Laser Vision Correction -- Lasik, IntraLase, and Lasik without a flap

Laser Vision Correction uses a laser's ultraviolet light to carefully eliminate a microscopic layer of cells, less than the thickness of a hair, from the surface of the cornea to change the curvature of the eye slightly.

Patients who are nearsighted (myopia) have trouble with distance vision. For them the cornea curvature will need to be decreased so that it is flatter. Farsighted (Hyperopia) patients have the opposite issue: their cornea needs to be increased because they have trouble seeing up close. This is done by using the laser to create a donut-shaped ring around the cornea. Patients with astigmatism have trouble with both distance and close vision, so they need to have their cornea curvature altered in a specific direction for proper vision correction.

There are many different variations of laser vision correction available at Caster Eye Center, each of which has advantages and disadvantages. We perform all variations of laser vision correction. We will discuss your specific situation with you after we have taken your personal history and performed measurements and calculations during your LASIK evaluation.

1. Lasik (laser in-situ keratomileusis). This is a popular and common type of laser vision correction treatment. LASIK is done by creating a protective flap with a device known as a keratome or the IntraLase laser. The flap is lifted and the laser treatment is done on the cornea of the eye, the flap is then replaced over the cornea, creating a natural bandage which allows for rapid healing. Both eyes easily can be treated on the same day.


2. Lasik without a flap (PRK, Advanced Surface Treatment, Lasek, Epi-Lasik). Some patients are not good candidates for LASIK because of thin corneas, dry eyes large pupils or very high corrections. For those patients, LASIK without a flap may be a good treatment option. This treatment is done under the epithelium located on the surface of the eye. The type of the procedure needed is determined by the amount of epithelium being removed. If all of the epithelium is removed, then the laser procedure is known as PRK (Photorefractive Keratectomy). If the epithelium is replaced, it is a LASEK procedure. If the epithelium is loosened with a machine it is known as Epi-LASIK. For more information about "Lasik without a flap", please click here.

In addtion, there are two types of treatment software that are available. Each of these software variations can be used with each of the flap variations discussed above:

1. Custom. Utilizing wavefront technology, custom treatment corrects nearsightedness, farsightedness, and astigmatism as well as other vision irregularities. At the Caster Eye Center, all treatments are Custom.


2. Conventional. This is a more traditional treatment that can be compared to correcting the vision with glasses or contact lenses; a single prescription is applied over the entire treatment area. This treatment might be used for patients with thinner corneas, higher amounts of correction, or other vision issues.

Procedure Results

After vision correction surgery, the majority of patients are able to get rid of the contact lenses and glasses they used for distance vision. Virtually all patients have better vision without glasses after the laser vision correction procedure. After the laser treatment, 90% of patients will have 20/25 or better vision without glasses or contacts, and 99% will have 20/40 or better vision without contacts or glasses. To pass most driver vision tests, you must have 20/40 vision without glasses.

Custom treatment results are even better: some 96% of the patients achieve 20/20 or better vision without glasses or corrective lenses, with 99% of the patients achieving 20/25 or better vision.

The results are better for patients with mild nearsightedness, farsightedness, or astigmatism. Patients that require a higher level of correction will have less accurate results. The general rule is: more accurate results will be obtained in people who require less treatment. For patients that need it, the laser treatment can be repeated. No additional fee is required if a "touch-up" or enhancement is needed. Enhancements are done for about 4 percent of our patients.

While the laser vision correction results are remarkable, Caster Eye Center is unable to tell patients exactly what their results will be after treatment because each patient responds slightly differently. If you will only be satisfied with "perfect" 20/20 vision without glasses after laser treatment, without a touch-up or enhancement treatment, then please do not have the surgery. Avoid any doctor or clinic that promises you a specific result, because that simply is not possible.

Complications

Complications can occur during laser vision correction. While the complication rate is very low, problems can be treated easily. Complications are more common in patients with a high degree of nearsightedness, farsightedness, or astigmatism, because these patients require larger amounts of treatment.

Over-correction and under-correction is a common complication. This can happen when the patient absorbs a little more or less of the laser energy than expected or the patient heals abnormally. An "enhancement" or "touch-up" may be done and usually achieves great vision without the need for glasses or contact lenses.

Only about one percent of laser vision correction patients have increased optical aberrations that can include glare and halos at night. It is important to note that glare and halos are common problems for all people, even people who have not had laser vision correction or LASIK. While patients are healing from laser surgery, glare and halos are more common for the first three months. While most patients actually have a decrease in the amount of glares and halos after surgery, a small percentage can have more. New technology, such as eye tracking systems, and lasers that focus on larger treatment areas have improved the glare and halo issues.

Dry eyes are common in the first few weeks and months after laser vision correction surgery. Dry eyes are more common in patients that had dry eyes before surgery. A combination of eye drops and pills can be used to control dry eyes, and the condition typically resolves about three months after surgery.

Because the eyes can be more prone to infection while they are healing; a series of antibiotic eye drops are used after surgery to protect the eye from any infection. Careful use of the eye drops reduces the infection rate to far less than one percent.

It is important to use steroid drops after laser vision correction to help with healing, but the drops must be used properly. When these drops are used improperly, they can cause cataracts or glaucoma. This is why when taking steroid eye drops, patient need to be sure to go to all follow-up appointments and carefully follow aftercare instructions.

Which laser treatment is best for me?

The most popular laser vision correction surgery is LASIK (laser in-situ keratomileusis). This first step in the Lasik procedure is to create a protective flap with either a keratome or laser in the front of the cornea. The flap is then folded back and the laser treatment is done directly within the cornea to correct the vision. The flap is then placed over the eye, where is acts as a natural bandage.

The Lasik flap is created with a keratome machine or with the IntraLase laser. Making the Lasik flap is about a 15 second process and is practically painless. While complications can rarely occur, most complications are mild and treated easily.

Advanced Surface Treatment, also known as Lasik without a flap, is a vision correction treatment that is performed on the surface of the cornea. Variations of this technique are called PRK (photo-refractive keratectomy), LASEK, and Epi-Lasik, and are all very similar.

While healing from Advance Surface Ablation takes longer than Lasik, the visual results are the same. The healing process for Lasik without a flap can take about a week.

Before Lasik or "Lasik without a flap" is done, computer software is used to generate a Custom eye measurement. The conventional software measurement is much like a traditional glasses or contact lens prescription with one prescription covering the entire eye. Like glasses and contact lenses, this creates good vision.

The Custom software treatment creates a topographical map of the eye and is used to address additional irregularities in vision. Custom treatments, also know as Wavefront treatments, do generate slightly better vision than the conventional software.

Full Distance Correction or Monovision?

As patients reach the ages of 40 to 50, they begin to develop presbyopia or middle-aged eyes. When one is presbyopic, it becomes difficult to see things close up; for example reading a menu or a newspaper is challenging without the use of reading glasses or bifocals.

There are three options possible for patients with presbyopia:

1. Adjusting both eyes for good distance vision – These patients will have their eyes corrected for excellent distance vision with laser vision correction. However, they will still require the use of reading glasses for good reading or close vision beginning around the ages of 40 to 50 years old.


2. Blended vision (also known as monovision) – With blended vision, one eye is corrected for distance vision and one eye for near or reading vision. This type of correction is often used with contact lenses for patients over 40 years old. Blended vision can also be used with laser vision correction. Blended vision allows patients to have both distance and near vision without the need for glasses.


3. Modified blended vision – This is a combination of the two options above, in which distance vision is created for one eye and a little near vision is created for the other eye.