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List indications for Intraocular Examination
Opaque Ocular Media, Clear Ocular Media, & Intraocular Foreign Bodies
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List Opaque Ocular Media
Anterior: corneal opacification, hyphema or hypopyon, miosis, cataract, pupillary membrane; posterior: vitreous hemorrhage or inflammation
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List clear ocular media
Anterior: iris lesions, ciliary body lesions; posterior tumors, choroidal detachments, retinal detachments, optic disc abnormalities, retinitis or choroditis
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List Intraocular Foreign Bodies
detection & localizatio
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Identify the direction of the marker based on theprobe position of Transverse/Axial scans & Longitudinal scans
T/A: horizontal=nasal, vertical & oblique=superior; L: toward center of cornea and meridian being examined
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What properties are used to differentiate intraocular lesions?
Topographic, Quantitative, & Kinetic
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Topographic evaluates what?
Location, Extension, & Shape
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Quantitative evaluates what?
Reflectivity, Internal structure, & Sound attenuation
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Kinetic evaluates for what?
Aftermovement, Vascularity, & Convection motion
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What are the reflectivity categories & their spike height (%)?
Extremely low=0‐5%, Low=5‐40%, Medium=40‐60%, Medium‐High=60‐80%, High=80‐100%
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Describe positioning the patient for exam
US instrument placed on cart, patient seated in reclinable chair, echographer seated onexamadjustableexamstooltotherightofpatientpatient'shead&, patient's screen situated closely together to view both simultaneously
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The probe marker indicates what part of the screen & the opposite of the probe marker represents what part of the screen?
the probe marker represents the upper portion of the b‐scan screen display, the opposite of the probe represents the bottom of the display screen
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Which direction does the transducer oscillate?
always occurs away from and towards the probe marker
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The left & right side of the screen indicates what?
the left side is the face of the probe, the right side is the opposite of the probe face
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Where is the best resolution on the display screen & where should the area of interest be displayed?
the center of the screen has the best resolution & is where pathology should be displayed
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For transverse & longitudinal scans where should the patients gaze be directed?
away from the probe
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For axial scans where should the patient fixate?
in primary gaze
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What is considered the anatomic center for ultrasound?
the optic nerve (macula is the true anatomic center)
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In a transverse scan the transducer moves in whadirection?
parallel to the limbus
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In a longitudinal scan the transducer mover in what direction?
perpendicular to the limbus
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List the primary transverse scans and the direction of the marker
12:00‐marker nasal, probe inferior; 3:00‐marker superior, probe temporal; 6:00‐marker nasal, probe superior; 9:00‐marker superior, probe nasal
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In a longitudinal scan on the display screen what is the top, center & bottom?
top of screen is anterior, middle equator, bottom optic nerve
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What are para‐Axial scans?
useful in the evaluation of the peripapillary region
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How is the para‐Axial scan done?
start w/ an Axial scan then move probe slight shift; horizontal move superior or inferior, verticle move nasal or temporal
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List basic screening process
superior, nasal, inferior, temporal (in that order); move from the limbus to the lower fornix
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Where is it suggested to do longitudinal scans?
along the 4 major meridians
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Last part of the ultrasound evaluation is…
both vertical and horizontal axial scans
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A‐scan exam techniques?
not normally used for screening, when needed have patient fixate in the opposite direction of the probe and move from limbus to fornix
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What is the standard for topographic evaluation?
b‐scan transverse, longitudinal & axial based on location; a‐scan to determine height or shape
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