At his practice, Gemoules uses the Visante OCT from
Carl Zeiss. The device uses an interferometer with a low
coherence diode laser, sending light
along two optical paths: the sample
path into the eye, and the reference path of the interferometer.
The intersecting paths result in an accurate image of the eye.
The wavefront abberrometer, an FDA approved laser
device, measures more than 44 different optical character-
istics, all of which are incorporated into the lens in order
to cancel out the aberration of the eye.
Scientists have been using wavefront-guided treatments
in order to improve LASIK outcomes for years. Yet the idea of
individualized wavefront optics in contact lenses was long ago
abandoned by the scientific community as being unachievable.
"This was primarily because lenses were too unstable on the
eye," explains Gemoules.
However, after noticing the inherent on-eye centering and
non-rotational properties of his lenses, Gemoules realized the
potential for individualized corrections. Now he routinely uses
this technology to obtain better visual results.
While Gemoules was one of the first to use these advanced
imaging techniques, it wasn't until recently that he began using
CAD to design the lenses.
"I was using a lot of spreadsheets to do the calculations,"
explains Gemoules, who had to use multiple platforms to assemble his data.
With patients coming in on a Monday, and out the door with
complete contacts by Friday, there was little time for error. After
being introduced to Inceptra, a partner of Dassault Systemes,
providing CATIA product lifecycle management (PLM) solutions,
Gemoules was able to scale back on the number of spreadsheets,
making iterations and adjustments much quicker.
"When you aren't working in 3D, you can't see the finished prod-uct," he explains. "Now, I can manipulate the contacts and develop
a template eye that we can use to engineer the product."
Before using CATIA, Gemoules was unable to manipulate the
image in 3D and the scrap rate for the lenses was as high as
30% or 40%, a rate that has been cut down to virtually zero.
Manufactured by Truform Optics, a Bedford, Texas company,
the lenses are made from polymer buttons cut from extruded
rods using three diamond tools used in the process: roughing,
edging, and an oscillating "waviness" finishing tool for sub-nanometer precision.
Individual Customized Optics
The average reported improvement in visual acuity is between
one to two lines. This means that 20/30 becomes 20/25, 20/20,
or better. One patient obtained better than 20/10 vision. Because
of the ultra-clear vision, patients in visually demanding occupations or sports might find the scleral lenses useful.
Gemoules is in the process of reaching out to various professional sports teams, and has been contacted by the Army, which
is looking to fit soldiers coming back from Afghanistan with the
As OCT technology and the scleral lens keep improving, the
applications for a rigid, large diameter contact could expand to
other applications including medicine delivery. PDD
Photo: Dr. Greg