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 within modern ophthalmology, offering patients the realistic prospect of safe, effective and significant visual improvement.
Historically, ophthalmologists have long performed refractive surgery. Procedures which 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 a 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. It's the wise consumer, and the thoughtful individual, who pursues LASIK after thorough study. 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 generally takes less than 60 seconds.
Our center uses the STAR S4 IR® Excimer Laser System. The laser features VSS technology (Variable Spot Scanning) and VRR (Variable Repetition Rate) pulse-packing algorithm, both proprietary technologies. The STAR S4 IR® Excimer Laser reduces thermal effects on the cornea, allowing you to perform wavefront guided procedures quickly and effectively, while maximizing patient safety.
Using the STAR S4 IR® Excimer Laser System, surgeons can deliver the broadest range of wavefront-guided laser vision correction treatments to patients with more than 94 percent of eligible candidates in the U.S., and more than 99.75 percent outside the U.S.
What is Wavefront Guided or Custom Lasik?
Wavefront-guided or custom LASIK creates a personalized 3D map of the patients visual pathway form 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 and consultation or prior to your surgery.
Wavefront-guided Lasik measures and treats lower-order aberrations such as nearsightedness, farsightedness, and astigmatism as well as higher-order aberrations (HOA's) with the goal of providing better vision than possible with eye glasses, contact lenses or conventional LASIK. Wavefront guided LASIK produces a higher level of personalization compared to conventional lasik which is based solely 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 fewer than 20 seconds.
What is Bladeless or iLASIK (intralaseLASIK)?
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 unique visual imperfections of your eye is created using wavefront eye-mapping technology that is 25x 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 with your doctor about the risks of this procedure. 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 PRK (Photorefractive Keratectomy), 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".