Ultrasound pachymetry is the most popular and accurate method for measuring corneal thickness today due to its low cost, easy use, and repeatability. While traditional slit-lamp pachymetry is an older technology used by few, ultrasonic pachymeters provide highly accurate density analysis of the cornea by measuring the front and back surfaces. Newer pachymeters that take multiple measurements with a low standard deviation of under 5 microns are also considered accurate, but new imaging devices using Scheimpflug cameras are currently more expensive than ultrasound options.

1. Today's Five Biggest
Pachymeter Considerations

2. Today's ultrasound pachymetry is
popular due to its low cost, simple
usage and its ease of repeatable
use. Elliot M. Kirstein, OD, FAAO,
director of Harper’s Point Eye
Associates in Cincinnati,
believes ultrasound represents at least
98% of today's pachymetry market.

3. Traditional optical slit-lamp pachymetry is
an aging technology that few use anymore.
• According to J. James Thimons, OD, Medical Director for
Ophthalmic Consultants of Connecticut; pachymeters like the
scanning-slit devices are using optical principles to discover
relative changes in corneal thicknesses. These kinds of
pachymeters are not equally accurate to other technology
approaches.
• Within the variations on this technology, Within the variations
on this technology, optical pachymeters “tend to read thinner in
my experience,” Dr. Thimons said.
• Some factors can cause a cornea to be thicker or thinner than
average, according to Dr. Kirstein, research coordinator at Ziemer
Ophthalmology.

4. These ultrasonic probes will provide highly
accurate density analysis of this tissue.
They analyze front and back so that surface
reflection properties are measured accurately.
Ultrasonic pachymeters are the most accurate of
those now available.

5. A nomogram can compensate for the discrepancy
of optical pachymeters that
read a bit thinner.
• Most doctors prefer the ultrasound systems.
This is due to correlation with important
Ocular Hypertension Treatment Studies –
a set baseline for all basic decisions about
treatment of glaucoma patients.

6. About The New Pachymeter Options
Murray Fingeret, OD, chief of optometry at the
Department of Veterans Administration New York
Harbor Healthcare System in Brooklyn,
acknowledged that newer pachymeters take
multiple measurements at one time. “As long as
the standard deviation is relatively low – preferably
under 5 microns – these measurements are
accurate,” Fingeret said.

7. New imaging devices that utilize Scheimpflug
cameras - are also showing reliable corneal
thicknesses from one limbus to the other, however
they are not competitive with ultrasound price
point.