Medical Terminology Simplified

Imaging technique used to study retinal blood vessels and circulation of blood in the

retina using photographs of the retina after injection of a fluorescent dye

IVFA produces images that show retinal blood flow and an angiogram that helps detect

vascular changes in diabetic retinopathy, macular degeneration, and retinal vascular

disease, as well as other types of macular disease.

Examination that identifies the smallest letters that can be correctly read on a stan-

dardized Snellen vision chart from a distance of 20 feet

VA is expressed as a ratio. The first number is the distance at which a person reads the chart,

and the second number is the distance at which a person with normal vision can read the same

chart. For example, 20/20 indicates that the person correctly read letters at 20 feet that could

be read by a person with normal vision at 20 feet. Normal vision is 20/20. (See Fig. 11–12.)

Ear

Test that measures hearing acuity at various sound frequencies

In audiometry, an instrument called an audiometer delivers acoustic stimuli at different

frequencies, and results are plotted on a graph called an audiogram.

Additional Medical Terms • CHAPTER 11 531531

intravenous fluorescein

angiography (IVFA)

intra-: in, within

ven: vein

-ous: pertaining to

angi/o: vessel (usually

blood or

lymph)

-graphy: process of

recording

Figure 11-11Slit-lamp examination measuring intraocular pressure by tonometry.

visual acuity (VA) test

ă-KŪ-ĭ-tē

audiometry

ăw-dē-ŎM-ĕ-trē

audi/o: hearing

-metry: act of

measuring