COT Flashcards : Ophthalmic Imaging
When performing A-scan biometry, correct alignment of the probe is BEST determined by
A. tissue spikes that gradually increase in height
B. an axial length measurement between 22 mm and 25 mm
C. tissue spikes that are equally tall and sharp
D. an axial length measurement that is almost equal between the two eyes
C. tissue spikes that are equally tall and sharp
Why is immersion A-scan considered more accurate than contact A-scan?
A. Faster to perform
B. Compression of the cornea is eliminated
C. Abrading the cornea is eliminated
D. Uses light instead of sound
B. Compression of the cornea is eliminated
The most common error made in contact biometry is
A. improper gate placement
B. erroneous K readings
C. corneal compression
D. wrong eye type
C. corneal compression
B-scan biometry is necessary when
A. the IOL cannot measure the eye
B. there is a cataract
C. there is any media opacity
D. there is a Staphyloma in the eye
C. there is any media opacity
What is the term for a noncontact method that allows for detailed cross-sectional imaging of the anterior eye and retina?
A. Optical Coherence Tomography (OCT)
B. Magnetic Resonance Imaging (MRI)
C. Computed Tomography (CT)
D. Position Emission Tomography (PET)
A. Optical Coherence Tomography (OCT)
Instead of sound, the OCT is an optical imaging technique that uses
A. lasers
B. air
C. water
D. light
D. light
What imaging technique is used to identify liquefaction of the vitreous that results in vitreous detachment?
A. MRI
B. CT
C. PET
D. OCT
D. OCT
OCT testing can accurately measure the thickness of the
A. iris
B. cornea
C. retina
D. lens capsule
B. cornea
Intracorneal rings are used primarily in the treatment of which condition?
A. Keratoconus
B. Retinal detachment
C. Glaucoma
D. Age-related macular degeneration
A. Keratoconus
Computerized corneal topography analysis is the measurement of the curvature of the
A. corneal surface
B. anterior chamber
C. posterior chamber
D. vitreous body
A. corneal surface
OCT imaging is NOT useful in determining which of the following conditions?
A. Glaucoma
B. Macular edema
C. Macular Holes
D. Dextroversion
D. Dextroversion
When a sound wave travels from one medium to another an echo is produced by
A. frequency
B. acoustic impedance
C. optical density
D. gain setting
B. acoustic impedance
The source used to obtain the image in Optical Coherence Tomography (OCT) is
A. utrasonic energy
B. visible white light
C. visible red-green light
D. high resolution imaging
D. high resolution imaging
How many dimensions are represented in a B-scan image?
A. 1
B. 2
C. 3
D. 4
B. 2
