Purpose:
To compare 3 different ultrasound pachymeters, as well as anoptical scanning device for measuring central corneal thickness(CCT).
Methods:
This was a prospective study of 45 consecutive patients, 90eyes, who were seen in consultation for corneal refractive surgeryand were tested by the same clinician on one visit. Thirty fivepatients with no previous corneal eye surgery (group I) andten who undergone LASIK (group II) and were analyzed separately.Pachymetry was measured with the Pach V, PachPen, PachMate,and OrbscanIIz instruments.
Results:
Generalized Estimation Equations (GEE) did show significantdifferences between the OrbscanIIz and ultrasound instruments(PachPen or PachMate) in either group I or group II, betweenthe PachV and the ultrasound instruments (PachPen or PachMate)in group I, and between the PachV and OrbscanIIz in group II.Ingroup II, 10 of 20 eyes had a range of measurements over 20microns.
Conclusions:
45 consecutive patients tested on one visit by the same clinician,CCT measured with 3 ultrasonic pachymeters, including two handheld units, were clinically comparable in group II; and CCTmeasured with 2 ultrasonic pachmeters (PachMate and PachPen)were clinically comparable in group I. The OrbscanIIz data didshow more variation and was greater than the other 3 instrumentsin the patients who had previous LASIK (group II).
Keywords: cornea: clinical science • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • refractive surgery: other technologies