Extended depth of focus intraocular lenses (IOLs) are for people with presbyopia. (Learn More) In some cases, they can help with cataracts and astigmatism. (Learn More)

These lenses can be implanted to alleviate the need for eyeglasses or contact lenses. They work well as an alternative to these eye correction devices for some people. (Learn More)

Once someone determines that these lenses are a good choice, they are implanted via a fairly simple surgical procedure. (Learn More) As part of the process, the doctor will discuss the brands and options that are available, so patients can make an informed decision. (Learn More)

 

What Are Extended Depth of Focus Intraocular Lenses?

multifocal intraocular lenses

Extended depth of focus IOLs were approved by the FDA in July 2016, so this is a very new technology. This lens works by compensating for a chromatic aberration of the cornea.

A chromatic aberration is characterized by the lens of the eye failing to focus on all the colors at the same point, according to research published in the Journal of Optical Society of America. When this aberration is present, people see fringes of color along the lines that separate the bright and dark elements of an image.

When someone is using these lenses, it enhances the sharpness of their vision at intermediate, far, and near distances. This eliminates chromatic aberration, so color boundaries are clearly distinguished.

Facts About Astigmatism

astigmatism vs normal vision graphic

Astigmatism is common, and it results in blurry vision. It happens due to an irregularly shaped cornea.

In some cases, the eye’s lens is curved, causing the symptoms. When this curvature of corneal shape abnormality is present, it prevents light from being able to focus on the retina properly. This causes blurry vision at any distance. Headaches and eye discomfort are also possible.

The majority of people have astigmatism to some degree. When this condition is slight, it typically does not require treatment since it does not affect vision.

When someone has astigmatism, they often have other eye issues, especially refractive errors, such as farsightedness or nearsightedness.

No one knows exactly what causes this condition. It is thought to be present at birth and hereditary, so it may run in families. Over time, the degree of astigmatism that someone has can increase or decrease.

Contact lenses and eyeglasses are the most common treatment. There are also lens replacement and corneal procedures that might be considered.

Facts About Presbyopia

presbyopia diagram

Presbyopia is a common vision problem that happens as people get older. When this condition is present, the eyes cannot focus up close.

By 2020, it is estimated that approximately 123 million people in the U.S. will have presbyopia.

When someone has presbyopia, they have to hold objects further from their eyes to see more clearly. For example, if they are looking at their cellphone, they have to hold it at a distance, or the letters and numbers on the screen can appear blurry. Other symptoms include headaches, visual fatigue, and eye strain.

This is an age-related deterioration, so no specific factor besides aging causes it. It happens because the lens gets harder as the proteins in the lens experience changes related to aging.

The muscle fibers around the lens can also experience age-related changes. The result is a loss in elasticity that makes it more difficult for the eye to focus up close.

The most popular treatments are progressive lenses in eyeglasses. However, replacing the lens of the eye is another option to help people see better without having to wear glasses.

Facts About Cataracts

eye with cataracts

In the U.S., more than half of all people age 80 and older either have had cataract surgery or currently have a cataract. It can happen in both eyes or just one.

When a cataract is present, the lens of the eye becomes cloudy. This prevents light being able to pass to the retina normally. This results in images appearing blurred.

Other symptoms can include the following:

  • Dim vision
  • Sensitivity to glare and light
  • Seeing halos around lights
  • Yellowing or fading of colors
  • Reduced night vision
  • Needing bright light to read
  • Double vision in one eye

There are proteins that make up the lens of the eye. They are arranged precisely to ensure that the lens remains clear. However, as people get older, these proteins may start to bunch together.

A clump of proteins is what causes the cloudiness. The cataract can become bigger with time.

Experts believe that aging is a major risk factor for cataracts. Other risk factors may include the following:

  • Diabetes
  • Smoking
  • High blood pressure
  • Previous eye surgery, inflammation, or surgery
  • Excessive sunlight exposure
  • Obesity
  • Prolonged corticosteroid use
  • Excessive alcohol consumption

Removing the cloudy lens and replacing it with an artificial one is how cataracts are treated.

Woman with glasses suffering from eyestrain after long hours working on computer

Who May Not Benefit From These Lenses?

Not everyone is a good candidate for these IOLs.

Presence of any of the following should be conveyed to the eye doctor, so they can determine if the person should have these lenses implanted:

  • Fuchs’ dystrophy
  • Advanced macular degeneration
  • History of post-refractive surgeries
  • Advanced dry eye
  • Anterior basement membrane dystrophy
  • Weak zonules
  • Glaucoma

Extended Depth of Focus IOL Brands

TECNIS is the only brand that offers extended depth of focus IOLs. They offer the Symfony Extended Range of Vision IOL in the ZXR00 model. This is for correcting aphakia in adults. Aphakia is a term to describe the natural lens no longer being in the eye.

There are also the TECNIS Symfony Toric Extended Range of Vision IOLs. There are multiple models available, including the ZXT150, ZXT300, ZXT225, and ZXT375. These are used to astigmatism and aphakia.

Since this is such a new technology, the long-term potential remains unknown. Lens replacement for cataracts has long-term success, however, so the belief is that these lenses will be similarly beneficial.

The Surgical Procedure

The purpose of the surgery is to remove a person’s natural lens and replace it with an extended depth of focus IOL. The surgeon usually does each eye about a week apart, and each surgery takes approximately 15 minutes.

Before the surgery, the doctor will put drops into the eyes to anesthetize them, so the patient is comfortable. People are not put to sleep with general anesthesia for this procedure.

Surgeons performing an eye surgery under the microscope at the hospital - healthcare and medicine concepts

During the procedure, the doctor will start by removing the eye’s natural lens. Once this is successfully removed, the new IOL is put into place.

About a week after surgery, people can resume their normal activities. It may be several weeks before they get the final results from the lens replacement. Ultimately, the usual results are that people no longer need to wear contact lenses or glasses.

During the recovery period, it is not uncommon to experience halos, a scratchy sensation in the eye, blurry vision, and glare.

Make sure to follow all the recovery instructions exactly. Proper use of all medications and resting the eyes are recommended. These practices may decrease the risk of complications.

Possible Surgical Complications

The possible complications of surgery are very similar to those of cataract surgery since the procedures are essentially the same. These complications may include the following:

  • Inflammation
  • Bleeding
  • Drooping eyelid
  • Retinal detachment
  • Infection
  • Swelling
  • Artificial lens dislocation
  • Glaucoma
  • Vision loss

If someone has a serious medical condition or another eye disease, they are at a higher risk for experiencing complications. It is important to follow all of the preparation instructions before the surgery as these can reduce the risk of complications.

For example, the doctor might prescribe antibiotic eyedrops before the lens replacement. Using these reduces the risk of an infection during the recovery process.

People who have presbyopia might consider extended depth of focus intraocular lenses. They may help to improve vision without the need for contact lenses or eyeglasses. Talk to your doctor about what is best for your particular situation.

References

FDA Approves First Intraocular Lens with Extended Range of Vision for Cataract Patients. U.S. Food and Drug Administration.

Matching Color Images: The Effects of Axial Chromatic Aberration. Journal of the Optical Society of America.

Premium IOLs: How to Spot Poor Candidates. Review of Ophthalmology.

Indications and Important Safety Information for TECNIS Symfony and TECNIS Symfony Toric Extended Range of Vision IOLs. Johnson & Johnson Vision.

Refractive Lens Exchange (Lens Replacement Surgery). All About Vision.

Cataract Surgery. Mayo Clinic.

Astigmatism. American Optometric Association.

Facts About Presbyopia. National Eye Institute.

Presbyopia. All About Vision.

Facts About Cataracts. National Eye Institute.