Standard Intraocular Lens Implants (IOLs)
Intraocular lens implants (IOLs) were first developed over 50 years ago and have been used routinely to correct vision after cataract surgery since the 1980’s. Traditional lens implants, whose costs are covered by health insurance, do an excellent job for many people in restoring vision after the removal of their natural lens. These implants provide good focusing at one specific distance (Monofocal) usually resulting in excellent distance vision and pretty good intermediate vision. To be able to also have excellent reading or near vision, reading glasses are usually required.
Toric Lens Implants
Blurred or distorted vision due to an irregularly shaped cornea is called astigmatism. In some cases astigmatism can be corrected during cataract surgery but this is not an option for all patients. Toric IOLs effectively eliminate astigmatism and may be a better option for many people.
Multifocal Lens Implants
For people with more demanding lifestyles, new multifocal lens implants provide much greater visual freedom. Multifocal lens implants offer a more complete range of good vision, day and night, from distance to near reading vision, without cumbersome or unsightly reading glasses or bifocals.
How Multifocal Lens Implants Work
Multifocal IOL’s with multiple optical zones have a series of concentric focusing rings extending from the center of the lens to the lens periphery. Each ring selection has its own focusing power and corresponding focal point. With these lens designs distant vision is very good right after surgery but intermediate and near vision may be blurry during the healing period. Over a short adjustment period the brain learns to “look” through the best area of the lens to provide good distant, intermediate or near vision as required by the object of attention.
AcrySof ReSTOR Multifocal IOL
The AcrySof ReSTOR IOL, marketed by Alcon, has been approved for use in the US since 2005. These multifocal lens implants feature a patented “apodized diffractive” design that optimally distributes light to distance, intermediate and near focal points, depending on the amount of ambient light available. This optimizes image quality in all lighting conditions, according to Alcon.
For example, in low-light conditions, as the pupil dilates, more light is distributed to elements in the lens required for clear distance vision. This improves a driver’s vision of the road ahead at night, the company says. But this also means near vision may not be as crisp with the ReSTOR lens in low light as it is in bright light conditions.
AcrySof IQ ReSTOR multifocal IOLs also feature aspheric optics to reduce a specific type of higher order aberration called spherical aberration. This reduces halos around lights at night and improves image quality for enhanced visual clarity, the company says. More than 93 percent of people who have had AcrySof IQ ReSTOR multifocal IOLs implanted in their eyes during cataract surgery have said they would do it again, according to Alcon.
TECNIS Multifocal IOL
The Tecnis Multifocal IOL, marketed by Abbott Medical Optics (AMO), has been approved for use in the U.S. since 2009. The fully diffractive surface of the Tecnis Multifocal IOL provides advanced image quality at all distances under any lighting conditions and regardless of pupil size, according to AMO. Nearly 9 out of 10 people who have had Tecnis Multifocal IOLs implanted in their eyes enjoy freedom from eyeglasses after cataract surgery.
Crystalens hinged IOL
The Crystalens IOL, marketed by Bausch + Lomb, uses a different lens design to achieve a more complete range of vision than standard Monofocal lenses. The Crystalens IOL uses the eyes zonules and ciliary body muscles to move the lens either forward or backward to adjust the focal point for good vision. With this lens design distant vision is good right after surgery, and over time, the brain learns how to manage the zonule and ciliary muscle combination to control the movement of the Crystalens IOL and provide good distant, intermediate or near vision as needed.
TRULIGN Toric IOL
For those patients with cataracts and astigmatism the TRULIGN Toric IOL, marketed by Bausch + Lomb, is a premium IOL that can treat both. The TRULIGN Toric IOL works the same as the Crystalens hinged IOL with the additional ability to improve or correct astigmatism.
Are You a Good Candidate for Multifocal IOLs?
Perhaps the most important factor in determining if you are a good candidate for multifocal IOLs is your willingness to honestly assess whether you’re willing to accept some compromise in the clarity of your distance vision for the convenience of being less dependent or computer glasses and/or reading glasses after cataract surgery.
If you’re not willing to accept this type of compromise, or your occupation requires the best possible distance vision at all times or excellent night vision — for example, if you are a pilot or someone who spends a lot of time driving in unfamiliar areas at night — then you are probably not be a good candidate for multifocal IOLs. You likely will be better served with standard monofocal IOLs for optimal distance vision — even though this means you will need bifocals, progressive lenses, or reading glasses to see clearly up close.
Also, if you have a pre-existing visual condition other than cataracts that affects your vision in one or both eyes (macular degeneration, for example), you typically will be happier with standard monofocal IOLs rather than multifocal IOLs, which require good visual capability in both eyes for best results.
Dr. Lum can evaluate the health of your eyes during your comprehensive eye exam prior to surgery to determine if you have any non-cataract-related eye problems that may affect your vision after cataract surgery.