DEAR DR. DONOHUE: Can decaffeinated coffee cause problems because of the way the caffeine is removed? The process leaves behind cancer-causing chemicals. Should I stop drinking decaf? – L.L.

ANSWER: Only if you want to.

In the past, methylene chloride was used to remove caffeine from coffee. In large amounts, it causes tumors in lab animals. It has never been proven to cause human cancer. Since the late ‘80s, most coffee manufacturers have stopped using methylene chloride. Those that still employ it have concentrations in their decaf coffee 100 times less than the Food and Drug Administration permits for consumption.

People have been drinking decaf for decades. If it caused cancer, surely, by now, there would be widespread reports of its danger.

DEAR DR. DONOHUE: My vision got a bit blurry, and I thought I needed a change in glasses. I went to an eye doctor, who told me I had keratoconus. I am now wearing contact lenses. Is this a common eye problem? I have never heard of it. Would you please provide a little information? – T.U.

ANSWER: It’s not common, but it’s not uncommon either. It’s somewhere in between.

The cornea is the clear but tough, plasticlike covering of the central part of the eye. You can see the pupil through the cornea. It’s the eye’s equivalent of a window.

With keratoconus, the cornea thins and protrudes. The cornea becomes cone-shaped. That’s where the “conus” of keratoconus comes from. “Kerato” is borrowed from Greek, and it stands for the tough tissue of the cornea.

Because the cornea is misshapen, vision blurs, and this usually starts in the late teens or early 20s.

The process can progress very slowly. In the early stages, glasses can correct distorted vision. Special contact lenses not only correct vision but seem to slow progression of keratoconus.

As long as glasses or contact lenses permit good vision, that’s about all the treatment that is needed. If the process reaches a point where lenses cannot restore good vision, corneal transplants can. These transplants are among the safest and most successful of any transplant.

DEAR DR. DONOHUE: I am under investigation for multiple sclerosis. The doctor wants me to have a brain scan. Why? Aren’t these scans for brain tumors? Do you think it is necessary for me to have one? – M.M.

ANSWER: It is quite necessary for you to have an MRI (magnetic resonance imaging) scan of the brain. The scan can pick up minute scars in the brain. Those scars furnish valuable evidence to confirm or refute the MS diagnosis.





DEAR DR. DONOHUE: What is Klinefelter’s syndrome? A relative has it. – F.G.

ANSWER: Humans have two sex chromosomes, X and Y. Women have an XX pair, and men have an XY pair. Chromosomes are long chains of genes.

Klinefelter patients have an extra chromosome. Their configuration is XXY.

People with this chromosome pattern are males and look like males. However, they might be infertile. Often they experience breast enlargement. Low levels of the male hormone testosterone do not permit the normal changes that usually happen with puberty – deepening voice, growth of facial hair, etc. Replacement therapy with testosterone can surmount the deficiency.

Sometimes Klinefelter men have learning difficulties.

I have simplified this far too much. There are many varieties of Klinefelter’s syndrome, and there are many different signs and symptoms of it. I gave you only the XXY story to provide a sketchy background of this genetic problem.