Chapter 18

Question 1

what is a capability for OPG-Gee?

Answer 1

detects hemodynamincally significant lesions of ICA by evaluating flow in one of the its terminal branches

Question 2

what are some limitations

Answer 2

cant establish exact location of disease
non-diagnostic when collaterals exist or with a non-hemodynamically significant lesion
patients with severe HTN

Question 3

how is the patient positioned for a OPG-Gee?

Answer 3

supine

Question 4

how does ocular pneumoplethysmography work?

Answer 4

records in volume

measures ophthalmic artery systolic pressure (osp) by applying a vacuum to the eye

Question 5

how does the vacuum work?

Answer 5

vacuum distorts shape of globe
intraocular pressure increases obliterating arterial inflow
strip chart recordings made as vacuum is slowly decreased and waveforms appear

Question 6

what are some contradictions to OPG-Gee?

Answer 6

allergies to local anesthetics
eye surgery within last 6 months
a past spontaneous retinal detachment
acute or unstable glaucoma

Question 7

what are normal OPG-Gee readings?

Answer 7

OSPs should not differ by >5mm Hg

Question 8

what are abnormal OPG-Gee readings?

Answer 8

abnormal OSPs that differ by >5 mm Hg