Your SlideShare is downloading. ×
7 th sem sq1
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

7 th sem sq1

2,178
views

Published on

Published in: Health & Medicine

0 Comments
2 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
2,178
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
164
Comments
0
Likes
2
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. OCULAR MOTILITY DISORDERS DR. MANALI HAZARIKA SINGH
  • 2.  
  • 3. Visual axis [line of vision]- Passes from the fovea, through the nodal point of the eye to the point of fixation. Anatomical axis- It is a line passing from the posterior pole through the centre of the cornea . Angle kappa- Angle subtended by the visual and anatomical axes (5˚).+ve – fovea temporal to the centre  nasal corneal reflex
  • 4.
    • -Lateral & medial walls of orbit are at an angle of 45 0 to each other
    • -Orbital axis forms an angle of 23 0 with both lateral & medial walls
    • In primary position of gaze, visual axis forms an angle of 23 0 degrees with orbital axis
    • -Actions of EOM depend upon position of globe at the time of muscle contraction
  • 5. Anatomy of the extraocular muscles
    • 4 recti & 2 obliques
    • -The recti have a
    • common tendinous
    • origin called the
    • annulus of Zinn , at
    • the orbital apex
  • 6. Insertions Medial rectus [MR] – 5.5 mm behind nasal limbus Lateral rectus [LR]- 6.9 mm behind temporal limbus Superior rectus [SR]- 7.7 mm behind superior limbus Inferior rectus [IR]- 6.5 mm behind inferior limbus
  • 7. Superior oblique [SO]- - Originates from body of sphenoid, superomedial to optic foramen & runs forwards through trochlea -Inserts in the posterior upper temporal quadrant of the globe Inferior oblique [IO] – -Originates from lower & inner orbital walls near lacrimal fossa -Inserts in the posterior lower temporal quadrant of the globe
  • 8. Nerve supply – MR, SR, IR and IO - 3rd, SO - 4th LR 6th cranial nerves
  • 9. Actions of Extraocular muscles Rotation of the eye around a centre of rotation 3 types of rotations possible 1.The globe rotates left or right on the vertical axis 2.The globe moves up or down on the horizontal axis 3.Torsional movements occur around the anteroposterior axis- Intorsion and extorsion
  • 10. Superior rectus – Primary action – Elevation Secondary - Adduction & Intorsion Globe abducted 23 0 - Visual & orbital axes coincide & SR acts only as an elevator Globe adducted 67 0 degrees - Angle between visual & orbital axes is 90 0 - SR acts only as an intortor
  • 11. Inferior rectus – Primary – Depression Secondary - Adduction & Extorsion Globe is abducted 23 degrees - IR acts only as a depressor Globe adducted 67 degrees - IR acts only as an extortor Medial rectus - Adducts the globe Lateral rectus – Abducts the globe
  • 12. Superior oblique – Primary – Intorsion Secondary - Depression Abduction Globe adducted 51 0 – Visual axis coincides with line of pull of muscle - SO acts only as depressor Eye abducted 39 0 – Visual axis & SO make an angle of 90 0 degrees - SO acts only as an intortor Inferior oblique – Primary- Extorsion Secondary – Elevation Abduction
  • 13. Muscle Primary Action Subsidiary Actions Lateral rectus Abduction None Medial rectus Adduction None Superior rectus Elevation Adduction, Intorsion Inferior rectus Depression Adduction, Extorsion Superior oblique Intorsion Depression, Abduction Inferior oblique Extorsion Elevation, Abduction
  • 14. Ocular movements Field of action – Direction of gaze in which the muscle exerts its greatest contraction force as an agonist eg. LR in abduction MR in adduction
  • 15. Ductions – Monocular eye movements Adduction, abduction, elevation, depression, intorsion & extorsion Versions- Binocular, simultaneous, conjugate movements [in the same direction] Vergences - Binocular, simultaneous movement of two eyes in opposite directions Movements - Convergence & divergence
  • 16. Ocular movements
  • 17. Positions of gaze- 6 cardinal and 9 diagnostic Dextroversion Primary position RE LE Laevoversion Dextroelevation Laevoelevation Elevation Depression Dextrodepression Laevodepression
  • 18. Agonists – Primary muscle, moving the eye in a given direction eg. LR in abduction Antagonists – Muscles of the same eye that move the eye in opposite directions eg. RLR to RMR Synergists – Muscles of the same eye that move the eye in the same direction eg. RSR & RIO in elevation of right eye
  • 19. Yoke muscles – Pairs of muscles, one in each eye, that produce conjugate ocular movements eg. Yoke muscle of RLR is LMR for right gaze Contralateral antagonists- A pair of muscles [one from each eye], having opposite action eg. RLR & LLR, RMR & LMR
  • 20. Laws of ocular motility Sherrington law of reciprocal innervation- This states that during ocular motility, increased innervation to a contracting extraocular muscle is accompanied by a reciprocal decrease in innervation to its antagonist Applies for both ductions and versions For example, during adduction, when MR contracts, LR automatically relaxes
  • 21. Laws of ocular motility Herring law of equal innervation- This states that during movement of both eyes in the same direction, equal and simultaneous innervation flows to a pair of yoke muscles For example, RLR & LMR receive equal innervation for right gaze
  • 22. Binocular single vision [BSV]- Perception of a single image Synaptophore – To assess BSV Grade I- Simultaneous perception Ability to see 2 dissimilar objects simultaneously Grade II- Fusion. Ability to superimpose 2 incomplete but similar images to form one complete image Grade III- Stereopsis Ability for depth perception .
  • 23. Corresponding points- Areas on each retina that share same subjective visual direction Eg. the foveae Points on nasal retina have corresponding points on temporal retina of the other eye
  • 24. Strabismus Normally, the visual axes of two eyes remain parallel to each other in all directions of gaze, except when they converge for near vision Strabismus or squint may be defined as a misalignment of the visual axes of the two eyes, that is, it is a condition in which the visual axes of the two eyes are not directed simultaneously to the same fixation point
  • 25.
    • HISTORY
    • AGE OF ONSET
    • SYMPTOMS
    • VARIABILITY
    • GENERAL HEALTH
    • BIRTH HISTORY
    • FAMILY HISTORY
    • PREV. OCULAR HISTORY
  • 26.
    • VISUAL ACUITY
    • CYCLOPLEGIC REFRACTION & FUNDUS
    • HP, EOM
    • DETAILS OF DEVIATION
    • TESTS FOR BINOCULARITY
    • FORCED DUCTION TEST (IF MOVTS ARE RESTRICTED)
  • 27.  
  • 28.  
  • 29.
    • DIRECTION – EXO,ESO,HYPER,HYPO,INCYCLO,EXCYCLO
    • FREQ- LATENT,MANIFEST,INTERMITTENT
    • MAGNITUDE- FOR DISTANCE & NEAR , WITH/WO GLASSES
    • COMITANCY –COMITANT/INCOMITANT
    • LATERALITY-UNI,ALTERNATING
    • ACCOMODATIVE CONVERGENCE/ACCOMO-LOW/N/HIGH
  • 30.  
  • 31.
    • Cover test: tropia
    • Uncover test: phoria
    • Alternate cover test: tropia + phoria
  • 32.  
  • 33.  
  • 34.
    • WORTH 4-DOT TEST
  • 35.  
  • 36.
    • TESTS FOR STEREOPSIS
  • 37.  
  • 38.  

×