Spotlight ON TECHNOLOGY & TECHNIQUE

Device Reveals Hidden Corneal Disorders

Oculus Pentacam can help prevent postoperative problems.

By Bill Kekevian, Associate Editor

The Pentacam by Oculus is an imaging device that performs many different tests, including corneal topography, optical corneal pachymetry and anterior segment tomography. For William Trattler, MD, its primary use is diagnosing early keratoconus. In fact, he even discovered a family member’s unexpected keratoconus.

Dr. Trattler specializes in refractive, corneal and cataract eye surgery at the Center For Excellence In Eye Care in Miami. During a routine exam of one of his own family members using the Pentacam, he says he was able to observe corneal abnormalities. Three years earlier, those maps came back completely normal, he says. Comparing the maps from the earlier visit to the later results, using software included in the device, Dr. Trattler was able to observe early keratoconus. He calls the Pentacam’s tomography function essential to his practice. “This technology is required to diagnose early keratoconus,” he says.

His anecdote typifies the machine’s use. Without it, countless patients’ developing keratoconus could go undiagnosed, and those considering LASIK or PRK could be at particular risk of further corneal damage.

Early Keratoconus

“We couldn’t diagnose these patients without this technology. What we’re looking at are patients who have abnormal corneal findings. We only see that on the maps. Sometimes you pick up undetectable conditions with the imaging. When a patient has early keratoconus, the cornea and the eye look completely normal. It’s really important. That’s why we image all patients before surgery.”

Imaging Capabilities

The Pentacam measures the cornea from limbus to limbus in about two seconds. In that time, the device uses a rotating camera with Scheimpflug technology to measure up to 25,000 true elevation points. That Scheimpflug technology keeps both the cornea and the anterior segment in focus at once. In addition, a second camera automatically detects and corrects for any eye movements. The included software provides an analysis of the central cornea.

“The Pentacam is a very important part of my practice,” Dr. Trattler says. “I use it for two main reasons. Number one, to evaluate patients for corneal laser refractive surgery. It’s really helpful at identifying patients that may have early keratoconus. Number two, it’s also useful for patients who have actual keratoconus because it can image eyes that are very steep and can help us monitor progression of keratoconus, as well as any improvements in corneal shape following crosslinking.”

The tomography shows individual levels of the anterior segment in a freely rotating model. Dr. Trattler calls this an improvement over older topography methods. “With regular topography, if the cornea is very steep or irregular, it can’t really image the eye,” he says. “The Pentacam can image very steep corneas and it’s reproducible. This means we can look at the progression and see either crosslinking or worsening.”

The anterior chamber depth, volume and angles are also automatically calculated for glaucoma screening.

Electronic Capabilities

Included in the Pentacam HR Premium Package are an iMac integrated into the table and an iPad, which can be used to display large images of exam results. Dr. Trattler uses these images to illustrate the changes in patients’ conditions like cataract progession or before and after images of iridectomy or corneal surgery. The images can also be used to demonstrate treatment options.

The machine’s software makes it compatible with many EHR systems, the company says, allowing for quick, paperless exchange of test results to all workstations. That includes the document management system Dr. Trattler’s team uses at the Center For Excellence In Eye Care. Recently, Oculus added a Digital Imaging and Communications in Medicine (DICOM) interface into the Pentacam software. OM