concomitant strabismus

1. CONCOMITANT
STRABISMUSSITI MARIAM BINTI MOHD HAMZAH

2. A type of manifest
squint in which the
amount of deviation in
the squinting eye
remains constant in all
directions of gaze; and
there is no associated
limitation of ocular
movements

3. ETIOLOG
Y
• Binocular vision and coordination of ocular
movements are not present since birth but are
acquired in the early childhood.
• The process starts by the age of 3-6 months and
is completed up to 5-6 years. Therefore, any
obstacle to the development of these processes
may result in concomitant squint.

4. ETIOLOG
Y
Sensory obstacles
• Refractive errors
• Prolonged use of
incorrect spectacles
• Anisometropia
• Corneal opacities
• Lenticular opacities
• Diseases of macula
• Optic atrophy
• Obstruction in the
pupillary area due to
congenital ptosis
Motor obstacles
• Congenital
abnormalities of the
shape and size of the
orbit
• Abnormalities of
extraocular muscles
• Abnormalities of
accommodation,
convergence and AC/A
ratio
Central obstacles
• Deficient development
of fusion faculty
• Abnormalities of cortical
control of ocular
movements, and
hyperexcitability of the
CNS during teething

5. 1. OCULAR DEVIATION
• Unilateral or alternating
• Inward deviation or outward deviation or vertical deviation
• Primary deviation is equal to secondary deviation
• Ocular deviation is equal in all directions of gaze
CLINICAL
FEATURES
IN GENERAL

6. 2. OCULAR MOVEMENT
• Not limited in any direction
3. REFRACTIVE ERROR
• May or may not be associated
4. SUPPRESSION AND AMBLYOPIA
• May be develop as sensory adaptation to strabismus
• Amblyopia develops in monocular strabismus only and is
responsible for poor visual acuity
5. A-V PATTERNS
• May be observed in horizontal strabismus.
• when this patterns associated, the horizontal concomitant
strabismus becomes vertically incomitant

7. V esotropia
A esotropia

8. Convergent
squint
(esotropia)
Divergent
squint
(exotropia)
Vertical
squint
(hypertropia)
TYPE
S

9. • Denotes inward deviation of one eye and is the
most common type of squint in children.
• Unilateral or alternating
COVERGENT
SQUINT

10. 1. INFANTILE ESOTROPIA
• Age of onset, usually 1-2 months, but may occur during first 6 months
of life
• Angle of deviation is constant and fairly large (>30 degree)
• Fixation pattern
• Binocular vision does not develop and there is alternate fixation in
primary gaze and cross fixation in the lateral gaze
• Amblyopia in 25-40% cases
• Treatment
• Amblyopia treatment by patching the normal eye should always be
done before performing surgery
• Recession of both medial recti is preferred over unilateral
recess-resect procedure
• Surgery should be done between 6 months – 2 years; preferably <1
year

11. 2. ACCOMMODATIVE ESOTROPIA
• Occurs due to overaction of convergence associated with accommodation reflex
• 3 types
• Refractive accommodative esotropia
• Associated with high hypermetropia (+4 to +7D)
• Fully correctable by use of spectacles
• Non-refractive accommodative esotropia
• Caused by AC/A ratio
• Esotropia is greater for near than that for distance
• Fully corrected by bifocal glasses with add +3DS for near vision
• Mixed accommodative esotropia
• Caused by combination of hypermetropia and high AC/A ratio
• Esotropia for distance is corrected by correction of hypermetropia; and
the residual esotropia for near is corrected by addition of +3DS lens

12. 3. ACQUIRED NON-ACCOMMODATIVE ESOTROPIAS
• Includes all those acquired primary esodeviations in which amount of
deviation is not affected by the state of accommodation
4. SENSORY ESOTROPIA
• Results from monocular lesions in childhood which either prevent the
development of normal binocular vision or interfere with its
maintenance
5. CONSECUTIVE ESOTROPIA
• Result from surgical overcorrection of exotropia

13. • Characterised by outward deviation of
one eye while the other eye fixates
DIVERGENT
SQUINT
Types
– Congenital exotropia
– Primary exotropia
– Secondary exotropia
– Consecutive exotropia
Rare, almost present at birth
May be unilateral or alternating
and may be intermittent or
constant exotropia
Constant unilateral deviation
which results from long-
standing monocular lesions
associated with low vision in the
affected eye
Constant unilateral exotropia
which results either due to
surgical overcorrection of
esotropia, or spontaneous
conversion of small degree
esotropia with amblyopia into
exotropia

14. EVALUATION
• History
• Examination:
- inspection
- ocular movements
- pupillary reactions
- media & fundus examination
- testing of vision & refractive
error
- cover tests (direct and alternate)
- estimation of angle of deviation
- tests for grade of binocular
vision and sensory functions
• Direct Cover Test
• confirms the presence of
manifest squint
• Alternate Cover Test
• Reveals whether the
squint is unilateral or
alternate
• Differentiates
concomitant squint from
incomitant squint
i. Hirschberg corneal
reflex test
ii. The prism and cover
test
iii. Krimsky corneal reflex
test
iv. Measurement of
deviation with
synoptophore

16. TREATMENT
• Goals of treatments:
- To achieve good cosmetic correction
- To improve visual acuity
- To maintain binocular single vision
• Treatment modalities:
- spectacles with full correction of refractive error
- occlusion therapy
- preoperative orthoptic exercises
- squint surgery
- postoperative orthoptic exercises

17. • Squint surgery
– Should always be instituted after the
correction of refractive error, treatment of
amblyopia and orthoptic exercises.
 Basic principles:
 These are to weaken the strong
muscle by recession (shifting the
insertion posteriorly) or to strengthen
the weak muscle by resection
(shortening the muscle).

19. thank you