comitant strabismus

1. PART ONE
Philosophies and Principles
of Binocular Vision Therapy
Ashkan Amirabadi
MSc.student of Optometry and Visual Science
Faculty of Rehabilitation
Departement Of Optometry and Visual science
Iran University Medical science

2. 2
Historical Context
• Strabismus has been a focus of treatment since ancient times due to
its visual and cosmetic implications.
• Historical remedies included:
• Ancient Egyptians: Ointments made from tortoise brain and
spices.
• Classical Greeks: Physical conditioning to relieve eyestrain.
• Medieval Europe: Hats with colored tassels to ward off the “evil
eye.”
• 16th Century: Squint masks aimed to provide visual feedback
and encourage eye alignment.

3. 3
Javal and the French School
•Louis Emile Javal (1839-1907): Recognized as the “father of orthoptics,” he
revolutionized the understanding of strabismus treatment through careful patient
observation and innovative exercises.
• Developed sensory and motor fusion exercises as alternatives to surgery.
• His techniques included:
• Equalizing vision with spectacles.
• Addressing amblyopia through occlusion.
• Using stereoscopes for antisuppression training.
• Javal’s philosophy emphasized the importance of mental effort in achieving
successful treatment outcomes, which laid the groundwork for modern
orthoptic practices.

4. 4
Worth and the English School
• Claud Worth (1869-1936) advanced the understanding that poor sensory
fusion is a primary cause of strabismus.
• Advocated for early detection and treatment, emphasizing the
importance of training the fusion faculty before the age of six.
• Introduced the amblyoscope for fusion training, reinforcing the idea
that a strong desire for binocular vision could be cultivated through
training.
• Worth’s philosophy acknowledged the possibility of genetic factors
influencing binocular vision, resonating with contemporary
understandings of developmental anomalies.

5. 5
The Amalgamation of Approaches
•The integration of French and English philosophies led to a more holistic approach to strabismus
treatment.
•Ernest Maddox (1863-1933) further synthesized surgical and orthoptic methods, establishing one of the
first orthoptic clinics.
•Modern orthoptics continues to be practiced across English-speaking countries, emphasizing both surgical
and nonsurgical treatment pathways.
Optometric Vision Therapy
•The early 20th century saw optometrists focusing on clarity of eyesight, which evolved to include the
analysis and management of binocular anomalies.
•Charles Sheard developed a vision examination that aligned with historical insights from Javal and Worth.
•Modern optometric vision therapy addresses a range of binocular dysfunctions, with a focus on enhancing
visual efficiency in daily activities.
•A significant percentage of patients (approximately 1 in 7) exhibit signs of deficient binocular vision, which
may lead to discomfort and task avoidance.

6. PART TWO
Types of comitant strabismus
Convergent squint {esoteopia}
Divergent squint (exotropia)
Vertical squint [hypertropia]

7. Convergent squint / Comitant esotropia
• Inward deviation of one eye
• Most common in children
• Can be unilateral or alternating (other eye takes up fixation)
• Clinico-etiological types
• Infantile
• Accomodative
• Essential acquired
• Other onset non accomodative
• Sensory
• Consecutive

8. Infantile esotropia
• Onset – 2 to 4 months
• Usually alternate
• Angle of deviation is constant and fairly large (>35°)
• Binocular vision doesn’t develop and there is alternate fixation in
primary gaze and cross fixation in lateral gaze
• Amblyopia in 25% to 40%
• Associations like inferior oblique overaction, dissociated vertical
deviation
• Surgery is the treatment of choice – Amblyopia : patch normal eye
Recession of both medial recti, done between 6 months to 2
years

10. Accomodative esotropia
• Most common in children
• Around 2 to 3 years
• Pathogenesis
• If due to some reason excessive accomodation is
required to focus at the near object; there will be
associated excessive convergence as well causing
accomodative esotropia
• Types
• Refractive
• Non refractive
• Mixed

11. Refractive accomodative esotropia
• Pathogenesis
• It is associated with high hypermetropia (+4 to
+7D). Esotropia develops due to associated
excessive convergence.
• Clinical features
• Age of onset: 2-3 years
• AC/A ratio is normal
• Esotropia is both for near as well as distance,
may be slightly more for near than distance; and
is fully correctable by the use of spectacles
• Treatment
• Full correction of hypermetropia, after
cycloplegic refraction is the treatment of choice

12. Non refractive
• Pathogenesis
• In this condition AC/A ratio is abnormally high.
• Clinical features include:
• Age of onset is 2-3 years
• AC/A ratio is abnormally high
• Refractive error, may or may not be present.
• Esotropia is typically greater for near than distance (minimal or no
deviation for distance)
• Treatment consists of decreasing the demand for accommodation by:
• Bifocal glasses with +3D add for near vision, corrects the esotropia
• Miotics facilitate accommodation by contracting ciliary muscles and this
reduce the associated accommodative convergence

13. Mixed
Pathogenesis.
It occurs partially due to
hypermetropia and
partially there in non-
accommodative element.
Clinical features include:
• Age of onset: 2-3 years
• Hypermetropia is present
• AC/A ratio is usually
normal
• Esotropia is both for near
and distance.
Treatment consists of:

14. Other acquired non-accomodative
esotropia
This group includes all those acquired primary esodeviations
in which amount of deviation is not affected by the state of
accommodation. It includes:
• Acute concomitant esotropia,
• Cyclic esotropia,
• Nystagmus blockage syndrome,
• Esotropia in myopia and microtropia.

15. • Sensory esotropia
• It results from monocular lesions (in childhood)
which either prevent the development of normal
binocular vision or interfere with its maintenance.
Examples of such lesions are:cataract, severe
congenital ptosis, aphakia, anisometropia,optic
atrophy, retinoblastoma, central chorioretinits, and
so on.
• Consecutive esotropia
• It results from surgical overcorrection of exotropia.

16. Divergent squint (Exotropia)
• It is characterized by outward deviation of one eye while
other eye fixates. It’s clinico-etiological types are
1. Congenital
2. Primary
3. Sensory
4. Consecutive

17. Congenital exotropia
• Age of onset. It is rare usually present at birth and
almostalways presents before six months of age.
• Occular deviation. It is characterised by a fairly large and
constant angle of squint, usually alternate with
homonymous fixation in lateral gaze.
• Amblyopia is seen in a minority of cases (from 0 to 25%).
• Both DVD and IOOA may be associated with infantile
exotropia.

18. Primary exotropia
• It may be unilateral or alternating and may
present as intermittent or constant
exotropia.
• Intermittent exotropia. It is the most
common type of exodeviation with following
features:
• Age of onset is usually early between 2 to 5
years.
• Deviation becomes manifest at times and
latent at others. Precipitating factors include
bright light, fatigue, ill health and day
dreaming.

19. • Constant exotropia.
• If not treated in time the intermittent exotropia may
decompensate to become constant exotropia
• Types. Primary exotropia may be of following three types:
• Convergence insufficiency type of exotropia is greater fornear
than distance,
• Divergence excess type of exotropia is greater for
distancethan near, or
• Basic non-specific type exotropia is equal for near anddistance

21. Sensory exotropia
It is a constant unilateral deviation which results from
longstanding monocular lesions (in adults), associated with
low vision in the affected eye.
Common causes include: traumatic cataract, corneal
opacity,optic atrophy, anisometropic amblyopia, retinal
detachment and organic macular lesions.
Consecutive exotropia
• It is a constant unilateral exotropia which results either due
to surgical overcorrection of esotropia, or rarely due to
spontaneous conversion of small degree esotropia with
amblyopia into exotropia.

22. 22
Principles of Vision Therapy
1.
Sequence of Therapy:
1. Correct significant refractive errors before addressing motor deficits.
2. Initiate amblyopia treatment before binocular techniques.
3. Monitor the development of normal retinal correspondence (NRC) before moving on to
training.
2.
Antisuppression Techniques:
1. Essential for re-establishing sensory and motor fusion.
2. Techniques include establishing both physiologic and pathologic diplopia.
3.
Fusional Vergence Training:
1. Aimed at expanding the range and quality of fusional vergence responses.
2. Various training methods include:
1. Sliding Vergence: Continuous disparities to improve vergence ranges.
2. Jump Vergence: Alternating fixation between two targets to enhance speed and s
3. Isometric Training: Using stationary demands to strengthen muscle responses.

23. 23
1.
Home vs. Office Training:
1. The severity of the condition dictates the required training environment.
2. Home training coupled with regular office visits enhances compliance and
effectiveness.
2.
Patient Motivation:
1. Building rapport with patients, especially children, is vital for successful
outcomes.
2. Effective communication and the use of rewards can enhance engagement
in therapy.
3.
Monitoring Progress:
1. Continuous feedback is essential for maintaining motivation and adapting
techniques.
2. Regular assessments of training techniques help identify areas needing
adjustment.
4.
Retainer Home Training:
1. Implementing periodic home exercises helps prevent regression of
learned skills.

24. Selecting visual aids
Enhancing your presentation

25. Speaking impact
25
Your ability to communicate
effectively will leave a lasting impact
on your audience
Effectively communicating involves
not only delivering a message but
also resonating with the
experiences, values, and emotions
of those listening

26. 26
Dynamic delivery
Learn to infuse energy
into your delivery to
leave a lasting
impression
One of the goals of
effective communication
is to motivate your
audience
Metric Measurement
Targe
t
Actua
l
Audience
attendance
# of attendees 150 120
Engagement
duration
Minutes 60 75
Q&A interaction # of questions 10 15
Positive feedback Percentage (%) 90 95
Rate of information
retention
Percentage (%) 80 85

27. 27
Final tips & takeaways
• Consistent rehearsal
• Strengthen your familiarity
• Refine delivery style
• Pacing, tone, and emphasis
• Timing and transitions
• Aim for seamless, professional delivery
• Practice audience
• Enlist colleagues to listen & provide feedback
Seek feedback
Reflect on performance
Explore new techniques
Set personal goals
Iterate and adapt

28. 28
Speaking engagement metrics
Impact factor Measurement Target Achieved
Audience interaction Percentage (%) 85 88
Knowledge retention Percentage (%) 75 80
Post-presentation surveys Average rating 4.2 4.5
Referral rate Percentage (%) 10 12
Collaboration opportunities # of opportunities 8 10

29. Thank
you
Brita Tamm
502-555-0152
brita@firstupconsultants.com
www.firstupconsultants.com