What is Lasik?
Refractive procedures manipulate the eye to improve vision. Though there are several types of refractive procedures, the most popular is known as LASIK (laser assisted in situ keratomileusis). LASIK involves reshaping the cornea using incisions and lasers. An incision creates a flap which is folded back.
The number of people considering refractive surgeries with LASIK is at an all-time high. LASIK (laser in-situ keratomileusis) is a procedure whereby an automated micro-keratome is used to create a corneal flap. Afterwards a cool, ultraviolet laser beam is applied, which reshapes the curvature of the cornea. Lastly, the flap is carefully laid back in its original position. The flap is held by suction just like when you put a drop of water between two pieces of glass. Within a short period of time the cornea’s healing strengthens the seal. Though no procedure is perfect, the excimer laser has an unparalleled degree of precision and safety. 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. To be eligible you should be 21 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 consultation we will advise you of your probable outcome based on your eyeglass prescription, healing profile and expectations. If your prescription has changed a great deal over the past year you are also not eligible Although we can’t promise patients “perfect” vision, most laser patients achieve 20/20 vision or close to 20/20 vision. They no longer need glasses or contacts for most daily distance activities. If you are over 40 or require reading glasses you will probably still require a reading prescription after the procedure.
For more information and a chance to talk to our eye doctor call Hartsdale Family Eyecare at (914) 725-1600.
Is LASIK safe?
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.
What Should I Know About Surgery?
There are three parts to LASIK surgery: pre-operative care, surgery, and follow-up care. All three are important to insure the best results.
The first step is the initial consultation to determine if you are a candidate. During this examination we will determine your refractive error, examine the front of the eye, make sure that there is no irregular astigmatism, or other corneal problem. We will have you remove your contact lenses (2 weeks for soft contact lenses and 1 month for every decade of CL wear for gas permeable/hard lenses). We will measure your eyes during this period of removal of contact lenses to make sure that your prescription is stable. No surgery should be done until the vision is stable. Proper LASIK requires multiple pre-operative visits. Determination of the proper refraction is extremely important. Remember garbage in garbage out, no matter how good the laser is.
What is Wavefront Technology and is it an Improvement?
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 wavefronts of light. Wafefront measurements are more accurate but they have a downside. Wavefront 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 wavefront and non-wave front guided LASIK. Ask anyone who has already had LASIK, they will tell you how thrilled they are.
Besides Lasik Are There Other Methods to Correct my 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 nearsightness. A lens implant similar to what is used in cataract surgery is inserted between the cornea and iris.
For patients under -6.00 sphere and -1.75 astigmatism there is a new procedure to reshape the corneal surface without surgery. This procedure uses a contact lens to reshape the cornea while you sleep. Ask Dr Schwartz for more details