Strabismus For Medical Students GP Samir Jamal MD

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

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

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

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

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

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

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

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

Classification of Strabismus l l l 9 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

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

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

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

Abnormal Head Posture 20

Role of GP 21 1. Confirm Diagnosis 2. Decide on urgency 3. Teach patients 4. Referral to Ophthalmologist

Management of Strabismus History: 4 most important questions: 1. 2. 3. 4. 22 Age of onset Constant or intermittent Unilateral or alternating Diplopia or torticollis

Management of Strabismus Examination: Three objectives: 1. Confirm the diagnosis 23 2. Diagnose type of strabismus 3. Differentiate paralysis from no paralysis

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. 24 Cover test

25

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? Ø Same = no paralysis. Ø Different = paralysis or restriction. 26

Examination Ø Test the extraocular movements in all directions of gaze. Paralysis / restriction Limitation Ø No Paralysis No limitation 3. 27

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

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

Accommodative Esotropia Before Glasses 30 After Glasses

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

Partially Accommodative Squint 32

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

Common Causes of Hypertropia or Hypotropia 34 1. Fourth nerve palsy 2. Third nerve palsy 3. Thyroid disease 4. Myasthenia gravis 5. Orbital floor fracture