What is LASIK?
What Happens During the LASIK Procedure?
When you arrive at the Laser center you will be asked to fill out some forms. If you are very anxious let us know. We can give you a Valium to take the edge off. Once in the laser room, one eye will be lightly patched, while the other eye receives some drops (antibiotic, and anesthetics). A speculum will be carefully placed in the eye to keep it open. Anesthetic drops are used to eliminate pain but not pressure or temperature. Therefore, you might be aware of the speculum. There is no pain during or after the procedure.
You are totally awake during the procedure. First, the cornea is marked, then the the keratome is placed over the eye. Suction is now applied so that the keratome will not move while on your eye. When your vision goes blank from the suction, the keratome creates a hinged flap. Now, the keratome is removed and the flap is laid back. You will be instructed to look at red light while the laser re-sculptures your cornea. Lastly, the corneal flap is laid back in place and smoothed out.
The laser removes 39 millionths of an inch of tissue in 12 billionths of a second which enables us to achieve a remarkable degree of accuracy. The stronger your prescription the longer the procedure takes. Even strong prescriptions take less than a minute of laser time. Afterwards, it is not unusual for the eyes to feel scratchy and irritated. A short nap or sleep eliminates many of these sensations. LASIK dramatically reduces recovery time with most patients returning to work and seeing quite well the next day.
Patients with higher prescriptions may recover more slowly from LASIK and may not notice dramatic visual results until a few days after their procedure. Some of the benefits of LASIK include short recovery time, rare infection, infrequent enhancement rate, low risk of scarring, absence of real pain, a high degree of predictability, preservation of all layers of the cornea and success in a wide range of refractive errors.
Am I a Candidate?
LASIK can correct vision in most patients who have near-sightness (myopia), far-sightness (hyperopia), astigmatism, and/or presbyopia (can’t focus anymore because you are a baby-boomer). To be eligible you should be 18 years of age or older and free from significant health or ocular disease such as cataracts, corneal disease or glaucoma. Also, you must not be pregnant or actively nursing. During your initial free consultation we will advise you of your probable outcome based on your eyeglass prescription, healing profile and expectations. The results and research gained from tens of thousands of procedures have been shared which allows: us to continually fine-tune techniques; more effectively forecast visual results; and counsel new patients. Although we can’t promise patients “perfect” vision, most laser patients achieve 20/20 vision. They no longer need glasses or contacts for most daily activities.
Laser vision correction has been performed around the world since the late 1980s. Clinical studies over the last six years have looked extensively at long-term effects of the laser on the cornea. No study has shown any negative long-term effects on the eye. The first nearsighted patient’s eye treated with laser vision correction in the USA was in 1987; that patient achieved 20/20 vision and still sees 20/20 today. The chance of having a vision-reducing complication is less than 1%. The most frequent long term complication is ghosting or flare at night. This usually happens when the treatment area is smaller than the pupil size. This complication usually can be be eliminated by using the new spot type of laser, which eliminates the junction between the area treated and not treated.
There have been no reported cases of permanent blindness resulting from laser refractive corrections. The few patients who do require an enhancement or develop a problem will usually do so within the first few months following the procedure rather than years later.
I Hear That There Are Different Lasers Which One is Best?
There are different lasers each having specific benefits for patients with different eyes. For example the flying spot are better for large pupils with larger refractive errors, while a broad beam laser, takes off less corneal tissue. Spot lasers remove more tissue, but eliminate problems of glare by feathering the junction zone. Different lasers are better for mixed astigmatism while others are better for hyperopia. Based on your eyes, pupil size and your refractive error we will use the appropriate laser.
When the Hubble telescope was sent into space, NASA wanted the best pictures ever. The optical engineers “re-invented optics”; they learned that there was more than just correcting simple focusing errors such as myopia (nearsightness), hyperopia (farsightness) and astigmatism. They corrected “higher order optical aberrations”. In English this means that they corrected small errors which nobody thought made a difference. Specifically, these small errors caused ghosting and glare which was often associated with LASIK procedures. These small errors become more important when the optical error is large (-6.00 and more) and when the pupils are big.
Correction of these fine errors requires specialized instruments that measure wave fronts of light. Wave front measurements are more accurate but they have a downside. Wave front technology with custom corneal ablation (shaping) removes more corneal tissue. Sometimes, this results in a cornea that is too thin. Most patients will not perceive the difference between wave front and non-wave front guided LASIK. Ask anyone who has already had LASIK, they will tell you how thrilled they are.
What Can Be Done If My Cornea is Too Thin or If I Have a High Refractive Error?
Photorefractive Keratectomy (PRK) was invented in the early ’80s and approved by the FDA in 1995. The procedure was practiced in other countries for years with many Americans going to Canada before it was approved in the U.S. PRK is performed with an excimer laser just like LASIK except there is no flap. The laser removes tissue from the surface of the cornea altering the shape of the cornea to correct the refractive error. PRK usually takes less than a minute per eye. Both myopia and hyperopia can be corrected with PRK. With myopia the procedure flattens the; with hyperopia the laser is used to steepen the cornea. PRK, can correct also correct astigmatism. PRK fell out of favor with advent of the almost painless LASIK procedure. It has been replaced with the newer more comfortable and predictiable LASEK and/or Epi-LASIK procedures.
LASEK (laser epithelial keratomileusis), epithelial LASIK and E-LASIK, which all the same procedure, is a relatively new procedure that is a variation of PRK. LASEK is used most commonly for people with corneas that are too thin or too flat for LASIK. It was developed to reduce the chance of complications that are associated with a flap created by LASIK, e.g. a cornea which is too thin. In LASEK, the epithelium, or outer layer of the cornea, is cut with a fine blade similar to a cookie cutter called a trephine. Afterwards, the surgeon covers the trephined section with an alcohol solution for approximately 30 seconds. The solution loosens the epithelium so that the surgeon can lift the edge of the epithelial flap and fold it back out of the way. Then the an excimer laser is used to sculpt the corneal tissue underneath. Lastly, the epithelial flap is placed back on the eye and smoothed down.
The flap edge heals in about a day, though patients usually wear a bandage contact lens for around four days. Most likely you will feel eye irritation during the first day or two. Vision may not recover for four to seven days. Of course, it varies from one person to the next.
Epi-LASIK is similiar to LASIK – an epikeratome is used to separate the outer layer of the cornea known as the epithelium. Since alcohol is not used, patients usually report less pain than with LASEK and tend to heal faster.
Are There Other Methods To Correct Refractive Error?
Good News - for patients with thin corneas or myopia over -12.00 – there are new ways to correct your refractive error. Lens implants can be used to eliminate near-sightness. A lens implant similar to what is used in cataract surgery is inserted between the cornea and iris. Currently, there are three major designs (Staar Surgical Implantable Contact Lens, Nuvita, and the Ophtec Artisan Lens). We have had the greatest success with the Artisan Lens. The advantage is that they can be removed, do not effect the focusing system of the eye, they do not cause thinning of the cornea, and they are not contra-indicated in patients who have or might have glaucoma.