Intra-Ocular Pressures

Equipment:

• Goldmann Applanation Tonometer

Procedures:

• Intra-Ocular Pressure Measurement
• All-Day Phasing
• AM-Phasing

 The eye contains a fluid which constantly flows through it, giving the eye its shape and supplying it with nutrients. Should the pressure of this liquid become too high, it is possible that the nerve fibres at the back of the eye may become compressed and damaged. This may happen if there is a blockage to the flow of the liquid in the eye, or if too much liquid is produced. Some eyes are more prone to this damage than others but as a general rule the higher the pressure, the greater the risk of damage.

The pressure in the eye is measured using a probe which touches lightly on the front surface of the eye. Drops are placed in the eye which cause it to become numb for several minutes while we take the readings. The drops also contain a yellow vegetable dye which stains the front surface of the eye. By adjusting the light pressure that we place on the eye, we are able to see patterns through the viewfinder of the machine. When the applied pressure is the same as the pressure in the eye, we see a particluar pattern. We can then read off the intra-ocular pressure from the machine.

For information about pressure phasing tests, please click here.