Applanation is a technique used
to flatten the cornea
(of the eye)
in order to determine the intraocular pressure. Applanation
applied during applanation tonometry.
That is, "intraocular pressure" is the pressure within
the eyeball, "intraocular" being an adjective that
refers to "within the eyeball".
"Applanation tonometry" refers to the use of an applanation
tonometer which is a type of ophthalmotonometer, sometimes known
more simply as just a "tonometer".
This is an instrument that works by measuring the force necessary to flatten
a known area of the cornea (after numbing the cornea using local anaesthetic).
More force is needed to flatten the cornea when the intraocular pressure
is relatively high, compared with if/when it is comparatively lower. Applanation
is therefore part of a test that may be used in some cases in the process
of assessing the condition of the eye(s) in order to diagnose and/or consider
and recommend options for treatment.
This section includes short definitions of clinical and surgical procedures
concerning the eyes and human visual system. For definitions of other
terms in this category, choose from the list to the left.
Other related pages include the diagram
of the eye, and definitions
of parts of the eye, a description
of the human retina, and the section about disorders
of the eye and visual system.