Utilizing the accuracy and precision of the excimer laser, LASIK changes the shape of the cornea to improve the way light is focused or “refracted” by the eye. By adjusting the pattern of the laser beam through its computer, it is possible to treat high levels of nearsightedness, farsightedness and astigmatism. LASIK surgery is performed as an outpatient procedure in the comfort and convenience of the excimer laser surgical suite. The entire vision correction procedure takes less than 20 minutes and both eyes are done the same day. The procedure is performed using topical anesthesia (eye drops). Post the procedure, some patients feels a burning sensation and a foreign body sensation, along with watering of the eyes. These symptoms can generally be relieved with eye drops, and go away in a few hours. Patients can feel a remarkable improvement in their vision within a day. Most patients return to their normal activities within a day.
LASIK Step by Step
The LASIK procedure takes a few minutes to complete, and the procedure is relatively painless. Patients are often amazed at the speed, comfort and ease of the LASIK procedure. Only topical anesthetic drops are used to numb the eye for the procedure. An eyelid holder is inserted to prevent blinking while the drops eliminate the reflex to blink.
A suction ring is placed on the eye to secure the eye and maintain pressure within the eye while the corneal flap is created. 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 beneath the upper eyelid.
The corneal flap is 160 to 180 microns thick, about 30% the corneal thickness which is typically about 550 microns. Patients do not feel or see
the cutting of the corneal flap, which takes only a few seconds. Corneal “flap making” has been researched and developed for 40 years, providing us with a long history of safety and stability.
The corneal flap is then laid back and the inner stromal layers of the cornea lasered with the patient’s prescription. An ultraviolet light from the excimer laser reshapes the internal cornea with an accuracy of 1/2000th of a milimetre.
For reshaping the cornea, the corneal surface is polished with the help of a pre-programmed excimer laser. This changes the refractive power of the cornea thus eliminating the refractive error of the eye.
The corneal flap is then repositioned and the flap and interface rinsed. Once the procedure is completed, the surgeon will 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 adherence within the cornea. While it is possible to dislodge the corneal flap during the first day or two by physically rubbing the eye, this event is actually quite rare.
After the first week, LASIK patients can resume their full exercise activities. No bandage or bandage contact lens is required after the LASIK procedure. However, sun glasses are usually recommended for constant wear during the first post procedure day, LASIK patients are placed on an antibiotic and anti-inflammatory drop regimen for around 5-7 days. Artificial tears are recommended for a few weeks after the LASIK procedure. Patients are able to travel by car or air after the first day.
LASIK is generally considered the method of choice for using the Excimer Laser for correcting refractive errors. Another popular technique is Photo Refractive Keratectomy or PRK. LASIK is generally the method of choice because it allows faster post-operative recovery of vision, requires less follow-up, and allows the patient to be more comfortable faster. However, there are circumstances under which it is more appropriate to use PRK in some patients. Your New Vision eye surgeon will advise you appropriately.
In more recent years, Step 1 in LASIK is increasingly performed using a femtosecond laser, in which case, the procedure is called Bladeless LASIK or Femto LASIK or iLasik. There is another, even more recent technique, ReLEx smile, which is done completely with the femtosecond laser.
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