ROUB COMPREHENSIVE EXAM STUDY
GUIDE WITH COMPLETE SOLUTIONS
●● If a gain setting is increased in order to obtain a 100% tall retina and
sclera echo, what type of cataract is being evaluated ?
Answer: A dense cataract
●● What transducer frequency is generally used for a biometry A-Scan
probe ?
Answer: 10 MHz
●● What is the velocity of a biometer that only uses an average velocity
to measure the entire axial length ?
Answer: 1550 m/sec
●● What is one of the most important features of a biometer ?
Answer: The display screen
●● What are the velocity settings for a phakic eye ?
Answer: (+) Aqueous : 1532 m/s
(+) Crystalline Lens : 1641 m/s
(+) Vitreous : 1532 m/s
, ●● What should the examiner do to reduce the presence of a
reverberation echo created by a dense cataract ?
Answer: Reduce the gain
●● What is the term for the electronic calipers that measure the distance
between two or more anatomic interfaces ?
Answer: Gates
●● Of the following settings on the biometer screen (gain, gates, A-scan
probe frequency, eye type and screen brightness), which cannot be
changed by the examiner ?
Answer: A-Scan probe frequency
●● What is the proper sound velocity used to measure the distance
between the anterior ans posterior lens interfaces in a phakic eye ?
Answer: 1641 m/s
●● when performing immersion biometry, which gate in relation to the
initial spike represents the cornea ?
Answer: Corneal gate is to the right of the initial spike
GUIDE WITH COMPLETE SOLUTIONS
●● If a gain setting is increased in order to obtain a 100% tall retina and
sclera echo, what type of cataract is being evaluated ?
Answer: A dense cataract
●● What transducer frequency is generally used for a biometry A-Scan
probe ?
Answer: 10 MHz
●● What is the velocity of a biometer that only uses an average velocity
to measure the entire axial length ?
Answer: 1550 m/sec
●● What is one of the most important features of a biometer ?
Answer: The display screen
●● What are the velocity settings for a phakic eye ?
Answer: (+) Aqueous : 1532 m/s
(+) Crystalline Lens : 1641 m/s
(+) Vitreous : 1532 m/s
, ●● What should the examiner do to reduce the presence of a
reverberation echo created by a dense cataract ?
Answer: Reduce the gain
●● What is the term for the electronic calipers that measure the distance
between two or more anatomic interfaces ?
Answer: Gates
●● Of the following settings on the biometer screen (gain, gates, A-scan
probe frequency, eye type and screen brightness), which cannot be
changed by the examiner ?
Answer: A-Scan probe frequency
●● What is the proper sound velocity used to measure the distance
between the anterior ans posterior lens interfaces in a phakic eye ?
Answer: 1641 m/s
●● when performing immersion biometry, which gate in relation to the
initial spike represents the cornea ?
Answer: Corneal gate is to the right of the initial spike
