Management strategy and Treatment Options of a pediatric patient Reference by: Visual development, diagnosis and treatment of the pediatric patient, 2nd edition by Pamela H. Schnell, Marc B. Taub and Robert H. Duckman

1. Unit IV:
Management Strategy and
Treatment Options
Dr. Rheza Marisse B. Tabasuares
Instructor

2. Management Strategy and Treatment Options
4.1 The General Treatment Strategy
4.2 Lens Therapy
4.3 Prism Therapy
4.4 Occlusion Therapy
4.5 Active Vision Therapy
4.6 Pharmacological Therapy
4.7 Surgical Therapy

3. 4.3 PRISM THERAPY
➢ Patients present with varying degrees of
strabismus.
➢ Diagnostically, strabismus may be termed as
intermittent if the eyes are aligned part of the time or
over a part of space.
➢ Fusion may be possible in a particular direction of
gaze or over a limited range of distances.
➢ Strabismus may emerge as a result of a
decompensated paretic muscle or for a variety of
medical reasons.
➢ As long as the brain had a prior history of fusing two
images into a single solid perspective, prisms may be
employed as a means of helping the patient with
intermittent strabismus to restabilize fusion.

4. ● Compensating prism may be considered in
cases of strabismus when the patient is
experiencing diplopia.
● Yoked prism can be useful for individuals with
hemi-field loss. In addition, the use of yoked
prism has been effective in enhancing self-
organization and orientation of individuals in
response to environmental–spatial demands, as
well as body posture and gaze control.

5. ● More specifically, they have been found to
improve both nonvisual and visual–motor task
performance, such as ball catching, in individuals
with autism.
● Yoked prism use has also been shown to reduce
some characteristic symptoms in these
individuals.The effect of wearing yoked prism is to
deflect peripheral light rays, shifting space in a way
that dramatically alters the patient’s view of the
external world, which forces them to reorganize
visual processes in order to achieve homeostasis.
● While initially remarkable, the effect of yoked prism
may fade with time if the individual does not have the
opportunity to integrate and to organize the
perceptual changes that occur when wearing the
prism.

6. A. Temporary application of prism:
➢ Temporary prism is readily provided with Fresnel
press-on prisms. They adhere to the lens via static and
can be cut at the proper orientation to fit the back surface
of the lens, trimmed to just inside the frame.
➢ In the event of a transient strabismus, apply the
temporary prism unilaterally to the deviating eye in order
to avoid reducing image quality OU. Depending on eye
preference and the prism strength required, Fresnel prism
may not be tolerated as a unilateral temporary solution. In
such cases, ground-in prism may be needed, or both
Fresnel and ground-in prism can be applied in
combination.
➢ There are limits to the amount of base-in prism that
can be ground into an ophthalmic lens without interfering
with the nose. In such cases, again, a combination of
ground-in prism and Fresnel prism may be the best
solution.
The following strategies may be applied to enhance binocular
performance in patients with strabismus:

7. B. Prism for vertical deviation:
1. It is helpful to begin with an assessment of the diagnostic action fields
(DAF) in order to identify whether there is a particular area in which the
deviation is greatest/smallest. Note that findings may differ depending on
which eye is fixating.
2. Observe the presence of a head tilt or turn. Prism may be used to shift the
images of both eyes toward the preferred field. This alleviates some of the
negative side effects of maintaining an AHP over time.
3. Use trial prism to determine the least amount of prism power that helps the
patient to recover binocularity in free space. Repeat for intermediate and
near distances and different directions of gaze.
4. In the event of a depression deficit, use free-space testing at near in
downgaze to apply sufficient base-down prism to the eye with the depression
deficit. This may be applied unilaterally or asymmetrically.
5. Be sure to educate the patient if a different amount of prism is needed for
distance fusion compared to near-point fusion. Sectoral application of
Fresnel prism can be applied over a near-point add if necessary.

8. C. Prism for lateral deviation:
1. Horizontal prism may be added to a prescription if
it facilitates fusion and/or vergence ranges.
2. Some medical issues respond well to the temporary
application of lateral prism, including denervation of
the lateral rectus (e.g., with diabetes) and transient
impacts of proptosis and orbital changes (e.g.,
Graves disease). In such cases, temporary
Fresnel prism may be sufficient.
3. Temporary prism may also be applied and
decreased in power over time, functioning like
training wheels, providing less and less external
support over time while neuromuscular
redistribution takes place.

9. D. Noncompensatory applications of prism:
1. Patients with dissociated vertical deviation (DVD)
show a tendency for both eyes to drift upward. These
patients often find relief with the application of yoked
base-down prism. Generally, they do not tolerate base-
up prism, so it is better not to try to split vertical prism in
these patients.
2. The spatial impact of low-power prisms (also referred
to as mini-prism) may have multiple positive effects.
Prisms transform the path of light, not only via lateral
displacement, but also with a net rotational change of
the incoming light. At low prism powers (e.g., ½∆, 1∆,
1.5∆), the lateral displacement is small enough to go
unnoticed for most patients who can make equivalent
vergence changes with ease. In particular, low base-in
prism creates a subtle horizontal image expansion.

10. 3. When provided OU, low base-in prism has been
demonstrated to:
- improve tracking abilities when reading
- reducing the perceived letter crowding common in
strabismic amblyopia and other functional vision
disorders.
4. Aniseikonic lens designs, such as the Shaw
lens, may also be used to reduce lens-induced
image disparities while providing refractive
compensation.

11. Shaw Lens is different….
https://www.youtube.com/watch?v=_idIDPBVegM&t=59s

12. A six-year-old girl had an eye exam several weeks prior, but her father was
concerned that she was still moving her body instead of her eyes while writing.
The patient’s medical history included ADHD and autism. She uses both
Focalin (dexmethylphenidate, Novartis) and guanfacine. She was born on time
and has been meeting all developmental milestones but is mildly delayed. She
is not currently reading and receives speech and occupational therapy several
times per week. Her father described her as “very clumsy” and said she bumps
into things a lot at home.
Case Study
Clinical Findings:
NVA OD 20/15 OS 20/15 OU 20/15
Stereo: 20 secs of arc
Phoria: Orthophoria at distance and near
Retinoscopy +0.50 -0.50x090 OU.
MEM response through plano was +0.50 with fluctuations.
Through +0.50, the response was plano with fewer fluctuations.
Gross eye movement demonstrated significant issues on both pursuits and saccades, showing
significant body overflow and head movement. When we were able to get her to sit down, the
patient was fidgety in the chair, and she was jumpy otherwise.

13. Management
We decided to trial 2.00D of base-up yoked prism. Interacting
with the hanging Marsden ball, the patient’s attention was
more focused with the yoked prism and she was better able to
catch the ball. Her father commented that he had never seen
his daughter so focused and with such good hand-eye
coordination.
We prescribed +0.25D of sphere with the 2.00D of base-up
yoked prism OU and initiated a course of vision therapy
focusing on eye and body movements. The patient is currently
on her 10th session and progressing wonderfully.
https://www.reviewofoptometry.com/article/make-way-for-yoked-prism

14. ● Passive treatment
● Occlusion of the sound eye is the most effective treatment for
amblyopia treatment by forcing the patient to use the amblyopic
eye.
● Mainstay of treatment since 18th century to till now.
● Highly effective until 8yo.
● Causes progressive changes in visual functioning.
● Success rate 30-92%
○ When fixation is central: simple & effective
○ When fixation is eccentric: <7 yo central fixation recover
○ The older the child, the harder to regain central fixation
4.4 Occlusion Therapy

15. Designed to improve visual performance
by the patient’s conscious involvement in
a sequence of a specific, controlled visual
task that provide feedback
1. Pleoptics
2. Near Activities
3. Active stimulation therapy using CAM
vision stimulator
4. Syntonic phototherapy
5. Role of perceptual learning
6. Binocular stimulation
7. Software-based active treatments
These therapies are briefly described with
occlusion therapy in detail.
The patient experiences a change in
visual stimulation without any conscious
effort.
1. Proper refractive correction
2. Occlusion
3. Penalization
4. Pharmacological manipulation
Passive Therapy Active Therapy

16. Prevent fixating eye taking part in act of vision and removes inhibitory stimulus
that arises form stimulation from fixating eye (non-amblyopic eye)
Goals
1. Differential diagnosis
2. Improvement of amblyopia
3. Elimination of suppression
4. Awareness or elimination of diplopia
5. Disruption of AC
Mode of Action

17. Types of Occlusion
Total or partial Conventional or Inverse Full time or Part time
TOTAL PARTIAL (LIGHT TRANSMISSION)
All light is prevented from entering the eye Doesn’t cut off the total light entering the
eye
Employed in amblyopic eyes with VA
<6/24
Degrades the vision of normal eye such
that amblyopic eye gets better vision and
preference
Occlusion using elastoplast, gauze pad,
tape,doynes rubber occluder
Occlusion using cellophane, transparent
nail polish, or a higher plus lens

18. Partial / translucent occlusion
Given in nystagmus
Total Occlusion
Amblyopia treatment

19. Conventional or Direct Inverse
● Occlusion of the sound eye
● Foveal or unsteady eccentric fixation
is present in amblyopic eye
● Occlusion of amblyopic eye so that
eccentric fixation becomes less fixed.
● Steady eccentric fixation
● Inverse occlusion is prescribed
whenever occlusion is needed but
direct occlusion is intolerable to the
patient.
● Given only if the patient is strongly
resistant to direct occlusion.
● Inverse occlusion is started first to
introduce the hesitant patient to a
patching regime.
Example:
A strabismus patient with deep amblyopia
may not be able to perform needed visual
tasks with amblyopic eye.
So 1st inverse occlusion is started &
changed to direct occlusion once more
central fixation and improved visual acuity
are obtained.

20. PART TIME (INTERMITTENT)
● Short time each day during
close work commonly (1-6
hrs/day)
● In relapses after Rx and also
for maintenance
● Given for intermittent
strabismus or non strabismic
amblyopes
FULL TIME
● Removed only while going to
bed at night (all waking
hours)
● Choice of initial RX
● Given for constant strabismic
amblyopes. (regardless of
size of deviation)
FULL TIME VS PART TIME

21. Some exceptions. . .
● CXT patients who change quickly to an intermittent strabismus with
therapy, instead of full-time occlusion may need only part time occlusion
or even no occlusion.
● Some strabismic amblyopes with dysfunctional BV may need minimal to
no occlusion esp when amblyopia is treated actively with simultaneous
improvement of sensorimotor processing. (Cohen 1981; Pickwell 1976)
● Intermittent strabismus or heterophoric patients with symptoms due to
inefficient BV may need full time occlusion rather part time to allay
binocular symptoms until BSV is improved. After recovery of symptoms,
patching schedule is changed to part time.
● In infants & toddlers <2 yo, due to greatest plasticity in neural processing
system to prevent occlusion amblyopia, maximum 2 hrs/day is given &
passive lens, prism therapy is given together with active therapy.

22. Occlusion in Intermittent Strabismus
➢ Time of occlusion depends on patient’s level of sensorimotor skills.
➢ SInce constant occlusion may break down binocular skills only part time occlusion is
recommended.
➢ When not wearing patch patient’s existing binocular skills can be reinforced through
passive therapy & sensory anomalies such as suppression can be eliminated when
wearing patch.
➢ In intermittent strabismus, part time occlusion eliminate central or foveal suppression
and treat shallow amblyopia eye after binocularity is achieved.
➢ Nonstrabismic anisometropes or intermittent strabismics with deep amblyopia requires
most hours of part time general occlusion
➢ Intermittent strabismics with good peripheral sensorimotor fusion and shallow or no
amblyopia requires least hours of part time general occlusion.

23. Occlusion in Constant strabismus
➢ Earlier, full time occlusion followed by a day of rest was
advocated. This allows constant strabismus to regress to
anomalous strabismus visual processing on free day.
➢ Nowadays, full time occlusion is prescribed initially. When
intermittency is achieved in open space, part-time occlusion is
given allowing some reinforcement of binocular skills in normal
activities.

24. Points on Occlusion
❖ The presence (or absence) of amblyopia and its fixation pattern determine
which eye to patch.
❖ The frequency of strabismus determines the amount of time that the eye is
patched
Alternate occlusion
❖ When equal visual is present in each eye, (e.g. :- a constant alternate
esotropia), full time occlusion is alternated daily between two eyes.
❖ The purpose of full time occlusion for strabismics with no amblyopia is to
eliminate suppression and possibly disrupt anomalous correspondence.

25. Types of occluders
➢ Adhesive skin patches - made of
microscope (best method)
➢ Commercially available opticlude
➢ Spectacle occluder - patched eye
remains visible to observer, diffuse
light enters occluded eye from
unblocked sides around the frame.
Child may look from top of glasses.
Good cosmesis.
➢ Contact lens occluder - Opaque
center on contact lens, total blockage
of form and light, good cosmesis
➢ Bandage occluder - Total blockage of
form and light, difficult to remove,
greater chances of occlusion
amblyopia, poor cosmesis

26. ➢ Tie-on occluder
○ Easily removed or flipped up
○ No skin problems as bandage
➢ Clip-on occluder
○ Attached to spectacle lens
○ Diffuse light enters as in spectacle
occluders
➢ Occlusion filters for the treatment of suppression
and amblyopia
○ Decrease both light and form transmission
○ Neutral density or red filters are placed before
normal eye and are increased in density until
fixation is forced to non preferred eye
➢ Occlusion lens - form recognition is reduced by
lens induced optical blur a/k/a penalized lens or
fogging lens

27. Field coverage
➢ Depends on how much of the visual field to block
➢ Either the visual stimulation is blocked to whole visual
field (total occlusion) or just specific portions of the visual
field (partial occlusion) (d/t presence and frequency of
strabismus in a specific gaze or distance)
➢ Other consideration is whether to cover both peripheral
and the central retina or just the central retina of the
deviating eye.

28. Field Coverage Occluders
Terminology Indication Visual Field Coverage
Total Constant strabismus at all distances and
gazes
Full field
Half-patch Constant strabismus at one distance and
intermittent or heterophoria at other.
Distance or near field
Sector patches Incomitant strabismus. (intermittent in one
field of gaze and constant in other)
● BSV remain in nonaffected and
nonoccluded field
● Anomalous sensory processing can
be disrupted or diplopia can be
eliminated in affected field
● Achieve goal of binocular therapy
sequence
Selected gazes

29. ● Bipatches block the visual stimulation to a specific retinal region of
nonfixating eye which under unoccluded conditions would receive
anomalous visual stimulation d/t turning of eye.
● Both trigger alternation in viewing to amblyopic eye, leading to
improved visual acuity or elimination of foveal suppression.
● Both are alternate to total occlusion.
● Bitemporal occlusion disturb panoramic vision. So, not much
favoured.
Terminology Indication Visual field coverage
Binasal Constant Esotropia Nasal Fields (temporal retina)
Bitemporal Constant Exotopia Temporal fields (nasal retina)

31. A simplified schedule for initial occlusion therapy for amblyopia
Age of patient
(in yrs)
Period of occlusion (days)
Direct vs Inverse
Follow up after every
Up to 2 2 : 1 15 days
3 3 : 1 15 days
4 4 : 1 1 month
5 5 : 1 1 month
6 or older 6 : 1 1 month

32. How to go about Occlusion
1. Compliance is the key. Motivation of child and parents is necessary. First the near vision
then distance starts improving.
2. Active vision exercises by amblyopic eye has developed equal vision and equal preference
of fixation.
3. May take 3-6 months
4. If there is no improvement, on three consecutive monthly follow-ups then treatment is
stopped, reevaluation is advised.
5. Incomplete response to occlusion tends to be associated with anisohypermetropia &
anisoastigmatism.
6. Follow-up depending on age, severity of amblyopia and compliance
7. To look for VA, fixation pattern and occlusion amblyopia
8. WHen to stop occlusion
a. VA equals in both eyes
b. Alternation of fiction (Repka 2008)
9. When VA is stable, patching may be decreased slowly.
10. Because amblyopia recurs is large number of points, maintenance therapy or tapering of
therapy should be strongly considered.

33. Disadvantages of Occlusion
1. Occlusion amblyopia
2. Psychological distress
3. Allergic skin rash
4. Cosmetically unacceptable
5. Strabismic diplopia
6. Deviation changes
https://www.slideshare.net/AayushChandan2/amblyopia-classification-occlusion-therapy-141098270

34. General Treatment Sequences for Accommodative and Nonstrabismic
Binocular Vision Anomalies
Occlusion - commonly used treatment option in the management of
strabismus and its associated associated conditions:
1. Amblyopia
2. Eccentric fixation
3. Suppression
4. Anomalous correspondence
There are also instances in which occlusion is necessary in the treatment of
patients with heterophoria, and it must be included as part of the sequential
considerations in the management of nonstrabismic binocular anomalies.
Occlusion

35. Occlusion
Occlusion - used when heterophoria is associated with
anisometropic amblyopia.
The length of occlusion is important in anisometropic
amblyopia.
Recommendations are based on randomized studies:
1. 2 hours of patching per day along with 1 hour per day of
near visual activities for moderate amblyopia (20/30 to
20/80)
2. 6 hours per day with 1 hour per day of near visual
activities for severe amblyopia (20/100 or worse)
Scheiman, Mitchell; Wick, Bruce. Clinical Management of Binocular Vision (pp.
97-98). Wolters Kluwer Health. Kindle Edition.

36. Occlusion-Based Treatment (Without Active Vision Therapy)
➢ Reasons for poor image fusion may include asymmetries in image quality due
to either refractive or organic dissimilarities.
➢ Difficulties in fine-motor control (as with hypotonia) may also thwart binocular
fusion. In such situations, patients may learn to posture their eyes
strabismically in order to remove the image conflict.
➢ Occlusion methods may be offered to provide an alternative means of
reducing image conflict over areas of space.
➢ The following occlusion strategies may be applied in order to enhance
binocular performance in patients with strabismus:

37. ➢ Occlusion - proposed as a nonsurgical treatment for young
children with intermittent exotropia.
➢ Part-time occlusion - sometimes prescribed in young children
until vision therapy is feasible, or to delay potential surgery.
The reported potential benefits of patching include:
○ preservation of binocularity
○ reduction in the frequency and/or magnitude of the exodeviation.
➢ In a recent PEDIG study, the authors reported that deterioration
of intermittent exotropia over a 6-month period was uncommon
among children 12 to 35 months of age with previously untreated
intermittent exotropia. The rate of deterioration 6 months after
randomization was 2.2% for the patching group, and 4.6% for
the observation group overall, or 2.3% for cases that met motor
deterioration criteria, making it unlikely that part-time patching
provides a meaningful short-term benefit for young children with
intermittent exotropia.

38. ➢ In another PEDIG study of older children with
intermittent exotropia, they evaluated the effectiveness
of prescribing 3 hours of daily patching compared with
observation alone for reducing the risk of deterioration
of intermittent exotropia in previously untreated 3 to
<11-year-old children.
➢ The rate of deterioration at 6 months post-
randomization was low in both groups—only 0.6% in
the patching group and 6.1% in the observation group
deteriorated. Thus, deterioration of previously
untreated childhood intermittent exotropia over a 6-
month period is uncommon with or without patching
treatment.

39. Regional occlusion
Another type of occlusion that should be considered in heterophoria.
This is particularly useful when a strabismus is present at one distance or one
direction of gaze, while a heterophoria exists at other distances or positions of
gaze.
Example:
Patient with a 25 Δ constant right XT at distance and a 5 Δ XP at near.
Treatment:
Occlusion of the upper portion of the lens of the right eye, with the lower
portion of the lens clear.
**This setup permits reinforcement of binocularity at near, while preventing
suppression and other adaptations at distance.

40. 1. Binasal occlusion
➢ Binasal (or uninasal) occlusion is a highly effective
means of reducing the angle of strabismus in a
variety of postures for the same basic reason: it
masks the area over which both eyes provide
conflicting image information.
➢ By masking the nasal visual fields, binasal occluders
reduce the visibility of the binocular visual field. Each
eye has ipsilateral access to its temporal visual field.
The binocular field is reduced to a narrowed strip,
reducing the visual field area over which there is a
perceived conflict.
Fig 24.7, the preferred OD is
masked more than OS

41. ➢ With binasals, each eye can offer novel information,
but neither eye can provide visual input on the full
field. This encourages the two eyes to team up
and to orient forward for the most consistent
acquisition of visual information when walking.
➢ In order to encourage flexibility in fixation preference,
binasal occlusion thickness can be applied
asymmetrically. Alternating thickness application at
subsequent visits can help to disembed head posture
adaptations and increase visual exploration as eye-
teaming develops.
Fig 24.7, the preferred OD is
masked more than OS

42. ➢ Binasals encourage the use of an
amblyopic and/or esotropic eye in its
temporal field.
➢ Binasals can reduce the fusion demand
in exotropia, providing a benefit to having
both eyes orient toward primary gaze and
fuse the two images along the midline.
➢ Binasals disrupt the suppression tendency
in hypertropia, providing an incentive for the
eyes to level and to generate a uniform
horizon across the midline.
Reach and grasp to encourage
movement. Note the change in
binasal placement relative to the
photo above.
https://www.youtube.com/watc
h?v=nUpBd31JEuc

43. Reach and grasp to encourage
movement. Note the change in
binasal placement relative to the
photo above.
https://www.youtube.com/watc
h?v=nUpBd31JEuc
➢ In a novel study of the impact of binasals on
patients with traumatic brain injury (TBI),
binasal occlusion was shown to improve
the amplitude on visually evoked
potential (VEP) testing, with a presumed
mechanism of alleviating the need for
suppression over an area of visual motion
sensitivity.
➢ A similar mechanism would reduce the need
for suppression with visual confusion or
visual–spatial processing dysfunction.

44. 2. Spot occlusion
1. In patients whose conflict arises from an organic
difference in image quality, spot occlusion may
offer a means of dampening the central/distorted
image while enabling access to the peripheral
orienting information from both eyes.
2. Spot occlusion is particularly helpful in cases
where medically induced differences in image
quality disrupt the preferred eye.

45. Applying Occlusion
1. Occlusion can be created by applying a small piece of
translucent tape, a piece of a Bangerter foil, or clear nail polish,
stippling it with the brush and adding a second coat for a
smoother surface that remains optically irregular.
2. Binasal occlusion thickness recommendations vary. It is
important to recognize that the spectacle plane rests in front of
the eye. From that location, setting the occlusion as a narrow
strip, covering only to the medial canthus, is often sufficient,
while still allowing a fusible binocular zone. A slightly wider
placement is sometimes suggested over the preferred eye and
may help to switch a dominance pattern for young children.

46. 3. Applying nasal occlusion temporal to the nasal iris limbus
is less well-tolerated. Once the occlusion is placed, assess
the placement by observing the patient’s tracking patterns
as they follow a target across midline.
4. In patients with strabismus, adjust the location of the
occluders to help the patient switch fixation within 5 to 10
degrees of midline, whether tracking left-to-right or right-to-
left.

48. TUESDAY = 50 - point Quiz
COVERAGE:
Unit 4.1 General Treatment Strategy
Unit 4.2 Lens Therapy
Unit 4.3 Prism Therapy
Unit 4.4 Occlusion Therapy