lasik-logoMultifocal Intraocular Lens Implants - Premium IOL's




With age, the natural lens inside the eye becomes less clear.   This change leads to a disease/condition known as a cataract*.  Cataracts are the leading cause of reversible vision loss in this country.  Fortunately, in most cases the cataract is removable and vision can be restored with an intraocular lens ("IOL")*.  When proceeding with cataract surgery, an important decision has to be made by the patient and doctor - choosing which IOL is best suited to restore vision and help meet thecataract diagram eye multifocal IOL lens implant patient's visual demands and lifestyle needs.  There are multiple types of IOLs to consider, including traditional monofocal lenses and premium lenses.  Standard monofocal lenses provide good distance vision but still require the use of reading glasses for near and intermediate work to overcome the presbyopia.  Premium lenses consist of multifocal and accommodating lenses.  Multifocal lenses provide various degrees of distance and near vision depending on the design of the lens.  Accommodating lenses* helps to correct presbyopia by restoring some of the eyes ability to accommodate* to near targets.

Will I Need Glasses after Cataract Surgery?

In general, patients who choose to have monofocal lens implants will be dependent on glasses either some or most of the time in about 95% of cases. Patients who choose to have multifocal lens implants will only be dependent on glasses either some or most of the time in about 15% of cases.  In general, with multifocal IOLs, most tasks can be performed without spectacles.  In some environments and with very fine print, reading glasses may be beneficial or necessary.

Disadvantages

A significant disadvantage of monofocal lenses is that they only correct for one distance, requiring the use of reading glasses even after cataract surgery.  With multifocal IOLs near vision may not be sufficient to see very small print, such as stock quotes, phonebook entries or medicine labels and eye fatigue after reading for prolonged periods of time or in poor lighting may occur.  In addition, 25% of patients note glare and haloes around lights at night with the refractive multifocal IOL, a feature that is inherent to multifocal lenses. These effects may interfere with your ability to drive comfortably at night.   However, most patients find that they get used to this phenomenon with time and the glare and haloes become less obvious.  It is important to note that 7-8% of patients implanted with standard monofocal lenses also notice glare and halos.

Another disadvantage of multifocal or premium lenses is that they are considered luxury and not a medical necessity. Therefore Medicare and most health care plans will not cover the extra cost for a premium IOL.  This means the patient must pay any extra fees related to the additional costs associated with the premium multifocal IOL lenses.  Also, because some of the premium IOLs are relatively new, not all cataract surgeons are trained to implant them. Master Eye Associates doctors will guide you through this process.

*See Glossary below for more information

Multifocal IOLs

AcrySof® IQ ReSTOR® Multifocal Lens

Acrysof Restor Multifocal lens implant IOLThe AcrySof® IQ ReSTOR® IOL Intraocular lens is also an artificial lens that is implanted in the eye during cataract surgery to replace the eye's natural lens that has become cloudy or opaque.  It is a unique technological innovation that can provide enhanced image quality and a full range of vision - near, far and intermediate - for increased independence from reading glasses or bifocals. It is intended for patients who are interested in decreasing or even eliminating their dependency on glasses and contact lenses. 

How AcrySof ReStor Works

The lens is compromised of 2 regions.  The central 3.6 mm optical zone is compromised of the patented apodized* diffractive optics to provide a range of vision from near to mid-range to distance activities.  This area is formed by 12 concentric rings of various step heights (all smaller than a strand of human hair) that deliver light energy to the back of the eye by distributing the appropriate amount of light to near and distance focal points, regardless of the lighting situation.  The second region or zone is outside of these concentric rings and is considered the refractive zone. This area directs light to a distance focal point and is dedicated to achieving clear distance vision. This unique lens technology isacrysof restor multifocal IOL cataract lens implant specially designed to distribute light in response to the size of your pupil at any given moment, distributing the appropriate amount of light to near and distant focal points.  It is convex on both sides and is made of a soft acrylic plastic.  Aspheric optics help to counter act the spherical aberrations* of the cornea.  It also has a built in UV blocker* to protect the eye from harmful UV rays.  It is folded and inserted into the eye through a small incision about 1/8 of an inch.  Once inside the eye, it gently unfolds into position.  Up to 80% of patients who use the ReSTOR® lens don't need to rely on glasses or contact lenses after surgery.

New and Improved AcrySof ReSTOR

Although there have been previous version of the AcrySof® IQ ReSTOR® IOL the +3.0 D add power is the best choice for true performance at all distances.  It provides improved intermediate vision over the original AcrySof® IQ ReSTOR® IOL +4.0 D, with similar near and distance visual acuity.

Disadvantages of AcrySof ReSTOR                                                                                    

Less-than-crisp distance vision, possible ghosting or "smeared" vision, and impaired intermediate (computer vision range) are possible outcomes of this multifocal.  Again, many patients adapt to the multifocal designs, but there is always a possibility that adaptation will not occur.  As with all multifocal IOLs, impaired night vision due to glare, halos, starbursts (which may be permanent) could occur.

These are considered premium so the additional costs not covered by insurance companies have to be paid by the patient.

TECNIS® Multifocal Foldable Acrylic Intraocular Lens

Like all implantable lenses, the TECNIS® multifocal lens is used to restore vision after cataract surgery.  It's a foldable, plastic lens that focuses light on the retina at various depths of field. What sets this lens apart from the rest is its ability to not only provide patients with excellent distance vision but also alleviate the need for reading glasses.   

This is a multifocal diffractive IOL with aspheric design using wavefront technology to reduce spherical aberrations that cause halos, glare, and other aberrations especially at night.  According to the company it has a proprietary design to enhance vision at all distances and is not dependent on pupil size like the Restor lens.  It is also made with diffractive technology similar to the ReZoom.  There are concentric circles with distance, near, and intermediate vision. 

Clinically, it delivers results superior to those of aTecnis Multifocal IOL lens implant standard multifocal lens.  When asked 4-6 months after surgery, 9 out of 10 patients who chose TECNIS® multifocal reported never wearing glasses. The TECNIS was FDA approved in 2009 and has shown promising clinical data regarding restoration of vision and patient satisfaction.  Tecnis offers patients the chance to become spectacle independent providing good distance, intermediate and near vision, even in low light conditions. 

Low-Light conditions

Another important aspect of the TECNIS® multifocal lens is that it offers superior reading vision, even in low-light conditions. Compared to the Acrysof® ReSTOR® IOL, patients with the TECNIS® multifocal lens read significantly more words per minute in low-light conditions. 

Night Driving with TECNIS

With most multifocal IOLs there is the possibility of having increased complaints of glare and halos but data supports that the TECNIS® multifocal lens consistently delivers high-quality vision with few reports of severe halos or glare.  When adjusting to the new lens, some patients may notice rings around lights when driving at night. However, the visual impression of rings may lessen or go away over time. 

Patient Satisfaction with TECNIS

Asked 1 year after surgery, 94% of patients would choose the TECNIS® multifocal again and over 90% of patients with TECNIS multifocal IOL's functioned comfortably without glasses at distance, intermediate and near when questioned 1 year after surgery. 

Disadvantages of TECNIS

Slightly blurred distance vision, possible ghosting or "waxy" vision, and impaired intermediate vision are possible outcomes of the Tecnis multifocal.  Another disadvantage of the TECNIS® multifocal lens is the possibility of impaired night vision due to glare, halos or starbursts (which may be permanent). Many patients adapt to the multifocal designs but there is always a possibility that adaptation doesn't occur. 

ReZoom® Multifocal Lens

ReZoom® is another intraocular multifocal lens offering a full range of vision.  It is intended for patients who are interested in decreasing or even eliminating their dependency on glasses and contact lenses.  It aims to provide quality vision at all distances - near (reading), intermediate (computer use or cooking), and far (driving).  

How ReZoom IOL's Provide Vision at Multiple Distances

It uses Balanced View OpticsTM Technology to provide full-range vision after cataract surgery.  This new technology involves a series of rings on the surface of the optic portion of the lens which vary in size and separation which allows the near to distance range of vision.  Each lens is divided into five different zones with each zone designed for different light and focal distances.  This is called zonal refractive optical technology.   Unlike other earlier multifocal lens designs, the ReZoom® lens has proportioned the size of its zones to provide for good vision in a range of light conditions. For instance, some zones have been designed to offer greater low light/ distance vision support during night driving.  It uses a biocompatible acrylic lens material with UV blocking properties, similar to many monofocal and other multifocal lenses.   It is folded and inserted into the eye through a small incision about 1/8 of an inch.  Once inside the eye, it gently unfolds into position.  Clinical data demonstrates that 92% of those who received the ReZoom® multifocal lens in both eyes reported wearing glasses "never" or "occasionally."

 

Rezoom refractive multifocal IOL

Disadvantages of the Rezoom IOL

Typically this multifocal tends to offer poorer near vision compared to some of the other multifocal IOLs on the market and requires the use of reading glasses in low-light conditions and for small print.  Additionally only moderate computer distance vision is expected.   Also, as with other multifocal lens designs, impaired night vision due to glare, halos, starbursts (which may be permanent) may result. This is a premium lens and again the patient will incur additional costs associated with the upgraded lens. 

 

Accommodating IOLs

Crystalens AO® Accommodating Posterior Chamber Intraocular Lens

Crystalens® is the first and only FDA approved accommodating IOL.  Like premium multifocal IOLs, it is also used for visual correction after the removal of a cataract lens.  It is an IOL that accommodates like the eye's natural lens, allowing for focusing at distance, intermediate and near.  Accommodation is the ability to change focus throughout the range of vision much like a zoom lens. 

Crystalens AO by Bausch & Lomb Premium IOLThe Crystalens AO® brings together traditional Crystalens accommodating lens technology with an aspheric lens design to help reduce aberrations.  Aberrations affect vision quality and when reduced it can enhance contrast sensitivity. This accommodating aspheric IOL attempts to deliver premium vision at all distances without any vision compromise. 

Another advantage is that optical performance is unaffected by pupil size or location of the optic due to uniform center-to-edge power, helping to have more consistent vision in various environments.

How Crystalens Works                                                       

The Crystalens® is attached to the ciliary muscle, a circular muscle that surrounds the lens in the eye. When the ciliary muscle contracts it bulges backwards and increases pressure behind the lens, thus forcing the optic forward. Relaxation of the muscle increases the pressure in front of the lens to move the optic backwards, thus enabling the lens to focus naturally at all distances.

Crystalens accommodating IOL lens implant for the eye 

Disadvantages of the Crystalens

Crystalens continues to improve with each new generation of lens.  The Crystalens AO is another great improvement and a very good product.  However, nothing is perfect.  A disadvantage of the Crystalens® involves the possibility that the IOL won't accommodate as advertised, resulting in a need for glasses to read or to use a computer (just like what you'd get with monofocals).  Some recipients have had problems with glare and halos.  It also lacks adequate UV protection that is found in other IOLs.  This leaves the eye unprotected from the harmful rays of the sun.  Additionally, it requires a well experienced surgeon and may take up to one year to fully adapt. 

Furthermore, since the Crystalens is again considered "premium", additional surgery costs have to be considered. 

 

Glossary

 

Apodized

A series of graduated steps that result in diffraction of light at both distance and near

Accommodation

The ability of the eye's natural lens to change shape to focus on objects at  various distances

Accommodating lens

As with the natural lens, an accommodating lens moves and flexes, in response to ciliary muscle contractions in the eye. These contractions drive forward movements of the lens so the eye can maintain a clear image as it focuses on near, intermediate and far objects. (Bausch + Lomb)

Cataract

A "clouding" of the lens in your eye. As light passes through the cataractous lens, it is diffused or scattered, resulting in blurred or defocused vision.

Chromophores

Material added to IOLs to increase absorption of even more of the potentially harmful visible light in the violet and blue spectrum.

Halos

A circular flare or hazy ring that may appear around a headlight or other light source.

Intraocular lenses (IOLs)

Implantable devices that replace the natural lens in the human eye.

Spherical Abberations

An irregularity in the shape of the lens. As the eye ages, the lens gets thicker and rounder, causing image quality to deteriorate. Often associated with loss of contrast sensitivity and poor night vision.

UV blocker

Ultraviolet (UV) absorber to prevent excessive exposure of UV light to the retina

Comparison Chart of Different Multifocal IOL Lens Implants

 

AcrySof IQ ReSTOR IOL (Alcon)

Tecnis Multifocal (AMO)

Crystalens AO (B&L)

ReZoom (AMO)

Material

Hydrophobic Acrylic

Acrylic

Biosil, a biocompatible third-generation silicone.

Acrylic

Design*

See chart below

Diffractive/Aspheric Multifocal based on the optical principal of apodization*

Diffractive/Aspheric Multifocal -  Aspheric front surface and a diffractive  posterior surface for near and distance images

Accommodating lens* with new aspheric design specific to AO version

Zonal Refractive Multifocal

Enchancements

UV blocker* with chromophores*

-UV blocker
-Chromatic aberration correction*

No UV blocker

UV blocker

 

 

Designs

Advantages

Disadvantages

Examples

Zonal Refractive Multifocal

Creates several simultaneous images, allows for viewing objects at all distances

Undesirable visual aberrations - including night glare, halos, and starburst

ReZoom

Diffractive/ Aspheric Multifocal

-They compensate for spherical abberation and improve visual quality in most patients

-Generate two distinct images, one for distance and one for near

Reduced intermediate vision

AcrySof ReStor, Tecnic Multifocal

Accommodating IOLs

-Simulates the natural accommodation process by allowing the IOL to move based on ocular muscle contraction, much like the natural lens did before cataract formation and removal

-Typically provide better distance vision compared to multifocals. 

Reduced near vision that often requires the use of reading glasses to improve reading at near.

Crystalens HD, Crystalens AO