Aging Eyes & Common Vision Problems
WHAT IS PRESBYOPIA?
If you have trouble reading up close, you may have presbyopia.
Other Presbyopia symptoms include:
- Holding books and magazines farther away
- Headaches or tired eyes with close work or reading
- Slow focusing from near objects to distant objects, a clock on the wall takes time to come into focus after reading
Presbyopia is the loss of the eye’s ability to focus on near objects because of age-related thickening and hardening within the natural lens. Typically, an individual with normal distance vision, without the need for eyeglasses, will begin to experience presbyopia by their mid-40s. It is a myth that eye exercises can overcome presbyopia.
UNDERSTANDING YOUR EYES – PRESBYOPIA
In youth, the natural (crystalline) lens of the eye is flexible and allows the eye to focus at near and far distances, a process called accommodation. This process involves the ciliary muscle inside the eye, which causes the lens to change shape and focus. Throughout life, the lens continues to add cells. Eventually, the lens becomes so rigid that the ciliary muscle can no longer exert adequate force on the lens to change its shape.
Loss of accommodation ability results in blurred near vision, or presbyopia. This can occur even in the presence of good distance vision. As the lens hardens, it also becomes opaque and becomes a cataract. Many people have presbyopia and cataracts simultaneously. While vision can temporarily be improved with glasses, eventually cataract surgery is required to restore vision.
If you are nearsighted (myopic), you see poorly at distance and see better at near.
If you are farsighted (hyperopic), you see well at all distances when young. As you age, near vision decreases, followed by a decrease in both near and distance vision.
Astigmatism reduces vision at all distances.
PRESBYOPIA SURGERY OPTIONS
Choosing the best surgical treatment option for presbyopia is very important. Many patients who need surgery for presbyopia will also develop cataracts in the next 10 years. While vision can temporarily be improved with glasses, eventually cataract surgery is required to restore vision.
Surgery for presbyopia involves either monovision LASIK or removing the inflexible natural lens from the eye and replacing it with a new lens that will help you to focus better. This is called a Refractive Lens Exchange (RLE). These lenses are called intraocular lenses, or IOLs.
Several types of procedures and IOLs are available. Decisions about which procedure is best for you should be made in consultation with Dr. Oyakawa. The right presbyopia solution for you will depend on your eye health, lifestyle, and personal preferences.
LASIK Vision Correction of Presbyopia
One of the first effective surgical options for presbyopia correction involved achieving what is known as "Monovision" during LASIK. The refractive error is corrected in the dominant eye and the other eye is set to see near. This can also be done in a patient who can see distance well in both eyes. One eye can be made nearsighted with the excimer laser.
Dr. Oyakawa recommends Monovision LASIK only for myopic eyes with no signs of cataracts. Dr. Oyakawa himself has had Monovision PRK.
In 2009, Dr. Oyakawa underwent presbyopia correcting cataract surgery with the Crystalens AO in the near eye set for mini-monovision. Recently he had cataract surgery in the other eye with a Trulign (astimagtism correcting Crystalens).
What you can expect with Monovision LASIK
- Successful Monovision adaptation occurs in 3 to 4 weeks in about 80% of patients
- Main advantage is not needing reading glasses for seeing near
- Disadvantage is some decrease in depth perception
- Patients in their 40s usually adapt to Monovision in 1 to 2 weeks, while older patients may take longer
- Patients who do not have significant astigmatism can try contact lenses before Monovision LASIK
- A few patients may need to use glasses for night driving or prolonged computer work and reading
- Some patients use one disposable contact lens in their near eye for good binocular vision during sports, such as tennis
- In rare situations, some patients may decide to have the eye with near vision corrected to allow distance vision
Refractive Lens Exchange "Off-label", click here.
During an elective procedure known as refractive lens exchange (RLE), the eye’s natural lens is replaced with an artificial lens. There are artificial lenses that also correct presbyopia. At the same time any refractive errors such as myopia, hyperopia, or astigmatism are corrected. This technique can also be used for patients beyond the range of correction for LASIK. An added benefit is not needing cataract surgery in the future. This results in freedom from glasses most of the time and in a significant number of patients complete freedom from glasses.
RLE is cataract surgery before the lens becomes a clinically significant cataract. This is essentially a specialized cataract surgery and will be discussed in the cataract surgery section.