What is an intraocular lens?
The eye contains a lens that focuses light so we can see. Sometimes the natural lens of the eye turns cloudy (which is called a cataract), and the only way to let light into the eye is to remove the whole lens. The natural lens is almost always replaced with an implantable medical device called an intraocular lens.
Why do people need intraocular lenses?
When natural lenses are removed from the eyes in cataract surgery, the eyes are left like cameras with no lenses. Even though light can get through, it will not make a clear image - just a fuzzy blur. The eyes need some kind of replacement lenses to be able to focus again.
Are there any alternatives to intraocular lenses?
Before intraocular lenses were invented, doctors could only prescribe eyeglasses or contact lenses after cataract surgery. Usually, the eyeglasses had to be very thick (“Coke-bottle” glasses) in order to match the strength of the eye's natural lens. But vision is not very good when eyeglass lenses are so thick, and thick contact lenses are not a much better option. Intraocular lenses were invented to solve these problems.
About 2 million people per year in the United States have cataract surgery, and almost all of them receive an intraocular lens. There are many different kinds of intraocular lenses. Your doctor can decide which lens is right for you only after a careful examination of your eye.
Intraocular lenses can be divided into two main groups: non-foldable and foldable. Intraocular lenses were originally made from a hard plastic material, but materials were later invented to make soft lenses that could be folded in half. This type of intraocular lens can be inserted through a smaller opening in the eye, which can be better for the patient because smaller incisions usually heal faster than larger ones.
What happens in the operation to implant intraocular lenses ?
Intraocular lenses are usually implanted during cataract surgery, which is usually performed with local anesthesia. That is, the patient is awake but does not feel the procedure. In a few cases, the surgeon will use general anesthesia (the patient is “asleep”).
The surgeon will make a very small opening in the front of the eye so the cloudy lens can be removed. There are two ways to remove the lens. One way is to remove it whole and the other is to use a special instrument to break the lens into pieces, then remove those pieces through a small incision.
Most cataract surgery is done with an instrument that breaks up lenses with ultrasound: sound waves that are too high in frequency for humans to hear. The energy from these ultrasound waves breaks up the lens in a process called phacoemulsification.
After the natural lenses have been removed, the intraocular lenses are placed into the eye. Usually, the intraocular lens goes where the natural lens had been. This area of the eye is called the posterior chamber. Sometimes, however, that might not be the best place for the intraocular lens so some lenses are designed to be placed in the anterior chamber, the area in front of the colored iris of the eye. Both types of lenses work well at putting the eye back into focus. Depending on which method of lens removal is used, the opening in the eye might not even need stitches. The patient is usually ready to go home about an hour after surgery.
Cataract surgery is sometimes performed without implanting intraocular lenses. It is usually possible to implant an intraocular lens at a later time. Surgeons often recommend the anterior chamber type of lens for those patients.
How successful are intraocular lenses?
More than 90% of the people who have cataracts removed see better after surgery than they did before. An important part of successful cataract surgery with an intraocular lens implant is following your doctor's instructions after surgery. Eye drops are prescribed after surgery to help the eye heal better and to prevent infection. Your doctor will have to examine your eye after surgery to make sure it is healing properly and to check your vision. It is important to keep these appointments with your doctor.
Does anyone need to wear eyeglasses or contact lenses after receiving an intraocular lens?
Most intraocular lenses are chosen to focus at what doctors call “distance” vision. By “distance,” they mean anything farther than 2 or 3 feet away from the eye. If the lenses are focusing at distance, eyeglasses will be needed to see clearly close-up. Many people who have cataract surgery are already used to wearing bifocals, so they are familiar with this type of vision.
Make an appointment now. Or call 216.444.2020 or 800.223.2273 Ext. 4-2020 to schedule an appointment with a Cole Eye Institute ophthalmologist.