Slowly progressing cataracts may not affect vision at first

Q: I'm 62, and during my routine eye exam yesterday, the doctor said that I am showing the first signs of cataracts. I know that cataracts develop slowly, but she wants to see me in six months. Does a six-month wait make sense?

A: As you noted, cataracts - which cloud the lens of the eye - are slow to develop, with initial symptoms amounting only to difficulties with night vision or an ability to read highway signs. But over the years, untreated cataracts can lead to blindness.

Before the advent of simple surgical procedures to remove the opacified lens and replace it with an artificial lens, cataracts were the most common cause of blindness in the United States. They are still the most common cause of blindness worldwide, leaving nearly 15 million people unable to see.

Cataracts develop because the cells of the lens create a complex lattice that continues to form even after the cells die. Because the lens does not shed these dead cells, they are susceptible to damage without any ability for repair.

Most of this damage simply occurs with age, but other factors can be involved. Smoking, alcohol, diabetes, damage from sunlight and poor nutrition can all cause cellular damage that increases the risk for cataracts. So, too, can exposure to oral or high-dose inhaled steroids.

Diets that are high in fruits and vegetables - specifically those containing high amounts of the compounds lutein and zeaxanthin - are associated with a lower risk of developing cataracts.

Your eye doctor, in addition to monitoring your cataracts, has also probably tested for glaucoma. On occasion, cataracts can lead to increased pressure in the eye and glaucoma.

If your cataracts are slowly progressing, I agree with your doctor about re-evaluating them at a later time. If the cataracts are creating glaucoma, or if your doctor cannot evaluate your retina because the lenses are too cloudy, that may be an indication to remove the lenses now.

Otherwise, surgery to remove cataracts is based on how they're affecting vision - meaning, how they impact daily life.

Previously, ophthalmologists didn't recommend cataract surgery until the cataract was considered "ripe" for removal. This philosophy was in place for many years because previous surgical techniques for cataracts led to many more complications than today's techniques.

However, cataract surgery today is a simple outpatient procedure, often done without anesthesia. In addition, new focal lenses can be implanted to provide better reading or distance vision.

Simply put, you should have your cataracts removed if you're having trouble reading road signs, seeing at night or deciphering fine print. If this is not occurring, you can wait - even for many years. It's possible that removing cataracts too early could potentially expose the retina to more light damage and increase the risk of macular degeneration, but that association is from observational data, not clinical trials.

Many of my patients who have cataracts wait an entire year to have their eyes rechecked, so six months should be fine. And remember: To decrease the progression of cataracts, avoid smoking, cut back on alcohol (if you drink) and follow a good diet. This will not only help your eyes, but also the rest of your body.

• Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles. Send your questions to askthedoctors@mednet.ucla.edu