12 April 2011


What is Lasik ? Why Lasik ?

Lasik is an elective procedure wherein the curvature of the eye is reshaped in a matter of seconds to correct the "power" of the eye. This is done with the help of the Excimer Laser. The Laser is controlled by a computer and the reshaping process is done under a thin flap of cornea which is lifted with the help of a microprecision instrument known as the Microkeratome.
It is the most advanced technology available in the world to help treat refractive errors such as SHORTSIGHT, LONGSIGHT, and ASTIGMATISM.
What is Lasik (Excimer Laser) ?
The excimer laser (lasik) is an ultraviolet laser, which utilizes Argon and Fluorine gas to create a non-thermal, or cool beam, of laser light which can break molecular bonds in a process commonly referred to as "photoablation". A simple way to imagine how the laser works is to think of it as placing the curvature from your glasses or contact lenses onto the front surface of your eye, allowing you to see without corrective eyewear.
The most important aspect of the excimer laser is that it is remarkably precise. It is able to remove 0.25 microns of tissue in a single pulse; that is, 1/200th the thickness of a human hair, 1/40th of a human cell, 1/28th of a red blood cell, or 39 millionths of an inch in 12 billionths of a second!
There are two procedures which use this unparalleled precision by applying computer controlled pulses of laser light to reshape the eye to correct nearsightedness,astigmatism and farsightedness; PRK and LASIK.
PRK, or photorefractive keratectomy, is a refractive surgery technique, which reshapes the surface of the cornea, while
LASIK, or laser in situ keratomileusis, reshapes the inner layers of the cornea. Lasik works well for even moderate & high degrees of myopia and is the procedure of choice today.
LASIK offers faster and more comfortable visual recovery, more accurate results and better corneal transperancy as compared to PRK.
It is this advantage of healing combined with the precision of the excimer laser that has made LASIK the overwhelming procedure of choice at LASER VISION and at other dedicated centers performing large numbers of procedures.
Why Choose LASIK?
The number of people considering refractive surgery is at an all time high and LASIK is considered by virtually all refractive surgeons worldwide to be the procedure of choice today.
LASIK dramatically reduces your recovery time (versus PRK) and decreases the chance of many of the procedural risks (compared to ALK or RK). The procedure itself takes only a few minutes to complete and involves minimal discomfort. LASIK requires more technical skill and training than other laser procedures.
The following are some of the benefits of LASIK:
  • brief recovery time
  • low enhancement rate
    very low infection risk
    relatively quick procedure to complete
    very low risk of scarring
    minimal discomfort & NO Pain
    high degree of predictability
    preservation of the cornea (all corneal layers preserved)
    excellent ocular integrity post-treatment
    widest range of correctable prescriptions

The LASIK Procedure - Step by Step
LASIK, when performed by an experienced surgeon, takes about 4 to 5 minutes to complete, about the same length of time as PRK. Both PRK and LASIK procedures are completely painless. Patients are always amazed at the ease of both these procedures because of their speed and comfort. In both procedures only topical anesthetic drops are used to numb the eye for the procedures. An eyelid holder is inserted to prevent blinking while the drops eliminate the reflex to blink.
In the PRK procedure, the protective epithelial layer is first removed revealing the next layer known as Bowman's layer. Epithelial removal can be performed mechanically or with the laser, with most surgeons using the mechanical technique, which is felt to be more predictable.
With LASIK, the epithelial layer is left intact, allowing for not only faster visual recovery but also improved comfort and safety. With PRK, the surface of the cornea is lasered with the patient's prescription, removing Bowman's layer.

Step 1
A suction ring is placed on the eye to secure the eye and maintain pressure within the eye while the corneal flap is created.
Step 2
A microkeratome, an automated microsurgical instrument similar in design to a carpenter's plane, is used to create a thin corneal flap, which remains hinged by the nose or beneath the upper eyelid. The corneal flap is about 150 microns thick, about 30% the corneal thickness, which is typically about 550 microns. The creation of corneal flaps has actually been performed for four decades providing us with a long history of safety and stability. Patients do not feel or see the cutting of the corneal flap, which takes only a few seconds.
Step 3
The corneal flap is then laid back and the inner stromal layers of the cornea lasered with the patient's prescription.
Step 4
The corneal flap is then closed and the flap and interface cleaned with a sterile solution.
Once the procedure is completed, most surgeons wait 2 to 3 minutes to ensure the corneal flap has fully re-adhered. At this point, patients can blink normally and the corneal flap remains secured in position by the natural suction within the cornea. While it is possible to dislodge the corneal flap during the first day or two by physically rubbing the eye vigorously, this event is actually quite rare. After the first week, LASIK patients can resume their normal exercise and activities.
Since the protective layer remains intact with LASIK, no bandage contact lens is required. LASIK patients are only placed on an antibiotic and anti-inflammatory eye-drops for 2-3 weeks. Whereas the vision is usually quite blurry with PRK for 3 to 5 days, it is usually quite good within 12-24 hours with LASIK.
LASIK patients are instructed not to vigorously rub their eyes for 3 days. Most patients are able to travel immediately and return to normal activities within 1 week.

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