LASIK – one of Laser vision correction has within the last decade emerged as a safe and effective means of correcting near-sightedness, far-sightedness, and astigmatism. It has been accepted worldwide as a valid permanent alternative to glasses or contact lenses wear and over two million people undergo the procedure each year with satisfying results.

Most patients find that they can combine an enjoyable vacation with their LASIK surgery here in Thailand for less than the cost of LASIK alone in their own country. LASIK can be both effective and affordable. Many find that the cost of replacing glasses and contact lenses can, over years, easily exceed the cost of LASIK surgery. In fact, the one-time LASIK procedure can be healthier for the eyes than decades of uncomfortable contact lenses wear.

What is LASIK ?
LASIK is a laser surgery technique used to correct refractive errors of the eye including nearsightedness , farsightedness and astigmatism . The word LASIK is an acronym for LAser In-situ Keratomileusis, which means, “to reshape the cornea with laser” The LASIK Procedure involved the use of a special type of laser called the Excimer Laser. The Excimer Laser creates a “cool” beam of ultraviolet light. This makes the Excimer Laser ideal for corneal surgery because it can vaporize (ablate) corneal tissue without causing thermal damage to surrounding tissue. 

LASIK Procedures :

• Before activating the laser, the doctor creates a flap on your cornea using a microkeratome . A microkeratome is a tool with a blade that cuts a circular flap of tissue from the surface of the cornea. 
• The doctor lifts the flap and folds it out of the way of the laser. 
• The excimer laser removes tissue from the eye according to the treatment plan. This unique treatment plan created for your eye from measurements included Wavefront system.
• After the laser finishes, the doctor repositions the flap.The flap will adhere tightly to the stromal bed without the need for sutures. 

Why it’s so popular ?
Introduced in the early 1990s, LASIK is currently the most popular laser corrective eye surgery because advantages of the results help : 

• Reduce or eliminate your dependence on contact lenses or glasses
• No more having hunt for glasses or struggle with contact lenses 
• Freedom to play sport. May even increase your performance edge when no optical lenses are needed. 
• Freedom to dive without the need for lenses prescription masks.
• Enjoy traveling without the need to bring along all of your extra glasses and contact supplies
• Improved career prospects with clear unaided vision

The procedure is less-invasive and convenient

• Consultation and surgery can be done in the same day 
• Both eyes can be treated at the same time 
• No injection, No suture, No hospitalization 
• Little discomfort 
• Rapid visual recovery 
• High accuracy and safety
• Minimal regression

Am I a good candidate for LASIK ? LASIK is not for everyone. Only an eye care professional trained in laser vision correction can determine whether you are a suitable candidate for the LASIK procedure. It is important to discuss the risks associated with the procedure and any questions you may have about the procedure with your doctor.

If you are considering LASIK, you must :

• Be at least 18 years of age with stable refraction
• Have healthy eyes that are free from eye diseases or corneal abnormality (e.g., scar, infection, etc.).
• Have documented evidence that your refraction did not change by more than 0.50 diopters during the year before your pre-operative examination. 
• Be informed of LASIK risks and benefits as compared to other available treatments for nearsightedness with or without astigmatism. 
• Be able to lie flat without difficulty. 
• Be able to tolerate local or topical anesthesia. 
• Be willing to sign an informed consent form as provided by your eye care professional. 
• Be able to keep your eye accurately on the fixation light for the entire laser surgical procedure. 

CONTRAINDICATIONS:
You should not have refractive surgery if

• You have active collagen vascular(e.g., rheumatoid arthritis), autoimmune (e.g., lupus), or immunodeficiency diseases (e.g., AIDS) because these conditions affect the body’s ability to heal. 
• You show signs of keratoconus (corneal disease) or abnormal corneal shape 
• You are pregnant or nursing, because these conditions may cause temporary and unpredictable changes in your cornea.

WARNINGS: Discuss with your doctor if 

• You are diabetic
• You have severe allergies and take medicines regularly. 
• You have had a history of Herpes simplex or Herpes zoster keratitis 
• You have a significant dry eye that is unresponsive to treatment
• You have a medical condition you are uncertain about
• You are taking
  • isotretinoin (Accutane) used for the treatment of acne because common side effects are dry eyes ,watery eyes conjunctivitis and lids inflammation. Prior to LASIK evaluation, please consult your doctor who prescribe this medication whether you have to stop using these medication at least 1 month before and after LASIK. 
  • amiodarone hydrochloride (Cordarone) used for heart rhythm control .Some patients develop symptoms of halos, photophobia, dry eyes or other sight-threatening ophthalmic abnormalities. 
  • sumatriptan (Imitrex) used for migraine headaches. This medication make wounds to heal harder and change in vision. Fortunately, sumatriptan is not for routine use, only to relieve your migraine headache as soon as symptoms of the migraine appear. 

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Adverse Events and Complications
Some patients experienced adverse events and complications after CustomVue™ LASIK treatment Flap complications ( less than 1%)  Incomplete or irregular flap creation

• Scratch on the surface of the eye with microkeratome
• Inflammation of the cornea under flap
• Wound infection Visual symptoms and problems Some patients experience these symptoms and problems during first to sixth months after LASIK due to corneal healing and remodeling. Severity and risk of having such problem permanently depends on pre operative eye conditions.
• Dry eyes
• Blurry of vision 
• Fluctuation of vision
• Difficulty at night with glare
• Halos ( hazy rings around bright lights)
• Ghost or double images 

What Warnings and Other Information Do You Need to Know About?

Warnings
If you have more severe nearsightedness or astigmatism, your results may not be as good as those reported in this clinical study. If you have any of the following conditions, you may have LASIK if your doctor evaluates the seriousness of your condition and believes the benefit of having LASIK is greater than the risk.

• Diabetes. If you have diabetes, LASIK may be risky for you because your diabetes may interfere with the healing of your eyes.
• History of Herpes simplex or Herpes zoster infection that has affected your eyes. If you have had a Herpes simplex or a Herpes zoster infection that affected your eyes, and have an infection now, LASIK is more risky for you. Pre-medication is recommended to decrease risk.
• Symptoms of significant dry eye. If you have severely dry eyes, LASIK may increase the dryness. This may or may not go away. This dryness may delay healing of the flap or interfere with the surface of the eye after surgery.

Precautions
It is unknown whether LASIK is safe and effective for the following conditions. You should discuss these conditions with your doctor:

• Unstable eyes that have changed in their visual acuity more than 0.5 diopters in nearsightedness or astigmatism in the last 12 months, and your nearsightedness or astigmatism is getting worse. If your eyes are unstable, the right amount of treatment cannot be determined. This may result in poor vision after LASIK.
• Corneal disease or abnormality (e.g., scar, infection, etc.). If you have an abnormal corneal condition, such as corneal scars, because it may affect the accuracy of the LASIK treatment or the way your cornea heals after LASIK. This may result in poor vision after LASIK. If your eyes have an active disease, it is unknown whether LASIK is safe and effective under this condition.
• History of injury or surgery to the center of the cornea (for example, surgery to correct vision such as RK, PRK, LASIK), or other surgery on the eye. If your eyes are injured or you have had surgery, it is unknown whether LASIK will weaken the cornea too much.This may result in poor vision after LASIK.
• Corneas are thin. If your corneas are too thin to allow your doctor to cut a proper flap in the LASIK procedure, you can’t have LASIK because it is necessary to have a flap.
• History of glaucoma or have had pressure greater than 23 mmHg inside your eyes, because it is unknown whether LASIK is safe and effective for you.
• Take medicines that might make it harder for wounds to heal, such as Sumatriptan (Imitrex®*) used for migraine headaches, because it is unknown whether LASIK is safe and effective for this condition.
• Undiagnosed dry eyes. Your doctor should also evaluate you for dry eyes before surgery. You may have dry eyes after LASIK surgery even if you did not have dry eyes before surgery.
• Large pupils. Before surgery, your doctor should measure your pupil size under dim lighting conditions.
• Dim lighting, rain, snow, fog, or bright glare. You might have difficulty seeing in dim lighting, rain, snow, fog, or bright glare. Whether you may have poor vision under these conditions is hard to predict because it has been studied so little.
• Any other medications you are taking. Let your doctor know if you taking any prescription medicines or any medicines you bought without a prescription.