This article is more than 5 years old. Information may no longer be current.
New topographer facilitates scleral lens fitting
Click Here to Manage Email Alerts
NEW ORLEANS – The SMap3D was designed to provide “cornea-scleral topography” for fitting scleral contact lenses, according to a presenter here at an American Academy of Optometry-sponsored press conference.
Gregory W. DeNaeyer, OD, FAAO, told attendees that this new topographer from Visionary Optics allows doctors to measure the cornea and sclera, analyze and customize the measurements and directly order scleral contact lenses.
“Scleral contact lenses are being used to fit irregular as well as regular corneas,” DeNaeyer said. “Sales have been skyrocketing. The problem is, as far as fitting is concerned, we’re living in the Dark Ages. Practitioners are using rudimentary techniques and scleral lens fitting sets to fit complicated designs. The process can be challenging for the novice practitioner. We know many practices are fitting back surface spherical lenses on scleras that aren’t spherical.”
DeNaeyer said current instrumentation cannot measure far enough out to include the sclera.
Precision Ocular Metrology teamed up with Visionary Optics to develop the SMap3D topographer to measure the cornea and sclera, with the capability of also using those measurements to design custom scleral contact lenses, he said.
“A fluorescein-based structured light topographer captures the true elevation profile,” DeNaeyer said. “The 22-mm field of view applies to the largest scleral lens and provides under-the-eyelid scleral measurements. Over 1 million measurement points are taken to obtain 10-micron precision.”
He continued, saying the light structure approach creates a 3-D model of the corneal-scleral surface. The instrument uses one projector and two cameras to provide three independent triangulating measurements.
“One interesting feature is its ability to combine serial topographical measurements at several gaze directions to provide a map of the entire scleral surface,” DeNaeyer added.
The topographer’s software also allows clinicians to custom-design Visionary Optics’ Europa scleral lenses.
“Doctors can measure the eye and send it directly to Visionary Optics to provide the lens, or they can design the lens themselves,” he said. “Virtual fitting image scan helps the doctors fit the lens. The software is able to custom design back surface toricity to exactly match the patient’s scleral profile.” – by Nancy Hemphill, ELS, FAAO
Disclosure: DeNaeyer is a consultant to Visionary Optics.