DR. MANALI HAZARIKA SINGH
Incomitant squints
Variation in the amount of deviation in different directions of gaze.
Differences Incomitant squint Comitant squint
1. Age of onset Usually late Early childhood
2. Type of onset Sudden Gradual
3. Magnitude of squint
Varies with eye position
Same in all positions
4. Diplopia Present Absent
5. Headposture Abnormal Normal
6. Sensory adaptations *
Rare Frequent
7. Past pointing/ false projection
Present Absent
8. EOM Restricted Full
9.Secondary deviation
More than primary Equal to primary
Incomitant strabismus
Paralytic - Neurogenic, Myogenic, NMJ
Restrictive – Duane’s , Brown’s syndrome, Dysthyroid ophthalmopathy, Blow out fracture with incarceration of EOM.
Paralytic strabismus etiology I. Neurogenic lesions 1. Congenital hypoplasia or absence of nucleus:
third and sixth cranial nerve palsies. 2. Inflammatory lesions: encephalitis,meningitis,
neurosyphilis,peripheral neuritis (viral),infectious lesions of cavernous sinus and orbit.
3. Neoplastic lesions. 4. Vascular lesions:HTN, DM and atherosclerosis. haemorrhage, thrombosis, embolism, aneurysms or vascular occlusions.
Paralytic strabismus etiology 5. Traumatic lesions: head injury 6. Toxic lesions:carbon monoxide
poisoning, effects of diphtheria toxins (rarely),alcoholic and lead neuropathy.
7. Demyelinating lesions:multiple sclerosis II. Myogenic lesions 1. Congenital lesions. These include
absence, hypoplasia, malinsertion, weakness and
musculofacial anomalies. 2. Traumatic lesions.
Paralytic strabismus etiology
3. Inflammatory lesions: Myositis (viral) , influenza, measles.
4. Myopathies:These include thyroid myopathy,carcinomatous myopathy,Progressive external ophthalmoplegia
III. Neuromuscular junction lesion It includes myasthenia gravis.
Paralytic strabismus
SYMPTOMS:
1.LIMITATION OF OCULAR MOVEMENTS
2.SUDDEN ONSET OCULAR DEVIATION3.DIPLOPIA4.CONFUSION5.NAUSEA , VERTIGO
Diplopia
DIPLOPIA-A)Uncrossed diplopia with an esotropia.B)Crossed diplopia with an exotropia.
Paralytic strabismus
SIGNS: Limitation of movement in the field
of action of the muscle Difference in primary and secondary
deviations Compensatory HP False projection
FALSE PROJECTION
OBJECT IS PROJECTED TOO FAR IN THE DIRECTION OF ACTION OF THE PARALYSED MUSCLE.
DUE TO INCREASE OF SECONDARY DEVIATION , THE OBJECT IS PROJECTED ACCORDING TO THE NERVOUS ENERGY EXERTED
Stages- SPREAD OF COMITANCE
Paresis of the particular muscle (LSO) Overaction of antagonist of same eye (LIO) Overaction of contralateral yoke
muscle(RIR) Secondary inhibitional palsy of antagonist of
the yoke muscle (RSR)
Pathological sequelae of the right lateral rectus muscle paralysis.
Clinical types of ocular palsies
1. Isolated muscle paralysis LR and superior oblique are the
most common muscles to be paralysed singly, as they have separate nerve supply.
Isolated paralysis of the remaining four muscles is less common, except in congenital lesions.
Clinical types of ocular palsies
2. 3rd nerve paralysis
Ptosis Eyeball is down, out and
slightly intorted Ocular movements are
restricted in all the directions except outward.
Pupil is fixed and dilated Accommodation is lost Crossed diplopia is elicited
on raising the eyelid.
Clinical types of ocular palsies 3. Double elevator
palsy. congenital caused by third
nerve nuclear lesion. characterised by
paresis of the superior rectus and the inferior oblique muscle of the involved eye.
Clinical types of ocular palsies
4. Total ophthalmoplegia
extraocular muscles including LPS and intraocular muscles,
viz., sphincter pupillae, and ciliary muscle
are paralysed third, fourth and sixth
cranial nerves. orbital apex syndrome and cavernous sinus thrmb
Clinical types of ocular palsies 5. External ophthalmoplegia. In
this condition, all extraocular muscles are paralysed,
sparing the intraocular muscles. It results from lesions at the level of
motor nuclei sparing the Edinger-Westphal
nucleus
Investigations
Diplopia charting Hess charting Forced duction test Force generation test
DIPLOPIA CHARTING
AREAS OF SINGLE VN AND DIPLOPIA DIST. BETWN THE TWO IMAGES IN
AREAS OF DIPLOPIA WHETHER THE IMAGES ARE AT THE
SAME LEVEL OR NOT WHETHER THE DIPLOPIA IS
HOMONYMOUS OR CROSSED
Diplopia chart of a patient with right lateral rectus palsy.
HESS SCREEN
DIFF. PARETIC FROM RESTRICTIVE RECENT ONSET PARESIS FROM LONG STANDING
Hess chart
Forced duction test
Investigations to find out the cause of paralysis orbital ultrasonography, orbital and skull computerised
tomography scanning and neurological investigations.
TREATMENT TREAT THE CAUSE WAIT N WATCH – 6MTHS – B
COMPLEX , SYSTEMIC STEROIDS TREAT DIPLOPIA- OCCLUDER ON THE
AFFECTED EYE WITH INTERMITTENT USE OF BOTH EYES TO AVOID SUPPRESSION AMBLYOPIA
SURGERY-STRENGTHENING OF THE PARALYSED MUSCLE - RESECTION; WEAKENING OF THE OVERACTING MUSCLE - RECESSION.
Restrictive strabismus
Duane’s retraction syndrome Superior oblique sheath syndrome
(Brown syndrome) Blow-out fractures – incarceration of
muscle Strabismus fixus, Dysthyroid ophthalmopathy
Duane’s retraction syndrome (DRS)
On attempted adduction there is retraction of globe : co-contraction of both MR and LR (narrowing of palpebral fissure)
On attempted abduction, the palpebral fissure opens
DUANE’S
• FAILURE OF INNERVATION OF LR BY 6TH N 3rd N.
• Type I LIMITED ABDUCTION, NORMAL ADDUCTION, PRIMARY POSITION- N
• Type II LIMITED ADDUCTION , NORMAL ABDUCTION
• Type III LIMITED ADDUC AND ABDUC
Brown syndrome
Superior oblique sheath syndrome A tight superior oblique sheath:
congenital or acquired Restriction of elevation in
adduction Positive forced duction test
Strabismus fixus
Bilateral fixation in convergent position due to fibrous tightening of the medial recti
The cornea was completely hidden in the right eye and only 2 mm of the superotemporal cornea was detectable in the left eye
BLOW OUT FRACTURE
SYNKINESES
Involuntary movement of muscles or limbs accompanying a voluntary movement.
Nystagmus
DEFN: Regular , rhythmic, to and fro involuntary oscillatory movements of the eyes.
ETIO: Disturbance of factors responsible for maintaining normal ocular posture-sensory visual pathway, vestibular apparatus,semicircular canals,midbrain, cerebellum
Features of nystagmus
Pendular/Jerk Rotatory/Horizontal/ Vertical Rapid/slow Latent/Manifest
TYPES OF NYSTAGMUS
1.PHYSIOLOGICAL NYSTAGMUS
A) OPTOKINETIC NYSTAGMUS B) END POINT NYSTAGMUS C) VESTIBULAR NYSTAGMUS
2. Pathological Sensory deprivation
Horizontal and pendular Central vision impairment in <2yr age *
Motor imbalance /neurologic diseases Congenital nystagmus / manifest nystagmus Latent nystagmus (congenital esotropia) Vestibular nystagmus Upbeat nystagmus Downbeat nystagmus See saw nystagmus of Maddox Convergence- retraction nystagmus Periodic alternating nystagmus Gaze evoked nystagmus Miner’s nystagmus
THANK YOU
Alphabet patterns : A-V
V pattern: difference in deviation in the upgaze and downgaze of >15 prism dioptres
A pattern: difference in deviation in the upgaze and downgaze of >10 PD
CAUSES
IOOA SO UNDERACTION SR UNDERACTION BROWN SYNDROME CRANIOFACIAL ANOMALIES
A PATTERN
CAUSES SOOA IO UNDERACTION IR UNDERACTION
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