1. Strabismus For Medical Students & GP
Samir Jamal
MD, FRCSC
KAUH

2. Strabismus
Misalignment of one or both eyes so as the eye (eyes) is not looking straight at the object of regard.

3. Significance In Children
Children need normally aligned eyes to develop vision.
Strabismus in childhood is the second most common presentation of retinoblastoma.
Strabismus is a common presentation for refractive errors.

4. Significance in Adults
Frequent sign of neurological disease
Frequent presentation of systemic disease ( Thyroid disease & Myasthenia)
Cosmetology

5. Types of Eye Movements Horizontal direction Vertical direction
Torsional direction
All superior muscles are intortors.
All inferior muscles are extortors.

6. Anatomy & Physiology Muscle Nerve Function Testing MR 3 rd Nasal
Look to nose LR
6th
Temporal
Look away SR
3rd
Elevate, intorts, adducts
Up & Out IR
Depress, extrorts, adduct
Down & Out

7. Anatomy & Physiology Muscle Nerve Function Testing Superior Oblique
4th
Intorts, depress, abducts
Look Down & In
Inferior
Oblique
3rd
Extrorts, elevates, abducts
Look Up & In

8. Types of Strabismus Esodeviation  eye turned in
Exodeviation  eye turned out
Hyperdeviation  eye turned up
Hpodeviation  eye turned down

9. Classification of Strabismus
Constant or intermittent
Latent or manifest (phoria or tropia)
Unilateral or alternating
Comitant or incomitant (restrictive or paralytic)
Paralytic or non-paralytic
Nuclear or supranuclear

10. Non-Accommodative Esotropia

11. Non-Accommodative Esotropia

12. Alternating Esotropia

13. Exotropia

15. Alternating Esotropia

17. Causes of Strabismus
Congenital: imbalance between innervations and contraction
Refractive errors
Loss of vision
Paralysis or Neuromuscular
Restrictive: thyroid eye disease
Tumors

18. Strabismus secondary to loss of vision from Cataract in Lt. eye

19. Presenting symptoms of Strabismus
Deviation of the eye (cosmesis)
Double vision
Torticollis (abnormal head posture)
Unexplained visual loss in a normal looking eye (Microtropia)

20. Abnormal Head Posture

21. Role of GP Confirm Diagnosis Decide on urgency Teach patients
Referral to Ophthalmologist

22. Management of Strabismus
History:
4 most important questions:
Age of onset
Constant or intermittent
Unilateral or alternating
Diplopia or torticollis

23. Management of Strabismus
Examination:
Three objectives:
Confirm the diagnosis
Diagnose type of strabismus
Differentiate paralysis from no paralysis

24. Examination of Strab Patient
To achieve the first and second objectives we do:
Simple observation for the nasal white of the eye
Corneal light reflex
Cover test

26. Examination of Strab Patient
To achieve the 3 rd objective we look for:
Presence of torticollis
Answer the following question:
Is the strabismus the same in all directions of gaze or not i.e. comitant or incomitant?
Same = no paralysis.
Different = paralysis or restriction.

27. Examination Test the extraocular movements in all directions of gaze.
Paralysis / restriction  Limitation
No Paralysis  No limitation

28. Doll's Head Manoeuvre
Used for testing the eye movement when the patient is uncooperative.
The eyes move in opposite direction to the head movement.

29. Common Forms of Esotropia
Congenital (No-Accommodative)  Surgery.
Accommodative  R/ Glasses.
P. Accommodative Glasses then surgery.
Sixth Nerve Palsy  observation for 6 M  surgery.

30. Accommodative Esotropia
Before Glasses
After Glasses

31. Non-Accommodative Squint
Non-Accommodative Esotropia Before and After Surgery

32. Partially Accommodative Squint

33. Common Forms of Exotropia
Congenital exotropia Surgery
Sensory deprivation exotropia
Third nerve paralysis

34. Common Causes of Hypertropia or Hypotropia
Fourth nerve palsy
Third nerve palsy
Thyroid disease
Myasthenia gravis
Orbital floor fracture