Influences upon intraocular pressure

In order to complete this exercise, you are required to first read the following article:

Now consider the following points regarding IOP variation from Bill Harvey.

The measurement of intraocular pressure (IOP) by tonometry is a routinely undertaken on adult patients in practice as both a screening process and for monitoring the impact of various influences upon the eye. In community practice, tonometry is often initially undertaken using a non-contact tonometer and often as a delegated function.

It is recommended by the College of Optometrists that four readings be taken each eye and then the averaged reading recorded. This is because the instantaneous IOP measurement taken by non-contact methods will also measure any short term influence upon the IOP. If any of the four readings is an outlier, for example if the patient has blinked, then this is usually indicated by the instrument by putting brackets around the result, the result flashing, or the result being asterisked. It is important to remember that the IOP is constantly changing – even in the few seconds between readings being taken. These short-term fluctuations may be due to a number of reasons including the following;