Everywhere you turn you hear and see ads for laser surgery. Lasic is a wonder surgery that frees many from glasses and contact lenses. But don't be fooled! These ads are not public service announcements but profit based. We select patients for this procedure based on a true benefit for the patient's quality of life. The surgeons we consult with offer high quality and reasonable fees. They don't even advertise, because they don't have to! Their reputations are that high.
Information on Laser Vision Correction

The eye works like a camera. The light rays of the image enter the eye through the cornea, a clear window similar to a lens filter, which provides most of the focusing power of the eye. The cornea is composed of several layers of tissue. The outer layer or epithelium is the eye's protective layer.
This layer is made up of cells that have the ability to grow back within five to seven days, and therefore, allow for fast healing of superficial injuries. Most of the inner layers provide strength to the eye. The middle inner layer, the stroma, is the largest layer and the part of the cornea that is typically modified in refractive surgery to change the focus. The last layer is the endothelium, a very important layer that is largely responsible for keeping the cornea clear.

After the cornea, the partially focused image then travels through the pupil. the pupil is the "black circle" that you see in people's eyes. The iris, the colored part of the eye (ie. blue, green, brown, or hazel) determines the size of the pupil. The primary function of the iris is to control the size of the pupil and therefore the amount of light entering the eye. This is achieved through contraction or expansion of the muscles of the iris. When you are in a bright environment, the iris contracts to allow less light through. when it is dark, the pupil expands to allow more light to reach the back of the eye.

The lens, the next element in this optical system, is a clear structure located just behind the pupil. Its primary function is to provide fine-tuning for focusing and reading. the lens performs this function by altering its shape. At about the age of 40-50, the lens becomes less flexible as presbyopia sets in. Presbyopia, or loss of near vision is why many of us who never had to wear glasses before, need them to read with after forty years of age. Finally, sometime around age 60 to 70, the lens becomes cloudy and hard (cataract formation), preventing light from entering the eye. These cataracts may then be removed with advanced techniques.

The lens fine-tunes the image to focus it properly on the retina. The retina is a thin layer of nerve tissue that lines the inside of the eye and functions like the film in a camera. The retina transforms the image into electric impulses that are then carried by the optic nerve to the brain transforms the light. For you to see clearly, light must be focused precisely on the retina. Glasses or contact lenses are required when your eye cannot focus light properly.

The Excimer Laser
By mixing different gases together, scientists can produce laser energy of varying wavelengths. scientists at IBM were experimenting back in the 1970's with different gas elements to create new lasers. They found that the 193-nanometer wavelength of the Argon-Fluoride excimer laser could remove molecules of corneal tissue with virtually no heat or damage to the surrounding tissue. This laser process was termed "Photoablation", meaning "vaporization through the use of laser light".

This type of laser is used industrially to etch computer microchips because of the extremely fine precision and smoothness of the excimer laser beam. The excimer laser uses Argon and Fluoride gases mixed together in a high-voltage cavity to produce a cool (non-thermal) ultraviolet beam of light. Guided by a sophisticated computer, this light beam is then used to vaporize eye tissue by breaking molecular bonds. the excimer laser is so precise that each pulse can remove 39 millionths of an inch of tissue in 12 billionths of a second.

Technology Updates
We are watching closely new technologies in refractive surgery. We believe the most exciting advances will be in wavefront technology. In addition, hyperopic correction will most likely be best treated by CK (conductive keratoplasty) as opposed to LTK (Laser Thermal Keratoplasty). The following topics will give you more complete information:

Wavefront Technology
Probably the most talked-about developments in vision surgery these days have to do with advanced eye-measurement systems using wavefront technology originally developed by astrophysicists.

Nobody's eye surface is a perfectly smooth hemisphere. Additional aberrations below the surface can cause refractive errors that a corneal topographer (which maps the eye's surface) wouldn't display. These unknown aberrations make it difficult for surgeons to plan procedures that yield a precise result. The new measurement systems could solve this problem.

Two companies, Visx and Alcon Summit Autonomous, received FDA clearance in May 2000 for their eye-measurement systems. The Visx WaveScan uses optics that project light into the eye and precisely analyze the returning wavefront using a sensor containing thousands of tiny lenses. The system outputs a kind of "fingerprint" of the eye — a map of the eye's refractive errors, both internal and on the surface, that is unique to that patient.

Visx started shipping the WaveScan systems to doctors in May 2001. The company thinks surgeons using its technology — which also includes an eye tracker, larger ablation zones and variable sizes of the laser spots — will be equipped to provide customized laser vision correction.

Summit's CustomCornea measurement device works in a similar way. It links the eye map to its LADARVision excimer laser to produce what the company says is a customized ablation pattern. This system is currently in clinical trials.

It's too early to tell whether these machines will definitely help more patients obtain perfect vision from LASIK and PRK. An unresolved question is whether anyone has harnessed the eye-measurement capabilities in a way that significantly improves the laser's accuracy. For now, the measurement technology may have outpaced anyone's ability to make the best use of it.

Flying-Spot Lasers
Some of the newer lasers for LASIK these days feature a narrow beam that moves around the cornea in a manner designed to produce a smooth and precise tissue ablation. Many doctors who have used these so-called "flying-spot" lasers are pleased with the results they are getting.

A flying-spot (or scanning-spot) excimer laser uses a 0.8mm to 2.0mm beam vs. the broader 6mm beams of other lasers. Three companies — Alcon Summit Autonomous, Bausch & Lomb and LaserSight — have won FDA approval for this type of laser.

Why should the spot size matter? "With a small spot, you can place the spots exactly where you need to tailor the treatment, and also be more refined and more exact," says Scott Corning, a senior product manager at Alcon's Summit Autonomous division in Waltham, Mass.

The smaller beam's shape makes a difference, too, Mr. Corning says. "The scanning spot is... sort of soft around the edges, so it's gentler on the tissue. And it is thought to heal faster. With a small spot you're not just pounding down on the same area each time [the laser fires]. You're putting small pulses down and they're away from each other. And you revisit a spot near a previous spot only after that previous spot has had a chance to relax." Call it a kinder, gentler ablation.

Corneal Inserts: Intacs
One safe and effective alternative to laser procedures for correcting mild nearsightedness is a procedure that reshapes the cornea using tiny crescent-shaped inserts called Intacs. Doctors and patients have reported favorable results. But availablity may be uncertain now that the manufacturer of the inserts, Keravision, has filed for bankruptcy.

Intacs are implanted in a brief outpatient procedure with a topical anesthetic. The patient cannot feel them in the eye following surgery. They do not remove tissue from the central cornea, as in laser surgery, so they may be removed or replaced if a problem occurs or if the patient needs a vision correction adjustment later.

"LASIK produces excellent visual results, but we're getting even better results with Intacs," says Anita Nevyas-Wallace, M.D., a clinical investigator in Philadelphia. "Patients are delighted. I have also used Intacs for LASIK patients who did not achieve 20/20 vision with that procedure."

Intacs are being tested now to correct other vision problems, including more severe nearsightedness, keratoconus, and under-correction after LASIK. A spokesman for Keravision reported that Intacs are available despite the company's bankruptcy actions.

Collagen Shrinkage for Hyperopia
A technology that corrects mild farsightedness using a holmium laser received FDA approval in June 2000. The Hyperion LTK Laser System from Sunrise Technologies gently heats the collagen in the periphery of the cornea, shrinking it and steepening its shape.

The procedure, called laser thermal keratoplasty (LTK), takes just three seconds for each eye. No instrument comes in contact with the cornea.

Patients must have +0.75 to +2.50 diopters of refractive error with up to 0.75 diopters of astigmatism. Patients must also be 40 years of age or older, with a six-month record of refractive stability (their prescription cannot have changed during that time).

"LTK is the ideal in 'no-touch' vision correction for farsightedness. It is quick, easy and has an extremely high level of safety," says Brian S. Wachler, M.D., assistant professor of ophthalmology at University of California at Los Angeles School of Medicine and a clinical investigator.

Ask our doctors if any of these procedures are right for you!