Author's Note: Ed Gold is one of the original designers of a missile-tracking system developed by a major defense contractor. Similar technology is being used in the latest laser-vision correction equipment. (In fact, Gold recalls demonstrating the tracking technology for Autonomous Technologies, which is now owned by Summit Technologies.) He has more than 13 years of tracking and image-processing experience. He warns the reader that he should not be considered an authority in business and finance, optics, lasers or ophthalmology. Moreover, he holds a long position in Summit stock.
Trackers are absolutely critical in missile guidance because humans just don't have the reflexes needed to steer a missile to its target. Computers can make these kinds of decisions incredibly fast, and that makes them equally well-suited to laser eye surgery -- a job at which a human will, at best, do a merely satisfactory job.
There is no valid engineering justification for designing a Lasik system without a tracker -- the only factors that might prohibit a company from using a tracker in its system are economic. As an engineer who cares to see all the prospective Lasik patients get the best possible outcomes -- and, candidly, as an investor in
-- I want to share my knowledge of these systems with you.
I believe that Summit's LadarVision System has a major technological edge over all its competition: the only integrated active tracking system with
I was initially concerned that the weakness in Summit's stock price was the result of doctors switching to discount laser systems. I hated the thought that profit was more important than the patient's well-being. I now believe that both doctors and investors are keenly aware of the technological improvements in the system.
Besides integrated tracking, this system has another advantage. After Excimer lasers are fired a certain number of times, the gas must be replaced. This usually requires alignment by a trained service person, so the machine is out of commission while the physician waits for servicing. The LadarVision system has a patented cartridge system that is supposed to allow physicians to change it themselves. The cartridge is factory-aligned, so there is no need for a trained service technician to supervise the operation.
The most recent news from Visx,
Bausch & Lomb
and Summit is their development of wavefront measurement devices, which shine a light into the eye and then measure the returned beam at each location outside the eye. This results in a two-dimensional map of the eye, which tells the surgeon exactly what correction is needed for the eye. This is great for use on children who may not know that their vision is not 20/20.
This is fantastic as a stand-alone device, but wavefront devices get really interesting when you connect them to a Lasik system. This would take the "defect" map from the wavefront system and pass it to the Lasik system, where it would be used to plot the laser's activities.
Doing this correctly requires a tracking system: Without a tracker, there is no way to correlate the map with the eye (except manually). While manual guidance is possible -- projecting the map into a heads-up display and then overlaying it on the doctor's view of the eye as he does the surgery -- this pretty much loses all the advantage of having such an accurate map in the first place.
A system that uses a tracker to align the map with the eye will be able to improve someone's vision well beyond 20/20 to 20/15, 20/10 or maybe even 20/5! What's more, they should be able to eliminate other optical defects like halos and star bursts.
I have spoken with doctors who think we might someday be able to use the tracker to allow a surgeon to conduct heart surgery on a beating heart! The tracker would essentially wobble back and forth with the beats of the heart, keeping the knife or laser aligned perfectly with the intended target.
This would be a major boon, since it would avoid all the trauma of unhooking the heart from the body, hooking the body up to bypass machines, and then sewing everything back together after surgery. Don't hold your breath for this one, but I hope it happens in my lifetime!