Accommodating lens implants are designed to reduce your dependence on eyeglasses. However, if you had a conventional ‘single focus” lens implant, the better you can see in distance without glasses the blurrier it will be up close. You would then need to wear reading glasses in order to see clearly at near.
What are the goals after cataract surgery with accommodating lens Implants?
Our goal is for you to function without glasses 90% of the time. This means that with both eye open, you should be able to legally drive without glasses and should be able to read a magazine article with good lighting and without glasses.
HOW DOES THE ACCCOMMODATING LENS IMPLANTS WORK?
With bifocal eyeglasses, you look through the top part of the lens for distance and the bottom part for near. The accommodating lens implant works entirely differently. The accommodating lens implant simulates focusing mechanism of the natural lens of the eye. The natural lens shifts the focus of the eye by changing its contour. As the eye changes its focus from far to near, the front surface of the natural lens becomes rounder, and as the eye changes focus from near to far, the natural lens reverts to a flatter contour. Similarly, the accommodating lens implants changes its position and shape, as the eye changes its focus. The accommodating implant provides only one focus at a time to the eye, in contrast to the multifocal implant, which provides both a distance focus and a near focus simultaneously. As eye becomes accustomed to the accommodating implant, the range of focus improves. For this reason many patients say that their vision continues to improve gradually in the first several months after surgery.
WILL ACCOMMODATING LENS IMPLANTS ELIMINATE THE NEED FOR GLASSES?
Unfortunately, accommodating lens implants usually do not eliminate eyeglasses entirely. There will be some times where the print or image is simply too small or too far away to be seen clearly without glasses. The print quality and the amount of available light will make also a difference. In addition, your eyes must be completely healthy to achieve optimal results.
How often an individual requires glasses varies. At one extreme is always (people who must wear their glasses constantly =100%); at the other extreme is never (some young individuals with perfect vision and a naturally focusing lens never need glasses = 0%). Most of us are somewhere in the middle. It is impossible to know in advance how often you will “need” glasses with your accommodating lens implant. This depends on your retina, any remaining astigmatism, and how visually demanding you activities are. However, when compared to the single-focus (conventional) lens implants, the accommodating implants should decrease your need for eyeglasses. This is because the accommodating lens implant provides you with much greater range of focus than the conventional lens implant
Regular conventional lens implants work well at providing distance vision. People, with these implants, can naturally see well in the distance, often go without eyeglasses outdoors or around the house. However, when they need to see something up close – even for just a moment – they might have to put on reading glasses. Examples of common momentary near tasks include looking at cell phone, a photo, a menu, a boarding pass, an envelope address, a handwritten note, a price tag or a receipt. Having to take their reading glasses on and off frequently is inconvenient to many people. Because of this, they might wear their reading glasses around their neck, scatter multiple pairs around the house or simply wear bifocals all the time. Although they might still prefer eyeglasses for prolonged reading, most people with accommodating lens implants enjoy the convenience of performing these simple near tasks without having to put on reading glasses.
WILL I SEE HALOS?
Every optical system, including the human eye with a natural lens, can produce halos. Similarly, every intraocular lens implant can produce halos at night, some more than others. The halos produced by the accommodating lens implants at night are comparable to those produced by the conventional lens implants. The halos produced by the conventional and accommodating lens implants are significantly less than those with multifocal lens implants.
CAN AN ACCOMMODATING LENS BE IMPLANTED IN JUST ONE EYE?
Yes, this is possible when the other eye already has a conventional implant, or when there is no cataract in the opposite eye. However, the ability to see both far and near without glasses is better when you have an accommodating lens in both eyes. With an accommodating lens implant in one eye, the brain simply focuses the images and blends together the vision from each eye. Some individuals might take longer than others to adapt to this situation. For this reason, you should not consistently compare one eye to the other. With an accommodating lens in one eye, you should still be able to see things close up. However, if you had received a conventional single-focus lens implant, you would need to wear glasses for near.
CAN THE ACCOMMODATING LENS BE REMOVED IF I DON’T LIKE IT?
This is always possible but entails the risks of additional surgery. However, there might be a rare individual, in whom the near focusing remains problematic. You could then elect to have the accommodating lens implant replaced with a conventional lens implant. One should not rush into this decision because range of focus usually improves over time.
DOES INSURANCE OVER THE EXTRA COSTS OF AN ACCOMMODATING LENS IMPLANT?
Unfortunately it does not. Health insurance, including PPO’s, HMO’s, and Medicare, covers a cataract operation with a conventional lens implant when the cataract is bad enough to be considered ‘medically necessary’. The additional fee to upgrade the lens implant to an accommodating implant is not covered, because the added convenience of reducing your dependence on eyeglasses is not ‘medically necessary’. We ask that you pay this premium out-of-pocket fee in advance. Rarely, unexpected situation might arise during surgery, during which if I determine that an accommodating lens implant might not be suitable for your particular eye, I would implant a conventional implant in this situation and your accommodating lens implant fee would be refunded.
CAN PATIENTS WITHOUT CATARACTS HAVE ACCOMMODATING LENS IMPLANTS?
The accommodating lens implant allows a 50-or-older eye to focus far and near 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 an accommodating lens, the procedure is performed in the same manner as in cataract surgery. Patients electing to have lens implant surgery to reduce their need for glasses will never develop cataracts.
WHO MIGHT NEED LASIK AFTER AN ACCOMMODATING LENS IMPLANT?
Like contact lenses or eyeglasses, every artificial lens implant model is manufactured in more than 60 different “powers”, similar to the numbers that you see on your eyeglass prescription. 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 eyes. 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 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 glasses.
Fortunately, an appropriate lens implant power can be estimated with mathematical formulas that use the preoperative measurements of your eye. Although these measurements are very accurate, there are individual variables that prevent this process from being 100% perfect.
Another problem is astigmatism, which is a naturally occurring imperfection in the optical shape of your cornea. Astigmatism is not corrected by the accommodating lens implant place inside the eye and is another reason that might reduce your ability to see without glasses. Overall, the process is accurate enough so that most patients will see well without glasses in the distance (assuming that was the target). However, it might still not be “perfect”, and you may choose to wear mild prescription glasses for those occasional tasks that require more precise distance focus.
For an accommodating lens implant to work well, it is very important for the selected lens power to match your individual eye. Despite flawless surgery, some patients with accommodating lens implants still cannot see as well as without glasses as they would like. What can be done if the vision is ‘off’? One option is to wear glasses or contact lenses. Another solution is to exchange the accommodating lens implant for another with a different power. Because of the inherent risks involved with removing a lens implant, it might be best fine-tune any residual prescription with a LASIK procedure on the cornea instead. LASIK can also correct any remaining astigmatism from your cornea.
All eye operations intended to reduce a person’s need for eyeglasses might need to be ‘enhanced’ with a second procedure. For example, nearsighted people choosing to have laser eye surgery (e.g., LASIK) might need a second treatment if the first one does not fully correct their prescription. This unpredictability is understandable because we are working with human tissues, not plastic or metal. Likewise, it is possible that the conventional or accommodating lens implant that has been selected may not adequately focus your distance vision without glasses. Depending on how far off we are, laser enhancement might be a good option. The odds this would need to be done with an accommodating implant are usually less that 5% to 15%, but these odds are greater in patients with significant astigmatism or strong prescriptions. The need for LASIK will also depend on how much better one wants to see without glasses. Because there would be an additional cost and procedure involved, you should know this possibility in advance before making your decision to have an accommodating lens implant.
WHAT DO YOU RECOMMEND I DO?
Like cosmetic surgery, taking extra steps to reduce dependence on eyeglasses is a discretionary, personal decision. Because having an accommodating lens implant is not medically necessary, the ultimate decision is yours. Start by evaluating how strongly you 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.
If you are a patient with cataracts and are considering surgery because your cataracts prevent you from seeing well with your correction glasses, both conventional and accommodating lens implants are good options. With conventional implant, after cataract surgery you should be able to see well for both far and near distances with your new eyeglasses (assuming no other eye health problems). However, accommodating lens implants will provide the added convenience of being able to see far and read many things up close without glasses. The decision about which type of artificial lens implants to have will only affect your ability to see without eyeglasses following cataract surgery.
No current technology can eliminate eyeglasses completely, and how well you will perform with accommodating lens implants can vary due to individual factors. Nevertheless, accommodating lens implants is an excellent option for patients who already need cataract surgery and who want to decrease their reliance on eyeglasses. While accommodating lens implants carry no guarantees, they should greatly improve the odds that you will be able to read and see better overall without eyeglasses.