Novel Pachymeter Demonstrates Central Corneal Thickness Measuring Precision

A novel pachymeter demonstrates good precision for measuring central corneal thickness (CCT) and may provide clinicians with a cost-effective alternative to other biometry devices, according to a study published in Ophthalmic and Physiologic Optics. 

Investigators included 105 participants (mean age, 41.3 years; 46.7% women) in the study and obtained CCT measurements using the novel pachymetry device and 2 non portable biometry devices in random order. A fourth CCT measurement, obtained with a handheld ultrasound biometer, was performed last due to the application of a topical anesthetic.  The team calculated reliability and reliability limits for each device and compared limits of agreement between the novel pachymeter and other instruments to determine whether the new device demonstrated reliability within a clinical setting. 

“A number of non-contact optical biometers are commercially available that integrate corneal topography with repeatable and accurate measurements of CCT and a range of ocular biometry measurements for intraocular lens power calculations and to aid myopia management,” the researchers explain. “However, these sophisticated instruments are expensive and lack portability.”

Overall, CCT measurements were 551.04 µm, 558.62 µm, 549.41 µm, and 539.73 µm obtained with the novel pachymeter, portable ultrasound biometer, and 2 other pachymetry instruments, respectively. While both non portable pachymetry devices demonstrated better repeatability compared with the novel device (within-subject standard deviation: 1.8 and 2.13 vs 5.06), the new instrument still showed excellent precision for measuring CCT, according to the report. 

The novel pachymeter demonstrated the best agreement with one of the the non portable devices (mean difference, −1.63; P =.009) and less agreement with the other non portable device (mean difference, −11.30; P <.001) and the handheld ultrasound instrument (mean difference, 7.58; P <.0001).

The study authors state that “[w]ith minimal training, the instrument is easy to use and the touch screen interface guides the operator to ensure correct alignment.” They add that the novel pachymeter “could be used by non-clinical staff and provides an opportunity for the measurement of CCT to become more firmly embedded in routine eye care.”

Study limitations include the strict inclusion of participants without ocular pathologies and a failure to examine the device’s repeatability and agreement using less experienced users. 

Disclosure: This research was supported by Occuity Ltd. Please see the original reference for a full list of disclosures.