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52 Cards in this Set
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- Back
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What is an esodeviation?
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A latent or manifest CONVERGENT misalignment of the visual axis; one visual axis turns toward the nose
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What are 3 types of esodeviations?
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- Esophoria [E]
- Esotropia [ET] - Intermittent Esotropia [E(T)] |
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What is esophoria [E]? Do the eyes ever look straight (orthotropic)?
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- An inward eye turn (esodeviation) which is controlled by fusion.
- As long as the eyes are fusing, they will look orthotropic. Turn only appears when something disrupts fusion. |
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What is different about an intermittent esotropia E(T) compared to an esophoria E?
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An intermittent esotropia is controlled only some of the time by fusional mechanisms. At other times the turn is not controlled (becomes manifest)
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What is an esotropia [ET]? Do the eyes ever look straight (orthotropic)?
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Esotropia is a manifest deviation which is NEVER controlled by fusional mechanisms. Therefore the eyes are never straight.
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What is a comitant deviation? Describe three types of comitant esodeviations.
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Comitant: same amount of deviation everywhere
1. Comitant Accommodative Esotropia - can be a.Fully Accommodative Eso, b.Nonaccommodative Eso (high AC/A) c.Partially Accommodative Eso d.Hypoaccommodative Eso (reduced NPA) 2. Comitant Nonaccommodative Esotropia - can be a.infantile esotropia b.nonaccommodative convergence excess c.acquired eso d.acute-onset eso e.divergence insufficiency f.cyclic eso g.recurrent eso 3. Comitant Microstrabismus - primary or secondary microtropia, nystagmus blockage |
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What is an incomitant deviation? Describe two types.
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Incomitant: measures a differing amount of deviation in different positions of gaze.
1. Paralytic 2. Nonparalytic - A/V eso - Retraction syndrome - Mechanical Eso |
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What is the term which describes the appearance of having an inward turn, when in actuality there is no real deviation?
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Pseudoesotropia
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Can you differentiate a microesotropia from a pseudoesotropia? How or how not?
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Yes - Cover test will be negative for pseudo
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What are some causes for pseudoesotropia?
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- prominant epicanthus - Down syndrome, Asian children
- narrow IPD - wide nasal bridge - enophthalmus - sinking of eye into orbit - negative angle kappa |
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What (where) is the angle kappa?
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The angle kappa is the angle formed between the visual axis of the eye and the mid-pupillary line
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Relate the terms: angle kappa & pseudoesotropia
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Patient may have negative angle kappa - meaning corneal light reflexes are displaced temporally, indicating an esodeviation. However, cover test is negative - patient has pseudoesotropia.
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Describe the parameters for Convergence Excess Esodeviation type patients under Duane's Classification.
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N>D (10 p.d. or more)
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Describe the parameters for Divergence Weakness/Insufficiency Esodeviation type patients under Duane's Classification.
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N<D (10 p.d. or more)
*BAD* |
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Give four important characteristics of COMITANT ACCOMMODATIVE /REFRACTIVE ACCOMMODATIVE ESOTROPIA.
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- eso affected by state of accommodation
- not present at birth usually within first 2 yrs - intermittent because when focusing eyes are ortho - larger at near (N>D) - initially intermittent, becomes manifest - common ** underlying hyperopia ** insufficient divergence amplitudes |
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What is amblyopia?
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Decreased vision in one eye induces the brain to start "ignoring" signals - blurring, diplopia - from the poor eye
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How do you treat an accommodative eso? What is the underlying refractive error?
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- GLASSES
- Hypermetropia (far sighted) |
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What adverse effects are associated with a microesotropia?
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- Reduced 3D
- fovea in turned eye will be slightly off-set - may even have negative cover test - anomalous retinal correspondance (not fovea to fovea) |
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When assessing using Duane's classification, would you do this with or without correction?
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cc - with correction
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Give important characteristics of COMITANT, NONREFRACTIVE ACCOMMODATIVE ESOTROPIA.
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- Greater at near (N>D) convergence excess type
- not related to refractive error - high AC/A ratio - control depends on divergence amplitudes - normal NPA - appears around age 2-3 when child begins to need to accommodate - usually ortho at distance but may still be eso |
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How would you treat a comitant nonrefractive accommodative esotropia?
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- Bifocals - diminish the patient's need to accommodate.
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What is a hypoaccommodative esotropia?
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Esotropia greater at near, unrelated to [hypermetropic] refractive error, caused by excess convergence from an increased accommodative effort to overcome accommodative weakness, reduced NPA. Extremely rare.
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What is the treatment for hypoaccommodative esotropia?
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Very low strength reading glasses.
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Give characteristics of PARTIALLY ACCOMMODATIVE ESOTROPIA.
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- refractive error does not account for ENTIRE deviation, therefore correction of ref error does not fully correct deviation
- treatment usually glasses AND surgery |
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Classify infantile esotropia as one of the following:
a) Comitant, accommodative eso b) incomitant esodeviation c) comitant, nonaccommodative eso d) microtropia |
c) comitant, nonaccommodative eso
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(T/F) Infantile esotropia is an intermittent deviation.
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F - manifest deviation, ~ 30 p.d. +
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Infantile esotropia constitutes:
a) ET N>D b) ET N=D c) XT N<D d) ET N<D |
b) ET N=D
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Why is surgery crucial while young in a case of infantile esotropia?
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to maintain the best depth perception and 3D vision since this develops at a very young age
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a characteristic pattern in infantile esotropia is:
a) V-pattern b) A-pattern c) no pattern - eye always in d) no pattern - incomitant deviation |
a) V-pattern: straight in upgaze, eso in primary position, larger eso in downgaze
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Define nystagmus.
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small, rhythmic horizontal movement of eyes when one is closed or occluded
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In _____________, the use of the right eye views the left visual field and vice versa.
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cross-fixation
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cross-fixation may occur as a result of?
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- infantile esotropia
- CN VI palsy |
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What is the treatment for infantile esotropia?
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Surgery
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Describe nystagmus blockage syndrome.
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- patient uses convergence to control nystagmus
- more nystagmus present when eyes not converged - controlled; pseudo - both eyes in ADDuction - larger the ET = less amount nystagmus (inverse relationship) |
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What would be the result in a nystagmus blockage syndrome if, at distance,
a) nystagmus is slow and not synchronized? b) nystagmus is rapid and synchronized? |
a) extremely blurred vision, very poor acuity
b) acuity may be mediocre |
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Nystagmus blockage syndrome may give the appearance of __________________________.
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CN VI palsy, affecting LR muscle --> eso
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Think cranial nerves
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Can a patient with nystagmus blockage syndrome have straight eyes? If yes, when?
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Only under anesthesia.
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How would you differentiate nystagmus blockage syndrome from infantile esotropia?
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Check for cross-fixation: pupil should constrict when eye converges
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Characteristics of Acquired Eso?
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- onset after 6 months of age
- comitant, N=D - small at onset, becomes very large - eyes ortho or exo under anesthesia |
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Characteristics of (acquired) acute comitant esotropia?
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- no EOM limitations
- good binocular potential - large eso 20 p.d. + - uncorrected hypermetropic error |
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Name 3 forms/causes of acute comitant esotropia.
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1. After disruption of binocularity
2. Decompensated esophoria without binocular disruption 3. Intercranial pathological process 4. Burian-Franceschetti (unknown) |
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What is the likely diagnosis of the following:
A child wore a pirate costume for Halloween, including a pirate patch on one eye. Child has developed an ET upon removal of the patch. |
Acute comitant esotropia (caused by disruption of binocularity)
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Child (unknowingly) had a small ET before the patch was worn
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What is the likely diagnosis of the following:
A child has a viral illness which precedes a large ET. |
Acute comitant esotropia (decompensated esophoria, without binocular disruption)
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Child has a small esophoria initially
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________ esotropia usually follows a 48 hour rhythm; i.e. for 24 hrs they are ortho, and the next 24 hrs they are eso.
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Cyclic
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What is microstrabismus?
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tiny angled deviations, may even escape diagnosis.
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What are some key components of microtropia?
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- reduced 3D (Hard Randot test below average)
- eye with micro has central suppression (they suppress the fovea of the deviated eye) -- W4dot to dx |
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Who coined the term "microtropia?"
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Lang
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Who coined the term "monofixation syndrome?"
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Parks
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Who used the term microtropia, but narrowed the criteria, including addition of eccentric fixation?
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Von Noorden
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What are the consistent findings between microtropia and monofixation syndrome?
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- central suppression scotoma
- peripheral fusion present - amblyopia - anisometropia |
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What are not consistent findings between microtropia and monofixation syndrome?
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- size of deviation
- cover test, -/+ ? - retinal correspondance |
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What are 2 types of microtropia?
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- Primary - unknown cause
- Secondary - most common - secondary to a previous optical or surgical treatment |
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