As the tail-end of the baby boomers enters their 50s and 60s, many are seeking surgical solutions to correct their nearsightedness, farsightedness, or astigmatism so they can minimize their need for glasses and contact lenses. Although very good surgical solutions exist, there are specific considerations that need to be considered for people in this age range.
In order to understand the special considerations patients in their 50s and 60s face, it is important to understand how the eye – and aging of the eye – works.
HOW THE EYE WORKS – AND AGES
When someone looks at an object, light coming from that object enters the eye through the cornea, which is the clear, domed cover of the eye. It can be compared to the windshield of a car. There is no other way for light to come into the eye other than through the cornea. As light passes through the cornea, it is focused by the cornea. As light continues into the eye, it passes through the pupil and then flows through the lens on its way to the retina in the back of the eye. The lens is the second structure light passes through and, like the cornea, it also focuses light. The cornea and the lens are the only two structures light passes through which focus the light. This means there are two possible places to use surgery to correct focus of light: the cornea and the lens. Corrective surgery on the cornea is LASIK (or its flapless cousin PRK). Corrective surgery on the lens is lens replacement surgery.
The cornea is the main focusing structure the eye. The lens is a weaker focusing structure than the cornea. When you are younger, the lens is very flexible. It bulges – and relaxes – to focus back and forth from close to distance. The lens squeezes, or bulges, to look up close and relaxes to look into the distance. This happens unconsciously all day long. After age 40, the lens gradually starts to get stiffer – and stiffer and stiffer as years go on. This process is called presbyopia and it continues to worsen relentlessly until your early 60s. After that, the lens is essentially stiff as a board and cannot bulge to focus at all. From a practical standpoint, if a patient sees well at distance (either by birth, from LASIK, or with glasses/contact lenses), then the distance remains good as presbyopia progresses and the close becomes progressively worse, requiring increasingly strong reading glasses or bifocals in glasses.
The next step in the aging of the lens after the lens becomes stiff typically is that the lens starts to gradually become cloudy. When the cloudiness of the lens becomes significant enough to impair vision, then this is called a cataract. The only treatment for a cataract with current technology ultimately is to remove it through cataract surgery. With cataract surgery, the lens is removed and a new plastic lens, called an implant, or intraocular lens (IOL), is put in its place. When cataract surgery is performed, the implant is adjusted in its strength with the goal of correcting vision. Essentially the patient’s prescription is built into the implant, or IOL. There even are IOLs designed to address presbyopia (called premium lenses or presbyopia correcting lenses). Presbyopia correcting lenses involve inherent trade-offs and are not for everybody. They should be carefully discussed with the lens surgeon.
SURGICAL CORRECTION OF NEARSIGHTEDNESS, FARSIGHTEDNESS, and ASTIGMATISM
Since light is focused by two structures in the eye – the cornea and the lens – there are two places to correct the vision surgically. LASIK works by reshaping the outer surface of the cornea to change its focus. Cataract surgery works by replacing the natural, but cloudy, lens with a clear plastic implant, or intraocular lens (IOL). The IOL is adjusted in its strength with the goal of correcting vision. It is important to understand that cataracts do not emerge overnight, but generally only slowly develop. This process can take even a decade or longer.
If there is no cloudiness – or only trivial cloudiness – to the eye, the same surgery as cataract surgery can be performed to correct vision: the essentially clear lens can be removed and replaced with an intraocular lens with the correct power to correct vision. Since there is no cataract in this case, this surgery changes its name from “cataract surgery” to refractive lens exchange (RLE). The only difference between cataract surgery and RLE is whether or not there is a cataract present when the surgery is done. This carries financial implications as well. Generally, insurance or Medicare will pay for cataract surgery but will not pay for RLE since it is elective and only being performed to reduce or eliminate the need for glasses/contacts. If someone has a cataract, their only option, of course, is cataract surgery.
LASIK vs LENS REPLACEMENT SURGERY (RLE)
This means that patients who do not yet have cataracts essentially have two elective options for surgical correction of their vision to reduce their need for glasses: LASIK or RLE. This is the choice that many patients in their 50s or 60s seeking surgical solutions face. In general, there is a time and a place for each approach as each has its own advantages and disadvantages. LASIK has the distinct advantage that it is a less invasive, less intrusive surgery. With LASIK (or PRK), the laser simply reshapes the cornea from the outer side to change its curvature and therefore its focus. RLE, by contrast, involves actually going inside the eye, removing the lens, and inserting the plastic intraocular lens. Because LASIK works outside the eye, it carries a lower risk level than RLE, which works inside the eye. Generally, the risk for serious problems with properly performed LASIK is considered to be approximately 1-2/10,000. The risk for properly performed RLE is approximately 1/100. The risk for RLE is understandably higher because the surgery enters inside the eye. This risk for RLE is quite acceptable for cataract surgery since patients do not have any other option than removing the lens and replacing it once the cataract limits vision. However, in the case of RLE, the lens is clear, so the risk profile difference between LASIK and RLE needs to be carefully considered. Another risk issue with RLE is that some studies suggest a slight elevation in the risk of retinal detachment after lens replacement surgery for the rest of the patient’s life. Again, in the case of cataract surgery, there is no real alternative. But assuming a lifetime small increase in retinal detachment risk after RLE is something that needs to be carefully considered for an elective surgery.
On the other hand, having LASIK still leaves the aging lens in place. Eventually we all will need cataract surgery if we live long enough. Having RLE, on the other hand, replaces the lens with a plastic lens which, meaning the patient never will develop cataracts since the lens has already been replaced. In essence, undergoing RLE means “killing two birds with one stone”: the patient’s nearsightedness, farsightedness, or astigmatism can be corrected and there will be no future need for cataract surgery. Some surgeons erroneously tout RLE as a way to “prevent” cataracts but the reality is RLE is essentially having cataract surgery to avoid future cataract surgery! Beside the inherently higher risk of RLE, one potential drawback of this approach is that it “locks” you in to current lens implant technology at a time it is not necessary to do so. Although intraocular lenses have progressed dramatically in recent years, future lenses will likely be even be more impressive. In this sense, there is no urgency about replacing your lens.
The other issue to consider is accuracy. Because LASIK uses a computer guided laser to reshape the cornea based on wavefront measurements of the eye, it ultimately is more accurate in its results than RLE. Even in the best of hands, RLE (or cataract surgery) cannot match the accuracy of LASIK because the lens is put in a sack in the eye. The lens power is based on generic formulas and its position can change after surgery as that sack heals, slightly altering the focus of the lens in the eye. This isn’t to say that lens replacement surgery isnt’ accurate – in fact its quite accurate – but data shows the advantage in accuracy goes to LASIK.
A final consideration is cost: even premium LASIK tends to be less costly than RLE. Insurance generally does not cover either LASIK or RLE.
MAKING THE DECISION: LASIK OR RLE?
With all this in mind, how does one decide between LASIK and RLE to correct nearsightedness, farsightedness, or astigmatism? On one extreme, if a patient is 35 years old with a clear and flexible lens, then then choice generally is quite obvious. This patient should have LASIK and not RLE. On the other extreme, if a patient is 75 years old and has a moderate degree of cloudiness to their lens, but can still get by without cataract surgery, this patient should have RLE. The concern with doing LASIK on this patient isn’t that it would not work. The concern is that the LASIK would only offer a very temporary solution because the lens would inevitably worsen and this patient would notice their vision slipping (due to the lens changing, not due to the LASIK) and soon need cataract surgery anyway.
Between these two extremes are patients whose lenses are aging, but do not yet have cataracts. This generally includes people in their 50s and 60s.
Obviously, each patient must make their own informed decision. My own bias as a LASIK specialist is to take the least invasive, most accurate, and least risky route to get the patient the best vision possible. If the lens is clear, I recommend LASIK for patients in this age range although it is important of course for patients to know all their options.
If the lens is mildly hazy, then the decision becomes more difficult. It is important to know that no one has a crystal ball to know when the lens will progress to a true cataract affecting vision and requiring removal. If the lens has trivial haze and the patient could go 10 years before needing cataract surgery, then I would prefer LASIK. If the patient could only be expected to go 1 year, I would prefer RLE. If the best estimate is in between, then the decision can be more difficult and the patient clearly needs to be involved in making this personal choice since the answer may be less clear cut.
In many cases, if the lens is in this intermediate place in terms of its proximity to developing a cataract, I will often seek out a second opinion from an experienced cataract surgeon as to whether LASIK or RLE is the most appropriate course. In many cases, there is no clear cut answer. The good news is that both procedures have very high success rates and if LASIK is performed, lens surgery always can be performed down the road. This means that if the best estimate for when the lens develops a cataract is wrong, successful cataract surgery certainly can be performed after LASIK, even if it comes sooner than we hoped it would.
Get more information at: https://shapirolaser.com/
Comentarios