What is Presbyopia?
Presbyopia is sometimes jokingly called ¡°short arm syndrome.¡± It¡¯s a problem common among people in their 40s and older, who have trouble focusing on near objects, and may complain that their arms are too short to hold a book at the right distance from their eyes! If you have to lean forward to reach your mouse, or need extra light to read a restaurant menu, you might already have it.
As we get older, our eyes become less flexible, and all of us are vulnerable to presbyopia, which occurs when the less-flexible lens can¡¯t adjust to focus on objects close at hand. If you¡¯re farsighted, you¡¯re likely to experience presbyopia¡¯s effects sooner than someone who is nearsighted. It also occurs earlier in women and in people whose jobs demand a lot of close vision.
Presbyopia Treatments
Presbyopia treatments start out very simply. Many people begin by buying a pair of ¡°reading glasses¡± at a supermarket or drugstore. Others get bifocal or multifocal glasses or contact lenses to correct their vision for different distances, or keep different pairs of glasses for distance and close vision.
Sometimes, doctors ¡°correct¡± presbyopia with a technique called ¡°monovision¡± ¨C engineering one eye for reading and close work, and the other for driving and other distance-related tasks.
Presbyopia surgery is increasingly becoming an option. Only one form of surgery, conductive keratoplasty, is currently approved by the FDA for treating presbyopia. CK is a type of monovision treatment, in which one eye is reshaped with radio waves for distance vision. It is a very brief and non-invasive procedure, but is not appropriate for everyone with presbyopia.
Monovision for Presbyopia
Monovision is an approach to presbyopia treatment that involves correcting one eye for distances and the other for close work. This can be done with glasses or contact lenses, or surgically with LASIK or CK.
Some people find they have trouble adjusting to monovision, which affects their depth perception. Those considering presybopia surgery are advised to try monovision with contact lenses first to see whether they can tolerate it. For those who cannot, the best option is probably keeping two pairs of glasses, one for reading and one for distances.
Monovision surgery is also not as accurate as corrective lenses, meaning the corrections between the two eyes may not be perfectly aligned.
Is Crystalens Right for Me?
Crystalens is a treatment for cataracts, which often occur with presbyopia. While crystalens is not specifically approved to treat presbyopia alone, the Crystalens is designed to address the chief problem of presbyopic people -- the inability to change the focus of the eye at different distances.
Crystalens is different from other intraocular implants because, its makers say, it revives the eye's ability to focus at short, middle, and long distances.
If you are on Medicare, you should know that a 2005 ruling allows cataract patients to receive the Crystalens, but makes them pay the difference in cost between the Crystalens and more traditional treatment.
What to Expect after Presbyopia Surgery
People who have presbyopia surgery will go through an adjustment period -- the length of time varies depending on the kind of surgery -- before reaching their final vision improvement.
Presbyopia surgery also may not eliminate the need for glasses or contact lenses. For one thing, their eyes will continue to lose focus, so that the correction that was right at age 42 will not be right five or 10 years later. This sometimes manifests as a loss of clarity in middle distances. The solution for this is a multifocal or bifocal contact lens in one eye, while correcting for distance vision in the other.
Side effects with monovision sometimes include "ghost images" visible at night and trouble with depth perception. Monovision treatments are not recommended for those who fly airplanes, do a lot of night driving or are required to maintain top athletic performance.
Signs of Presbyopia
Presbyopia is not a disease and cannot be prevented. It usually becomes noticeable after age 40, and tends to manifest at first as difficulty seeing close objects. Many people first notice it when they have trouble reading menus in dimly lit restaurants, or when it seems their arms aren't long enough to hold a book or magazine far enough away.
Many people also notice that they begin suffering from headaches when doing close work, or that their eyes get tired more quickly than they used to.
If these symptoms sound familiar, it may be time to see your optometrist to begin presbyopia treatment.
Types of Presbyopia Surgery
Doctors will sometimes use ordinary LASIK to create a "monovision" effect by correcting one eye (usually the dominant one) for distances and the other for reading. It is recommended that patients try this first with contact lenses before having the surgery. Some people take readily to the new way of seeing, but others find it difficult to tolerate.
In 2004 the FDA approved a new type of presbyopia surgery called conductive keratoplasty (CK). CK is a less invasive procedure that takes just three minutes to perform. Instead of cutting into the eye, the surgeon uses radio waves to shrink collagen in specific parts of the eye, making it more suitable for near vision. This is another monovision technique -- the second eye is left alone and corrected with a contact lens if need be for distances.
Several other treatments are in experimental phases and have not yet been approved.