All About losing your Glasses / Contact Lenses!
Refractive laser treatments are now the most popular procedure worldwide to correct nearsightedness, farsightedness and astigmatismAstigmatism is a condition caused by a cornea that has more than one curvature, similar to a rugby ball. The same image, therefore, focuses on multiple points in front of, on and/or behind the cornea, creating multiple and ghost images. Astigmatism may also be found in association with either myopia or hyperopia, which complicates the condition substantially. See Info on Eyes, Optics and Refractive Errors - Astigmatism.. Its popularity is based on the high rate of patient satisfaction, excellent visual results, quick recovery and the very few side effects and complications.
Not all patients are, however, suitable candidates for specific corrective laser treatments such as Laser Assisted in Situ Keratomileusis (LasikLasik is one of several types of laser treatments to permanently correct refractive errors of the eye. See Laser Vision – Introduction to Laser Treatment.). The good news is that, apart from the very popular Lasik treatment, several other options are also available, including the alternative techniques of Photo Refractive Keratectomy (PRKPRK is one of the laser treatment options to restore vision by permanently reshaping the cornea with an Excimer Laser. See Laser Vision – PRK.), Laser Assisted Sub-Epithelial Keratomileusis (LasekLasek is one of the older corneal refractive laser techniques which lost its popularity in favour of PRK, LASIK and SMILE. See Laser Vision – Lasek and Epi-lasik.), Femtosecond lenticuleA lenticule resembles a very thin contact lens and is formed within submicron accuracy inside the corneal stroma with a femtosecond laser. It may be removed through a very small incision on the side of the cornea, or from the corneal bed under a flap, depending upon the technique employed by the surgeon, which then achieves a refractive correction on the cornea. See About Us – Our Technology – Zeiss Femtosecond Laser. Extraction (FLExFLEx is one of the the latest techniques to restore vision by permanently reshaping the cornea with a femtosecond laser. See Laser Vision – RELEx - FLEx.), Small Incision Lenticule Extraction (SmileSmile is the latest and most modern laser technique to restore vision by permanently reshaping the cornea with a femtosecond laser. See Laser Vision – RELEx - Smile.), as well as the placement of intra-corneal ring segments, implantation of a Phakic intra-ocular lensPhakic intra-ocular lenses are implanted into the eye to assist the natural lens of the eye to correct severe refractive errors. Depending on the error to be treated, these lenses may be custom-made for each individual eye. See Other Options – Phakic Lenses. and a clear lens replacementA clear lens replacement is done when the natural lens in the eye is removed and replaced with one of several types of artificial lenses. See Other Options – Refractive Lens Exchange..
Therefore, before proceeding with corrective laser surgery, it is extremely important for a qualified ophthalmologist or eye specialist to thoroughly examine your eyes to rule out any contra-indications and also to determine which type of laser correctionA laser correction is the permanent reshaping of a cornea with a deficient curvature by laser to improve vision. See Laser Vision – About Laser Vision Correction. or alternative method is best suited to your particular needs. The modern diagnostic equipmentDiagnostic equipment is used to determine the root cause of eye problems so that the correct treatment may be applied. A variety of such devices are used at Optimed to very accurately diagnose a wide spectrum of eye problems. See About Us – Our Technology. can detect and measure obvious, as well as latent and hidden defects accurately within sub-micron levels.
If the answer to most of the following questions is 'YES', you are probably a good candidate for corrective laser surgery.
- According to your optometrist or the descriptions on this website, you are nearsighted, farsighted and/or astigmatic.
- You are at least 20 years of age (there is no upper age restriction), enjoy good health and your eyes are healthy.
- You had stable vision for the past two years with minimal change in your spectacle error.
- You currently wear glasses or contact lenses, but for professional-, sport- and/or social considerations, you would prefer to be without them.
- Your eyes require an optical correction, but glasses or contact lenses are unsuitable or inappropriate for the type of work you do, the environment in which you work or the type of sport you play.
Apart from the factors mentioned above, the following conditions must also be known and considered by the ophthalmologist:
- Potential pathology of your corneaThe cornea is the clear, transparent 'front window' of the eye through which light enters the eye. It handles about two-thirds of the focusing power of the eye and is critical for good vision. See Info on Eyes – Anatomy. (e.g. whether you have adverse eye conditions, such as keratoconusKeratoconus is an eye condition that causes the cornea to spontaneously bulge outward, like the tip of a rugby ball. It causes very high levels of myopia and astigmatism. See Eye Diseases – Keratoconus.).
- To what degree your cornea needs to be reshaped.
- The thickness of your cornea.
- The severity of the refractive error(s) that are to be corrected.
- If you are of the fairer sex, whether you are currently subject to hormonal changes, such as during pregnancy or nursing your baby.
- Whether you have systemic auto-immune diseasesA group of diseases where the body's defence mechanism (immune system) attacks various target tissues in the body, causing deficiencies of those tissues., infectionsInfections may be caused by bacteria, viral or fungal agents that penetrate and affect any part of the body, including the eyes. Treatment of an infection depends on the source and nature of the agent that caused it., amblyopiaAmblyopia is commonly known as 'lazy eye'. The eye appears healthy, but visual images are not properly recognized. It is the consequence of a developmental abnormality in the visual cortex of the brain, caused by suboptimal stimulation of the retina due to poor image projection onto it. Causes for this include a high uncorrected refractive error, a large difference in refractive powers of the eyes, an opacity in the optical system of the eye, or even a crossed-eye. Amblyopia should be treated before the age of seven to avoid permanent vision development problems., dry eye syndromeTears serve as a protective coating for the eyes. They keep the eyes moist, provide essential nutrients and wash away dust and other particles. When the eyes do not produce enough or the right quality of tears, which lead to changes to the surface of the eye, it is known as 'dry eye syndrome'., a fluctuating refractive errorAn eye has a refractive error when it is unable to clearly focus distant objects on the retina. If the error is not consistent and varies over time, it is known as a 'fluctuating refractive error'. and/or diabetes mellitusDiabetes mellitus, or simply diabetes, is a group of metabolic diseases in which the ability to process glucose is impaired. If left untreated, diabetes can cause a host of long-term complications, including damage to the retina..
Once these factors are verified and you receive an 'all clear', you may consider yourself a candidate for laser treatment. If not suitable for laser treatment, the consultation will provide the required information to recommend an alternative treatment to restore good vision.
How the process unfolds
Should you be a safe laser candidate, the first step Dr Potgieter will take is to establish the various parameters of the correction(s) to be made to each eye.
A highly-accurate measurement device, the Zeiss Atlas Topography System (below left), measures the characteristics and deviations of the cornea to within sub-micron accuracy. Complex software algorithms are then applied to these measurements by the patented CRS-Master software (below middle) to calculate the exact amount of corneal tissue to be removed at every point on the corneal curvature to optimise the visual outcome. It is then passed to our Zeiss MEL-80 laser (below right).
The laser is guided by an active eye tracking mechanism that samples the position of the eye 1050 times per second. So, if your eye should accidentally wander during the treatment, the eye tracking mechanism detects the movement and redirects the laser beam to the correct location on the surface of the cornea.
Since the laser fires at 250 pulses per second, the eye tracker samples the position of the eye 4 times faster than the laser, making it the only laser on the market to track each pulse individually. Many other lasers will only track between 30% and 50% of the pulses applied.
We recently acquired the very latest technology in corneal laser vision correctionLaser vision correction is a technique that has the ability to permanently correct refractive errors of the cornea by means of a laser treatment. Several types of laser vision correction treatments are available. See Laser Vision – Introduction to Laser Vision Correction. – the Zeiss VisuMax femtosecond laserA femtosecond laser is the latest high-tech laser device used to make extremely accurate corneal incisions. See About Us – Our Technology – femtosecond laser. (seen here on the left). This is a highly sophisticated laser with the ability to perform computer controlled surgery of various kinds, representing the top end of laser technology. This laser enables the ophthalmologist to perform femtosecond laser assisted Lasik (or FemtoLASIK), the ultra-modern ReLExReLEx is an acronym for Refractive Lenticule Extraction. See Laser Vision – ReLEx – Flex and Smile. techniques of FLEx and Smile, as well as the implantation of intra-corneal ring segments and femtosecond laser assisted corneal transplants.
While the final judgment call is that of Dr Potgieter, this technology helps to minimise human error. Due to the power of modern computing and technology, the process could not be more simple and accurate!