As people age, there are certain medical issues that they can practically bank on, and one of them is cataracts, or a clouding of the lens of the eye. If you're middle-aged and you're finding it difficult to take afternoon walks on sunny days because of the glare, or if the TV screen has started blurring even when you're wearing glasses, you may have cataracts.
According to the National Eye Institute, almost 20.5 million Americans aged 40 and over have cataracts, and more than half of Americans have cataracts by the time they are 80. As a result, more than 1.4 million cataract surgeries, in which the cloudy lens is replaced with an implant, are performed in the United States each year. Below, Penny A. Asbell, MD, a professor of ophthalmology at Mount Sinai School of Medicine in New York City, talks about the timing of cataract surgeries and improvements that have helped make this surgery so successful.
What are cataracts?
Inside the eye is a lens like a lens in glasses. If that lens gets cloudy, we change its name from lens to cataract. So a cataract is a cloudy lens inside the eye.
What causes cataracts?
We know that some diseases are associated with cataracts, such as diabetes, and that some drugs can cause cataracts, such as steroids or prednisone. Exposure to ultraviolet light causes a kind of cataract. But in general, we see an increased incidence of cataracts as we age. So it's one of those things that happens to almost everybody if they live long enough.
Can cataracts eventually cause blindness?
Cataracts gradually cause a loss of vision. If cataracts are not treated, vision can get so poor that you become legally blind, meaning you see light, but no images, no detail. Fortunately, in the United States, most people seek care before they get that bad.
How do you know that you have a cataract?
The symptoms of cataracts are typically a change in vision. Maybe you can't read anymore. Maybe you're having trouble driving. Another symptom can be glare, particularly when driving at night with headlights coming toward you, so you may feel you're not seeing as well as you used to when you drove at night. Some people also complain that colors don't seem as rich as they used to be. This change of vision isn't improved with glasses. So if you change your glasses and you still can't see well, the most common cause is cataracts.
How quickly does vision loss progress?
Cataracts typically progress slowly. At first you may not have any problem, and even if the doctor notices the cataract, your vision may still be very good and very functional. In most patients, it may be 10, 20 years before it's actually significant.
There is a certain kind of subgroup of cataracts that progress more quickly, and those patients usually are the ones who experience lots of glare, so sunlight really bothers them. Their cataracts often change over a period of months.
How are cataracts diagnosed?
In order to diagnose cataracts, we check to see if someone's glasses need to be corrected, and then we use a slit lamp, which is a machine to look at the eye and the lens with magnification. One of the reasons to have an eye exam is not just to diagnose cataracts, but to make sure there isn't any other problem that's causing loss of vision, such as glaucoma.
When is it time to think about having surgery to have the cataract removed?
The timing for cataract surgery almost always depends on the patient. When does your vision become a problem? When can you no longer drive, no longer do the activities you like to do, see TV, read, do your crossword puzzle? When you can't get by, that's the time to do cataract surgery.
Who is a good candidate for surgery?
Cataract surgery is one of the most successful surgeries that are done today. The patient comes in and goes home the same day, and the surgery only lasts about an hour or even less. Given all of that, it can be done in almost any patient at any age when it's appropriate for vision needs.
What happens during surgery?
The eye doctor will put drops in the eyes to numb up the surface of the eye. Sometimes we give an injection near the eye to numb the eye. If that's done, typically you work with an anesthesiologist who will sedate you so the injection doesn't bother you.
The eye doctor may ask you to look at a light to keep your eye from moving around too much during the surgery, and we make a tiny incision in the eye and then start removing the cataract. Typically what we do is take out the lens but leave a capsule behind to enclose the lens that we will be replacing it with. The replacement is an intraocular lens, or IOL. It's made out of plastic. It's measured to give the right power, and it's put back in after you take the cataract out.
Are there surgery complications?
There is some risk with every surgery, including cataract surgery. Some of the complications that can occur can be minor, but others can be more serious, such as bleeding, infection, damage to the inside of the eye, the retina, all of which can cause loss of vision. So that's why we don't just do the surgery on everybody who walks in. They have to have a visual complaint in order to consider taking on the risk, albeit a small risk.
Sometimes the envelope or capsule around the cataract that's left behind gets cloudy over time, and that is called an aftercataract. The good news is a laser administered in the office can make a little hole in that leftover envelope or capsule, and then your vision comes back again. So it's not back to the operating room.
Can you describe the recovery from surgery?
Typically, cataract surgery is done as an outpatient in an ambulatory surgery center. So you come in the morning, have the surgery and go home the same day. The next day, you're going to see your eye doctor to make sure it's beginning to heal. You'll typically see the doctor again about a week later, and then maybe about a month or so later after that.
During that time you're going to be using eye drops, maybe for a week to a month. After about a month, you'll find out if you need a change in your glasses. Or if you're lucky, maybe you won't use glasses at all.
The key thing after surgery is avoid getting hit in the eye. So some patients wear a plastic glasses or sunglasses to protect their eye. And for the first couple of weeks, you want to be careful with swimming, because that water probably isn't clean or sterile.
Should you have both eyes done if you have cataracts?
Cataracts usually develop in both eyes, though a slightly different rate. In most cases in the United States we do one eye and make sure it's healed and wait about a month before we proceed with the other eye. In some patients, the other eye still has good vision, so don't have to do anything about it. But if you do have loss of vision, the studies suggest if you do both eyes you improve your visual function. There are a few centers that are doing both eyes on the same day.
How has cataract surgery changed?
Cataracts surgery has undergone a tremendous improvement over the last quarter century. We do smaller and smaller incisions, and we have quicker and easier methods to take out the cataracts. We have implants now that can block UV light and correct astigmatism. And just recently an implant was approved that can correct for distance and reading vision. So it's a little bit like you are young again: you can see well at a distance and near.