INTRAOCULAR LENS IMPLANTS (IOLs)

LENS IMPLANT TYPES

Standard Monodical lenses are the most commonly used intraocular lens implants used at the time of cataract surgery. These standard lenses have been in use since 1949, and are normally going to be the only option that Medicare or a private insurer will cover.

They are spherical lenses that attempt to match a patient’s primary focal length, so they come in varying powers. This time-tested monovisual approach is still considered the standard when it comes to addressing long-distance vision.

With these monofocal lenses, vision is normally in focus at only one distance (near, intermediate or far). Alternatively, an IOL can be implanted in one eye to improve distance vision, while another is implanted in the other eye to improve near vision. This technique is known as monovision.

Advantages of monofocal lenses:
* The cost of standard monofocal lenses is fully covered by Medicare and private insurance companies.
* In cases where glasses or contacts are required after surgery, vision for driving at night or in low light is sometimes better than it is with multifocal IOLs.

Disadvantages of monofocal lenses:
* Those with IOLs for distance vision correction still require reading glasses to improve near vision.
* Those with IOLs for near vision correction still require glasses to improve distance vision.
* Some people do not adjust well to monovision as the brain has to process different information from each eye.
* Astigmatism may still cause blurred vision both near and far when glasses are not worn.

Multifocal IOLs and Accommodative lenses are designed to correct vision at near, intermediate and far distances. They contain several concentric rings of varying optical power, each of which bends incoming light into focus at different points simultaneously.

Accommodative lenses rely on the eye muscles to move the IOL backward and forward to change focus, and provides the best results when used in both eyes.

Advantages of Multifocal and Accommodative Lenses:

* Approximately 85% of people with multifocal IOLs do not need glasses for near or distance activities.
* Accommodative lenses normally offer very good distance (driving) and intermediate (computer) vision, but are not as good for near (reading) vision.

Disadvantages of Multifocal and Accommodative Lenses:

* Roughly 5-10% of multifocal implant patients experience some level of glare, halos or starbursts around lights at night. This is far less common with accommodative implants.
* Multifocal lenses are associated with some loss in contrast, typically as reduced near vision clarity in low light situations (like reading a menu in a dimly lit restaurant). This is not the case with accommodative implants.
* Non-Toric Multifocal and Accommodative lenses do nothing to correct astigmatism.
* Medicare and private insurers very rarely cover the costs of Multifocal and Accommodative lenses, or any of the associated costs exceeding that of a conventional IOL.