope in space to the point that is
conjugate to the retina

49. Types of dynamic retinoscopy
Frequently used in clinical practice:
Monocular Estimation Method (MEM)
Nott retinoscopy
Bell retinoscopy

50. Monocular estimated method (MEM)

51. Nott’s method

52. Extra Challenges in retinoscopy
Retinoscopy may be difficult to perform accurately in the conditions like
 Nystagmus
 Strabismus
 Aphakia
 Corneal opacities
 Miosed pupil
 Cataract
 Opacities in media
 Faint retinoscopic reflex

53. In case of nystagmus – retinoscopy should be performed in the null zone
if such is present
In case of strabismus-The pt. is asked to alter gaze to another fixation
target (or close that eye) so that the tested eye is better positioned
And should perform retinoscopy slightly off-axis
In case of aphakia – the retinoscopy should be performed after dilatation

54. Radical retinoscopy
This technique is applied in cases of small pupils,
cataract, media opacity and faint retinoscopic reflex
Instead of performing at usual WD ( 50 cm) the examiner
move closer to the patient
So that , observable reflex can be obtained
May involve WD as close as 20 cm or 10 cm
Finally, the dioptric power of the WD is deducted from
the retinoscopic value

55. Example
If gross refraction = +2.00 D -1.00 × 090
Working distance (WD) = 20 cm i.e. + 5.00 D
Net retinoscopy = (-3.00 D -1.00 × 090)

56. Risk of amblyopia
Risk of amblyopia is dependent on the magnitude of the refractive
error, type of refractive error (lesser risk in myopes, as near vision is
clear), as well as age of the child
Anisometropia is the most common cause of amblyopia
 Hypermetropic anisometropia is more amblyogenic then myopic
anisometropia.

57.  Since ,Astigmatism cannot be overcome by accommodation, and
thus, any cylindrical power above 1.5 to 2 D can be amblyogenic
Total cylindrical power is prescribed in children with the aim of
correcting both the meridians entirely, thus preventing any chance
of amblyopia
Oblique astigmatism degrades the visual acuity more and is more
amblyogenic

58. Amblyogenic refractive errors (preschool)
Hyperopia ≥ 3.5 D
Myopia ≥ 3.0 D
Astigmatism > 1.5 D at 90/180 deg
Astigmatism > 1.00 D >10 deg in any meridian
Anisometropia (sph or cyl) > 1.5 D

59. Spectacle power
prescription

60. Introduction :-
After detection & measurement of refractive error its proper
management is next most important part in pediatric refraction.
Clinician must be aware about normal and abnormal refractive findings
& also the normal development of various optical components
Along with Refraction & prescription other optometric test procedures
must go hand in hand (eg. Orthoptic examination , fundus evaluations )
so that proper management of an condition can be done.

61. Background :-
A number of researches had been carried out regarding power
prescription in pediatric age groups.
But there is no any strict protocol for the power prescription.
AAO , AOA and other well renowned associations have given their own
opinion regarding power prescription.
Beside this clinical experience of a clinician & his personal decision also
plays major role in power prescription.

62. Questions that must be considered before
prescribing for children’s b/w (0- 6 )yrs. age??
Is the refractive error in normal range with child’s age?
Will this refractive error of the child emmetropize?
Will this level of refractive error disturb normal level of
functional vision?
Will prescribing glass be beneficial for the child?
Will prescribing glass interfere with emmetropization?

63. Classification of Hyperopia:-
Classification is on the basis of refractive error amount.
Type Amount
Low hyperopia < or = 2.00 D
Moderate hyperopia + 2.25 to + 5.00 D
High hyperopia > 5.00 D

64. Sign & symptoms of a child in
hyperopic error
Symptoms depends on age of child and also the degree of error
Signs & symptoms
1. Squinting and rubbing of eyes
2. Frequent blinking
3. Avoidance of near work
4. Asthenopia
5. Poor school performance
6. Deviation of eyes (eso)
7. Blurring of vision
8. Asymptomatic (*)

65. Indications for prescribing in hyperopia
High amount of error.
Pts / child complains reduced VA.
Error A/w Amblyopia & Deviation.
A/w syndromes having probability of amblyopia
History of poor school performance
Family history

66. Before prescription proper VA must be determined and any deviation in
eyes must be ruled out.
If deviation is absent cycloplegic refraction with cyclopentolate (1%) can
be considered.
If deviation is present full cycloplegia is mandatory with Atropine

67. Guidelines for
prescription in
hyperopia in
flowchart:-

68. Infants (0-1) yrs.
Isometropic
Hyperopia
Deviation
+ce (eso)
Deviation
-ce
Full cycloplegic
correction given when
error is (> or = 2 D) and
regular F/U for error
below this
Prescribe only when
error is (> or = 5 D )
i.e. partial or 2/3rd
prescription is advised

69. Hyperopic
Anisometropia
< 2.50 D
> Or =
2.50 D
No prescription
needed ( follow up
3-6 monthly)
partial
prescription
(no devation )
Full prescription
(esodeviation
+ce )
Infants (0-1) yrs.

70. Toddlers ( 1-3 ) yrs.
Isometropic
Hyperopia
Deviation
+ce (eso)
Deviation
-ce
Full cycloplegic
correction given when
error is (> or = 2 D) and
regular F/U for error
below this
Prescribe only when
error is (> or = 3.5 D )
i.e. partial or 2/3rd
prescription is advised

71. Hyperopic
Anisometropia
< 2.00 D
> Or =
2.00 D
No prescription
needed ( follow up
3-6 monthly)
partial
prescription
(no devation )
Full prescription
(esodeviation
+ce )
Note:- If exodeviation is associated
plus correction must be reduced
Toddlers ( 1-3 ) yrs.

72. Preschoolers ( 3-6 ) yrs.
Isometropic
Hyperopia
Deviation
+ce (eso)
Deviation
-ce
Full cycloplegic
correction given when
error is (> or = 1.5 D)
and regular F/U for
error below this
Prescribe only when
error is (> or = 2.50 D )
i.e. partial or 2/3rd
prescription is advised

73. Hyperopic
Anisometropia
< 1.50 D
> Or =
1.50 D
No prescription
needed ( follow up
3-6 monthly)
partial
prescription
(no devation )
Full prescription
(esodeviation
+ce )
Note:- If exodeviation is associated
plus correction must be reduced
Preschoolers (3-6) yrs.

74. School age (above 6 yrs)
Cycloplegic refraction is always recommended when hyperopia is
present in initial retinoscopy.
Since school children need good vision for both distance and near
proper correction is always needed for better academic
performance.
At school age a child is expected to be nearly emmetropic.
Prevention of a child from amblyopia is major concern if high
hyperopia , deviation & anisometropia is present.

75. Contd…
Isometropic error (> or = 1.50 D) in the school years (without symptoms) is
indicated for correction.
A full or near full correction may be given at this age, as emmetropization
has essentially ended.
Hyperopic anisometropia (> or = 1.00 D ) needs full correction.

76. Guidelines for
prescription in
myopia

77. Classification of myopia
It is based on degree of refractive error
Type Amount of error
Low myopia < or = 2 .00 D
Moderate myopia 2.00-6.00 D
High myopia > 6.00 D

78. Signs and symptoms of myopia
signs
1. Predominant eyeball(
large & prominent)
2. AC is slightly deep
3. Pupils are somewhat
larger.
4. Temporal myopic
crescent in fundus
symptoms
1. Poor distance vision
2. Squinting eyes
3. Asthenopia
4. Change in psychological
outlook like as introvert ,
only interested in indoor
games close holding of books
5. Poor performance in class

79. Infants (0-1yrs.)
Infants with low-to-moderate myopia may not need prescription.
Because they don’t need to view things in fine details.
But AAO gives prescription guidelines in such condition as :-
Isometropic
myopia
< -
5.00D
> or =
-5.00D
No need to prescribe
(constant monitoring)
Needs prescription
(Reduce by 1-2 D)

80. Infants ( 0-1 yrs )
AAO suggests prescription of glasses when Myopic anisometropia
is ( > or = 2.50 D) in infants to reduce possible chance of
amblyopia.
High amount of myopia at birth is likely to produce esotropia
becoz far point is very close to eye .

81. Toddlers (1-3 yrs.)
No prescription is given for low myopia in toddlers but given for
moderate and high myopia.
Prescription indicated as per guidelines of AAO.
Isometropic
myopia
< -
4.00 D
> or =
-4.00 D
No need to prescribe
(constant monitoring)
Needs prescription
(Reduce by 1-2 D)
(for no deviation)
Example : Highly myopic children appear to do well without correction and cannot
always tolerate their full prescription. A two-year-old myope needing - 15.00DS may
cope better with -10.00DS for a few months before gradually increasing the
prescription.

82. AAO suggests Anisometropic myopia > or = 2.50 D needs prescription in
toddlers to prevent probable chance of amblyopia & deviation .
For muscle imbalances
For eso deviation : minimum minus for clear vision
For exo deviation : maximum minus for clear vision

83. Preschool age ( 3-6 yrs )
Isometropic
myopia
< -
3.00 D
> or =
-3.00 D
No need to prescribe
(constant monitoring)
Needs prescription
(Reduce by 1-2 D)
(for no deviation)

84. AAO suggests Anisometropic myopia > or = 2.00 D needs prescription in
preschoolers to prevent probable chance of amblyopia & deviation .
Similarly if amblyopia is associated with myopia but no strabismus 2/3rd of
cycloplegic correction can be given for children’s below 6yrs .
For muscle imbalances
For eso deviation : minimum minus for clear vision
For exo deviation : maximum minus for clear vision

85. School age ( above 6yrs.)
Need proper vision for both near & distance at school age so proper Rx for
both near & distance is needed.
Although emmetropization almost completed at 6 yrs. of age but still risk of
deviation & amblyopia is present
Guidelines
Full prescription must be given to abolish amblyopia , deviation & avoid
symptoms like squinting eyes.
Over correction must be avoided becoz overcorrecting myopia can be
detrimental and may cause accommodative spasm leading to severe
asthenopia and esotropia

86. Contd..
Only one circumstance where over minus glasses may be prescribed is
the presence of intermittent divergent strabismus.
Minus glasses are used to induce accommodation and thus
accommodative convergence to control exotropia.
Slight under correction is done if a/w esophoria child more than 6 yrs.
In very high myopia (> or = 10.00 D ) full correction can be barely
tolerated so under correction is recommended.

87. Similarly in Anisometropic myopia ( > or = -3.00 D ) must be prescribed
to prevent amblyopia.
For muscle imbalances
For eso deviation : minimum minus for clear vision
For exo deviation : maximum minus for clear vision

88. Some scientist & research finding claim that partial
correction of myopia contributes towards myopia progression
This finding is actually in contrast with our clinical
assumption.

89. Guidelines for
spectacle
prescription in
Astigmatism

90. Introduction & background
Studies show that 30-50 percent of infants less than 12 months of age have
significant astigmatism, which declines over the first few years of life,
becoming stable by approximately 2½ to 5 years of age
Large cylinders in infancy will usually emmetropise, so do not prescribe
immediately and not before one year.
About 2.00 D astigmatism is normal in infants and 1.25 D astigmatism in
toddlers and preschoolers
Main risk & challenge with astigmatism is prevention of meridional
amblyopia .

91. Contd..
The visual system may not be very sensitive to uncorrected astigmatism in the first
year of life.
From 1 year onwards, there is evidence that uncorrected astigmatism, particularly
oblique astigmatism, is associated with meridional amblyopia.
But in contrast Dobson and colleagues found no evidence of meridional amblyopia
in six‐month‐olds up to three‐year‐olds with astigmatism of 2.00 D or more.

92. Contd..
In three‐ to four‐year‐olds, 1.50 D or more of astigmatism is associated with
poorer recognition acuity, such that for every dioptre increase in cylinder,
there was a half‐line decrease in VA.
Astigmatic anisometropia (either myopic or hyperopic) had to be greater
than 1.50 D before amblyopia occurred.

93. Signs and symptoms of a child with
astigmatism
1. Blurring of vision (even with low astigmatism)
2. Habit of rubbing & squinting
3. Pts complains circle being oval shaped &
point light appears tailed off
4. Asthenopia ,tiredness , fatigue
5. Tilting of head
6. Burning & itching sensation
In regard of symptoms and severity astigmatic patients are more symptomatic..

94. Question gallery
Which type of astigmatism among two is more symptomatic?

95. Infants (0-1 yrs.)
Flowchart is according to AAO guidelines
Isometropic
astigmatism
<
3.00D
> or =
3D
No need to prescribe
(constant monitoring)
Needs prescription i.e 3/4th can
be given (*we usually prefer to
monitor in consecutive follow up)
Anisometropic
astigmatism
<
2.50D
> or =
2.50D
No need to prescribe
(constant monitoring)
Needs prescription ( AAO).
Prescribing only after monitoring
and without hampering
emmetropization

96. Flowchart is according to AAO guidelines
Isometropic
astigmatism
<
2.50D
> or
=2.50
No need to prescribe
(constant monitoring)
Needs prescription i.e 3/4th can
be given.
Anisometropic
astigmatism
<
2.00D
> or =
2.00D
No need to prescribe
(constant monitoring)
Needs prescription ( AAO).
Prescribing full if amblyopia is +ce
Partial (3/4th) if amblyopia is -ce
Toddlers (1-3)yrs.

97. Flowchart is according to AAO guidelines
Isometropic
astigmatism
<
1.50D
> or
=1.50D
No need to prescribe
(constant monitoring)
Needs full prescription(reduced
prescription can be given to
adapt initially)
Anisometropic
Astigmatism
(*above 4yrs)
1.50<
> or =
1.50D
No need to prescribe
(constant monitoring & F/U)
Needs full prescription ( AAO) if
amblyopia (+ce) & if no amblyopia
is seen initial partial can be given
later shifting to full Rx
Pre Schoolers(3-6)yrs.

98. Flowchart is according to AAO guidelines
Isometropic
astigmatism
<
0.75D
> or
=0.75
No need to prescribe
(constant monitoring)
Needs full prescription(
prescription also depends on
symptoms)
Anisometropic
Astigmatism
(*above 4yrs)
<1.50
> or =
1.50D
No need to prescribe
(constant monitoring & F/U),
(*prescription if symptomatic)
Needs full prescription ( AAO) if
amblyopia (+ce) & if no amblyopia
is seen initial partial can be given
later shifting to full Rx
Schoolers(above 6)yrs.

99. Oblique astigmatism as antagonist in normal
visual development.
Mayer and colleagues explained that oblique astigmatism of (> or =1.00
D) is rare after 12 months.
Oblique astigmatism at any age has greater chance of developing
amblyopia than regular astigmatism.
Oblique astigmatism of 1.00 D and greater must be corrected from 1 year
onwards.
Approximately ¾ correction up to the age of 2 yrs.& then correct the full
amount after then.

100. While considering deviation…….
If hyperopia is associated with Exophoria/ tropia with astigmatism then
minimum minus cylinder can be prescribed after transpose.
If myopia is associated with esodeviation and astigmatism plus cylinder
can be prescribed.

101. Summary table for power prescription in various
pediatric age group by AAO

102. Prescription in Aphakic children's
There are several reasons for which the correction of aphakia differs
between children and adults.
Child's eye is still growing during the first few years of life and during
early childhood.
 The immature visual system in young children puts them at risk of
developing amblyopia.
 So treatment and optical rehabilitation in pediatric aphakic patients
remains a challenge for optometrist.

103. Optical defects seen in Aphakia..
High induced hyperopia
Against rule astigmatism
Absence of accommodation
Astigmatism ( + 1.00 - + 3.00 D * 180 ) which is gradually decreasing
So all above problems must be properly
addressed during power prescription

104. Correction guidelines
In first few months Overcorrect by (2.00 to 3.00 D), because the child’s
world is near.
Later at about 1 yrs of life overcorrection us reduced to (+1 to + 1.50 D) to
single vision intermediate add.
After 1yrs of age or on reaching pre school period bifocal prescription can
be considered.

105. Contd..
Laurence gave a formula to predict spectacle power in aphakic
children's.
Example:- A child is (B/L) hyperopic by +2 D before surgery and
power that must be given to him after surgery is + 12 D..
F aphakic = +11.00D + ½ ( F preoperative)

106. Other considerations
Repeated refraction and follow up in 3-6 months
Aspheric lenses , lenticular design as glass option .
High index glasses can be given
Unilateral aphakia is better corrected
with contact lenses than spectacles Pseudophakics should be corrected
fully for distance as well as near with
bifocals or progressive lenses

107. Disadvantage of spectacles in Aphakics
Poor cosmesis
Decreased field of view
Reduced retinal image size
Increased ocular rotation
Demand of convergence
Ring scotoma and lens aberrations
Anisometropia exceeding 3D in
spherical error or 1.5D in cylindrical
error make glasses an improper choice.
Becoz anisometropia produces
confusion which may lead to permanent
suppression, amblyopia or anomalous
retinal correspondence and
development of concomitant
strabismus.

108. Conditions for prescribing bifocals in pediatrics..
Accommodative
Esotropia
congenital
Aphakia
Down’s
syndrome
Pseudophakic
child
Constant Esotropia
Or IET
Esophoria

109. Some articles even mentioned that prescribing bifocals in
myopic children’s will prevent myopic progression but it lacks
proper and widely accepted evidences

110. Albinism
Astigmatism in all
subtypes a/w myopia
or hyperopia
ROP High myopia
Commonly encountered condition in pediatric clinic
with type of refractive error seen in those

111. Down’s
syndrome
 Hyperopia a/w WTR
astigmatism
Nanopthalmos
High hyperopia upto
+ 20 D

112. Contd..
Sclerocornea &
Cornea plana
High hyperopia
Congenital defects
like marfan’s
syndrome ,
homocystinuria
Myopic error ( most
commonly)

113. Children’s spectacles are not always prescribed just to correct the
refractive error. Children may also require spectacles to correct
binocular vision anomalies, such as strabismus, amblyopia or
convergence problems so clinician must be very careful regarding
dispensing.
Fitting errors in a child can result in discomfort or, in severe cases, facial
disfigurement.

114. Frames for children’s:-
Ideal criteria's for pediatric frame selection:-
1. The frame must fit correctly anatomically .
2. Pupils and lenses are correctly centered.
3. The frame should be comfortable and durable.
4. Frame must not hamper the natural
development of the nose.
5. The frame must be aesthetically acceptable .

115. Characteristics of good children frame:-
Lower crest
Larger frontal angle
Large splay

116. Flatter pantoscopic tilt ( angle equals zero)
Shorter back vertex distance.

117. Contd…
Smaller angle of side
Shorter length to bend
Shorter length of drop
Smaller boxed lens size
Differing shape of lens aperture

118. Summary
The human eye undergoes dramatic anatomical and physiological
development through out infancy and early childhood
Inappropriate refractive correction will hamper child’s optical &
neural development as a result of which child will suffer life long.
Clinical experience of a clinician & his personal decision also plays
major role in power prescription.
Hence making pediatric refraction & spectacle prescription a major
part of routine pediatric examination.

119. References :-
Resource : To prescribe or not to
prescribe? Guidelines for spectacle
prescribing in infants and children.
Clin Exp Optom 2011; 94: 6: 514–527
DOI:10.1111/j.1444-0938.2011.00600.x
Susan J Leat BSc PhD FCOptom FAAO
School of Optometry, University of
Waterloo, Waterloo, Ontario, Canada
E-mail: leat@uwaterloo.ca

120. Thank
you
For ur
valuable
time
Special thanks to my dear seniors:-
Mr .Suraj chhetri
Ms. Rajani sujaku
Mr. Suraj thapa magar
Ms. Neha karn
Who guided me alot