Intraocular lenses (IOLs) are tiny, clear, plastic lenses that are surgically implanted into the eye, most commonly during cataract surgery. A variety of IOLs have been approved for the treatment of different vision conditions.
Accommodating IOLs are a unique type of IOL primarily used for the treatment of cataracts, though they are more frequently being used to treat presbyopia. Unlike other IOLs, accommodating IOLs shift and adjust as your eye moves in order to provide focusing power for multiple distances.
Accommodation is the process that allows the eye to focus on objects at varying distances. As the lens becomes more rigid with age, accommodation declines. Accommodating IOLs are designed to restore the accommodation process in the eye.
Accommodating IOLs differ from other types of IOLs in their function and capabilities. Other types of IOLs include monofocal, multifocal, and toric IOLs.
Benefits associated with accommodating IOLs include sharper distance vision, few post-surgery complications, and reduced or eliminated dependence on reading glasses.
As with most procedures, there can be drawbacks to using accommodating IOLs. Reported downsides of accommodating IOLs include experiencing too little or too much amplification of accommodation.
Since accommodating IOLs are not usually considered a medical necessity, they come at a higher out-of-pocket cost than other vision treatments, though insurance will likely cover a large percentage of the procedure. Cataract surgery may cost upward of $3,500, plus an upcharge for the use of premium lenses, such as accommodating IOLs.
The future of accommodating IOLs is encouraging, as a lot of new scientific research is being conducted on how to make the lenses even more effective and reliable.
What Are IOLs?
Intraocular lenses (IOLs) are small artificial lenses that are surgically placed into the eye. They are traditionally used for the treatment of cataracts, which cause your lens to become foggy or cloudy, making it difficult to see objects clearly. Through cataract surgery, the damaged lens is removed and replaced by a clear IOL.
Similar to glasses or contact lenses, IOLs come in different focusing powers. Prior to cataract surgery, the length and curvature of your cornea are measured to ensure that an IOL with the correct focusing power is being placed in your eye.
Most IOLs are made of silicone, acrylic, or other types of plastic. They are about a third of the size of a dime. The lenses can have a special coating on them to protect against UV rays.
How Are Accommodating IOLs Unique?
Accommodating IOLs are unique because they move inside your eye in order to accommodate focusing at different distances. They are designed to change shape like the eye’s natural lens, explains the American Academy of Ophthalmology (AAO).
With an accommodative IOL, most people find that they do not need eyeglasses or contact lenses after surgery. Some people, however, still prefer to wear glasses for extended periods of reading or other close-up activities.
What Is Accommodation Used For?
Accommodation is an important process that allows the eye to focus on things at varying distances. This focusing process occurs through the lens’s ability to change shape. Over the course of life, the hardness or stiffness of the lens increases more than 1,000 times, greatly impacting its ability to change shape well.
Around the age of 40, which is when many age-related eye conditions start to appear, the lens exhibits a clinically significant reduction in accommodation. Researchers believe that the stiffening of the lens as one gets older is the main cause of presbyopia, also known as the loss of accommodation.
Accommodating IOLs Compared to Other IOLs
There are a few different types of IOLs that have been developed for different purposes. Currently, the types of IOLs that are available in addition to accommodating IOLs include:
- Monofocal. Monofocal IOLs are the most common type of IOL used for cataract surgery. The lens is set to focus on one vision range, either close, intermediate, or distance vision. Most people choose to have the monofocal lens set for distance vision and then wear glasses for close-up activities, such as reading.
- Multifocal. Multifocal IOLs correct for both near and distance vision. Different zones or rings on the lens are set at different focusing powers. This allows individuals to be less dependent on reading glasses.
- Toric. Toric IOLs are used for the treatment of astigmatism. A toric lens can correct refractive errors caused by an uneven curve in your cornea or lens. Accommodating toric lenses are also available.
Benefits of Accommodating IOLs
Accommodating IOLs provide a good treatment option for people who need a high level of visual performance. Benefits of accommodating IOLs include:
- Sharper distance vision.
- Reduced dependence on glasses for reading.
- Improved near vision without compromising distance vision.
- Minimal complications after surgery.
In general, accommodating IOLs have a history of higher patient satisfaction rates than other types of IOLs. The design and material of accommodating IOLs make them very effective at improving accommodation with little or no side effects.
Drawbacks of Accommodating IOLs
Accommodating IOLs can greatly increase your quality of vision and reduce your dependence on glasses, but there are still some drawbacks.
Researchers have identified some potential drawbacks of accommodating IOLs:
- You may still need glasses for near-vision activities after surgery.
- They may have a limited amplitude of accommodation.
- Vision can temporarily become cloudy again after surgery, though it is easily and quickly treatable.
- There may be too much amplitude of accommodation.
More research is needed to confirm the long-term effects and efficacy of accommodating IOLs, but so far, the results are promising. Though there are a few potential drawbacks of accommodating IOLs, negative side effects can quickly be addressed after surgery.
The cost of accommodating IOLs can be an additional drawback for some people. They are a premium type of lens that requires customization, so they are naturally more expensive than monofocal or even multifocal lenses.
Additionally, many private insurance plans, as well as Medicaid, don’t always cover the costs of accommodating IOLs for the correction of presbyopia. This is because they aren’t always deemed medically necessary.
The typical fee for presbyopia-correcting IOLs, such as accommodating IOLs, is about $1,200 to $3,500. Many insurance providers, including Medicaid, cover a percentage of the cost of procedures like cataract surgery. The remaining percentage, or copay, becomes an out-of-pocket cost for the patient.
Outlook for Accommodating IOLs
Accommodating IOLs were developed to improve the outcomes of cataract surgery and to help patients with presbyopia regain clear close vision without compromising any of their long-distance vision. Researchers agree, however, that more controlled studies are needed to confirm the efficacy of accommodating IOLs and to discover how to make them even more effective.
Accommodating IOLs have a promising future, as they are a treatment for presbyopia, not just compensation. They are able to restore accommodation in the eye, which is the primary function lost through presbyopia. Not all accommodating IOLs have been entirely effective in the past, however, so their use is still somewhat controversial.
Multiple independent researchers have reported the results of accommodating IOLs as modest in their ability to restore accommodation. Additionally, these benefits are sometimes lost over time due to changes in the capsular bag in which the lens is implanted.
Because of these findings, the development of accommodating IOLs was nearly deserted a couple of years ago. New insights, however, have led researchers to focus on new mechanisms of action to better utilize the potential of accommodating IOLs.
The Food and Drug Administration (FDA) has been slow to approve the use of accommodating IOLs due to their history of not always being effective, though one type of accommodating IOL has already been approved. Doctors in the U.S. have also already been prescribing accommodating IOLs for off-label uses with great results when it has been in their patients’ best interests.
As the FDA continues to review the data on accommodating IOLs, scientists are working on new ways to implant the lenses to make them more reliable and just as safe as any other type of IOL.
- Accommodation. American Academy of Ophthalmology.
- Accommodative IOLs: Feasible? (September 2018). Ophthalmology Times: Europe.
- Accommodative Intraocular Lenses: Where Are We and Where Are We Going? (June 2017). Eye and Vision: BioMed Central.
- Axial Movement of the Dual-Optic Accommodating Intraocular Lens for the Correction of Presbyopia: Optical Performance and Clinical Outcomes. (June 2015). Journal of Optometry.
- Clinical Application of Accommodating Intraocular Lens. (June 2018). International Journal of Ophthalmology.
- IOL Implants: Lens Replacement After Cataracts. (October 2019). American Academy of Ophthalmology.
- Multifocal Intraocular Lenses for Cataract Surgery. (November 2019). Verywell Health.