Different Types of LASIK Surgery
A device called a wavefront analyzer measures the way light travels through your eye and compares it to the way light travels through an eye with perfect vision.
LASIK an acronym for Laser in-situ Keratomileusis (kerah-to-mih-lu-sis) is currently the most common type of laser vision correction. It can correct nearsightedness farsightedness and astigmatism. Light is properly focused on the retina by permanently reshaping the central area of the cornea. Nearsighted people have their cornea flattened during the LASIK procedure while farsighted people have theirs made steeper. For astigmatism the surgeon alters the cornea to a more typical spherical shape.
The procedure uses an instrument called a microkeratome to create a thin hinged flap in the cornea. The surgeon folds back the flap and then removes a thin layer of corneal tissue using an excimer laser. Following the laser treatment the surgeon replaces the flap. It bonds naturally and securely into place without the need for stitches.
After lying down and properly positioning your eye under the laser the surgeon places an eyelid holder in the eye to keep it open throughout the procedure. The surgeon then creates a corneal flap with the microkeratome and a cool laser beam of light from the excimer laser gently reshapes the cornea. Patients must focus on a target light for a short time while the laser sends pulses of light to the cornea.
The goal of LASIK is to dramatically improve vision and reduce dependence on corrective eyewear but it is not to eliminate glasses and contacts. Some people achieve 20/20 vision or better with LASIK while others may achieve only 20/40 vision. This prescription is satisfactory for driving without corrective lenses. Prescription levels will be much lower than before but patients might still require reading glasses or contact lenses following the procedure.
In addition LASIK will not prevent patients from developing naturally occurring eye problems associated with aging such as glaucoma, cataracts, macular degeneration or retinal degeneration. Reading glasses multifocal lenses or progressive lenses might still be necessary with the onset of presbyopia a common age-related vision condition that affects near vision. There are other risks and complications associated with the procedure that you should discuss with a surgeon before the operation.
Enhancement or 'touch-up' procedures are sometimes necessary when a patient has a very strong prescription. This is a normal occurrence. Once your vision has stabilized the surgeon will perform the enhancement procedure.
With IntraLASIK the surgeon uses a femtosecond laser to create the corneal flap instead of using the traditional microkeratome. The femtosecond laser beams pulses at the speed of one quadrillionth of a second. This offers patients a safer computer-controlled alternative for creating the corneal flap since it provides the surgeon with greater precision and accuracy. Computer software is used to guide the laser beam into the exact desired location on the cornea. The laser is programmed to leave an uncut section of tissue to form a hinge so the flap may be hinged back. The surgeon then proceeds to reshape the cornea with an excimer laser as in traditional LASIK.
The microkeratome uses a significant vacuum level through a suction ring while the femtosecond laser creates a flap under a low vacuum delivering the laser energy through a disposable glass lens. The lower vacuum level reduces the risk of complications arising from high pressure procedures. The outer surface of the cornea suffers no trauma and the procedure is painless.
The femtosecond laser produces a corneal flap with more vertical edges than does the microkeratome. This reduces the risk of epithelial ingrowth corneal wrinkles and thick flaps all complications of traditional LASIK. In addition flaps made during an IntraLASIK procedure appear to adhere more tightly to the corneal bed once the procedure is finished.
IntraLASIK makes it possible to operate on many patients who were not considered candidates due to their thin corneas. The femtosecond laser is able to make thinner more precise cuts in the corneal flap thus allowing surgeons to perform IntraLASIK on people with thinner or flatter corneas.
3. Custom LASIK
Custom LASIK is a laser vision correction procedure that uses the unique visual characteristics of your eye to customize your treatment.
Custom LASIK provides an additional level of precise data about your vision requirements using wavefront technology. A device called a wavefront analyzer measures the way light travels through your eye and compares it to the way light travels through an eye with perfect vision. This device then creates a 3-D wavefront map which is a detailed diagram of your vision that is unique in the same way that your DNA is unique to you. This map is then transmitted to the laser allowing your doctor to customize the LASIK procedure to your individual vision requirements. This process accounts for each patient's unique corneal shape, corneal thickness, pupil size and a number of other variables. There is a greater potential for achieving 20/20 vision and can in some instances restore eyes to better than 20/20 vision.
Several types of visual imperfections referred to as lower- and higher- order aberrations exist within the eye and can affect your vision. Lower-order aberrations also called refractive errors include nearsightedness, farsightedness or astigmatism. Conventional LASIK procedures treat these lower-order aberrations. Higher-order aberrations are irregularities beyond refractive errors that cause vision problems such as glare,halos decreased night vision and decreased contrast sensitivity. Custom LASIK can correct these higher-order aberrations which in the past could not be adequately corrected with glasses, contacts or traditional LASIK treatments.
Like conventional LASIK Custom LASIK won't cure all vision-related problems but it is important to discuss its applications with me or the surgeon to determine if you would benefit from this newest level of technology. In order to find out if any of these procedures are right for you please contact our office.