Cataract Awareness

WebMD Live Events Transcript

Cataracts are one of the leading causes of vision loss in the United States. As part of Cataract Awareness Month, ophthalmologist Guy Knolle, MD, joined us to answer your questions about cataracts -- symptoms, prevention, and the latest treatments -- on Aug. 3, 2004.

The opinions expressed herein are the guests' alone and have not been reviewed by a WebMD physician. If you have questions about your health, you should consult your personal physician. This event is meant for informational purposes only.

MODERATOR:
Welcome to WebMD Live, Dr. Knolle. It's cataract awareness month. What are the most important things you want us to be aware of about cataracts?

KNOLLE:
I think the most important thing is number one, it's a clouding of the lens inside the eye and is not significant until it interferes with vision. They can be treated successfully in at last 98 times out of 100. I tell my patients that when they close one eye if they can't see to do all of the things visually that they want to do out of the other eye with their best corrective lenses, that they need to consider having cataract surgery to correct this loss of vision.

Of course, the first thing that has to be determined is whether or not there are any other causes for their reduced vision. If a diagnosis of significant cataract is established by examination, this can be treated surgically and often, even if they have a small amount of macular degeneration, removal of significantly dense cataracts can result in improved vision.

MEMBER QUESTION:
What is the first symptom of cataracts?

KNOLLE:
The first symptom of a cataract can be glare, especially when looking into lights at night; and this can be associated with haze, which prevents clear visualization of the roadbed and highway markings. But to an astute observer, it's simply the loss of clarity of vision, loss of sharp images. The problem is that frequently cataracts develop very slowly, and minimal changes that become maximal changes are often overlooked or not noticed.

It's hard to remember sometimes what good vision is like compared with the gradual loss of definition that occurs with a cataract. This is especially true when the cataracts develop at about the same rate in each eye, so that there's no good standard of comparison.

We do have a way to roughly evaluate glare with an examination called the brightness acuity test, abbreviated BAT. This can give the examining surgeon a good idea of the patient's ability to see in bright daylight and when looking into oncoming headlights at night.

The examining doctor can help the patient evaluate their gradually deteriorating vision when this is occurring, and more objectively than the patients can sometimes evaluate their own vision. The average age for cataract surgery is approximately 73 to 75 years old. But cataracts can occur in the 30s, 40s, and 50s. Of course the older the patient gets the more common the cataracts. But again, the presence of a cataract is not significant in itself. The associated loss of vision, if present, is significant.

MODERATOR:
Given your description of the development of cataracts, how often should we be getting eye exams?

KNOLLE:
Thinking of the people that are in the cataract age group, age 60 and over, I would think it would be prudent to be examined yearly to be certain that corrective lenses were up to date and as fully corrective as they can be made.

MEMBER QUESTION:
I was told by my ophthalmologist recently I had the starting of a cataract in one eye. How long should I wait to have surgery on it? Should I wait until the other eye starts getting one to have anything done?

KNOLLE:
When a patient develops a cataract in one eye that is causing a loss of vision to less than useful levels, it's time to have the cataracts removed and replaced with an intraocular lens. The best guideline is to keep in mind that we want to keep both eyes in as good a repair as we possibly can. Once a significant cataract develops that reduces the vision in one eye, we know two things for sure: one is that the patient is out of spares, and number two, their ability to judge distance is deteriorating.

Many years ago, patients were told that the cataract should not be removed until it was "ripe." This was because prior to the 1970s, the entire crystalline lens was usually removed and it was easier to remove the lens if its attachment's zonules were weak. The analogy was that it's easier to pull a pear off a tree if it's ripe than if it's green. If it's green you could pull the tree down trying to pull the pear off. When the entire lens was removed through a large 180-degree incision, the surgeons preferred that the lens could be easily removed so that the fluid behind the lens would not be disturbed.

Beginning in the 1970s, small-incision cataract surgery became gradually more and more popular as a result of the late Dr. Charles Kelman from New York City. Currently, almost every good cataract surgeon in the world uses this small-incision technique called phacoemulcification. During this operation, parts of the lens are selectively removed and a part of the lens is left behind to support an intraocular lens. A 3-millimeter or less incision is required. The anterior capsule of the lens is opened and removed through the dilated pupil and ultrasound, in association with irrigation of balanced salt solution and aspiration, is used to soften and emulsify the lens material so that it can be aspirated through this small incision.

We now use foldable injectable intraocular lenses that can then be delivered into the remaining lens capsule supported by the zonules. The injected, foldable intraocular lens spontaneously unfolds and the incision can be closed by injecting balanced salt solution into the margins of the incision without the use of sutures that can create unwanted astigmatisms. If corneal astigmatism is present, it can be treated with relaxing corneal incisions in the periphery of the cornea at the same time cataract surgery is performed.