Extended Depth of Focus Lens Implants
Extended depth of focus lens implants are a relatively recent addition to our IOL armamentarium. These cataract lenses are similar to multifocal IOLs in that they allow distance activities and reduced dependence on glasses for some near activities. Extended depth of focus lens implants elongate the focus point of the eye to provide continuous high-quality vision as well as correcting color distortion known as a chromatic aberration to provide sharper vision in different lighting conditions.
Because these IOLs extend the range of focus, they may reduce the frequency of wearing glasses for near or intermediate activity. However, similar to multifocal lenses, they are associated with starburst glare, halos and other visual phenomena when viewing light sources. Some patients may be bothered by these visual phenomena. These lenses are not designed for detailed close work, and some patients may prefer low powered over the counter glasses to assist in prolonged reading or fine visual tasks.
Tecnis Symfony Multifocal Lens
Is placement of the Tecnis Symfony lens different than other IOLs?
The surgery to place the Tecnis Symfony IOL is the same as any other intraocular lens surgery. Once the cataract-clouded lens is removed, the Tecnis Symfony is implanted. The Tecnis Symfony does come in a regular or spherical version as well as a toric version to correct for astigmatism. The toric Tecnis Symfony lenses are precisely positioned by Dr. Aizuss at the axis of astigmatism in the eye.
How is the Tecnis Symfony lens different from other IOLs?
When cataract surgery was first developed, the traditional intraocular lenses that replaced the cataract-clouded natural lens could only correct for one distance, either near or distance vision. These are known as monofocal lenses. With the monofocal lenses, patients have to choose which distance they want to see without correction — most people choose distance vision — and then opt to use glasses to correct near or reading vision.
In recent years, multifocal IOLs have been developed that provide vision correction across multiple distances. These multifocal lenses allow patients to see both distance and near thus permitting less spectacle or eyeglass dependence for a variety of their activities. Some patients, in whom these multifocal IOLs have been implanted, reported bothersome side effects such as loss of contrast sensitivity (particularly in low light), halos, glare, and nighttime dysphotopsia where the patients saw rings around headlights and taillights. A small percentage of patients were bothered enough by the issues with their multifocal implants that they asked to have them removed and exchanged for standard monofocal lens implants.
Tecnis Symfony lenses are known as extended range of focus IOLs or extended depth of focus lenses. These lenses elongate the focus point. Multifocal IOLs are primarily for distance or near, but not intermediate vision. They are excellent for near and distant objects, but for the areas in between patients find they don’t adapt as well. The Symfony lens boasts no drop off in vision regardless of the distance. This gives the patient quality distance over a wide range of viewing conditions, just as their natural eye lenses used to do if they weren’t overly near- or farsighted.
The Tecnis Symfony lens also mitigates the effects of presbyopia, the near-universal loss of the ability of the natural eye to focus at close distance as we move past 40 years of age and upward. The Symfony lens allows for good intermediate vision without reading glasses. It also corrects for astigmatism with the Tecnis Symfony Toric IOL. For very close vision or reading a book with small print, most patients will still need an inexpensive pair of drugstore or over the counter reading glasses usually between +1.50 and +2.00 diopters in power.
Am I a good candidate for the Tecnis Symfony IOL?
Unless you’ve had previous eye trauma or significant retinal pathology, most anyone who is having cataract surgery is a good candidate for the Tecnis Symfony IOL as a replacement lens. These lenses are more expensive than monofocal IOLs. However, if you are an active person who doesn’t want to constantly have glasses with them for tasks such as looking at a computer or iPad or seeing the dashboard or glancing at their cell phone, then these IOLs could be a great option. The Tecnis Symfony provides the closest thing to the wide range of vision delivered by the natural eye that doesn’t have large refractive errors (nearsightedness or farsightedness).
What are the benefits of the Tecnis Symfony IOLs?
The Tecnis Symfony IOLs allow patients to see at most distances without the use of eyeglasses except for prolonged close work or sitting and reading a book or low contrast newspaper. This allows people to be active and not have to find their glasses to correct the vision not handled by their IOLs. Although there may still be some minor need for glasses, the Tecnis Symfony IOLs dramatically reduce that need, and may totally eliminate it in many people.
These are some benefits that have come through studies involving over 2,000 eyes, as reported by Symfony maker Johnson and Johnson Vision. The Symfony lens:
- Provided seamless, day-to-night vision. Patients could see objects sharply and clearly at intermediate and far away distances, and at points in between.
- Provided high-quality vision. Some IOLs may leave patients with an inability to focus clearly due to competing wavelengths of light passing through the lens at different angles (known as chromatic aberration), or with vision that is not completely focused because of the shape of the lens (known as spherical aberration). The Symfony lens corrects for these issues.
- Demonstrated a low incidence of halo and glare, which may be perceived as rings or blurring around bright lights. These issues with multifocal IOLs can affect an individual’s ability to drive at night or perform other visual tasks in low light.
Are there risks with the Tecnis Symfony IOL?
As with all IOLs, there are the risks involved with cataract surgery, regardless of the lens choice. These involve rare complications of worsening vision, bleeding, and infection.
With the Tecnis Symfony IOL, there is a risk of a slight loss in vision sharpness because of the decreased use of eyeglasses. Even with glasses, there may be a loss of sharpness under poor visibility conditions such as dim light or fog. There is also the risk of patients seeing halos, starbursts, glare, and other visual symptoms that occur with extended range of vision IOLs (which the Tecnis Symfony is classified under). Patients should not receive this lens if they had previous eye trauma or have significant retinal or corneal abnormalities.