SQUINT - Dr. Ajay Dudani, Mumbai Retina Centre. DEFINITION Squint is a disorder in which one eye...
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Transcript of SQUINT - Dr. Ajay Dudani, Mumbai Retina Centre. DEFINITION Squint is a disorder in which one eye...
SQUINTSQUINT
-Dr. Ajay Dudani,Dr. Ajay Dudani,
Mumbai Retina CentreMumbai Retina Centre
DEFINITIONDEFINITION
Squint is a disorder in which one eye misaligns Squint is a disorder in which one eye misaligns with the other when focusing in a primary with the other when focusing in a primary direction of gaze. It is an imbalance in the direction of gaze. It is an imbalance in the normal tone or coordination of one or more normal tone or coordination of one or more extra ocular muscle which results in a manifest extra ocular muscle which results in a manifest deviation of the affected eye. deviation of the affected eye.
EXTRAOCULAR MUSCLESEXTRAOCULAR MUSCLES
CARDINAL GAZESCARDINAL GAZES
CLASSIFICATIONCLASSIFICATION
1. Direction of deviation:1. Direction of deviation: - convergent (esotropia)- convergent (esotropia) - divergent (exotropia) - divergent (exotropia) - hypodeviation- hypodeviation - hyperdeviation- hyperdeviation
2. Comitancy:2. Comitancy: - comitant or non paralytic- comitant or non paralytic - incomitant or paralytic- incomitant or paralytic
3. Constancy:3. Constancy: - intermittent- intermittent - constant- constant
4. Onset:4. Onset: - childhood (congenital)- childhood (congenital) - adult (acquired)- adult (acquired)
5. Unilateral or Alternating5. Unilateral or Alternating
6. Apparent (psuedostrabismus)6. Apparent (psuedostrabismus)
Manifest (tropias)Manifest (tropias)
Latent (phorias)Latent (phorias)
PSEUDOSTRABISMUSPSEUDOSTRABISMUS
Pseudoesotropia- in Pseudoesotropia- in prominent epicanthal prominent epicanthal folds, high myopiafolds, high myopia
Pseudoexotropia- in Pseudoexotropia- in hypertelorismhypertelorism
ETIOLOGYETIOLOGY
1.1. High Refractive errors - High Refractive errors - High degree of High degree of uncorrected refractive uncorrected refractive error in children may error in children may cause deviation of the cause deviation of the most affected eye.most affected eye.
2.2. Ocular conditions- Ocular conditions- causing visual axis causing visual axis obstruction eg. cataract, obstruction eg. cataract, corneal opacities, corneal opacities, retinoblastoma, ROP, retinoblastoma, ROP, macular disease etc.macular disease etc.
3. Trauma3. Trauma
4. Lesions affecting the 4. Lesions affecting the EOM’s or CN’s EOM’s or CN’s especially no. III especially no. III
5. Systemic dis- DM, 5. Systemic dis- DM, stroke, botulism stroke, botulism
PREDISPOSING FACTORSPREDISPOSING FACTORS
General debility and lowered vitalityGeneral debility and lowered vitality Psychosis, neurosis and mental stressPsychosis, neurosis and mental stress Inadequacy of fusional reserveInadequacy of fusional reserve Precision of jobPrecision of job Advancing ageAdvancing age
CAUSES OF CHILDHOOD CAUSES OF CHILDHOOD STRABISMUSSTRABISMUS
CataractCataract Corneal opacitiesCorneal opacities ROPROP RetinoblastomaRetinoblastoma Traumatic brain injuryTraumatic brain injury Hemangioma near the eye Hemangioma near the eye
during infancyduring infancy Trisomy 18Trisomy 18 Congenital rubellaCongenital rubella Cerebral palsy Cerebral palsy
SYMPTOMSSYMPTOMS
Deviated eye Deviated eye Abnormal head postureAbnormal head posture Poor visionPoor vision Headache Headache DiplopiaDiplopia
EXAMINATIONEXAMINATION
1.HISTORY1.HISTORY A. Deviation: Age of onsetA. Deviation: Age of onset
Description of deviationDescription of deviation Previous treatmentPrevious treatment B. Pre and post natal factorsB. Pre and post natal factors Growth and developmentGrowth and development Family history of strabismusFamily history of strabismus2.GENERAL OBSERVATION.2.GENERAL OBSERVATION. Abnormal head postureAbnormal head posture
3. VISUAL ACUITY3. VISUAL ACUITY a. Without glasses and with glassesa. Without glasses and with glasses b. Near and distant visionb. Near and distant vision c. Amblyopia testingc. Amblyopia testing
4.MOTOR:4.MOTOR: a. Extra ocular movements.a. Extra ocular movements. b. Phorias or tropiasb. Phorias or tropias c. Near point of convergence and near point of accommodation.c. Near point of convergence and near point of accommodation.
5. MEASUREMENT OF DEVIATION.5. MEASUREMENT OF DEVIATION.
Distance and nearDistance and near
Without glasses and with glasses( if worn)Without glasses and with glasses( if worn)
6. SENSORY TESTS6. SENSORY TESTS
Worth 4 dot test.Worth 4 dot test.
StereopsisStereopsis
7. FIXATION: monocular , alternating, binocular7. FIXATION: monocular , alternating, binocular
8. SLIT LAMP EXAMINATION.8. SLIT LAMP EXAMINATION.
9 . FUNDUS EXAMINATION.9 . FUNDUS EXAMINATION.
10 . CYCLOPLEGIC REFRACTION.10 . CYCLOPLEGIC REFRACTION.
VISION TESTSVISION TESTS
In infants:In infants:
- fixation and following - fixation and following lightlight
- Catford drum test- Catford drum test
- preferential looking - preferential looking testtest
- Cardiff acuity test- Cardiff acuity test
- VER- VER
- reflex responses - reflex responses
In 1 to 2 yr old:In 1 to 2 yr old:
- Boeck candy test- Boeck candy test
- Worth’s ivory ball test- Worth’s ivory ball test In 2 to 3 yr old:In 2 to 3 yr old:
- coin test - coin test
- miniature toys test- miniature toys test
- dot visual acquity test- dot visual acquity test
In 3 to 5 yr old:In 3 to 5 yr old:
- tumbling E test- tumbling E test
- Landolt’s C test- Landolt’s C test
- Sheridan letter test - Sheridan letter test
SENSORY TESTSSENSORY TESTS
Worth’s 4 dot testWorth’s 4 dot test Bielchowsky’s after Bielchowsky’s after
image testimage test Striated glasses of Striated glasses of
BagoliniBagolini 4 diopter prism base out 4 diopter prism base out
testtest SynaptophoreSynaptophore
STEREOPSIS TESTSSTEREOPSIS TESTS
Titmus stereo testTitmus stereo test Random dot stereogram testRandom dot stereogram test Random dot e testRandom dot e test TNO testTNO test Lang testLang test Frisby testFrisby test 2 pencil test2 pencil test
Titmus fly testTitmus fly test
TNO testTNO test
Lang testLang test
HEAD POSTUREHEAD POSTURE
Incomitant squint Position of head in which
the eyes are in a position of no deviation or very small deviation so that fusion is possible.
3 components:
-Chin
-Face turn
-Head tilt
TESTS TO MEASURE TESTS TO MEASURE DEVIATION ANGLEDEVIATION ANGLE
Hirschberg corneal Hirschberg corneal reflex testreflex test
Krimsky’s testKrimsky’s test Cover test Cover test Alternate cover uncover Alternate cover uncover
testtest Prism bar cover testPrism bar cover test Maddox wing testMaddox wing test Maddox rod testMaddox rod test
MOTILITY TESTSMOTILITY TESTS
Ocular movementsOcular movements
- versions- versions
- ductions- ductions Near point of convergence- RAF ruleNear point of convergence- RAF rule Near point of accomodation- RAF ruleNear point of accomodation- RAF rule Fusional amplitudes- with prism bar or Fusional amplitudes- with prism bar or
synaptophoresynaptophore
DIPLOPIA TESTSDIPLOPIA TESTS
Hess test Hess test Lees screenLees screen
AMBLYOPIAAMBLYOPIA Unilateral or bilateral DOV Unilateral or bilateral DOV
due to form deprivation due to form deprivation &/or abnormal binocular &/or abnormal binocular interaction for which there interaction for which there is no ocular or visual is no ocular or visual pathway pathologypathway pathology
Most commonly due to Most commonly due to squint, large uncorrected squint, large uncorrected refractive errors etc.refractive errors etc.
Treatment: Treatment: - occlusion- occlusion - penalisation- penalisation
MANAGEMENTMANAGEMENT
Refractive error Refractive error correction by spectacle correction by spectacle lenses, prisms, orthoptic lenses, prisms, orthoptic exercises. exercises.
Patching, reducing the Patching, reducing the VA or occluding the VA or occluding the good eye so as to good eye so as to activate the deviated activate the deviated eye. This is only done in eye. This is only done in children with unilateral children with unilateral deviation. deviation.
Medical :Medical :
- miotics in - miotics in accomodative esotropiaaccomodative esotropia
- cycloplegics in - cycloplegics in accomodative esotropiaaccomodative esotropia
- levodopa, carbidopa in - levodopa, carbidopa in amblyopiaamblyopia
- botulinum toxin A - botulinum toxin A (botox) (botox)
Surgery:Surgery:
- weakening procedures eg. - weakening procedures eg. recession, marginal recession, marginal myotomy, myectomy.myotomy, myectomy.
- strengthening procedures - strengthening procedures eg. resection, tucking, eg. resection, tucking, advancement.advancement.
THANK YOUTHANK YOU