Many of you may have heard of the terms “custom LASIK“ wavefront-guided LASIK, and topography-guided LASIK. It can be very confusing, and even make you reluctant to have the procedure. In this blog post, I will talk at length about the different procedures, outcomes, expectations, and technology available today.
What is LASIK?
First, it’s important to understand exactly what LASIK is. LASIK stands for: laser-assisted in situ keratomileusis, a mouthful which means that a laser is shaping your cornea to the perfect curvature to allow you to see distant objects clearly. It is highly successful and has been performed on tens of millions of people over the past 30 years. The technology improved drastically in the early years from 1998-2005, and incrementally and continuously since then. There are different types of technology that do one of two basic functions:
Make the flap:
The flap is created either by a blade or by a laser. At SharpeVision, we have never used the blade. I personally performed over 30,000 procedures with the blade, but since about 2006. I have not used the bladed keratome. We have always made the flap with a femtosecond laser. There are numerous advantages to making the flap with a femtosecond laser. The femtosecond lasers have also improved. They are faster, more versatile, more customizable, and make the procedure easier and more accurate than ever before. The flap creation is important, but has nothing to do with wavefront-guided LASIK. The second (excimer) laser is the one that shapes the cornea and designs a unique (custom) wavefront-guided treatment for your eyes.
Shaping the cornea with the Excimer laser:
The word “Excimer” is a combination of two word and stands for “excited dimer.“ It basically means there is a gas in the laser that is excited by very high voltage electricity that then emits a very precise laser wavelength. Lasers, in general, are very precise and accurate because the light emitted is extremely focused, is of one wavelength, and the lightwaves are all in coordination, much like an army marching at the exact same pace versus a crowd of people walking in different directions and at different speeds. Thus, the laser can remove tissue without heating or damaging it. This is the key to the Excimer laser. Currently there are three laser companies in the United States that make up the majority of the market. The names are Nidek, Alcon, and Visx. The lasers all emit the same wavelength. They also all have infrared tracking technology to keep the laser centered on the pupil during the treatment. You don’t have to worry if your eyes move because if they move a little bit, the laser follows them. If they move a lot, the laser will stop. This has been around for over 20 years now and was the first major upgrade to LASIK technology, in my opinion. The lasers all have custom (wavefront-guided or topography-guided) platforms available.
What is Custom LASIK?
There are various terms used for custom LASIK. In general, they include “wavefront-guided LASIK“ and “topography-guided LASIK“. They are basically the same thing, that take your standard eyeglasses prescription and add the custom component. Your basic eyeglasses prescription consists of three elements:
- the nearsighted/farsighted component
- the astigmatism component
- the direction of astigmatism.
Eyeballs are Imperfect Organic Objects.
But they are astounding and amazing!
The other thing that should be fairly intuitive is that our eyeballs are not perfectly round objects. There is high variability in the shape and length of our eyes. These factors all affect the ability of our eyes to see clearly. If there is a mismatch between the curvature and length of our eyes, our vision will be blurry. We must correct this mismatch with either contact lenses, glasses, or refractive surgery to see clearly. In the refractive surgery arena, there are multiple different procedures that all have an excellent place in our armamentarium. Standard LASIK, custom LASIK, wavefront-guided LASIK, and topography-guided LASIK all are commonly recommended. PRK also uses the same laser, achieves the same results, but does not involve the femtosecond created flap as mentioned above.
The excimer laser shapes the eye with both the standard eyeglasses prescription and a “custom“ component. The custom component takes into account the very unique, individual variations in the shapes of our eyes and the optical properties of our eyes. Wavefront is an amazing technology that detects all the tiny aberrations that each person has in their eyes. Using AI, wavefront-guided LASIK computes and designs a “perfect“ reshaping of our eyes to achieve the best possible visual quality. Wavefront treatments do not generally improve the letters we can see on a vision chart, but may improve the quality of vision in low light conditions, improve contrast, sensitivity, and overall satisfaction with the procedure.
Other Factors Affecting Custom Wavefront Guided LASIK Outcomes
There are many other factors that account for a lot of the outcomes of LASIK. The two most influential factors are your age and your glasses prescription, but there are also factors such as your general eye health and systemic health. Dryness, clogged oil glands, slight cataract, and retinal pathology can all affect your topography guided LASIK outcome.
Age for Custom LASIK
Your age when you have wavefront guided LASIK is very important, because our eyes change throughout our lives. Our eyes undergo maturation generally up to age 18. From age 18 to 45 our eyes are fairly stable in terms of what we experience. By age 45. however, there is enough loss of flexibility in the lens located inside our eyes that causes us to need reading glasses, or to remove our glasses to see near objects. After about age 45, you cannot have perfect distance vision and perfect near vision in both eyes.
“Some people are able to put off the use of bifocals or reading glasses until their late 40s, but eventually presbyopia affects us all.”
This particular problem has not been solved adequately and is an area of intense research in vision. After age 60, the lens of our eyes begins to lose its transparency. As this happens, neither glasses, LASIK, nor contact lenses correct vision as well as if you have LASIK in your 20s or 30s. It’s sort of like trying to look through a dirty window. No glasses will allow you to see through a dirty window, so you must clean the window. In this case, that means having the lens of your eye removed and replaced with a clear, artificial lens. The good news is that these artificial lenses can allow you to see distant objects and near objects clearly without any glasses.
How does Custom LASIK Differ from Standard LASIK?
Custom/wavefront-guided/topography-guided LASIK are all basically different names for the same thing. What it means is that your standard eyeglass prescription is treated first and then the custom laser is applied. The custom laser addresses the unique aberrations in your visual pathway. Wavefront-guided LASIK cannot correct dryness, cataract, or other pathology of your eyes, but can potentially improve your overall vision by 1% to 5%. For most healthy young people, that makes little to no difference, but if you do have higher degrees of aberration in your visual system, wavefront-guided LASIK may be a benefit to you.
The actual performance of the procedure is no different in terms of what you experience. The difference is in the shape of the laser treatment that is unique to your eyes. The only way to know if wavefront-guided LASIK would be helpful is to get a comprehensive and free LASIK evaluation at SharpeVision.
Call us at 425-451-2020 or schedule online at sharpe–vision.com. At this comprehensive consultation, we will discuss the differences in the various treatments depending on your age, refractive error (glasses prescription), and eye anatomy. We will explain what procedure we recommend, as well as why we recommend it, so you can make the informed decision that is right for you!