Dr. Dean Dornic: I am Dr. Dean Dornic of the Laser Eye Center of Carolina. We are talking about how to reduce your dependence on eye glasses and contact lenses. We are going to be talking now about success rates and complications of the LASIK procedure. How we define the success rate of LASIK just depends on a particular individual? We can talk about how many patients reach 20/20 or how many patients reach 20/40 or able to drive without glasses or contact lenses or we can also talk in terms of patient satisfaction. In general, most of the studies that have followed LASIK procedures over the years agree that the success rate in terms of patient satisfaction range somewhere between 95 and 98%. With some of the newer technology that we have today like Custom LASIK, there are many individuals who have about 98% chance of getting to 20/20 or better levels of vision. There are no medical procedures in which the success rate is 100%, in which there are no complications. So LASIK is no different than that. There is certainly the risk of a complication from a LASIK procedure as there would be from any type of eye surgery that's out there. Of course, again, how we define a complication depends on the particular individual. There are some complications that are minor and temporary, there are some that can be vision threatening. The nice thing about the LASIK procedure is that the risk of vision threatening complications are actually quite low. In fact, there have been some studies that show that the risk associated with significant vision loss from LASIK is actually less than the risk of years of contact lens wear. There are other complications that might not be vision threatening but might lead to patient dissatisfaction. For instance, if you went in to the procedure assuming that you'd be free of glasses and contact lenses and that was not achieved, then you might consider that a complication if you would. So some patients won't be satisfied with the results and for instance, might require a touch-up procedure or second laser procedure. There are other complications that are less frequent. For instance, night time glare, halos, star bursting, dry eyes are an almost universal complication of the LASIK procedure, but for most individuals, that's a temporary problem. There is not a particular limit to number of times that the LASIK procedure can be repeated. However, what you have to remember is that during a LASIK procedure, we are actually removing some tissue in the reshaping process, so it could be possible that we would run out of corneal tissue and so you might be limited. For some individuals, they might only be allowed to have one procedure and other patients could have four or five procedures. It is possible to lose vision from a LASIK procedure, but the risk of that is actually very small. The great majority of patients are very satisfied with the procedure. Some patients will require a second laser procedure, but in terms of significant vision loss, as we stated earlier, the risk is actually greater from contact lens wear.Night vision problems from LASIK were common years ago. Some of these night vision problems resulted as a result of the laser ablation being smaller than the pupil so that if a person had a pupil that dilated very large at night, their pupil might extend beyond the treatment area of the procedure and so some of the light that went into the eye would go through treated cornea, some would go through untreated cornea. That might not be the only reason for night vision problems. If there was some residual refractive air, that is if there was some nearsightedness left or some astigmatism left, that can lead to some night driving difficulties. Dry eyes can also lead to night driving difficulties and finally, the induction of what we call higher order abrasions or distortions on the cornea can lead to night time glare or halos. During the LASIK procedure, lasers are used to reshape the cornea and in doing so, we actually ablate through some of the nerves on the cornea that detect how wet the cornea is. The purpose of these nerves is to send a signal to the tear glands to tell the tear glands to secrete tears. Since there won't be that feedback, then the tear glands are still capable of secreting tears, but they don't receive the message to do so. So in other words, the cornea doesn't recognize that it's dry. So some of the patients after their LASIK procedure will notice some symptoms associated with dry eyes, the most common one is fluctuating vision. Patients will say things like they have to keep blinking their eyes in order to clear their vision or they have to use lubricating drops to clear their vision. In general, the great majority of nerves will grow back within about 90 days and so the average duration of symptoms of dry eyes from a LASIK procedure is 90 days or so, but for some individuals, those symptoms can last much longer, a year, rarely longer than a year after the procedure. In general, the LASIK procedure is very safe. It has a very high level of success and that's what has led to its approval by the FDA. As we stated earlier also, the great majority of patients are very satisfied with the results. Of course, there are no medical procedures in which the success rate is 100%. Patients will be asked to sign a consent form before the procedure to indicate that they understand that there are some risks associated with the procedure. Most of those risks are minor or temporary. Although vision loss is the lost significant risk of the procedure and you need to make sure that you do everything possible to make sure the procedure is as safe as possible for you.