LASER VISION CORRECTION

The word “laser” is an acronym for Light Amplification by Stimulated Emission of Radiation. A laser is a concentrated beam of light, created when an electrical current passes through a special material. Used in eye surgery since the 1970’s, the laser is popular for its unparalleled degree of precision and predictability. Lasers are being used for an increasing variety of eye diseases.

A laser’s specific wavelength allows energy to be absorbed in selected tissues and not damage surrounding tissues. The laser beam is so precise it can cut notches in a strand of human hair without breaking it.

Thermal lasers convert light to heat. This type of laser seals blood vessels and destroys abnormal tissues. Photoablative lasers cut or sculpt tissue and are used to remove tissue, changing the shape and surface of the eye.

Lasers can preserve vision, sometimes for many years, for diabetics with diabetic retinopathy. In treating diabetic retinopathy, the laser light seals leaking blood vessels in the retina, the light-sensitive layer of cells lining the back of the eye. Lasers also treat more unusual retinal disorders, including blood vessel problems and tumors.

Also used to treat glaucoma, lasers can create a new passage through the iris to relieve eye pressure or open the eye’s blocked drainage canals.

Although lasers do not remove cataracts, they may one day. Right now, they open the posterior capsule, which often becomes cloudy after cataract surgery, restoring vision in a matter of hours.

More recently, the excimer laser has received a great deal of attention as a tool for permanently correcting refractive errors such as nearsightedness, farsightedness and astigmatism. Refractive laser surgery can decrease or eliminate the need for glasses and contact lenses by reshaping the cornea.

What is LASIK?

Until recently, if you were one of the millions of people with a refractive error, eyeglasses and contact lenses were the only options for correcting vision. But with the arrival of refractive surgery, some people with myopia (nearsightedness), hyperopia (farsightedness), or astigmatism (a cornea with unequal curves), may have their vision improved through surgery.

Laser assisted in situ keratomileusis, or LASIK, is a refractive procedure that uses an automated blade and a laser to permanently reshape the cornea. The reshaped cornea helps focus light directly onto the retina to produce clearer vision.

LASIK is usually performed as an outpatient procedure using topical anesthesia with drops. The procedure itself generally takes about fifteen minutes.

Dr. Najafi-Tagol creates a flap in the cornea with a microkeratome*.

LASIK-a flap is created in the cornea

The flap is lifted to the side and the cool beam of the excimer laser is used to remove a layer of corneal tissue.

LASIK- corneal tissue is removed

The flap is folded back to its normal position and sealed without sutures. The removal of corneal tissue permanently reshapes the cornea.

LASIK- flap is folded back and sealed

A shield protects the flap for the first day and night. Vision should be clear by the next day. Healing after surgery is often less painful than with other methods of refractive surgery since the laser removes tissue from the inside of the cornea and not the surface. If needed, eyedrops can be taken for pain and usually are only needed up to one week.

Some people experience poor night vision after LASIK. The surgery may result in undercorrection or overcorrection, which can often be improved with a second surgery. More rare and serious complications include a dislocated flap, epithelial ingrowth and inflammation underneath the flap. Most complications can be managed without any loss of vision. Permanent vision loss is very rare.

The ideal candidate for LASIK has a stable refractive error within the correctable range, is free of eye disease, is at least 18 years old and is willing to accept the potential risks, complications and side effects of LASIK.

*Now Intralase™ is also available.

What is PRK?

Until recently, if you were one of the millions of people with a refractive error—light rays not focusing precisely on the retina—eyeglasses and contact lenses were the only options for correcting vision. But with the arrival of refractive surgery, some people may have their vision corrected through surgery. Photorefractive keratectomy (PRK) is one of several refractive surgery procedures used by Dr. Najafi-Tagol to permanently change the shape of the cornea to improve the way it focuses light on the retina.

PRK is an outpatient procedure done under topical anesthetic eyedrops. It takes about 15 minutes. The epithelium, the outer cell layer of the cornea, is removed with a blade, alcohol or a laser.

PRK- outer layer of the cornea is removed

An excimer laser, which produces ultraviolet light and emits high-energy pulses, is used to remove a thin layer of corneal tissue.

PRK- thin layer of corneal tissue is removed

Dr. Najafi-Tagol enters your vision correction information in a computer and the laser beam vaporizes the surface of the cornea up to that precise depth. By breaking the bonds that hold the tissue molecules together, your cornea is reshaped, correcting the refractive error. Because no incisions are made, the procedure does not weaken the structure of the cornea.

Immediately following surgery the eye is patched or a bandage contact lens is placed on the eye. After PRK, vision is blurry for 3 days to one week. It may take a month or longer to achieve one’s best vision. Patients may be on eyedrops for up to three months.

Possible complications of PRK surgery include undercorrection, overcorrection, poor night vision and corneal scarring. Permanent vision loss is very rare. In recent studies monitored by the FDA, 95% of eyes were corrected to 20/40, the legal limit for driving without corrective lenses in most states.

To be a candidate for the procedure you must have a stable and appropriate refractive error, be free of eye disease, be at least 18 years old and be willing to accept the potential risks, complications and side effects of PRK.