Strabismus and palsies - not my own ppt

1. Nadia Northway

2.  Deviation varies with size and or direction of
gaze
 In truth nearly all forms of strabismus are
incomitant to a degree but clinically there is
usually more than 5o difference before
incomitancy is noted.

3. C la s s if ic a t io n
C o n g e n it a l
N e u r o g e n ic M e c h a n ic a l
T h ir d n e r v e p a ls y B r o w n 's S y n d r o m e
F o u rth n e r v e p a ls y D u a n e 's S y n d r o m e
S ix t h n e r v e p la s y

4. C la s s if ic a t io n
A c q u ir e d
A d u lt s a n d c h ild h o o d
N e u r o g e n ic M e c h a n ic a l M y o g e n ic
T h ir d n e r v e p a ls y B r o w n 's S y n d r o m e D y s t h y ro id E y e d is e a s e
F o u rt h n e r v e p a ls y D u a n e 's S y n d r o m e M y a s th e n ia G r a v is
S ix t h n e r v e p la s y R a re

5.  Vascular affects all nerves equally
 Head trauma more commonly affects IVth
nerve but may affect all
 Aneurysm most commonly affects IIIrd nerve
 Neoplasm
 Unknown
 Other

6.  Diabetes
 Thyrotoxicosis
 Hypertension
 Aneurysm
 Giant cell arteritis
 Multiple Sclerosis
 Myasthenia Gravis

7.  History and symptoms
 External Examination
 Cover test
 Motility
 Ophthalmoscopy
 Fields

8.  Diplopia
 Abnormal head posture-chin, turn and tilt
 Acuity
 Associated symptoms
 General health
 Injury

9.  Strabismus
 Lid position
 Injury- chemosis, oedema
 Proptosis
 Pupils
 Asymmetry

10.  Always turn in direction of action of palsied
muscle e.g. LMR palsy will turn to right
 Always move chin in direction of action of
palsied muscle e.g. LSR palsy will elevate chin
 Always tilt to lower eye

11.  Small deviation in primary position may
indicate very recent onset < 36 hours or
mechanical problem
 In palsy- will be greater when fixing with the
affected eye and usually larger size of
deviation

12.  Know muscle actions
 Take patients eyes into extremes of gaze
 Use objective and subjective assessment-
corneal reflexes and CT. Do not rely on pt
reporting diplopia since suppression or poor
VA may affect results.
 Hess chart and diplopia chart.

13.  RAD SIN- recti adduct and superiors intort
 Recti muscles pull the eye in the direction of
their name in the abducted position
 Obliques push the eye in the direction
opposite to their name in the adducted
position

14.  Original palsy
 Overaction of the contralateral synergist
 Overaction of the ipsilateral antagonist
 Inhibitional palsy
 This applies to neurogenic palsy and
after all stages of sequelae have occurred
concomitancy is achieved

15. IO IO
SR SR
MR
LR
LR
IR SO SO

16.  Overaction of contralateral synergist only
 Left Brown’s syndrome overaction of right
superior rectus is seen

17.  Look for smallest field to identify affected eye
 Look at center circle to determine deviation in
primary position
 Look for area with greatest deflection to
identify affected muscles

18.  Used to differentiate between SR and SO palsy
 Muscle sequelae identical
 In left SO palsy deviation will increase when
head tilted to left due to unopposed action of
the LIO

21.  Complete or partial
 Rare to find individual muscles affected but
Congenital SR palsy quite common
 May also be multiple muscle involvement
including pupil and ciliary body

23.  Hypotropia of affected eye and may be
slightly exo
 Chin elevation
 Can be longstanding -usually have enlarged
fusion range and some suppression

24.  Hypertropia in primary position

25.  Hypotropia in primary position with possible
slight eso.

26.  Exo deviation

28.  Exotropia with hypotropia, ptosis and
possible dilation of pupil and accommodation
palsy

31.  Esotropia which is greater on distance
fixation

33.  Hypertropia with slight eso , eye also
extorted, greater at near

39.  Small devation in primary position but
hypotropia of affected eye on elevation in
adduction

41.  May be hypotrpia or hypertropia
 Infraorbital anaesthesia
 Chemosis
 Vertical diplopia
 Restricted eye movement in upgaze and
downgaze

44.  Wet phase when muscles swell -myogenic
 Dry phase when eye movement restrictions
become mechanical in characteristics
 Muscles affected - IR MR SR rarely LR
 Proptosis or exophthalmos
 Check Fields
 Lid retraction and lid lag

46.  Mechanical  Neurogenic
 Small deviation in pp  Large deviation in pp
 Ductions and  Ductions better than
versions equal versions
 Ceasing of  Gradual failure of
movement abrupt movement
 Pain  No pain
 Reversal of diplopia  No upshoots and
 Upshoots and downshoots
downshoots

47. Differentiation of mechanical and
neurogenic palsy
• Mechanical • Neurogenic
• Muscle sequelae- only • Full muscle sequelae
overaction of contra • Smoother filed on
syn Hess
• Hess chart -pointed
field which look
squashed

48.  Newly acquired
 Longstanding  Pt aware of AHP and
 AHP - fixed and pt uncomfortable
usually unaware  Diplopia
 No diplopia  Sudden onset
 Enlarged fusion  No enlarged fusion
ranges range
 Old photographs
 Gradual onset of
symptoms usually
 Amblyopia
 Suppression

49. Differentiate SR and SO palsy
• SO • SR
• Eso deviation more typical • Exo deviation more
• AHP - chin depression typical
• V eso pattern • AHP- chin elevation
• Greater vertical deviation • V exo pattern
at near • Greater deviation in
• Bielchowsky +ve distance
• Diplopia greatest on • Bielchowsky -ve
depression • May have history of ptosis
• Diplopia greatest on
elevation

51.  Sudden onset diplopia
 Incomitant deviation previously unidentified
 Uncomfortable head posture
 Patient has localisation disturbance
 Patient symptomatic
 Other signs and symptoms