However, the latest model, the Pentacam AXL Wave, is now being inexplicably compared to the iTrace in its stated clinical applications. Here’s a breakdown of where the two devices are vastly different, and how the AXL Wave cannot stand up to the iTrace, (just like the Nidek/Marco OPD Scan III fell short).
HOW WE COMPARE
Using proprietary ocular Ray Tracing technology, the iTrace sends 256 consecutive beams of light into the eye, tracking where each beam lands on the retina. By measuring the pattern created by the collective points, the iTrace produces an exact simulation of how light enters and passes through the eye during the process of vision. As a result, only Ray Tracing provides the most objective and accurate refraction possible.
Hartmann-Shack aberrometry sends a single beam into the eye and measures the point spread as light bounces off the retina and exits the eye. This has been proven as a reliable aberrometry method for typical refractive patients, but when higher order aberrations (HOAs) are present — as is the case in many candidates for lens-based procedures — Hartmann-Shack data cannot be trusted to measure them. 
WHY IT MATTERS
Getting the most precise measurement possible of any eye is extremely important when planning a lens-based procedure like cataract surgery. The presence and effect of HOAs can impact a patient’s candidacy for certain lens implants. Consequently, the difference between Hartmann-Shack and Ray Tracing can be a patient who is satisfied with their vision after surgery and one who isn’t.
In the history of our industry, Hartmann-Shack aberrometry has rarely, if ever, been used to assess candidates for cataract surgery — there are better and more precise alternatives that leading physicians prefer.
In Practical Terms: The iTrace vs. The Pentacam AXL Wave
The Tracey Dysfunctional Lens Index (DLI)
The Pentacam AXL Wave now offers a similar looking display — but it lacks a truly objective way to track lens dysfunction. And, instead of an easy-to-interpret map, users have to rely on retro-illumination to subjectively assess opacities in the eye.
Toric IOL Planning
This is one of the keys areas where the Pentacam AXL Wave’s Hartmann-Shack technology falls short. This potential for error in measuring higher order aberrations (HOAs) means that the iTrace use of Ray Tracing and proven Placido Topography is the clear choice for doctors who want to provide their patients with the best chance for optimal vision after surgery.
The iTrace Toric Check
The Pentacam AXL Wave allows doctors to use retro-illumination for post-operative review of toric IOL placement. However, this requires that the patient is dilated and the process will be similar to what can already be done using a slit lamp.
The iTrace comes equipped with the Toric Check, a feature specifically designed for verifying the placement of a toric lens BEFORE any dilation. If the lens is inserted off axis, even by the slightest of margins, the Toric Check display will provide guidance on the exact correction needed — down to the degree — without wasting time on or causing discomfort with dilation. The Toric Check also tells you the cylinder correction you are getting from the lens you just implanted.
Ready to Learn More
About the iTrace Advantage?
When you purchase an iTrace, you’re getting more than just a tool — you’re also getting support from a team dedicated to your success. At Tracey Technologies, we’ll make sure that you have the resources you need to best serve your patients and grow your practice!