What is an accommodative intraocular lens (IOL) implant?
Traditional monofocal lenses, including lens implants, focus light to only one point in space. An accommodative lens is able to provide vision at multiple distances, in a mechanism similar to the natural, crystalline lens.
What is the benefit of an accommodative lens implant?
An accommodative lens implant moves inside the eye as the eye’s focusing muscle contracts, mimicking the eye’s natural ability to focus. This feature addresses distance, intermediate and near vision and makes the recipient less dependent on glasses or contact lenses. The lens is typically used in patients who have both a cataract (cloudiness in the natural lens) and presbyopia (the loss of focusing power of the natural lens that occurs in eyes older than 40 years).
Is an accommodative IOL similar to the natural lens of the eye?
Yes and no. The ability of the natural lens of a young person’s eye to change shape and produce dramatic changes in focus is magnificent. As a person ages, the natural lens becomes more rigid and functions more like a monofocal lens. The accommodative lens can restore some focusing power back to the ageing eye but will certainly not restore the same level of focusing available in a young person’s eye.
What are the different accommodative IOLs now available?
There is only one accommodative IOL currently available: The crystalensTM IOL by eyeonics, inc. The lens design features a silicone optic held in place by hinged footplates that allow the lens to move forward and backward inside the eye.
How good is the near vision with an accommodative IOL?
Patients should expect to achieve”social” near vision with the accommodative IOL. Social near vision includes items such as menus, watch faces, cell phones, price tags, grocery labels, computer screen text and magazine size print under average lighting conditions. Patients whose main goal is to sit and read small print in dim lighting conditions for prolonged periods of time or do other very precise near work are likely to be disappointed with the unaided near vision available from the accommodative IOLs. Of course, reading glasses may be worn to improve the near vision for precise or prolonged near tasks.
What are the advantages and disadvantages of the accommodative IOL?
The advantage of the accommodative IOL is that it has the potential to restore the most natural focusing mechanism back to the aging eye of any IOL currently available. The reason for this is that it is the only IOL that moves and, thus, changes the focal length of the eye optics, similar to that of the natural lens. However, because the lens is able to move inside the eye, some disadvantages occur. The main disadvantage is that the lens must heal into place inside the natural lens capsule of the eye from which the natural lens has been removed. The precise position the accommodative IOL ends up in cannot be accurately predicted preoperatively and depends on each individual eye’s healing mechanism. The front to back position that the lens ends up in determines both how clear the unaided distance vision will be and also how much near vision will be available. On average, the accommodative IOL heals into position such that the distance vision is quite good and”social” near vision is achieved. If the lens heals into position slightly more forward than average, the near vision may be better than”social” while the distance vision will be more blurry. Conversely, if the lens heals into position slightly further back than average, the distance vision will likely be quite good but the near vision will be more blurry. On average, about 20% of the time, the accommodative IOL will heal into position slightly away from the average location. In these situations, it may be possible to perform additional refractive surgery (e.g. LASIK, PRK, CK) to improve the range of unaided vision available. Of course, patients can always wear a pair of glasses to improve their vision during certain tasks as necessary.
Are there any alternatives to accommodative intraocular lenses?
The primary alternative to an accommodative lens implantation is monofocal lens implantation. If you request a monofocal lens, you will have to decide whether you want distance vision lens implants in both eyes or whether you want a distance vision implant in one eye and a near vision implant in the other eye. This latter arrangement, called monovision, provides adequate distance and near vision and is best suited for patients who have tried monovision in contact lenses previously and like the effect. Another alternative to an accommodative lens is a multifocal lens implant. Please see the multifocal IOL section for frequently asked questions (FAQs) about these lenses.
Are there any risks or side effects to accommodative lens implant surgery?
Implantation of an accommodative lens is associated with all the risks and side effects of cataract surgery, a procedure performed more than 2.5 million times annually in the U.S. and more than 7 million times annually throughout the world. The risks and side effects of cataract surgery will be explained separately by your doctor. In addition, because the accommodative IOL has a hinged, flexible design, under very rare circumstances, the lens may heal into position with one of the hinges further forward than the other, causing the optic to be slightly tilted. This can cause unwanted astigmatism. This rare complication can usually be treated with a laser procedure commonly used following standard cataract surgery called a YAG laser.
Will I see 20/20 after surgery?
We hope so, but we can’t guarantee it. You are paying for the service and the implant, not a guaranteed result. If the eye is otherwise healthy, the vast majority of patients can achieve 20/20 vision with glasses, contact lenses or refractive surgery (e.g. LASIK, PRK, CK).
Will I need glasses after surgery?
If you opt to receive a monofocal lens implanted in both eyes for distance vision, you will definitely need reading glasses after surgery. If you receive an accommodative lens there is a good chance you won’t need glasses. More than 80% of patients implanted with the accommodative IOL in the FDA clinical trial did not need glasses after surgery for distance or near vision. Of course, not every patient in the trial was spectacle independent. The odds of becoming free of spectacles are better if your corneal astigmatism is low and your eyes are healthy.
Is an accommodative IOL recommended for every patient?
No. It is recommended for most patients, but not for patients who have problems with their retina (e.g. significant macular degeneration, epiretinal membrane”macular pucker”, macular holes, significant diabetic retinopathy, history of severe retinal detachment, retinal dystrophies or degenerations, retinal vascular occlusions), advanced glaucoma affecting central vision, irregular corneal astigmatism, corneal scarring, keratoconus, corneal dystrophies or optic neuropathy. Patients with a history of corneal refractive surgery (CK, RK, PRK, LASIK, etc.) may require additional refractive surgery following implantation of an accommodative lens to optimize its performance. In addition, your doctor will discuss the advantages and disadvantages of an accommodative lens as it pertains to your individual lifestyle and expectations. Patients with unrealistic expectations may not be appropriate for accommodative lenses.
What if I don't see 20/20 without glasses after surgery?
We will prescribe glasses to optimize your vision. You may also elect to wear contact lenses. If you want to improve your unaided vision further, we will offer you discounted refractive surgery (e.g. LASIK, PRK, CK). Only if there is a significant error in lens power calculation will we consider a lens implant exchange.
Why doesn't insurance (or Medicare) pay for an accommodative lens?
These entities pay for surgery and devices that restore functional vision. They will not pay for services that reduce dependence on glasses or contact lenses. While Medicare and insurance will cover the cost of a standard lens implant, they will not pay for the”portion” of a deluxe implant that imparts multifocality or partially restores accommodation.
Can I have an accommodative lens implanted later if I decide to have a monofocal lens implanted now?
No. The decision needs to be made prior to cataract surgery.
Must I pay the Astigmatism Management charge if I receive an accommodative lens?
Yes. The Astigmatism Management fee must be paid; otherwise, an accommodative lens cannot be implanted. It is very important that we measure and correct your corneal astigmatism when we implant an accommodative lens. Please see the Astigmatism Management section for FAQs.
Can I be implanted with an accommodative lens in one eye only?
Yes you can, as long as your other eye has a clear natural lens or an early cataract. If your other eye already has a monofocal implant, you may not realize the full benefit of the accommodative lens implant.
Will I need accommodative lenses in both eyes?
It is our current feeling that an accommodative lens should be implanted in both eyes ultimately to realize the full benefit of the technology. There are currently no studies demonstrating the advantages or disadvantages of combining accommodative, multifocal or monofocal lenses when surgery is performed in both eyes.
Will it take longer for my eye to recover from surgery?
Recovery from cataract surgery is the same whether you receive a monofocal, multifocal or accommodative implant. The number of appointments before and after surgery is also the same. However, the brain must adjust and”relearn” how to use the eye’s focusing muscle, which becomes useful again after the implantation of the accommodative lens. This adjustment period takes from weeks to months to occur. Patients typically notice that they become less”aware” of their vision as this adjustment takes place. When the accommodative is implanted, your doctor will give you some near vision exercises in the form of word jumbles to assist your brain in “relearning” how to use the focusing muscle of the eye.