What is LASIK laser eye surgery?
LASIK (Laser assisted in-situ keratomileusis) is an elective eye “re-shaping” surgical procedure used to improve the refractive state of the eye and decrease the dependency on contact lenses or glasses. It is used on nearsighted, farsighted and astigmatic eyes. LASIK surgery typically results in rapid recovery of vision. It is the most commonly performed refractive eye surgery.
About the LASIK Procedure
Potential LASIK candidates will receive a complete and thorough eye exam. Very careful refraction tests will be performed to determine the precise refractive error of the operative eye.
In order to rule out possible irregular corneal defects, a detailed surface map of the cornea will be performed.
Prior to the surgery, an Excimer laser instrument is customized and pre-programmed to treat the specific refractive error of the patient.
During the LASIK procedure, anesthetic eye drops will be used to numb the eyeball and corneal surface. The patient should experience no discomfort.
An instrument called a speculum is placed on the eyelids to prevent blinking and eye movement. A ring will be placed on the eye to hold it steady.
A thin surface flap of the cornea is made using a microkeratome — a precision surgical blade. The flap is lifted like a hinged door exposing the underlying corneal tissue. The surgeon then applies the Excimer laser beam to the exposed corneal layer. This laser “ablation”, which usually takes less than one minute, removes targeted inner-corneal tissue, reshaping its surface and giving it a more normal curvature. The thin, outer flap is then replaced. The surgeon observes the eye under a microscope for a few minutes to make sure the flap is securely in its place. The speculum is removed and the patient usually leaves the eye center within an hour after surgery.
Visual Results with LASIK
Surgical results are often dramatic, with most patients noticing a very rapid increase in visual acuity. Same or next day improvements in vision are common. Vision usually continues to improve for3-4 weeks as the cornea heals.
In some cases, it may take a few months to realize final visual acuity gains.
The overwhelming majority of cases result in vision improvements good enough to eliminate distance glasses. Although technology continues to improve LASIK’s success, it should be stated that not all patients can expect to see well without glasses or contact lenses postoperatively. Patients with large amounts of myopia, hyperopia or astigmatism should avoid expectations of “perfect” vision.
LASIK Candidates
LASIK is used to treat refractive errors like myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. LASIK candidates are those patients with moderate levels of refractive error. The candidate should be one who no longer wishes to wear glasses or contact lenses. LASIK is an elective procedure that carries, like any surgical procedure, a certain amount of risk and benefits. The patient should be counseled regarding outcome expectations and be willing to accept these the potential risks.
Possible Complications
The most common complications include postoperative glare, halos or starbursts around lights at night, corneal infection. Complications that threaten the vision and eye itself are very rare.
PRK (Photorefractive Keratectomy)
Like LASIK, Photorefractive keratectomy (PRK) is a corneal “re-shaping” surgical procedure intended to reduce the patients need for glasses or contact lenses. The PRK procedure also employs an Excimer laser. PRK may be used to treat myopia (nearsightedness), hyperopia (farsightedness), or astigmatism.
Unlike LASIK, PRK does not involve creation of a corneal flap. The laser is applied directly to the top, outer surface of the cornea. PRK does not involve a cutting blade and therefore does not carry the postoperative risks of corneal flap complications. However, there is a greater risk of postoperative scarring, infection (rare) and unpredictable healing of the cornea with PRK.
The Procedure
Anesthetic eye drops are applied to the eye to numb the eye and prevent discomfort during the procedure. An instrument called a speculum is placed on the eyelids to prevent blinking and eye movement.
The surgeon then gently removes the surface corneal cells. Prior to the surgery, an Excimer laser instrument is customized and pre-programmed to treat the specific refractive error of the patient. This laser is focused on the cornea and activated for less than one minute. The laser re-shapes the outer surface of the cornea to the desired refractive correction. Medication to prevent corneal hazing may be applied.
The surgeon will then place a bandage contact lens on the eye to decrease postoperative discomfort. The patient is given anti-inflammatory eye drops to use for several weeks to months. Patients can typically leave the eye surgery center within an hour of the procedure.
PRK Recovery
Unlike LASIK, patients can experience some discomfort and irritation in the eye after surgery. Multiple follow-up visits to the eye surgeon will be required to monitor the condition and healing of the cornea.
The bandage contact lens will remain on the eye for 1 to 3 days, on average.
Visual Results with PRK
Surgical results are very good — with most patients noticing an increase in visual acuity. However, unlike LASIK, same or next day improvements in vision are not common. Vision will recover at a somewhat slower pace than with LASIK.
PRK Candidates
PRK is used to treat refractive errors like myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. PRK candidates are those patients with moderate levels of refractive error. The candidate should be one who no longer wishes to wear glasses or contact lenses. The PRK candidate should understand that enhancement procedures may be required during the first year after surgery. PRK is an elective procedure that carries, like any surgical procedure, a certain amount of risk and benefits. The patient should be counseled regarding outcome expectations and be willing to accept these the potential risks.
Possible Complications
PRK is an elective procedure which, like any procedure, has risks and benefits. The potential patient should understand this. The possible complications of PRK surgery are: postoperative glare, halos or starbursts around lights at night, corneal infection, pain, long healing periods, over-under refractive correction, reduced visual acuity.
