Various Options for Eye Surgery
Until the 1950s before contact lenses became popular, eyeglasses were the only choice to rectify refractive vision problems and they were in use for seven long centuries. Today there are several eye surgery options available ranging from laser reshaping the surface of the eye in procedures like LASIK and PRK to surgical placement of artificial lenses to rectify defective eyesight.
In procedures like LASIK, PRK and others, laser energy is used to reshape the curvature of the front clear surface of the eye (named cornea) to change the way light enters the eye. The surgically inserted artificial lenses in the eye also do the job of refocusing rays of light to sharpen vision.
Progress in Corrective Eye Surgery
During the past 25 years, techniques, equipment and methods in the surgery for vision correction have progressed tremendously. The journey is interesting.
Radial Keratotomy (RK) was being used in the US mainly during the 80s and involved taking spoke-like incisions to even out the surface of the eye. This surgery was being done mainly to rectify nearsightedness. But the results of the surgery were problematic in some cases, where regression fluctuating vision, a significant amount of glare and adverse side effects like night vision problems were observed in patients who underwent RK for greater prescription strengths, whereas these side effects were less common in patients having lower prescription.
RK has now become an outdated technique because of the problems it can create and also because of the emergence of new techniques like laser vision correction.
The first successful vision correction procedure with laser was Photorefractive Keratectomy (PRK) in which tissue is removed (ablated) directly from the surface of the eye and thereby curvature of cornea is changed. This was also called surface ablation. In the USA, it got the FDA consent in 1995 and since then it is by far the most popular laser surgery at present.
LASIK Vs PRK
PRK made a return especially in recent years because of the research which indicates that PRK and LASIK give similar results. Moreover, regeneration of nerves in the eye surface seems to occur quicker with PRK than with LASIK. This could reduce dry eye and other problems that might appear during the healing process.
Also because PRK is a surgery done to the surface, the risk of surgical flap complications is eliminated. PRK doesn’t create the thin flap on the surface of the eye, which occurs with LASIK. PRK is also a procedure of choice for persons having a cornea too thin for LASIK.
However, it also should be noted that the latest advances in technology have offered eye surgeons better techniques of forming thinner flaps in a guaranteed way. This means, that people having thin corneas too can undergo LASIK procedure.
However, you should probably consider a different procedure for vision correction if you have a high myopia and thin cornea that might require additional ablation for reshaping the eye.
The main advantage of LASIK over PRK is it creates a very little to no discomfort after the procedure and vision often becomes clear within hours, rather than days. LASIK exists in different types, many of which depend on how the flap is formed.
LASEK: LASEK involves forming an ultra-thin flap in the thin exterior covering (epithelium) of eye and taking it away from the surface of the eye using alcohol so that the eye’s laser reshaping can take place.
Epi-LASIK: This is just like LASEK, but there is a difference that the flap is lifted using a special cutting tool.
Bladeless, All-Laser or Blade-free LASIK: This involves another laser instead of a cutting tool to form the flap used in LASIK. This is also called IntraLASIK because the laser used for creating the flap was originally created and marketed by IntraLase Corp. The IntraLase technology was obtained by Abbott Medical Optics in 2007. There are other brands of blade-free LASIK too like zLASIK’s Ziemer Femto LDV.
Wavefront LASIK or PRK: This technique is also called wavefront-assisted, wavefront-guided or custom LASIK/PRK and involves ultra-modern analysis, called wavefront, to accurately measure how light passes through eye. Excimer lasers having built-in wavefront analysis can find and automatically adjust even subtle vision defects when laser energy is used to reshape the cornea.
Conductive Keratoplasty (CK): This uses low heat radio waves and a small probe to place “spots” around the border of the clear front surface of the eye. This is a relatively non-invasive technique and steepens the cornea to rectify near vision for farsighted people. CK can also be used to rectify presbyopia or for enhancing near vision for patients who had cataract surgery or LASIK.
Implantable Lenses: These lenses too, like contact lenses, got FDA endorsement in 2004. These lenses are implanted surgically and are considered apt for high levels of nearsightedness. With the implantable lenses, your original lens is not removed but is left in place.
Refractive Lens Exchange (RLE): This is another internal, non-laser procedure. It is much similar to cataract surgery. However, instead of removal of the natural lens of the eye which becomes cloudy due to cataract, RLE involves removal of a clear natural lens and inserting an artificial lens in its place of a different shape, normally to lessen or eliminate great degrees of farsightedness.
Cataract surgery can also now be regarded as a vision correction surgery. A new lens implant is developed for the surgery which can restore a person’s near vision partially along with rectifying nearsightedness as well as farsightedness. Multifocal IOLs as they are called, these lenses are popular nowadays with many cataract surgeons and give promising results.
Which Corrective Eye Surgery to Choose?
With a plethora of procedures, anyone can be confused about which one to use. Here we should consider that as we age, the type of laser surgery for our eyes or other vision correction procedure may also change. Some LASIK or other procedures which work fine for younger persons may not work very well for older patients. It may also happen that vision correction procedure may have to be totally ruled out, e.g. children under 18 can hardly be considered as apt candidates for laser procedures because their eye changes fast with growth of their body and maturity.
It’s a general observation that people in their 20s or 30s having mild to moderate nearsightedness, farsightedness are apt candidates for PRK, LASIK and other laser procedures.
And after all, your eye surgeon is the best person to decide which vision correction surgery you should undergo. So, act upon her/his advice and enjoy clear vision.