Laser Assisted in-situ Keratomileusis: Who are the candidates, How is it Done, Risks, Success Rate?

Keratomileusis is a surgical procedure for correcting the refractive power of the eye to improve vision that typically involves reshaping the cornea in place with the use of an excimer laser. This is considered to be a very effective treatment for myopia, astigmatism, and hyperopia due to many advantages over other procedures. Success of a LASIK procedure largely depends on the selection of a proper candidate. According to Market Scope, around 10 million Americans have had LASIK procedure since it was first approved by the FDA in 1999. The latest research reports 99 percent of patients achieve better than 20/40 vision and more than 90 percent achieve 20/20 or better.

Keratomileusis a surgical procedure for correcting the refractive power of the eye to improve vision that formerly involved removing, freezing, reshaping, and reinserting a section of the cornea but now typically involves reshaping the cornea in place with the use of an excimer laser. The term keratomileusis comes from the Greek language meaning “cornea” and “to carve.” When keratomileusis is combined with the accuracy of laser excimer for correction of different refractive abnormalities, the process is called LASIK or laser-assisted in-situ keratomileusis. This is considered to be a very effective treatment for myopia, astigmatism, and hyperopia due to many advantages over other procedures. Laser Assisted in-situ Keratomileusis procedure is highly efficacious, provides a quick visual recovery, and the patient as to undergo minimum discomfort.

Success of a Laser Assisted in-situ Keratomileusis or LASIK procedure largely depends on the selection of proper candidate. The selection depends on many criteria; some of them are mentioned here.

The person who is considered for a Laser Assisted in-situ Keratomileusis procedure or LASIK procedure must not have any eye condition that may affect healing of the eye after the LASIK procedure. Some of these conditions are conjunctivitis, severe dry eye syndrome, infection or any type of injury to the eye. Cataract that interferes with your vision and glaucoma can also prevent you from having a LASIK procedure.

Corneal thickness makes a big difference in choosing a candidate for LASIK procedure. Laser Assisted in-situ Keratomileusis procedure or LASIK procedure involves reshaping the cornea to correct different refractive errors. If the corneal thickness is thin or its surface is extremely irregular or misshapen (keratoconus), the procedure may compromise your results and impair your vision.

Overly large pupils could increase the risk of side effects like glares, halos, and startbursts.

Age plays an important role in selecting a candidate for LASIK. The U.S. Food and Drug Administration has not approved Laser Assisted in-situ Keratomileusis procedure or LASIK procedure for people under 18 years of age. Since young eyes are still developing, there is a good chance that children’s vision will continue to change even after LASIK procedure. LASIK should not be performed until the patient’s vision does not become stable.

Another criterion is that the vision should be stable in at least past one year. It is important for refractive errors to be stable for at least 12 months before undergoing LASIK.

Certain types of diseases are considered to affect the outcome of the Laser Assisted in-situ Keratomileusis procedure or LASIK procedure and hence are contraindicated in patients who are willing to go for this procedure. These conditions are some uncontrolled degenerative conditions, uncontrolled autoimmune diseases like Sjogren’s syndrome, rheumatoid arthritis, type 1 diabetes, and AIDS.

During pregnancy you should avoid having LASIK as the hormonal changes can change the shape of the cornea. Laser Assisted in-situ Keratomileusis procedure or LASIK is usually not advised to people who have keratoconus or have a family history of it, have fairly good overall vision, have severe nearsightedness, have very large pupils or thin corneas.

Before the Laser Assisted in-situ Keratomileusis procedure or LASIK procedure, your caregiver will discuss what to expect before and after the procedure. Your medical history will be discussed as this will help your caregiver to understand if this procedure is suitable for you at the time or you will have to wait. Your eyes will be tested for measuring corneal thickness, refraction, and corneal mapping. After all your questions are answered by your surgeon, you will be given your date of procedure. Your surgeon will guide you when you need to stop wearing the lenses depending on the type of lens that you are using.

Laser Assisted in-situ Keratomileusis procedure or LASIK is performed to reduce the dependency of a person on glasses or contact lenses. This is an outpatient surgical procedure that usually requires about 15 to 30 minutes. Firstly, topical eye drops are applied to numb the eye. Area around the eye is cleansed. You may also be given a sedative (oral diazepam 5 to 1 0 mg) to help you relax. A lid speculum is used to keep the eye open throughout the procedure. A suction ring is placed that creates suction on the cornea. You may feel pressure and experience dimming of your vision at this point in the procedure. Once the ring is attached, your doctor will attach a device called microkeratome to the suction ring. With the help of the blade on the microkeratome, your doctor will create a thin flap by cutting the outermost layer of the cornea and lifting it carefully to one side. After removing the ring and the microkeratome, your doctor will use pulses from a computer-controlled excimer laser to reshape your cornea. The patient is asked to look at the fixation light. After the corneal correction, the flap is placed into its original position and the eye is observed for several minutes, because the cornea binds so quickly, healing is rapid and the eye does not require stitches.

If you need correction in both the eyes, the doctor will generally do it the same day.

Immediately after the procedure, itching, burning, or a feeling of something stuck in the eyes is normal. You may feel like there is a particle in your eyes. In any case, you should not rub your eyes as it may disturb the flap that needs some time to settle. You may be instructed to wear a patch for few days. You will be given eye drops and you must take them on time. The machinery and instruments used during procedure are sterile, but during the healing process bacteria can invade below your flap.

American Refractive Procedure Council suggests avoiding bacterial infections after LASIK. You should avoid contacting any source of contaminated water such as lakes, rivers, ocean, swimming pools, and hot tubs. You should keep soaps and other chemicals out of your eyes.

If your vision is bothersome after 3 months of the procedure, you may be recommended a LASIK enhancement procedure to sharpen your eyesight.

Dry eye is a common risk of Laser Assisted in-situ Keratomileusis procedure or LASIK surgery. After surgery you may have difficulty seeing at night. You might get glare, halos around bright lights. If the laser removes too little tissue from the eye (undercorrection), you will not get the kind of clear vision that you were expecting. You may need another LASIK to overcome this problem. Laser may also remove too much tissue from your eye (overcorrections). Overcorrections are more difficult to fix. Uneven tissue removal can cause astigmatism, which may require another surgery, glass, or contact lens. Sometimes the outermost layer of the cornea can grow abnormally underneath the flat during the healing process.

The latest research reports 99 percent of Laser Assisted in-situ Keratomileusis procedure patients achieve better than 20/40 vision and more than 90 percent achieve 20/20 or better. In addition, LASIK has an unprecedented 96 percent patient satisfaction rate – the highest of any elective procedure. (Journal of Cataract & Refractive Surgery, Vol. 42, Issue 8, August 2016, Pages 1224-1234).

According to Market Scope, around 10 million Americans have had Laser Assisted in-situ Keratomileusis procedure or LASIK procedure since it was first approved by the FDA in 1999. Around 700,000 LASIK surgeries are done each year, but that’s down from a peak of 1.4 million in 2000.

Before deciding to get a Laser Assisted in-situ Keratomileusis procedure or LASIK done, you should sit down with a LASIK surgeon. It’s only by talking with a surgeon that you can find out whether you’re a good candidate for LASIK and ask your questions about the LASIK success rate. The surgeon can help you understand what to expect from the procedure, what the experience will be like during and after the surgery, and how your life and your lifestyle will change.