Intraocular Lens for Presbyopia
There are two problems that occur to the eye as it ages that now, thanks to evolving new technology, may be managed together – cataracts and presbyopia. Presbyopia is the loss of the ability of the eye to change focus and see close due to a less elastic lens and lens capsule. Cataracts are natural intraocular lenses with opacities most of which develop with age, and this article discusses Intraocular lenses (IOLs) for this type of cataract surgery.
Presbyopia is a natural age processing that affects people older than 44 years old. Also it can occurs after cataract surgery because the natural lens which is responsible for accommodation and near vision is removed.
Cataracts have been treated surgically for a long time. At first, glasses or contact lenses were needed after the natural lens was removed. Intraocular lenses were invented that could take the place of the natural lens, and these are still used. What is new and developing rapidly is manufacturing of “premium” intra-ocular lenses that use a variety of technologies to also correct presbyopia.
New intraocular lenses are in development and testing stages, and are continuing to improve. The FDA has to approve any new lens used in this way. However, while they are FDA approved, many premium intraocular lenses are not covered by Medicare due to their cost and the fact that there are other ways to correct presbyopia. Many healthcare providers offer premium IOLs to patients who are willing to pay for them at the time of their cataract surgery.
IOLs are not used for people without cataracts. Since presbyopia frequently develops many years before cataracts, these patients are already using glasses or contact lenses to deal with their presbyopia. Since they are going to undergo surgery and the risks that entails, they may chose to try and correct their presbyopia.
Intraocular lens for presbyopia is far from perfect but are getting better. None are able to give a person a lens that works like their original, young, healthy lens.
In 2010 there were 4 new versions of IOLs for Presbyopia with FDA approval, including:
1- AcrySof IQ
AcrySof IQ ReStor (Alcon) – Restor +3 approved late 2008. Acrysof Toric Intraocular lens approved in May of 2011.
2- ReZoom (Abbott Medical Optics)
3- Tecnis (Abbott Medical Optics)
Tecnis Multifocal approved early 2009
4- Crystalens (Bausch & Lomb)
These lenses have been developed further, to improve vision in a variety of ways. Current versions of Restor and Tecnis both improve near vision and provide better quality of vision as well as a deeper field of vision. However, both are still problematic for night driving and other low lighting conditions, when vision may not be clear enough. People considering these lenses need to be aware of the problems. Tecnis, however, is made slightly differently and reading under low light like in restaurants is better.
Depending on what version of these lenses is available, and depending on what other visual problems a patient has, it is possible to improve essentially all vision with some of these lenses for the right patients. The quality of some of these lenses is dependent on the size of the pupil. The Tecnis Multifocal Acrylic lens for presbyopia provides the same improvement in vision regardless of pupil size.
Crystalens’ first IOL was approved in 2003. In 2010 it was into its fourth generation. It is made differently than the other lens, as the first “aspheric accommodating lens.” It is better for anyone with an irregular cornea, for example, someone who has had a Lasik procedure or has astigmatism. However, reading glasses may still be needed.
In some studies, distance vision is better with Crystalens lenses, while near vision is better with the Tecnis lenses.
One extra issue is that of protected the eye from ultraviolet (UV) light. Only the Crytalens of the lenses listed here does not protect against UV light, so that sunglasses are recommended.
In addition to how well vision is corrected, and whether or not the need for other correction with glasses or contacts occurs, patient satisfaction depends on whether or not they experience problems with glare or halos. Research involving patient satisfaction in large groups of patients with these lenses always lags behind the newest version of a lens, because they are approved before large numbers of people get them. Patient satisfaction with all of the lenses is high, but never 100%.
Regardless of the lens, there is frequently the case that a person getting an IOL under these conditions will not have perfect vision at all distances and no distortion. In addition to the person’s specific eye condition and choice of lens, the skill of the surgeon is critical as is managing any problems after surgery. This means that a prospective patient should select not only the right lens, but a surgeon who does many of these procedures.
There are other lenses being developed, including the Synchrony, Tetraflex, and FluidVision lens for presbyopia. Some are being tested, some are in use in Europe, and other new lenses are in various testing phases.
According to researchers in this field, “10% of presbyopic patients reported a willingness to trade 5% of their life expectancy to get rid of presbyopia.That being said while not everyone wants to pay the extra thousands of dollars an IOL costs when used for cataracts, every patient deserves to have the option presented and the possibilities discussed.
An informed choice should be made as to whether or not an Intraocular lens for Presbyopia is the best way to go.