About half of patients taking hydroxychloroquine, which is used for lupus and rheuamtoid arthritis, aren't tested in time for its blinding effects on the retina, says a review. There are simple ways to use the drug safely.
Marmor MF, Melles RB. Hydroxychloroquine and the Retina. JAMA. 2015;313:847-848. doi:10.1001/jama.2014.14558
Hydroxychloroquine retinopathyis not rare, but it should be, concludes this short review. Many people who take this standard medication, which is indicated for lupus and rheumatoid arthritis, are not seeing eye care professionals or getting the tests necessary to prevent permanent vision loss.
Among new users of this drug, fewer than half had a baseline examination within the first year, according to Nika et al., writing last October in JAMA Ophthalmology (Regular Examinations for Toxic Maculopathy in Long-term Chloroquine or Hydroxychloroquine Users). Among patients at high risk, one-third had no diagnostic testing at all during the five years of the study.
Patients under a rheumatologist’s care and those with higher education receive more screening. So patient understanding seems to be an important factor.
Some physicians have questioned whether screening for retinopathy is necessary or cost-effective, because reported toxicity is only about 1%. But the prevalence in long-term users is closer to 7.5%. Furthermore, the 1% toxicity was defined by “bulls-eye” maculopathy, which is a late and severe stage at which the patient is at high risk of losing vision.
Studies using more sensitive equipment can identify maculopathy before it reaches that stage.
Hydroxychloroquine can be safe. The requirements: Calculate the threshold dose correctly, and assure that patients receive regular screening from ophthalmologists usingsensitive diagnostic tests to identify retinal damage by an early stage, when the risk is minimal.