If you've ever driven an old car with cloudy headlights, you know that the amount of light that passes through the lens is reduced. This is the basic principle behind cataracts in the human eye, and most are related to aging.
This week on “Take Care,” Dr. David Chang explains how a cataract forms and what cataract surgery is like, along the benefits of the procedure. Chang, one of the world’s top cataract surgeons, is a clinical professor of optometry at the University of California San Francisco and author of “Cataracts: A Patient’s Guide to Treatment.”
“Inside everyone’s eyes, we have a lens,” Chang says. “And it’s more than just a window, it has basic focusing power, and the most important purpose is that when we’re young and the lens is soft enough, it can change shape in response to our focusing muscles. And that’s how we adjust the focus of our eyes from far to near when we’re young.”
Chang added that as people get older, the lens get stiffer and starts to lose its clarity, eventually to the point of affecting their visual function. That’s when it’s described as a cataract. Once that occurs, an operation is needed to remove it and replace it with an artificial lens that’s permanently implanted.
“But if that’s not done, many people would be surprised to know that you’ll eventually go blind,” Chang says.
Not everyone will have a cataract problem, but Chang says the majority of people will reach a point in their lives where it becomes a big enough issue that needs to be addressed.
The problem is, people’s vision gradually changes over time and they automatically adjust to that, so it is difficult for them to really know if they have a cataract. Chang says that those who undergo cataract surgery tell him how objects and colors are much more definitive than before, meaning it is easier to tell the difference once the surgery happens and the vision change is instant.
Cataracts start with symptoms of frustration of vision, and if diagnosed, Chang recommends considering surgery, as it is almost certain that the symptoms will continue to worsen over time. He says convincing people to go through with the operation is not altogether difficult.
“Nowadays, the success rate is so high and the complication rate is so low, that we’re generally able to encourage people to have this done if it’s affecting some of their important lifestyle activities, and this can include driving, driving at night, it could include glare symptoms under certain conditions and it could include just some difficulty with reading,” Chang says.
According to Chang, people are naturally wary of the surgery because it is so close to the eye and patients remain awake during it. However, he says the eye gets numbed with anesthetic eye drops, which prevents the need to give a shot in the area of the eye. In addition, the patient can’t see anything because the eye is out of focus, and mostly witness a “psychedelic light show” coming from the microscope lights.
The cataract is removed through a tiny incision less than an eighth of an inch wide, so small that it fills up without the need to stitch it. The replaced artificial lens, usually made of either silicone or acrylic plastic, is foldable so it can fit into that small incision.
The procedure usually takes about 15 to 20 minutes and patients can usually see improvements in their vision in the next day to two days following.
According to the National Eye Institute, by age 80, more than half of all Americans either have a cataract or have had cataract surgery.
“The bottom line, a patient should not be afraid to the experience of surgery,” Chang says. “It’s done very quickly and for the most part, comfortably.”
