Refractive Eye Surgery Options
Refractive surgery refers to a family of new surgical procedures designed to produce better eye focus with less dependence upon glasses or contact lenses for near-sighted, far-sighted, and astigmatic individuals. This field is one of the most exciting and intensively studied in modern ophthalmology, offering patients the realistic prospect of safe, effective, and significant visual improvement.
Historically, ophthalmologists have long performed refractive surgery. Procedures that have an influence on either of the eye's natural focusing elements—the cornea or the internal crystalline lens—will have an impact on how well the eye can focus. Cataract surgery and corneal transplantation are therefore also members of the family of refractive surgical procedures performed routinely by ophthalmologists every day.
The most common laser procedures are photo-refractive keratectomy and Laser Assisted In-Situ Kertomielusis (LASIK).
What is LASIK?
LASIK, or laser in-situ keratomileus, simply means "to shape the cornea from within." In LASIK surgery, an excimer laser reshapes the cornea in a precise and controlled fashion to change its focusing power.
During the procedure, a delicate instrument—a mechanical microkeratome or a femtosecond laser—is used to create a very thin flap of corneal tissue. Once this tissue flap is created, the surgeon positions an excimer laser beam over the eye, directing light pulses to achieve the desired correction. The flap is carefully put back in its original position. LASIK can treat both nearsightedness (myopia) and farsightedness (hyperopia) with or without astigmatism.
LASIK has several favorable benefits including fast visual recovery, little or no discomfort, and a lower risk of haze, glare, and halos. In the vast majority of LASIK patients, visual outcome is excellent. There is minimal discomfort during an overnight recovery period. Results are nearly immediate.
Nonetheless, LASIK is surgery. Every precaution should be taken to ensure a safe, healthy result. Patients are encouraged to study and explore their options carefully.
What is an Excimer Laser?
An excimer laser is an ultra-precise medical laser that creates a highly focused beam of cool ultraviolet (UV) light to gently reshape the cornea. The excimer laser reshaping procedure is called photoablation, and it generally takes less than 60 seconds.
Our center uses the STAR S4 IR® Excimer Laser System, which features VSS technology (Variable Spot Scanning) and VRR (Variable Repetition Rate) pulse-packing algorithm. This laser lessens the thermal effects on the cornea, which lets the doctor perform wavefront-guided procedures more efficiently with maximum patient safety.
What is Wavefront-Guided or Custom Lasik?
Wavefront-guided or custom LASIK creates a personalized 3D map of a patient’s visual pathway from the front of the cornea to the back of the retina. These measurements are obtained with an instrument called a wavefront aberrometer either during your initial preoperative exam or prior to surgery.
Wavefront-guided LASIK treats lower-order aberrations, like nearsightedness, farsightedness, and astigmatism, as well as higher-order aberrations, in order to achieve better vision than possible with contact lenses, eye glasses, or conventional LASIK. Wavefront-guided LASIK produces more personalization than conventional LASIK, which is based only on the eyes’ refractive error.
What is a Femtosecond Laser?
A femtosecond laser is an ultra-fast medical laser that creates a thin flap to prepare the cornea for treatment. The femtosecond laser creates a pattern of pulses of laser energy at a specific targeted depth within the cornea. The cornea tissue is separated by a process called photodisruption. The creation of the LASIK flap with a femtosecond laser takes less than 20 seconds.
What is Bladeless or iLASIK (intralase LASIK)?
iLASIK or bladeless LASIK uses two sophisticated state-of-the-art medical lasers: The ultra-fast femtosecond laser (iFS Advanced Femtosecond Laser) that creates a thin flap to prepare the cornea for treatment, and an ultra-precise excimer laser (STAR S4 IR Excimer Laser) that gently reshapes the cornea based on the digital information recorded from the personalized eye map (Wavescan System).
There are three steps to the iLASIK procdure:
- Creating your eye map: A detailed 3D map of the visual imperfections of your eye is created using wavefront eye-mapping technology that is 25 times more precise than the measurements used to write standard prescriptions for eyeglasses or contacts.
- Preparing your eye: An ultrafast femtosecond laser creates a thin flap to prepare your cornea for your personalized wavefront correction.
- Delivering your personal treatment: In the final step, the Star S4 IR excimer laser gently reshapes your cornea to the desired curvature, based on the digital information from your personalized eye map measurements.
Is the iLASIK procedure safe?
iLASIK technologies have been used in more than 15 million vision correction procedures worldwide. Discuss the risks of this procedure with your doctor. Complications from laser vision correction can usually be successfully managed medically and with follow-up care.
Photorefractive Keratectomy (PRK)
Some laser vision correction patients are not candidates for LASIK. In Photorefractive Keratectomy (PRK), the eye surgeon does not create a flap of corneal tissue. During the PRK procedure, the outer layer of the cornea, called the epithelium, is removed. A cool laser beam is applied to the cornea and a soft contact lens is applied to serve as a bandage during the healing process. This makes PRK a better choice for people whose eyes meet certain criteria, such as having thin corneas or chronically dry eyes. This contact lens will be removed within five to seven days of the procedure.
Recovery is usually one to two weeks, during which the patient may have mild to marked discomfort and blurry vision. Most of the vision improvement is seen in the first month, but there is still gradual improvement over the year after the initial procedure. PRK patients may also have wavefront-guided or custom laser correction sometimes termed "advanced surface ablation."