Q: What are some downfalls of radial keratotomy surgery?

A: Radial keratotomy (RK) surgery can be helpful to many people, but not to all.

Some of the best things you can do to prepare for radial keratotomy surgery are: do in-depth research; ask many questions of your physician and eye surgeon; and be aware of side effects.

RK corrects myopia, or nearsightedness. A surgeon flattens the cornea by using a super-sharp diamond blade to make a number of cuts on the cornea surface.

It's possible you will be under corrected; and it's possible you will be over corrected. You might even shift from being nearsighted to being farsighted after the surgery is complete. These are possibilities a patient needs to be aware of before having the surgery.

Be aware that RK is not for everyone. Although the patients who are happy with this procedure are some of the happiest patients I've had.

Robert Snyder, M.D., head, Department of Ophthalmology, The University of Arizona College of Medicine

Q: How should I decide what medication to take for cold and allergy symptoms?

A: Make sure you get medication that treats only the symptoms you have.

If you have a cough and you're trying to get to sleep at night try a cough medicine with an expectorant and cough suppressant. You don't need the antihistamines and the decongestants that are found in many over-the-counter cough preparations.

If you have nasal congestion--where you can't breath or you have a sinus headache--take a decongestant and not three or four medications that you don't need.

Time release medications can be useful in some limited areas. For the most part, I recommend going with short action products because you may find you don't need the product released over a long period. And if you have an allergy or sensitivity to one of those time-release drugs you have a lot more in your system and you're going to have that effect for a longer time.

It's also a good idea to check the expiration date of the medication, too. And don't leave medications exposed to direct sunlight or moisture. This causes them to break-down more quickly.

If you're not sure about the type of medication you do need, consult your local pharmacist.

Mark Murphy, poison control specialist, Arizona Poison and Drug Information Center administered by The University of Arizona College of Pharmacy