Vision Correction with LASIK

Laser In Situ Keratomileusis (LASIK) is a laser surgical procedure effective for correcting all ranges of nearsightedness, farsightedness and astigmatism, except extremely high degrees. The most commonly performed vision correction procedure, LASIK is performed on nearly 1 million patients per year. LASIK combines corneal flap surgery with excimer laser reshaping for dramatic results and rapid visual recovery.

LASIK was first performed in the early 1990s in Greece, but the two main components of the surgery were performed separately long before then. South American surgeons began developing corrective procedures in the 1960s by removing a portion of corneal tissue, reshaping it, and then placing it back on the eye. Excimer laser correction has been done on the surface of eyes since 1987. Combining the advanced forms of both types of technology gives LASIK certain advantages for correcting vision.

For the procedure, the patient sits in a surgical chair which reclines into a horizontal position. A surgical assistant instills topical anesthetic drops to numb the eye for a painless correction. Assistants then carefully drape the patient's face around the eye to ensure a perfectly clean surrounding area for the surgery.

During LASIK surgery, a flap is created in the outer layers of the cornea, using either the IntraLase FS laser or a microsurgical instrument called a microkeratome. The flap is then lifted and pulled back so the excimer laser can treat only the middle layer of the cornea. Traditionally, the instrument used for creating a flap has been the microkeratome. It cuts and lifts a flap that is approximately 1/4 to 1/3 of the corneal thickness. This circular flap remains attached to the cornea by a small hinge of tissue. The hinge enables the flap to be lifted away from the central cornea. The excimer laser can then be used to reshape the exposed mid-layer of the cornea.

In recent years, the IntraLase Wavefront laser has become available to create a flap using multiple short pulses. These pulses are so close together they create an almost complete separation of the flap from the rest of the cornea, but they do not actually lift the flap. If the flap pattern is judged to be complete and satisfactory, a delicate separation of the flap is performed with a few gentle manipulations using a surgical instrument.

Wave front - Custom LASIK

The LASIK Procedure

After the LASIK Procedure

The Risks of LASIK

LASIK correction is a very safe procedure. When complications do arise, they can generally be effectively treated with further surgery. As with any surgical procedure, there are risks involved with LASIK. Side effects may include overcorrection or undercorrection, excessively dry eyes, corneal scarring, corneal edema, infection, persistent eye pain or discomfort, inability to wear contact lenses, glare and halos in the line of vision, and a decreased ability to see well at night or in fog. However, most of these subside as the healing progresses after LASIK surgery.

The chance of having a serious vision-threatening complication from LASIK is less than 1%. To our knowledge, there have been no reported cases of blindness in the United States from LASIK.

The low incidence of complications listed here reflects the exclusive Digby Eye Associates experience:

* Infection (less than 1/5,000)
Infections are very rare, but they can damage the cornea if not resolved with early treatment. They are usually identified early and effectively treated with medications.

* Difficulty Creating a Flap (1%)
The unusual shape or characteristics of some eyes can make it difficult for a surgeon to create a proper flap, although surgeon skill and microkeratome quality and maintenance are also factors. When difficulties are encountered, they are often resolved with adjustments. However, effective adjustments are not always possible, resulting in the LASIK procedure being discontinued. When discontinued, the procedure is postponed or another corrective option may be recommended.

While Digby Eye Associates has had excellent results and an enviable safety record with microkeratome LASIK, we now consider IntraLase LASIK to be our preferred method.
The reasons for this include:

* Safety: Because microkeratome LASIK completely cuts and lifts the flap, if an irregularity occurs, the surgeon has no choice but to deal with the irregularity immediately. However, with IntraLase, since the flap is not separated completely and not lifted immediately, the character and quality of the flap can be judged first. If deemed unsatisfactory, the flap pattern can be left untouched and the IntraLase pattern can be repeated later.
* Stability: Because the IntraLase laser can make a flap more precisely, it only needs to be about half as thick as a microkeratome flap, which ensures greater long-term structural stability for the cornea and more room for future treatment, if necessary.
* Comfort: IntraLase flaps induce considerably less dryness after surgery than LASIK flaps made with the microkeratome.
* Optical quality: Results are more predictable and quality of vision appears to be better with IntraLase.

* Haze and Irregular Astigmatism (less than 2%)
Sometimes a slight haze or a small amount of uneven astigmatism results from surgery. These problems usually resolve as the eye heals. However, if they do not, they are usually treatable through a second surgery.

* Epithelial Growth Under the Flap (less than 1%)
Cells from the protective surface layer of the cornea can get into the incision area and interfere with the healing process. This problem is resolved by the surgeon gently lifting the flap, removing the interfering cells and then positioning the flap again.

* Shifting or Wrinkling of the Flap (less than 1%)
Occasionally wrinkles develop during the healing process. This problem usually resolves itself within three to six months. In cases where the flap has significantly shifted, a repositioning is necessary. The surgeon gently lifts the flap and replaces it in the proper position. Re-treatments may be performed if vision is affected significantly from either of these situations.

* Interface Inflammation (less than 1%)
Most LASIK patients show some interface inflammation as a normal part of the healing process. This inflammation is usually self-limiting and requires no treatment. In cases of increased inflammation, medicated drops are used to treat the symptoms.

The Benefit of LASIK

LASIK FAQ's