DEAR DR. ROACH: My niece was diagnosed with birdshot chorioretinopathy. Can you please explain what this is, which treatments are involved, and what the typical prognoses are?

• P.Z.

ANSWER: Birdshot chorioretinopathy is an inflammatory condition of the choroid and retina (the very back of the eye). The average age of diagnosis is 53. This disease is an autoimmune disease that is strongly associated with genetics. Nearly everyone with this disease has the same human lymphocyte antigen group (HLA-A29), even though only 7% of people have this antigen present in their T cells.

The disease is characterized by inflammatory aggregates that resemble birdshot, which are small metal pellets for shooting game birds. These inflammatory processes attack specific protein targets in the eye, leading to floaters and vision changes (such as flashes and difficulty seeing at night). People with this condition can still have normal visual acuity when tested traditionally.

Like most autoimmune diseases, the treatment is to “turn down” the immune system a bit with systemic treatments (such as steroids like prednisone initially), then changing to a less-toxic, long-term treatment (like mycophenolate or cyclosporine). Some people may need a combination of medications, but with the best treatment, 80% to 90% of people can have stable vision.

DEAR DR. ROACH: Which is better for joint aches, arthritis and the like: methylsulfonylmethane (MSM) or turmeric?

O.S.

ANSWER: Since there hasn’t been a trial comparing the two of them against each other directly, I can’t answer this with certainty. However, the studies on turmeric generally show larger beneficial effects than the studies on MSM.

Neither supplement had higher adverse effects than a placebo in the trials; however, both of them can cause adverse effects, which are mostly nausea and diarrhea. There was one report of bilateral angle-closure glaucoma in a person who was on MSM.

Turmeric has been better studied than MSM. Several analyses of available studies have shown a significant (greater than 30%) improvement in arthritic pain and function scores. In a small study on MSM using the same scale, it reduced pain by about 15%, while a placebo reduced pain by 10%.

Given the centuries-long history of turmeric use (and its active extract, curcumin), its extensive safety profile (it’s used as a spice), and its robust effectiveness in studies, I recommend turmeric or curcumin above MSM. However, some people will have adverse effects, and some people won’t receive a benefit.

ToYourGoodHealth@med.cornell.edu.