A few years ago, there was no choice in cataract surgery. Everyone received the same basic surgery: Standard MONOFOCAL implants with standard Phacoemulsification surgery
Now everyone has many options. It can be very confusing and very scary, so I hope this will help you make the best informed decision for you! I would encourage you to talk to your family and friends who might have had to make this decision and ask them about their experience. Circumstances are different per person, but meeting someone who is happy having a Premium Implant and/or Laser Cataract Surgery can help relieve your fears of making a “wrong” decision. Also, be aware, that if you are not happy with your result, there is very often a way to make it better.
1. The First most important decision is the type of cataract surgery you should have.
Laser Cataract Surgery is the most innovative technology ever created for removing a cataract. Lasers, such as the LenSx femtosecond laser, are very precise in cutting the delicate tissues of the eye and thus decreasing the total amount of energy we need to use inside the eye to remove the cataract. Studies are showing Laser Cataract Surgery improves recovery time (as the cornea or window of the eye has less fluid/edema because less energy was used), decreases risk of implant de-centration (moving out of position), decreases the risk of cystoid macular edema (swelling in the back of the retina that can decrease vision temporarily or in rare cases permanently), decreases the risk of needing a corneal transplant due to a swollen cornea (pseudophakic cataract surgery): note many of these studies have been published in peer-review journals, some are poster presentations, and/or studies being prepared for publication.
2. The Second most important decision is the type of Implant you should have.
There are 3 different types of Advanced Intraocular Lens Implant options:
1. Multifocal Intraocular Implants: (attempts to correct for all ranges of vision)
–Restor (slightly better if need very good reading vision)
–Tecnis (slightly better if need very good computer vision)
2. Accommodating Lens Implants: (attempts to correct for all ranges of vision)
–Crystalens: (a monofocal type lens that moves inside the capsular bag to allow one to see better for reading, intermediate/computer, and distance)
–Trulign (a Crystalens (attempts to correct for all ranges of vision) that corrects for Astigmatism)
3. Toric Lens Implants (corrects astigmatism >1.0D and only for 1 distance range (distance, computer or reading; these do not correct for all ranges of vision)
–Tecnis Toric or –Alcon Toric
These are all designed to REDUCE your dependence on glasses as compared to if you had received a standard “single-focus,” monofocal, lens implant, though in many patients they can eliminate the need for glasses completely.
A standard, MONOFOCAL lens implant will provide your eye with optimum focus set at one particular distance that does not change. You would then wear glasses in order to change this focus (e.g., moving the focus farther away or closer up).
How do multifocal and accommodating lens implants differ?
Conventional single-focus lens implants are called monofocal lenses because they optimize the
focus at a single location. Multifocal lens implants are designed to produce a dual focus. Part of
the lens is set for distance focus, and part of the lens is set for near, and this technology can
significantly reduce your dependence on reading glasses. Accommodating lens implants seek to
reduce eyeglass dependence according to a completely different principle. Accommodation is the
medical term which describes the natural ability of a young eye to focus by changing the lens
shape. If the lens implant could also change its shape or position, some focusing ability could be
restored.
The Crystalens implant is the first and only accommodating lens to be approved by the FDA. This
lens implant has an ingenious hinged design, to allow it to flex slightly. This enables your eye’s
natural focusing muscles to cause some flexing and movement of the lens, thereby adjusting the
focus. There is usually not enough lens movement to allow you to see far off in the distance one
moment and to read up close the next. As you would imagine, there is also individual variability in
the ability of the eye muscles to move the implanted lens. While the Crystalens does increase
one’s capacity to change focus relative to a standard single-focus lens implant, unfortunately it
does not duplicate the focusing ability that we all enjoyed when we were young.
The Crystalens should provide the ability to see without glasses across a greater range of different
viewing distances when compared to a single-focus lens implant. For example, if an individual can
see well enough to drive with the Crystalens, they should also be able to focus in toward the
dashboard. The latter is a good example of our need to see many things at a mid-range or
“intermediate” distance – that is neither far off in the distance nor up close. Other examples of
tasks performed at an intermediate distance would include working on a desktop computer, playing
the piano, cooking, or viewing items on a shelf at arms length. For reading up close, patients with
the Crystalens typically wear low power reading glasses.
Will this expensive technology eliminate the need for glasses?
Multifocal implants and the Crystalens were designed to decrease one’s dependance on glasses and not necessarily eliminate the need for eyeglasses 100% of the time. Nevertheless, many patients have been able to eliminate using glasses full time depending on their activities of daily living and general comfort level (we know that patients who are more easy going tend to be happier with Advanced Intraocular Implants than “type A” personalities, who may tend to notice all the imperfections and aberrations in their vision).
There may always be situations where you are trying to see details at some distance that are simply too small to be seen clearly. The print size and the amount of available light will make a difference. In addition, your retina must be completely healthy to achieve the
optimum results.
Because a single Crystalens implant does not provide enough focusing range to encompass both
the far and near distance extremes, one common strategy is to slightly stagger the separate
focusing range of each eye. For example, imagine that after the first eye surgery, you can see well
in the distance but cannot read without glasses up close. One option is to implant a Crystalens in
your second eye that is focused closer in, rather than far away. Although this particular eye might
not see as well far away as the first eye does without glasses, the benefit is that it should see
better at near distances when you are not wearing glasses. Unless you were to test each eye
separately, this intended slight difference will generally go unnoticed, because the brain “blends”
what is seen by the two eyes together. The result would be an expanded ability to see across a
greater range of distances (from near to mid-range to far) than would be possible with either eye
alone. This concept is similar to the “monovision” strategy that many contact lens wearers over the
age of 40 have used, except that it is accomplished without wearing contact lenses.
In a different situation, imagine that your first eye has good vision at the intermediate and near
ranges with the Crystalens, but is not very clear in the distance. Your second eye could then be
targeted for far distance to complement and supplement what you can already see with the first
eye. Again, improved distance focus would come at the cost of decreased near performance in that
one eye. Regardless of the strategy, your ability to see without glasses should improve after the
second eye receives a Crystalens. Finally, in select circumstances, there is even an option to
combine a Crystalens in one eye, with a multifocal lens implant in the second eye.
Remember that how often an individual requires glasses varies across a broad range of
percentages. At one extreme is always (people who must wear their glasses constantly = 100%); at
the other end of the continuum is never (some young individuals with perfect vision and a naturally
focusing lens never need glasses = 0%). Most of us are somewhere along this continuum in
between the two extremes. t is impossible to know in advance how often you will “need” glasses
after your Crystalens implants. This depends upon variables such as your retina, any remaining
astigmatism, and how visually demanding your everyday activities are. However, when compared
to a standard single-focus lens implant, the Crystalens should put you much closer to the desirable
end of the spectrum discussed above. This is because the Crystalens provides your eye with some
ability to adjust and vary the focus. Therefore, the Crystalens implants do offer the convenience of
being less dependent on glasses compared to standard single-focus lens implants.
There is always normal variability in the rate of visual improvement following uncomplicated
cataract surgery. Beyond the initial postoperative period, however, many Crystalens patients have
observed a gradual improvement in their ability to change focus over time. Since the Crystalens is
designed to be flexed and moved by the focusing muscles of the eye, it makes sense that in some
eyes, the strength of these focusing muscles improves with greater use.
Will I see halos?
The design of the multifocal lens implant will always produce mild ghost images that appear as
rings or halos, particularly around lights at night. Although halos are much less apparent with the
newest generation of multifocal lens implants, and they always become less distracting over time, there is a small risk that a particular individual may struggle to adapt to them. In gneral, the quality of vision at night is slightly less with a multifocal lens compared to a conventional single-focus lens implant.
Because the Crystalens, by design, is thought to move within the eye, it will not produce the halos that are seen with a multifocal lens. Studies have shown that the percent of patients with halos and glare is statistically the same as those symptoms with a Monofocal lens. Also the clairty and quality of vision at night should be equally good as with a conventional lens implant.
Does Insurance cover Advanced Implants or Laser Cataract Surgery?
Most all insurances cover over 80% of the cataract surgery with a standard monofocal implant when the cataract inhibits vision to less than 20/40 vision on vision testing or glare testing and/or considered “medically necessary.” There are additional fees to upgrade to a Laser Cataract Surgery and to Multifocal Implants (Restor or Tecnis), a Crystalens or Trulign Toric, or a Toric Implant (to correct astigmatism). The added convenience of reducing your dependance on eyeglasses is not considered “medically necessary” by insurance providers. Rarely, during surgery, the capsular bag can become compromised which prohibits the implantation of a Crystalens. In these rare cases a monofocal implant is placed with the vision goal usually for distance (unless specified for another distance prior to surgery).
Can patients without cataracts have the Crystalens?
Many people are interested in surgical methods to reduce their dependence upon eyeglasses and
contact lenses. Laser eye surgery, such as LASIK, is the most common way to correct
nearsightedness if one is under the age of 40. However, for patients over the age of 50, laser
surgery by itself is less advantageous. By this time of life, any method that corrects your distance
vision (including contact lenses, LASIK, or a standard lens implant) will not work for reading up
close without glasses. Another problem with laser eye surgery, such as LASIK, is that it
complicates any lens implant surgery that is done later on for a cataract. Unfortunately,
determination of the correct lens implant power is very unpredictable in eyes that have had prior
LASIK.
The Crystalens implant is a technology that can allow a 50+ year-old eye to have some focusing
ability without glasses. For this reason, people over the age of 50 wearing strong prescription
glasses but with no other eye problems may elect to have accommodating lens implants in order to
see much better without glasses. Health insurance covers none of the costs, however, if there is no
cataract present. Because the natural lens must still be removed before implanting the Crystalens,
the procedure is performed in the same way as for cataract surgery. Thus, patients electing to have
lens implant surgery to reduce their need for glasses will never have to worry about developing
cataracts later on in life.
Who might need a LASIK “enhancement” after a Crystalens implant?
Like contact lenses or eyeglasses, every artificial lens implant model (standard, multifocal, or
Crystalens) is manufactured in more than 60 different “powers”. As with prescription eyeglasses or
contact lenses, it is important to match the appropriate artificial lens implant power to your eye. To
prescribe the correct spectacle or contact lens power, we utilize trial and error to preview different
lens powers placed in front of your eye. When you are asked, “which is better, one or two?” you are
selecting the lens power that you see best with. However, because the artificial lens implant is
inserted inside the eye, and only after your natural lens (cataract) has been removed, it is
impossible for you to preview or “try out” different powers before surgery. Furthermore, once it is implanted, we cannot easily exchange the lens implant the way we could with contact lenses or
eyeglasses.
Fortunately, an appropriate lens implant power can be estimated using mathematical formulas that
utilize preoperative measurements of your eye’s dimensions. Although the measurements are very
accurate, there are individual variables that prevent this process from being 100% perfect. One
variable is the final precise position where the implant will end up inside your eye. Another
individual variable that may reduce your ability to see without glasses is astigmatism, which is a
naturally occurring imperfection in the optical shape of your cornea. Astigmatism is therefore not
corrected by the lens implant placed inside the eye. The overall process is accurate enough so that
most patients will see quite well without glasses in the distance. However, it usually won’t be
“perfect” and you might choose to wear mild prescription glasses for those occasional tasks that
require more precise distance focus.
For a Crystalens implant to work well, it is very important for the selected lens power to match your
individual eye. Despite flawless surgery, some patients with Crystalens implants are still not able to
see as well without glasses as they would like. What can be done if this is because the lens power
is “off”? One option is to wear glasses or contact lenses. A theoretical solution might be to
exchange the Crystalens implant for another with a different power. However, because of the risks
involved with removing a lens implant, it is usually safer to “enhance” or fine-tune any residual
prescription with an external LASIK procedure on the cornea instead. LASIK can also correct any
remaining astigmatism coming from your cornea.
All eye operations intending to reduce a person’s need for eyeglasses may need to be “enhanced”
with a second procedure. For example, nearsighted people choosing to have laser eye surgery
(e.g. LASIK) may need a second treatment if the first one does not fully correct their prescription.
This unpredictability is understandable because we are working with human tissue and not plastic
or metal. Likewise, it is possible that either the standard or Crystalens implant that has been
selected may not adequately focus your distance vision without glasses. Depending upon how far
off we are, laser enhancement may be a good option. The odds that this would need to be done
with a Crystalens are usually less than 5-10%, but the chances are greater in patients with a lot of
astigmatism or who are wearing very strong prescription glasses to begin with. The need will also
depend upon how much better one wants to see without glasses. You should know about this
possibility in advance before making your decision to have a Crystalens implant.
What do you recommend I do?
Ultimately the decision is up to you. If you want to be less reliant on glasses (maybe for the first time in your life), choosing an advanced implant is the best option. There may be exceptions to the suggestions below, but in general (assuming, your macula is normal and have otherwise normal eye function and structures.)
-If you do a great deal of driving at night, choose a Crystalens.
-If you have any macular issues (epiretinal membrane, macular changes/degeneration), choose a Crystalens
-If you do not do a great deal of night driving:
—- and want to have good computer vision, choose a Tecnis.
—- and want to have good reading vision, choose a Restor
-If money is tight, the majority of EyeMDs still highly recommend Laser Cataract Surgery as Laser Cataract Surgery provides the most precise results possible (the Laser cuts the front capsule precisely which allows Most eyeMDs, including myself, would choose Laser Cataract Surgery and a Multifocal Like cosmetic surgery, taking extra steps to reduce spectacle dependence is a discretionary and
personal decision. Because this does not involve health advice or medical needs, the ultimate
decision is yours. Start by evaluating how strong your desire is to see as much as possible without
glasses. Every individual will value such convenience quite differently. My role, as your eye
surgeon, is to explain your options to you. To implant these special lenses, eye surgeons must be
trained and certified by the manufacturers. I have extensive experience with all types of lens
implants, and frequently lecture or write articles on this subject. Many lens manufacturers have
asked me to consult or to assist in training other eye surgeons. Fortunately, your options are not
limited by any lack of experience on my part.
If you are a patient with cataracts, you are considering surgery because your cataracts prevent you
from seeing well with your corrective eyeglasses. After cataract surgery you should be able to see
well for far, mid-range, and near distances with your new eyeglasses (assuming no other eye
health problems). The decision about which type of artificial lens implant to have will only affect
your ability to see without eyeglasses following cataract surgery. Compared to a standard lens
implant, the Crystalens should provide the added convenience of being able to adjust your focus
across a larger range of different distances without eyeglasses.
No current technology can eliminate eyeglasses, and how well you will perform with Crystalens
implants can vary because of individual factors. Nevertheless, they are an excellent option for
patients who already need cataract surgery and who want to decrease their reliance upon
eyeglasses. While Crystalens implants carry no guarantees, they should greatly improve the odds
that you will be able to see better overall without eyeglasses.
(This handout is modified from an original authored by Dr. David Chang.)