||WHAT PROCEDURE SHOULD I HAVE?|
Confused About LASIK-LASEK-INTACS- LTK-PRK?RK- to Correct Nearsightedness, Farsightedness, Astigmatism and Reading Vision problems- Read On
If you're confused about whether to have Excimer Laser LASIK, LASEK or PRK for the correction of myopia, (nearsightedness) hyperopia,(farsightedness) or astigmatism, you're not alone. A tremendous amount of money and time has been spent by advertising agencies to present an appealing "product" for you to purchase! The problem is, this isn't just any product, it's your eyes. Yes, your eyes, and these are the only ones you're going to get for the rest of your life! So what is the answer? Simple! Don't believe anyone's commercials or ads. Use the ads to identify people doing the surgery, and then investigate, investigate, investigate this product like you would any other product! To do that, you need to educate yourself on the facts not the hype. The" proven" scientific facts about all the procedures. (i.e. Check out the FDA's website at www.fda.gov/cdrh/lasik). Then, you investigate the credentials not the commercials of the surgeon you want to do the surgery.
Excimer laser Lasik surgery is the most common refractive surgery procedure in the world. LASIK (Laser in Situ Keratomileusis) is a combination of two procedures.
First, a special instrument called a keratome is used to create a flap of corneal tissue on the surface of the eye. This is much like a carpenters wood plane elevating a sliver of wood or like splitting a layer cake in two halves. The excimer laser is then used to reshape the bottom layer. The corneal flap or upper layer is then placed back in its original position, covering the lasered area. The eye holds the flap in place naturally and sutures are rarely needed. The resulting flattening or steeping of the cornea causes light rays to focus more directly on the retina, making images clearer. THIS PROCEDURE CAN CORRECT NEARSIGHTEDNESS, FARSIGHTEDNESS AND ASTIGMATISM. Success rates are exceptional with over 95% of patients seeing 20/40 or better without glasses (legal driving) after the laser surgery. Success rates are somewhat lower for higher levels of correction and with corrections with astigmatism.
The MAIN advantages of this procedure are less post-operative discomfort and faster visual recovery (than LASEK or PRK )--usually 1-2 days.
Success rates for Excimer Laser Lasik mirror those of PRK at about 96% of patients seeing 20/40 or better without glasses or contacts after the procedure (The success rates run higher for lower levels and lower for higher levels of correction/astigmatism).
The lack of pain, ability to treat both eyes at the same time and the speed of vision recovery (next day) has made this procedure the first choice of patients world wide.
EXCIMER LASER PRK & LASEK
Excimer Laser PRK and Lasek are also treatments for the correction of nearsightedness, farsightedness and astigmatism These procedures have been approved in almost every country in the world and over 1,000,000 procedures have been performed worldwide. After extensive study, the FDA approved it in the U.S.
The Excimer laser procedure is performed by a highly sophisticated, computerized laser.
As in the Lasik procedure, vision correction is due to flattening or steepening of the cornea by the laser treatment.
In Excimer laser PRK, the Epithelial or Skin surface of the cornea is removed and discarded. Laser energy is then applied directly to the surface of the cornea. The laser energy vaporizes surface tissue and molds the cornea to the same prescription as a persons glasses or contact lenses. It's like peeling the top five sheets of paper off of a pad of paper. Since there are no deep cuts in the cornea there is no weakening of the cornea, and almost no variable vision with this procedure.
The newer LASEK procedure "rolls up" and "saves" the Epithelium or skin surface like a taco or the top of a sardine can, then applies the laser as in PRK, and finally rolls the "Skin" surface back in place over the lasered area. This maneuver reduces pain and haze associated with standard PRK.
The success rates for the PRK Excimer Laser Procedure in the
U.S. FDA studies were impressive, with over 95% of patients seeing 20/40 or better after a single Excimer laser procedure. Lasek is assumed to be equal, or better, due to the reduction in haze.
Intacs are small pieces of plastic, which are placed between the layers of the cornea, inducing shape changes to correct vision. At present, this procedure will only correct mild amounts of nearsightedness and does not correct farsightedness or astigmatism. Few procedures have been performed world wide compared to laser procedures. At present, this is a promising but fairly uncommon procedure.
Laser Thermal Keratoplasty, or LTK is a new, revolutionary procedure which takes 3 seconds per eye to perform and can correct up to 2.5 Units of farsightedness with up to one diopter of astigmatism.
This procedure can also be used to create monovision so patients over 40 would not need distance or reading glasses. One eye is essentially corrected for near reading and the other for distance.
Patients, who do not need glasses for distance but do need glasses to read, can also have one eye treated for reading so they won't have to wear reading glasses at all.
Patients already wearing monovision contacts are perfect candidates for this procedure.
Patients interested in trying monovision out before surgery can do a contact lens trial of monovision to see if they like it.
A Japanese doctor by the name of Sato, began RK surgery in the 1950's. Many successful cases were performed, but because of poor techniques, most cases eventually ended with a total loss of vision and the procedure was abandoned. In the late 1970's the procedure was revived in Russia, with improvements in technique, and later brought to the United States with even further refinements.
Because of the lack of knowledge about the safety and the results of this technique, a large multicenter study was established called the "Perk" study at many University's around the country. The surgery was performed by well trained surgeons all using the same equipment and techniques. The basic technique consisted of making 8 incisions in "spoke-wheel" fashion in the cornea, the front surface of the eye. The incisions were made by hand with very sharp diamond knives. The incisions were made very deep to 95% of the depth of the cornea.
The data was collected and reviewed at 1, 3, 5, and recently 10 years. The basic findings for each of the intervals published were basically the same. Only the percentages of success, failure, and complications changed. The statistics are based on reduction in nearsightedness to useful levels, which is considered to be 20/40 vision. This is the legal level for driving without glasses in all 50 states. (RK ONLY CORRECTS NEARSIGHTEDNESS)
At 10 years after RK, results for low nearsightedness between 2 and 3 units, showed 92% were 20/40 or better. For middle nearsightedness between 3 and 4.5 units, 86% were 20/40 or better. For high nearsightedness between 4.5 and 8 units, 77% were 20/40 or better.
Twenty percent of cases needed second or third surgeries, referred to as enhancements.
The results don't sound too bad. But what about the problems and complications? I find, as a physician, that most people ask the wrong questions about surgeries! People always ask about the success rates, which are important, but I want to know what the failure rate is and what problems comprise the failure rate! If I told you that an eye surgery procedure has a 98% success rate you would think that's really great! But, what if the 2% failure rate was total loss of vision! This is not the case, of course, for any of these procedures, but if you don't ask the question, you can't know the answer!
Most of the complications of radial Keratotomy were fairly low in incidence and included things we would expect in any eye surgery such as scarring, misplaced incisions, blurred vision, starburst effect, ineffectiveness of the surgery, perforation of the cornea, and infection. These complications were shown to be fairly rare, but there was no way to predict who would have these problems.
The major and most controversial finding, however, and the biggest long-term problem for radial Keratotomy was the finding that 43% of RK patients had unstable, variable vision for at least 10 years after surgery! Many showed what is called progressive hyperopia, which means that the vision slowly progressed from "corrected" nearsightedness to "farsightedness" over time, leading to the need for glasses!
This finding also put the success rate statistics into doubt, since perfect results at one year could be poor results at year 5 or 10!
SINCE THE ADVENT OF EXCIMER LASER SURGERY, RK HAS VIRTUALLY VANISHED AND IS OF HISTORICAL INTEREST ONLY.
POTENTIAL COMPLICATIONS AND SIDE EFFECTS FOR ANY OF THESE PROCEDURES:
1. Delayed epithelial or poor epithelial healing which can lead to scarring, vision loss or further
2. Under or over correction which may lead to further surgery or may not be correctable
3. Night halo, glare and ghosting can occur with any of these procedures and has an
increased incidence when astigmatism is corrected and in people with larger than
normal pupils. These effects usually fade with time, but may be permanent.
4. Light sensitivity can occur for a short time after these surgeries. This usually fades with time but can be permanent.
5. Corneal haze or scarring can occur with these Procedures. This usually diminishes with time and
does not affect the vision but in some cases may be permanent and/or effect vision.
6. Eye co-ordination: when both eyes need correction, there is a problem with eye co- ordination aftersurgery has been done on one eye. Wearing glasses, a patch or contact lens may be necessary until both eyes can be corrected.
7. Contact lens tolerance may be diminished after these procedures
8. Bilateral surgery (both eyes) entails all the same risks as single eye surgery, however, if complications do occur, they may affect both eyes leading to loss of vision in or loss of, both eyes.
9. Infection can occur in these procedures and can be blinding or lead to loss of an eye
10. Dry eye syndrome may result from these surgeries or become worse in previously affected individuals
11. Corneal thinning and progressive ectasia may occur and lead to the need for corneal transplantsurgery
12. Unknown or presently unanticipated complications can occur with these procedures leading to loss of vision or loss of an eye(eyes) at present or in the future.
13. To prevent injury after surgery, all patients MUST wear certified sports goggles or safety glasses duringsports or work where potential for eye injury exists.
Dr. Mackman is now performing Excimer Laser LASIK, PRK & LASEK, for the correction of nearsightedness, farsightedness and astigmatism