Your Eye Myopia Astigmatism Hyperopia Presbyopia 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. Top of Page

Surgical Treatments 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. While we are proud of our statistics, meeting your expectations is our most important measure of success. During your pre-operative consultation we will assess your individual condition and provide you with your statistical chance of achieving a successful outcome, based upon our patient experience. This may facilitate your decision as to whether you should proceed with your refractive lasik surgery.   LASIK (Laser Assisted In-Situ Keratomileusis) Introduction For many years, the search for a surgical procedure, which would allow individuals freedom from glasses or contact lenses, has continued. In the late 1970's Radial Keratotomy (RK) was available for a select few patients with low levels of nearsightedness and astigmatism. Now refractive surgery is entering a new era with the advent of the excimer laser and ocular implants. We now have the ability to correct most levels of nearsightedness (myopia), farsightedness (hyperopia), and astigmatism with Laser Vision Correction. Laser Vision Correction Laser Assisted In-Situ Keratomileusis, or LASIK, has become the leading procedure in the Laser Vision Correction field allowing patients less dependency on corrective lenses. LASIK combines the precision of the excimer laser with the benefits of Lamellar Keratoplasty (LK) to treat wide ranges of refractive needs. In the United States the excimer laser was first approved for treatment on the "surface" of the cornea which was called Photorefractive Keratectomy (PRK). LASIK consists of making a small hinged flap of tissue and treating the deeper corneal tissue. LASIK has shown faster visual recovery, minimal discomfort, less risk of haze and ease of enhancement (or touch up) without an increased risk of adverse results. It has become the procedure of choice for the use of the excimer laser. How Successful is LASIK? The majority of patients who undergo LASIK are able to see 20/40 or better right away and are able to pass the driver's license test without glasses or contact lenses. Because some people treated have high degrees of correction and/or astigmatism, it is occasionally necessary to fine tune or enhance the primary treatment to obtain the best final result. Statistically, each patient has about a 95% chance of only requiring a single treatment to achieve their desired visual outcome. Approximately, less than 5% return to the laser for enhancement of any residual astigmatism, or a slight over or under-correction. How is LASIK performed? LASIK is a painless procedure performed in an outpatient setting with topical anesthesia. The eye drops are used to completely numb the eye but not the eyelids. The eyelids are held open with a small instrument to prevent blinking. The patient feels the sensation of the instruments around the lid area but does not feel any pain. A suction ring is placed on the eye and the patient feels a little pressure while the vision goes dim for a brief period of seconds. A microkeratome slides across the cornea in less than 15 seconds to create a thin lamellar corneal flap. After proper alignment, the high-energy pulses from the excimer laser are delivered to reshape the surface. By adjusting the pattern of the laser beam it is possible to treat myopia, hyperopia and astigmatism. After the laser treatment has obtained the proper contour the corneal flap is replaced in its original position. A protective eye shield is placed over the eye and worn for the first 12 to 24 hours as well as when sleeping for the next 3 to 4 days. The cornea has rapid healing qualities and no sutures are needed. However, fluctuation in vision and intermittent dry eyes are not uncommon for the first several weeks and months. Postoperative recovery is quick and easy. Most patients feel minimal to no eye irritation during the first two hours and many patients see a dramatic improvement in vision by the first day. However, fluctuation in vision and intermittent dry eyes are not uncommon for the first several weeks. What can I expect after LASIK? Many patients are somewhat nervous before the procedure so a small dose of Valium is given to most patients to help take the edge off. This also relaxes you so that you are able to go right home and go to sleep, at least for a few hours. Don't expect your vision to be clear the first day. It's somewhat like looking under water. Since the flap is repositioned by floating back into place, a minor amount of swelling occurs. Plus, we protect your eyes with plastic shields which can also blur your vision. But, after a good nights rest, most patients are ecstatic with their new vision. You must then use antibiotic drops and mild steroid drops for the next few days and lubricating drops as needed for the dry eye feeling. What about dry eyes after LASIK? Dry eye symptoms are the most common complaint after LASIK. Everyone has dry eyes after LASIK surgery, but some notice it more than others. In this type of laser vision correction, a thin corneal flap is created on the surface of the eye. When the flap is made, the abundant supply of corneal nerves are also cut. This results in a partially anaesthetized corneal surface. It requires 3-6 months for these nerves to re-grow and provide the cornea normal sensation. As a result, the normal tear production is also interrupted and everyone experiences some degree of dryness, especially the first 2-4 weeks. There are numerous artificial tears and lubricating drops available as over-the-counter products. We initially recommend the preservative free products to prevent any unnecessary toxic response. But, as your eyes improve, switching to the more convenient bottles of preserved products is allowed. If the frequent use (at least every hour) of artificial tears does not improve your symptoms, then temporary or permanent closure of a tear duct can provide added relief. Since this is a temporary condition (3-6 months) in most cases, many patients do extremely well by simply lubricating their eyes with artificial tears. How do I know if I need an enhancement? The schedule of routine post-op visits includes a one day, two week and 3 month visit. Since the vision may fluctuate as the cornea heals, we recommend waiting a minimum of 3 months to reevaluate your visual results. When we reevaluate, we look at such things as your vision without glasses & your prescription where we measure any residual astigmatism or mild over or under-correction. We ask about your night time driving and your reading vision. If your vision is not as good as you think it should be, and if there is a minor residual correction that can be treated with the laser, than an enhancement is discussed. Enhancement surgery is actually easier than the initial procedure because a flap is already present. In most cases, our surgeons simply identifies the edge and lifts up the original flap without cutting a new one. Because the cornea heals this layer very slowly, it can easily be lifted up to 1-2 years after surgery. In some instances a new flap is required and your surgeon can explain why it might be best in your particular situation. Either way, with LASIK touchup surgery is easy and usually requires much less laser energy to fine tune your vision. However, the healing process is the same and requires another 3 months to determine the final result. Implantable Contact Lens (ICL) LASIK is highly effective method of treating moderate amounts of myopia (nearsightedness) and low amounts of hyperopia (farsightedness), but is not effective for larger amounts of myopia or even moderate amounts of hyperopia. Clear Lensectomy, discussed elsewhere, is a viable alternative, particularly in the age group that requires bifocals or reading glasses. For those patients below the age of 40 however, a new alternative will shortly be available. This alternative is the "Implantable Contact Lens". The Implantable Contact Lens or "ICL" is an extremely thin lens made of a new material called "Collamer". It is inserted surgically into the eye in a five minute procedure. It can be made in any power, therefore it can correct even extremely high amounts of refractive error. We have been involved with this lens since inception. Doctor Shepherd made two trips to Russia with engineers from STAAR Surgical in 1991 and 1992 to observe the Russian model. The STAAR ICL is a refined version of this original lens and has subsequently been implanted in over 5000 eyes throughout the world. Doctor Shepherd was the first American to implant the ICL and has been one of five Americans to test both the myopic and the hyperopic model during the ongoing FDA investigative series. Once these ICL's are approved, they in combination with LASIK, will allow your surgeon to achieve most refractive corrections. Shepherd Eye Center is proud to offer patients the skills of our highly qualified and prominent physicians. Our center has been chosen as one of the first sites in the nation to use the latest advancement in the field of refractive error correction and this reflects the caliber of staff and quality of eye care that patients receive here on a daily basis. Shepherd Eye Center awaits the opportunity to consult with your on all of your eye care needs. Clear Lens Replacements This procedure uses the same highly advanced technique practiced during routine cataract surgery. This accurate process involves the surgical removal of the clear, natural lens of the eye. It is then replaced with an artificial lens implant calculated specifically for the necessary amount of nearsightedness or farsightedness. This surgery does involve a slightly greater degree of surgical intervention so it is usually reserved for those patients who do not fit the criteria for LASIK. These are patients with higher degrees of nearsightedness or farsightedness which are not safely treated with laser vision correction or those patients with early cataract changes. Our surgeons perform  cataract procedures with artificial lens implantations that can correct both far and near vision , working best for those with advancing cataracts. The newest multifocal ReStor and ReZoom intraocular lens has allowed many of our patients minimal dependence on their spectacles. This exciting advancement in lens technology allows patients to see both distance and near, even for those patients over the age of forty who might otherwise need bifocals or reading glasses. One added benefit: these patients will never need cataract surgery since the natural lens that turns cloudy with a cataract has already been removed!   Top of Page   Click Here to go to the LVC FAQs