on technology & technique
New Use for Wavefront Technology
The Ophthonix system creates glasses and contact lenses based on fast aberrometer measurements.
By John Parkinson, Associate Editor
With the realization that wavefront technology is the future, the ophthalmic industry is working towards its greater utilization. One new use that has emerged is using wavefront measurements as the basis for creating eyeglasses and contact lenses. This new use, developed by San Diego-based
Ophthonix, allows doctors to treat patients' higher-order aberrations without surgery, and the company says it also saves chair time.
Part of this new system is the Z-View
Aberrometer, which measures sphere, cylinder and axis, and higher-order aberrations. It then analyzes that data and creates a prescription -- all in about 1 minute.
The other part of the system is the unique Ophthonix manufacturing process, which allows the creation of eyeglasses and contact lenses based on the prescription generated by the
The iZon glasses will be manufactured by
Ophthonix, while its partner, Optical Connection Inc., will manufacture the contact lenses, with Ophthonix being the distributor. The contact lenses will be referred to as the
"iZon Wavefront-Guided Contact Lenses by Definition."
The Z-View Aberrometer is easily
transportable and compact enough to not take up a lot of space in the office.
How The System Works
The entire process is broken up into three steps. The first step is the capture of the wavefront measurement. Seated at the
aberrometer, the patient looks through binocular optics at either a real target or an internal fixation target. The patient's eyes are then measured by the Z-View using a low-power invisible laser beam that passes through the eye. The beam is reflected out of the eye, detected, and analyzed by the
aberrometer. The Z-View is different from widely used Hartmann-Shack aberrometers because it is based on a proprietary holographic measuring principle.
In about 1 minute the device determines the patient's low and higher-order aberrations and generates a prescription. The prescription comes out as a bar code. The instrument has a touch screen, and the doctor can override the system to modify the low-order components of a prescription if needed. The prescription is then sent to an Ophthonix lab where the lens programmer reads the digital prescription created by the Z-View and manufactures the lenses.
The lenses are not molded or grounded; the manufacturing process does not touch the surface of the lens or remove material, it changes the actual optical properties of Ophthonix's patented material on a point-by-point basis.
The material is deposited between a front and base lens surface. After the polymer is cured, the lens is programmed with a patented process that is comparable to burning a CD. The final index lens is completely customized to the individual patient. After manufacturing, the glasses are sent to the doctor's office.
Z-View and iZon Features
The Z-View unit is 12 inches X 24 inches, portable, and self-contained. It has the ability to measure refractive errors from 12.0D to +8.0D. It comes with a printer, or for those practices that are looking to go paperless, the aberrometer is
ethernet-enabled, allowing electronic record-keeping via a link to office management software.
Perry Binder M.D., discusses what it's like to work with the Z-View. "It's easier to use physically than the other aberrometers in terms of alignment, capturing the image, time used to do it, and keyboard strokes -- which aren't necessary with this."
Both the contact lenses and eyeglasses will correct for myopia and
hyperopia, but will also correct higher-order aberrations, which cause visual symptoms such as halos, fuzziness and shadows.
To improve both the vision through the lenses and the appearance of the glasses, an anti-reflective (AR) coating is applied during the manufacturing process. AR coatings are similar to the coatings found on microscopes and camera lenses. They consist of several layers of metal oxides applied to the front and back lens surfaces. Because of the layering effect, AR coatings sometimes have a hint of green or purple coloring, depending on the individual manufacturer's formula.
The Z-View features internal targeting for near vision testing and real world external targeting for distance
One of the chief benefits of the Z-View according to Ophthonix is the fast measurement and accurate analysis of the eye's
wavefront, thus saving chair time. Dr. Binder is doing research studies on the
Z-View addressing both concerns. "If I bought one of these will it decrease my chair time without sacrificing accuracy? Our preliminary data shows that's the case," observes Dr. Binder.
In an age where managed care is challenging medical practitioners, ophthalmologists are looking for ways to increase opportunities to serve patients. The iZon lenses are a way to do this as well as create another revenue stream.
The glasses and contact lenses will be high-end high-performance according to Dennis Jarvis, vice president of Marketing at
Ophthonix. He estimates that doctors can expect to pay approximately $140 a pair for fully-loaded, high-index, single-vision glasses and about $120 per eye annually for frequent replacement, soft contact lenses.
For post-refractive surgery patients who have residual or induced higher-order aberrations causing nighttime driving issues, the iZons are a treatment option. "Because the iZon Lens corrects higher-order aberrations, which represent about 20% of refractive error, patients who experience any of a variety vision compromises, such as glare or starbursts form the light at night, will benefit," says Jarvis. "The difference between the iZon Lens and conventional lenses is analogous to the difference between regular and high-definition television. We have had some excellent case studies with LASIK patients. We have provided them with
wavefront-guided spectacle lens correction and their vision has improved dramatically."
Jarvis notes that it will take a few days to manufacture the lenses, apply the premium coatings, and send the glasses or contact lenses to the practice. Patients and practices will have the option to have them
overnighted, at cost.
Jarvis says the details of delivery are still being worked out, and at the time of this printing, nothing had been finalized yet. He did provide a potential mailing scenario for buying bulk merchandise. "If a doctor has five orders waiting and he or she wants them overnighted based upon the quantity, we might want to do that without a charge."
Another consideration for doctors will be teaching patients how to use the glasses. "Because they are higher-order correction and there will be center optical zones, there is some instruction that the doctor has to provide for the patient, particularly in respect to the eyeglasses as opposed to the contact lens," explains Jarvis.
Broad Potential Application
Almost every patient can benefit from the
iZons. "It could be for anybody who potentially has higher-order aberrations that account for any significant part of their visual system," explains Dr. Binder. "Lets say you are an emmetrope and you have zero refractive error but 10% of your vision is due to high-order aberration. You would see better with those
[iZon] glasses than your regular glasses."
The Z-View aberrometer is now available. The iZon glasses are expected to be ready on a limited basis at the end of the first quarter of this year, along with the contact lenses. To learn more, visit
www.ophthonix.com or call (858) 646-5531.
Ophthamology Management, Issue: February 2005