9. MUSCLE ORIGIN INSERTION NERVE SUPPLY ACTION
SUPERIOR TARSAL
/MULLER’S MUSCLE
UNDERSURFACE OF
LPS
SUPERIOR TARSAL
PLATE OF UPPER
EYELID
POSTGANGLIONIC
SYMPATHETIC FIBRES
OF SUPERIOR
CERVICAL
SYMPATHETIC
GANGLION
ELEVATION OF
UPPER EYELID
INFERIOR TARSAL CAPSULOPALPEBRAL
FASCIA
INFERIOR TARSAL
PLATE
POSTGANGLIONIC
SYMPATHETIC FIBRES
OF SUPERIOR
CERVICAL
SYMPATHETIC
GANGLION
LOWER LID
RETRACTION
ORBITALIS MUSCLE
(VESTIGISL MUSCLE)
CROSSES INFERIOR
ORBITAL FISSURE &
SPHENOMAXILLARY
FISSURE
UNITES WITH
PERIOSTEUM OF
ORBIT
POSTGANGLIONIC
SYMPATHETIC FIBRES
OF SUPERIOR
CERVICAL
SYMPATHETIC
GANGLION
FORWARD
PROTRUSION OF
EYEBALL
10.
11.
12.
13. • OCULAR MOTILITY
• A Uniocular movements are called ‘ductions’ and
• 1. Adduction.
• 2. Abduction
• 3. Supraduction.
• 4. Infraduction.
• 5. Incycloduction
• 6. Excycloduction
14.
15. • B Binocular movements.
• versions and vergences.
• Versions (conjugate movements)
1.Dextroversion
2.Levoversion
3.Supraversion
4.Infraversion
5.Dextrocycloversion
6.Levocycloversion
16.
17. • Vergences (dysconjugate movement)
• 1. Convergence
• 2. Divergence
• 1.Synergists-Two muscles that moves the eye in the same direction ( Elevation
by SR & IO )
• 2.Antagonists-Muscles having opposite action in the same eye (MR & LR )
• 3.Yoke muscles-Contralateral synergists ,
-pair of muscles (one from each eye) which contract
simultaneously during version movements
-Rt. LR & Lt. MR (for dextroversion)
• 4.Contralateral antagonists-Muscle whose contraction moves a part of the body
directly
-Abduction by Rt. Eye LR
18. A equal and simultaneous innervation flows from the
brain to a pair of yoke muscles which contracts
simultaneously in different binocular movements
Ex: RLR and LMR during dextroversion
Hering’s law of equal innervation
19. An increased flow of innervation to the contracting agonist muscle is
accompanied by a decreased flow of innervation to the relaxing antagonist
muscle.
During levoversion, an increased innervational flow to the RMR and LLR,
accompanied by decreased flow of innervation to RLR and LMR
Sherrington’s law of reciprocal innervation
20. • When a normal individual fixes on an object of
regard, the image is formed on the fovea of both
the eyes separately; but the individual perceives a
single image.
• This state is called binocular single vision.
Binocular single Vision
21. Grade I — Simultaneous perception. Ability to see two dissimilar objects
simultaneously.
Grade II—Fusion. It consists of the power to superimpose two
incomplete but similar images to form one complete image.
Grade III— Stereopsis : Depth perception.
Grades of binocular single vision
22. • Straight eyes (motor mechanism)
• Clear vision in both eyes (Sensory
mechanism)
• Ability of visual cortex to promote BSV
(Central mechanism)
Prerequisites of development of BSV
23. • Advantage of BSV
• Enlargement of field of vision
• Depth perception
• Combined binocular visual acuity is better than
uniocular VA.
24. • Anomalies of binocular vision
• Suppression
• Amblyopia
• Suppression
• It is a temporary active cortical inhibition of the
image of an object formed on the retina of the
squinting eye.
25. AMBLYOPIA: DEFINITION
• Amblyopia refers to partial loss of vision in
one or both eyes, in the absence of any
detectable organic cause.
Understanding Amblyopia
26. AMBLYOPIA: SIGNIFICANCE
• 2%–4% of population affected
• Commonly unilateral
• Bilateral amblyopia (rare) may mean permanently decreased visual
acuity
Understanding Amblyopia
27. Amblyogenic factors include :
Visual (form sense) deprivation as occurs in
anisometropia,
Light deprivation e.g., due to congenital cataract,
Abnormal binocular interaction e.g., in strabismus.
28. SCREENING: IMPORTANCE
• Amblyopia is usually preventable or treatable
• Early detection is key to effective treatment
• Life-threatening disorders may present as
amblyopia
• Screening responsibility rests with primary
care physician
Understanding Amblyopia
30. • Diagnosis
1. Reduced VA
2. Effect of neutral density filter.
3. Crowding phenomenon
4. Fixation pattern
5. Colour vision unaffected
31. • Treatment
Treatment of underlying cause followed by:
1. Occlusion therapy
2. Atropine Penalization
3. Drugs like levodopa.
32. EARLY DETECTION: IMPORTANCE
• Visual function develops early in life
• Treatment depends on plasticity of visual
system
• Treatment less likely to be effective as
children age increases
Understanding Amblyopia
43. NORMAL INFANT VISION
• Good visual function
• Fixate and follow with each eye
• Steady fixation
Preventing Amblyopia
44. REFERRAL: IMMEDIATE
• Poor red reflex in one or both eyes
• Concern about visual function by parent or doctor
• Asymmetric or diminishing visual acuity
• Constant or acute-onset strabismus
Preventing Amblyopia
47. • Improves visual acuity
• Does not eliminate strabismus
Preventing Amblyopia
OCCLUSION THERAPY: PURPOSE
48. OCCLUSION THERAPY:
PRECAUTIONS 1
• Monitor visual acuity carefully at close intervals
• Ensure vision is not being reduced in non-patched eye
(“occlusion amblyopia”)
Preventing Amblyopia
49. Part-time occlusion may suffice
Ensure parents understand purpose of patching and importance of
compliance
Follow child’s visual status into the teen years
• Preventing Amblyopia
OCCLUSION THERAPY:
PRECAUTIONS 2
50. ATROPINE PENALIZATION THERAPY
Atropine ointment or drops in non-amblyopic eye at
prescribed levels
Atropinized eye cannot accommodate for near vision
Child can still use better-seeing eye for distance
Child switches fixation at near to amblyopic eye
Preventing Amblyopia
51. Monitor VA carefully.
Ensure near VA in amblyopic eye
can support near tasks
Allergic reactions are rare (<1%)
Systemic side effects are
uncommon and minimal
Preventing Amblyopia
ATROPINE THERAPY: PRECAUTIONS
Warn parents that one eye will
have a “fixed and dilated pupil.”
52. STRABISMUS
• Normally, visual axis of Lhe two eyes are parallel to each other in the
'primary position ofgaze' and this alignment is maintained in all positions
ofgaze.
• A misalignment o f the visual axes of the two eyes is called squint or
strabismus.
54. What is the difference between tropia and
phoria?
• In tropia, the eyes are deviated all the time.
• In phoria, eye deviations are present only some of the time;
usually under conditions of stress/ illness/ fatigue/ interruption
of binocular vision.
55. "PSEUDOSTRABISMUS
• This is nothing but an optical illusion caused by
prominent epicanthal folds/ wide interpupillary
distances (IPD).
• It is of 2 types:
1.Pseudo-esotropia/ Apparent convergent squint.
2.Pseudo-exotropia/ Apparent divergent squint.
57. LATENT STRABISMUS/
HETEROPHORIA
• It is defined as a condition in which there is a tendency
to misalignment of the visual axis, which is corrected
by the fusional capacity; therefore, when the influence
of fusion is removed, the visual axis of one eye
deviates away (by covering one eye).
• Orthophoria is a condition of perfect alignment of the
two eyes which is maintained even after the removal
of influence of fusion.
58.
59.
60. ETIOLOGY OF HETEROPHORIA:
A. Anatomical Factors
1.Orbital asymmetry.
2.Abnormal IPD
3.Wide IPD: Exophoria.
4.Small IPD: Esophoria.
5.Extraocular muscles:Faulty insertion,Mild weakness,Abnormal
innervation
6.Anatomical variation in the position of macula in relation to optical axis
of the eye.
61. B. Physiological factors
• Age:
1.Old age: Exophoria.
2.Younger age: Esophoria.
• Role of accommodation and convergence:
1.Increased accommodation and excessive use of convergence: Esophoria.
2.Decreased accommodation and decreased use of convergence: Exophoria.
• Dissociation factor: Prolonged constant use of one eye may result in
exophoria (as in case of persons working with uniocular microscope/
magnifying glass).
62. SYMPTOMS OF HETEROPHORIA
• Depending upon the symptoms, heterophoria can be divided into
compensated and decompensated heterophoria.
• In compensated heterophoria, no subjective symptoms are
present.
• In decompensated heterophoria, the symptoms which will be
present are:
63.
64. TREATMENT OF A HETEROPHORIA
CASE
1.Correction of refractive error.
2.Orthoptic exercises.
3.Prescription of prism in glasses.
4.Surgical treatment.
65. ORTHOPTIC EXERCISE
• Orthoptics aims to strengthen the eye muscles to
correct common eye problems such as convergence
insufficiency.
• It includes:
1.Barrel cards.
2.Brock string.
3.Stereograms etc.
66. WHAT IS A MANIFEST/ TRUE
STRABISMUS?
• In apparent strabismus/ heterophoria, the alignment of
the eyes is maintained by continuing efforts of fusion
and it becomes manifest only when the fusional
capacity is withdrawn (by covering one eye in "Cover
test
• On the other hand, when the maintenance of
alignment of the eyes becomes impossible by means
of fusional capacity alone, a true/ manifest strabismus
develops.
68. COMITANT STRABISMUS
• It is a type of manifest strabismus in which the amount
of deviation in the squinting eye remains constant in all
the directions of gaze and there is no associated
limitation in ocular movement.
• 2 common types of comitant squint are:
1.Esotropia (convergent squint),
2.Exotropia (divergent squint)
73. SENSORY ESOTROPIA
• It occurs due to monocular lesions that prevents the development of
binocular vision/ maintenance of it.
• Ex.
• Cataract, Aphakia, Anisometropia,
• Severe congenital ptosis,
• Retinoblastoma etc
[* Note that in Retinoblastoma, strabismus is the second most common
manifestation after leukocoria.]
77. CONGENITAL EXOTROPIA
• It is rare.
• It almost always presents at birth.
• It presents with a fairly large angle of squint
• It is usually alternating in character with no amblyopia
(partial loss of sight in one/ both eves in the absence
of any marked ophthalmoscopic signs).
80. SECONDARY EXOTROPIA
• It is an unilateral constant exotropia resulting from long
standing monocular lesions in adults.
• Common causes are
• Traumatic cataract,
• Corneal opacity,
• Retinal detachments,
• •Macular lesions etc.
81. CONSECUTIVE EXOTROPIA
• It is an uniocular constant exotropia resulting from:
1.Surgical overcorrection of esotropia,
2.Spontaneous conversion of (small degree of esotropia
+ amblyopia) into exotropia.
82. TREATMENT OF COMITANT STRABISMUS
Goals of treatment:
• To achieve good cosmetic correction
• To improve visual acuity.
• To maintain binocular single vision.
Treatment modalities:
• Full correction of refractive error.
• Occlusion therapy: It is indicated in the presence of amblyopia. After
correction of refractive error, the normal eye is occluded and the squinting
eye is advised to be used
• Orthoptic exercises
• Squint surgery.
83. INCOMITANT STRABISMUS
• It is a type of manifest squint in which the amount of
deviation varies in different directions of gaze.
87. SYMPTOMS OF PARALYTIC
SQUINT
1.Diplopia: It occurs due to formation of image on
disparate points of the retina of two eyes.
2.Confusion.
3.Nausea and vertigo.
4.Ocular deviation.
88. SIGNS OF PARALYTIC SQUINT
1. Primary deviation:
• It is deviation of the affected eye and is away from the
action of paralyzed muscles.
• Ex.: If Lateral rectus is paralyzed, the eye is
• converged because action of L is abduction.
89. 2. Secondary deviation:
• It is the deviation of the normal eye seen undercover, when the
patient is made to fix with the squinting eye.
• It is greater than primary deviation.
3. Restriction of ocular movements:
• It occurs in the direction of the action of paralyzed muscles.
4. Compensatory head posture:
• Head is turned towards the action of paralyzed muscle as an attempt
to avoid diplopia and confusion.
90. 5. False projection:
• •It is due to increased innervation impulse conveyed to the paralyzed
muscle.
• Demonstration of false projection:
• Ask the patient to close the sound eye.
• Ask the patient to fix an object placed on the side of the paralyzed
muscle.
• Patient will locate it further away in the same
• direction.
• For example, a patient with RL paralysis will point towards more right
than where the object actually is.
91. CLINICAL VARIETIES OF OCULAR
PALSIES
• Isolated muscle paralysis
• LR and SO are the most common muscles to be
paralyzed singly as they have separate nerve supply.
92. PARALYSIS OF 3RD CRANIAL
NERVE
• Clinical features are:
1. Ptosis (due to paralysis of Levator Palpebrae
Superioris muscle).
2. Eyeball is turned downwards, outwards and slightly intorted (due to
actions of LR and SO).
3. Ocular movements are restricted in all directions except outwards.
4. Pupil is fixed and dilated (due to paralysis of sphincter pupillae
muscle).
5. Accommodation is completely lost (due to paralysis of ciliary
muscle.
93.
94. TOTAL OPHTHALMOPLEGIA
• In this condition, all extraocular and intraocular
muscles are paralyzed.
• It results from combined paralysis of 3rd, 4th and 6th
cranial nerve.
• It is a common feature of cavernous sinus thrombosis
and orbital apex syndrome.
95.
96. EXTERNAL OPHTHALMOPLEGIA
• In this condition, all
extraocular muscles are
paralyzed (sparing
intraocular muscles).
• It results from lesion at
the level of motor nuclei
sparing the Edinger-
Westphal Nucleus.
97. RESTRICTIVE SQUINT
• In restrictive squint, the extraocular muscle involved is
not paralyzed but its movement is mechanically
restricted.
• It is characterized by a smaller amount of ocular
deviation and a positive Forced Duction
Test (see next presentation).
98. MANAGEMENT
• Treatment of the cause
• Conservative measures-vit b complex,systemic steroids
• Treatment of diplopia
• Chemodenervation of the C/L muscle with botulinium
toxin
• Surgical treatment-resection of the paralyzed
muscle,recession of the overacting muscle and
transplantation of the normal muscle tendon at or near
the insertion of paralysed muscle
99.
100. A AND V PATTERN
HETEROTROPIAS
• * AXDID/ VSDID:
• A Exotropia/ V esotropia denotes that deviation will
increase in downward gaze.
