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 diseaseFrequent presentation of systemic

disease ( Thyroid disease & Myasthenia)Cosmetology

5

Types of Eye Movements

Horizontal directionVertical directionTorsional direction

All superior muscles are intortors.

All inferior muscles are extortors.

6

Anatomy & Physiology

MuscleNerveFunctionTesting

MR3 rdNasalLook to nose

LR6thTemporalLook away

SR3rdElevate, intorts, adducts

Up & Out

IR3 rdDepress, extrorts, adduct

Down & Out

7

Anatomy & Physiology

MuscleNerveFunctionTesting

Superior Oblique

4thIntorts, depress, abducts

Look Down & In

Inferior

Oblique

3rdExtrorts, 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

Non-Accommodative Esotropia

10

Non-Accommodative Esotropia

11

Alternating Esotropia

12

Exotropia

13

14

Alternating Esotropia

15

16

17

Causes of Strabismus

Congenital: imbalance between innervations and contraction

Refractive errorsLoss of visionParalysis or NeuromuscularRestrictive: 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 visionTorticollis (abnormal head posture)Unexplained visual loss in a normal

looking eye (Microtropia)

20

Abnormal Head Posture

21

Role of GP

1. Confirm Diagnosis

2. Decide on urgency

3. Teach patients

4. Referral to Ophthalmologist

22

Management of Strabismus

History:

4 most important questions:

1. Age of onset

2. Constant or intermittent

3. Unilateral or alternating

4. Diplopia or torticollis

23

Management of Strabismus

Examination:Three objectives:1. Confirm the diagnosis

2. Diagnose type of strabismus

3. Differentiate paralysis from no paralysis

24

Examination of Strab Patient

To achieve the first and second objectives we do:

1. Simple observation for the nasal white of the eye

2. Corneal light reflex

3. Cover test

25

26

Examination of Strab Patient

To achieve the 3 rd objective we look for:

1. Presence of torticollis

2. 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

3. 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.

Accommodative Esotropia

Before Glasses After Glasses

30

Non-Accommodative Squint

Non-Accommodative Esotropia Before and After Surgery

31

Partially Accommodative Squint

32

33

Common Forms of Exotropia

Congenital exotropia Surgery

Sensory deprivation exotropia

Third nerve paralysis

34

Common Causes of Hypertropia or Hypotropia

1. Fourth nerve palsy

2. Third nerve palsy

3. Thyroid disease

4. Myasthenia gravis

5. Orbital floor fracture