What Is LASIK?
LASIK, an acronym for Laser-Assisted In Situ Keratomileusis, is the most common refractive procedure. Using targeted laser beam energy, Lasik reshapes the cornea so that light rays are focused more precisely on the retina. As a result, patients can now have clear, sharp vision without the need for glasses or contacts. Lasik can correct nearsightedness, farsightedness, and astigmatism.
What Is Blade-Free LASIK?
During traditional Lasik, the doctor will create a corneal flap. A hand-held instrument called a microkeratome that moves across the eye creates the thin tissue flap. Lasik is extremely safe, but if complications do occur, the microkeratome is frequently the cause. With the IntraLase Method, patients can choose a 100% blade-free approach to corneal flap creation. This will allow our team at Central Valley Eye Medical Group to create an individualized flap without a blade ever touching your eye. During the IntraLase Method, our staff only uses the IntraLase FS or iFS laser.
How Does Blade-Free LASIK Work?
Unlike traditional Lasik, the IntraLase Method creates the corneal flap by applying tiny, rapid pulses of laser light. Each pulse of light passes through the top layers of your cornea and forms a microscopic bubble at a predetermined depth and position within your eye. As the IntraLase or iFS Laser moves back and forth across your eye, a uniform layer of bubbles forms just below the corneal surface. After that layer is complete a member of our staff will gently separate the tissue, creating the blade-free flap.
The IntraLase Method creates a precise layer of bubbles just beneath the surface of your eye, which results in a smooth, even surface under the corneal flap. The IntraLase Method process takes less than 15 seconds per eye. This includes preparation time, whereas the entire Lasik procedure typically takes about 10 minutes. Once the entire procedure is complete, the corneal flap “locks” back into position.
Just like a fingerprint, each person’s vision is 100 percent unique to their eyes. Before the recent advancements in technology, doctors were only able to use standard measurements to correct vision. This meant that prescriptions could only provide a certain level of correction regardless of an individual’s needs. CustomVue™ Individualized Laser Vision Correction, developed by VISX, established a new standard in laser vision correction. In addition, CustomVue™ provides a precise level of measurement and correction never before possible.
CustomVue uses WaveScan®-based digital technology, originally developed for use in high-powered telescopes. Doctors can now identify, measure, and correct imperfections in an individual’s eyes 25 times more precisely than with standard methods. As a result, providing patients with the potential to experience better vision. If you’re over the age of 21 and are nearsighted and/or astigmatic, you may be a candidate for the CustomVue procedure.
CustomVue™ Laser Vision Correction Procedure
Before the procedure, patients will need to schedule a consultation. There, they can share any questions or concerns with our staff and determine if they are a good candidate. Then, our staff will assess the patient’s overall health and create a detailed, unique map of their eyes. After this is all complete we can schedule the procedure.
On the day of the procedure, the patient will receive anesthetic drops. Then, we transfer the patient’s unique correction information from the WaveScan to the laser. Laser vision correction works by gently reshaping the cornea with the cool beam from the laser. Additionally, the laser removes microscopic amounts of tissue to create a new curvature. The procedure typically takes several seconds and the majority of individuals feel no discomfort.
Results of CustomVue™
Many patients notice immediate results after CustomVue and vision continues to improve over several days. One year after the CustomVue procedure, patients in a clinical study reported these great results without glasses and contact lenses.
- 100 percent could pass a driving test
- 98 percent could see 20/20 or better
- 70 percent could see better than 20/20
- 4 times as many people experienced improved night vision
What Is Photo-Refractive Keratectomy?
Photorefractive keratectomy, or PRK, is a type of laser eye surgery that reshapes the cornea. Photorefractive keratectomy was the first procedure to use the Excimer laser and, after Lasik, is the second most common type of refractive surgery. Lasik makes a flap and applies the laser to the inner tissue of the cornea. However, with PRK, the epithelium, or outer skin of the cornea, is removed and a laser is applied to the surface of the cornea.
What Does PRK Treat?
PRK can correct low to high levels of nearsightedness, farsightedness, and astigmatism. To treat nearsightedness, the steep cornea is made flatter by removing tissue from the center of the cornea. This moves the point of focus from in front of the retina to directly on the retina. To treat farsightedness, the flat cornea is made steeper by removing tissue outside of the central optical zone of the cornea. This moves the point of focus from behind the retina to directly on the retina. To treat astigmatism, the cornea is made more spherical. This eliminates multiple focus points within the eye and creates one point of focus on the retina. Additionally, PRK can treat astigmatism at the same time as nearsightedness and farsightedness.
Patients who experience any combination of the following may be candidates for PRK surgery.
- Corneas are too thin for Lasik
- Had a stable eye prescription for at least one year
- Have no health issues affecting their eyes
- Large pupils
- Over 18 years of age
- Want to reduce or eliminate their dependence on glasses or contacts
The Photo-Refractive Keratectomy Procedure
Patients should expect to arrive an hour prior to their procedure. Patients can choose to take a sedative to help them relax. Then, the area around your eyes will be sterilized and a drape may be applied around your eye. Anesthetic eye drops will be used to numb your eyes. Once your eye is completely numb, a member of our staff will place an eyelid holder between your eyelids. This will keep you from blinking during the procedure.
Next, one of our highly skilled doctors at Central Valley Eye Medical Group will remove the epithelium, a thin layer of protective skin that covers the cornea. While the laser reshapes the cornea patients will need to look directly at a target light. Depending on the amount of correction, the laser treatment will be complete in less than two minutes.
Recovery from PRK
Following your procedure, a member of our staff will examine your eye(s) with a slit lamp microscope. Your vision may be blurry or hazy for up to five days. Patients will likely experience some discomfort as the epithelium heals and covers the treated area. To minimize discomfort, patients can use eye drops, pain medication and possibly a protective contact lens. While vision can fluctuate for up to six months, most patients resume normal activities within 3 days.
Photo-Refractive Keratectomy Results
The decision to have PRK is an important one that only you can make. The goal of any refractive surgical procedure is to reduce your dependence on corrective lenses. However, we cannot guarantee you will have the results you desire. The vast majority of our patients are extremely happy with their vision after PRK and can do most activities without dependence on corrective lenses.
Since everyone heals somewhat differently, some patients may overreact to the procedure and some may underreact resulting in over corrections and under corrections. Once the eye has stabilized, after about 3 to 6 months, our staff can discuss whether a re-treatment is necessary.
PRK Side Effects
PRK is a safe, effective and permanent procedure, but like any surgical procedure, it does have some risks. After PRK, almost everyone experiences some visual side effects. These visual side effects are usually mild and temporary and have a tendency to diminish over time. However, there is a slight chance that some of these side effects won’t go away completely, including light sensitivity, glare, and halos. Serious complications to PRK are extremely rare.
What Is Wavefront Diagnostic Technology?
Until recently, laser vision correction treated patients based strictly on their optical prescription. In other words, if you were a minus-four nearsighted person, glasses with minus-four lenses would allow you to see the best that you could. If you had laser vision correction, that same prescription would be programmed into the excimer laser and the exact amount of tissue would be removed to make a minus-four into a zero. Therefore, anyone with the same prescription was receiving the same treatment which we call conventional laser vision correction.
Today, with the arrival of wavefront diagnostic technology, wavefront-guided excimer lasers can now treat patients according to the uniqueness of their entire optical system, not just their prescription. Wavefront technology was pioneered for astronomy and physics to aid in reducing aberrations or imperfections in the optical systems of telescopes. In much the same way, wavefront-sensing devices produce an accurate picture of the optical imperfections found in the human eye.
How Does Wavefront Technology Work?
Light travels in a procession of flat sheets, also known as wavefronts. These wavefronts enter the eye, pass through the entire optical system including the cornea, lens, and retina, and reflect back. When the optical system has perfect refracting surfaces, these wavefronts exit the eye as flat sheets. But when the cornea is irregular or the lens is imperfect, higher-order aberrations are created, and the wavefronts exit the eye as irregular, curved sheets.
Wavefront technology captures the reflected wavefronts and compares these curved sheets to a perfect wavefront. Then, we create a 3-D map of the eye’s optical irregularities. This map, just like with CustomVue, is a guide to reshape the cornea during laser vision treatment. This technology differs from traditional testing methods in its ability to measure the entire optical system of the eye, instead of simply the front surface of the eye.
Results of Wavefront Technology
Results have shown that custom laser vision correction can reduce some of the unwanted visual effects experienced from conventional laser vision correction, especially those associated with night vision such as glare and halos. By addressing both a person’s prescription and the higher order aberrations within their eye’s optical system, custom laser vision correction has the potential of making patients see better than they could with conventional glasses or conventional laser vision correction.