Ultrasound Pachymetry
An ultrasound pachymeter is an instrument used to measure the thickness of the cornea. This is a very important measure in the treatment and management of glaucoma, an eye disease which causes optic nerve damage and can result in progressive blindness.
When your eye pressure is measured, an assumption is made that your cornea is of normal thickness (approx. 550 microns). This is not always the case. For example, if your eye pressure was measured at 18 mmHg, but your cornea is 500 microns thick, then the pressure measurement needs to be corrected to allow for a thinner cornea. The actual pressure reading in this case corrects to about 21 mmHg (over 20 mmHg is classified as high). The converse is also true for a thick cornea. For the same measured pressure reading, if the corneal thickness value was 600 microns instead, the corrected pressure reading would be about 15 mmHg.
Clinically, there is an even more important reason why your corneal thickness should be measured. Research shows people with thin corneas are at a much higher risk of developing glaucoma than those with normal or thick corneas. This can sometimes mean the difference between keeping a closer watch on your optic nerve, or simply scheduling standard routine visits every couple of years.
When your eye pressure is measured, an assumption is made that your cornea is of normal thickness (approx. 550 microns). This is not always the case. For example, if your eye pressure was measured at 18 mmHg, but your cornea is 500 microns thick, then the pressure measurement needs to be corrected to allow for a thinner cornea. The actual pressure reading in this case corrects to about 21 mmHg (over 20 mmHg is classified as high). The converse is also true for a thick cornea. For the same measured pressure reading, if the corneal thickness value was 600 microns instead, the corrected pressure reading would be about 15 mmHg.
Clinically, there is an even more important reason why your corneal thickness should be measured. Research shows people with thin corneas are at a much higher risk of developing glaucoma than those with normal or thick corneas. This can sometimes mean the difference between keeping a closer watch on your optic nerve, or simply scheduling standard routine visits every couple of years.