Peadiatric ophthalmology

1. Exotropia
Dr. Aseel Al Rashdi

2. Definitions
• Exodeviation = eye turned outward
• Fovea is Temporal to the pupillary axis , LR will be nasal
Exodeviation = Divergence strabismus
Latent ( Phoria ) X Manifist (Tropia)
• Intermittent X(T)
• Constant XT

3. Pseudoexotropia ( Pseudo= false )
An appearance of exo deviation when
in fact the eyes are properly aligned
Why???
 Wide IPD
 positive angle kappa without other
ocular abnormalities
 positive angle kappa together with
other ocular abnormalities such as
temporal dragging of the macula in
ROP.

4. Exophoria X
1. Exodeviations controlled
by fusion under usual
conditions of seeing
2. detected by alternate
cover test
3. Tx usually unnecessary
4. Can progress to exotropia

5. Intermittent Exotropia X(T)
• Intermittent X(T) / Most common exotropia.
• Eliminated by fusional convergence ( Near 38PD , Distance14PD)
• Manifest with inattention , fatigue , end of the day ( loose ability to
convert ) .
• Exposure to bright light cause reflex closure of 1 eye .
• Good binocular vision , no diplopia .
• Amblyopia is rare.
• 80% progress to constant Exotropia in months to years .

6. • Phase 1 : occasional exotropia when binocular vision is lost at
distance , ortho at near .
• Phase 2 : increase exotropia at distance , occasional exophoria at
near.
• Phase 3 : constant exotropia at distance and near .
Exotropia Phases :

7. Intermittent Exotropia classificatios
Basic
exsotropia
True
divergence
excess
Pseudo-
divergence
excess
Convergence
weakness
Deviation same
at distance and
near
Deviation at
near only (CI)
or
near > distance
Divergence
distance > near
-Intially Divergence
distance > near
After 30 45 min monocular
occlusion
Near = Distance
Eg. Distance X(T) 35 PD
Near X(T) 30 PD

8. Patch Test ( monocular occlusion test ) differentiate
btw pseudo and tru divergence excess.
Step 1 ( true or pseud?):
studying tenacious proximal fusion.
Do monocular occlusion for 45 mins.
• If near PD did not change. It is TRUE DXT
• If near PCT (N) gets higher ( diffirence btw N and D > 10
PD) it is pseudo XDT.
Step 2 ( true with high AC/A ratio or true with normal AC/A
ration?):
Bilateral +3.00 lens.
if near PD gets high after +3 then it is true with high AC/A
ratio.
If near PD didn’t change, it is true WITH NORMAL
AC/Aratio.

9. Conclusion
Change in
findings ?
Monoculr
patch test ( 45
mins )
PCT (N) 20 PD
PCT ( D) 35 PD
remeasure
Yes
PCT ( N) 30PD
PCT ( D) 35 PD
PCT (N) becomes higher
Pesudo divergence
excess
No True Divergent execss
PCT ( N) same afer +3
lens
Normal AC/A ration
PCT ( N) higher after +3
lens
High AC/A ratio

10. Convergence weakness
• Convergence insufficiency ( CI) : only exodeviation at near .
• Usually older patients and complain of symptoms like asthenopia and
double vision when trying to read .
• Poor near fusional convergence amplitude .
• Tx :
• orthoptic exercise , pencil push-ups .
• Base-in reading prisms
• Surgical intervetion (MR rescess)
repeated 15 to 20 times during each session and repeated 2
to 3 times per day

11. Management of Intermittent Exotropia
1. Refractive error
• Myopia : correct fully
• Hyperopia : of > +4 D or hyperopic anisomeropia > +1.5 D
2. Add – (2-4) D lens to induce accommodative convergence .( for
some time ).
3. Patching the dominant eye / makes the divergent eye straight .
4. Alternate patching if no visual preference
5. Orthoptic treatment.
6. Prism : Base-in long term

13. Surgical management of Intermittent
Exotropia
1. Performed if intermittent X( T ) progress or progressing to consant
X(T) .
• Weakening of LR ( LR recession )
• Strengthening MR ( MR resection )
2. Botulinum toxin.

14. Constant X(T)
1. Infantile
2. Sensory
3. Consecutive
4. Decompensated intermittent X(T)

15. Infantile
• < 6 months
• Large angle constant deviation (usually > 35PD)
• Possibly associated neurological or craniofacial impairments .
• Tx :
• Amblyopia
• Refractive error
• Surgical correction ( 4m – 1 yr)

16. Sensory
• Caused by any condition that severely reduces VA in 1 eye
• Eg:
• ansometropia
• corneal/lens/retinal /optic N pathology such as :
• Retinoblastoma
• Unilateral cataract

17. Consecutive
• Formerly esotropic patient
• Either spontaneously
• after surgical overcorrection ( beyound 3-4 wks )
• After over refractive correction of esotropia ( ++ lens )
• Treatment:
◦ Correction of refractive error if present
◦ surgery(cosmetic)

18. Others : Secondary / Incomitant
 Neuromuscular (3rd nerve palsy , Mysthenia gravis )
 Restrictive
 Musculofascial innervational anomalies (Duane syndrome type 2 )
Duane syndrome
Oculomotor
nerve palsy

19. Clinical assessment
Brief History
• Presenting ocular ( onset , timing , near or distance , H/O trauma …)
• Presenting medical
• Past ocular
• Past medical
• Birth hx:
• Developmental hx: milestones
• Family hx:
• Treatment hx:

20. Clinical assessment
Examination :
AHP
VA
Light reflex LR ( Hirschberg LR test )
Steroacuity (check binocularity if possible )
EOM
CT
ACT
PCT
Patch test if needed
Cyclorefraction
Send for anterior and posterior segment examination .

21. Hirschberg Light reflex test

23. CT = LE XT
• Primary gaze
• Cover RE
• Uncover RE

24. Document the control of exotropia
• Good control : resumes fusion rapidly after removing the cover
• Fair control : resumes fusion rapidly after blinking or refixating.
• Poor control : exotropia manifest spontaneously and remain for a
while after cover removal .

25. Prism Alternate cover test
Base –In

26. ACT
Exophoria X
No Exotropia

27. EOM

28. Intermittent exotropia may be associated with
V pattern with Inferior oblique over action
A pattern with Superior oblique over action

29. Q& A
• 7 years old , RE deviated outwards intermittently, but most of the day
.
• Refraction : OD +2.5 , OS + 4 .
• Would you correct the refractive error with spectacles ?

30. Thank you ..
• Watch CT and ACT:
https://www.youtube.com/watch?v=PRa7mPx2XVs