Laser eye surgery is generally considered safe but this should not be equated with "risk-free" as all surgical procedures involve risk. Although countless patients have retired their glasses or contact lenses with 20/40 vision or better, there are many considerations before opting for laser eye surgery and not everyone is a candidate. Aside from complications there can be side effects. A small percentage of people actually see worse after laser eye surgery.
There are two main steps to correcting the vision through laser eye surgery. The first step involves moving the epithelium, or topmost layer of the cornea. This can be done by "surface ablation" techniques or by "cutting a flap." The second step utilizes an excimer laser to vaporize small amounts of tissue in order to reshape the cornea to attain proper vision. The excimer laser is guided by one of several technologies that vary in their ability to precisely map and reshape the eye, bearing different results. Both steps carry their own associated risks specific to the particular procedure used.
A good surgeon certainly helps to make laser eye surgery safer, but post-op infection is always a risk and runs higher with surface ablation techniques like PRK and LASEK verses cutting techniques like LASIK. Infections can usually be treated with drops and normally do not result in long-term problems, though severe complications could create temporary loss of vision or worse. The healing process associated with surface ablation techniques is longer and more uncomfortable, compared to LASIK.
Corneal haze is common after surface ablation techniques but usually fades with time, though not always. Hazing cannot be corrected with glasses or contact lenses. A further laser procedure might be recommended using advanced technology such as CustomVue WaveFront to target the scarred tissues.
LASIK procedures that use a microkeratome blade for cutting a flap run the risk of cutting the flap off, rather than leaving it hinged. If the flap is unrecoverable or unusable permanent damage or loss of vision could occur. Even successful procedures using a blade can leave tiny imperfections or scars in the corneal tissues that can result in blurred vision — a lack of crispness formerly achievable with corrective lenses. Advanced types of laser eye surgery can usually correct imperfections created by a microkeratome blade. (CustomVue IntraLasik, for example, uses a laser rather than a blade to create a corneal flap, in addition to utilizing advanced mapping techniques for the excimer laser to target imperfections left by other less advanced forms of laser eye surgery, making this form of laser eye surgery comparatively safe and accurate, though more expensive.)
Because of the likelihood that small amounts of scar tissue can result from many kinds of laser eye surgery, 20/20 vision may not be as crisp as the 20/20 vision experienced prior to surgery with corrective lenses. Also, the risk of ending with vision that is over corrected or under corrected is not uncommon as the eye's exact response to laser surgery is unpredictable. In this case glasses or lenses may still need to be worn or a second surgery may be recommended to improve the result.
Some patients report sensitivity to light, glare, night vision problems and/or problems with double vision after surgery. In most cases these effects subside over time, but there are no guarantees. The shape of the eye can also change as one ages, eventually requiring a second procedure or the use of glasses or contacts. The issue then isn't only, is laser eye surgery safe, but are your expectations realistic?
Various excimer lasers are FDA-approved to work with certain technologies and to correct vision that falls within a specific range. You can also learn more about the dangers, what you might expect before and after surgery, and how to find a good doctor.
People who are pregnant, have diabetes, experience problems with binocular vision, have very dry eyes, thin corneas, or very large pupils are just a few examples of those that are not good candidates for laser eye surgery. Before making any decisions about whether or not laser eye surgery is safe for you, make sure to see your ophthalmologist to discuss the pros and cons of the various techniques as they relate to your specific needs.
This article is not to be taken as medical advice and is only provided for purposes of general information.