DEAR DR. ROACH: I have bad knee arthritis. My doctor is suggesting a genicular nerve block. Is this a good idea? Will it fix the problem?

• P.O.V.

ANSWER: Chronic knee pain from osteoarthritis is a common problem in middle-aged and older adults. Before a person receives treatment, the diagnosis should be confirmed by an X-ray. First-line treatments are exercise and anti-inflammatory drugs, like naproxen (orally) or diclofenac (topically).

When first-line treatments are ineffective, there are other options. Knee injections with steroids have long been used, but recent studies cast doubt on their effectiveness and raise concern for damage to knee cartilage. Hyaluronic acid and plasma-rich platelet injections have been shown in recent trials to be only slightly better than saline injections, and they are much more expensive. Duloxetine, an antidepressant that has pain-relieving properties, is effective for some people but not everyone.

Before considering knee-replacement surgery, a nerve block or ablation of the nerves that carry pain information can be attempted when an expert is available. There is significant pain relief from this procedure, although the benefit is greatest within a few weeks and generally lessens after three to four months. About half of the people who got the procedure report being “much improved” or “very much improved” afterward. It is generally safe with a low risk of side effects.

DEAR DR. ROACH: I am 81 years old and have been diagnosed by my ophthalmologist with age-related macular degeneration (the dry type). I was advised to start taking the AREDS2 eye vitamin and mineral supplement. Shortly afterward, I came across a magazine advertisement for AREDS2, which included a disclaimer from the Food and Drug Administration (in fine print, ironically) that stated the product is “not intended to diagnose, treat, cure or prevent any disease.”

I’m confused. If the over-the-counter mineral supplement doesn’t do any of this, then of what value is it, and why take it?

• E.D.

ANSWER: There is strong evidence that the AREDS and AREDS2 formulations of over-the-counter supplemental vitamins and minerals do slow the progression of the dry type of AMD. I agree with your ophthalmologist that it is worthwhile for you to take this formulation. I also recommend the AREDS2 formulation for current or former smokers as the beta-carotene in the original AREDS formulation was associated with an increase in lung cancer risk.