Early-Onset Hydroxychloroquine Retinopathy and a Possible Relationship to Blood Levels: Comment on the Article by Petri et al.

Petri et al reported that higher hydroxychloroquine (HCQ)　blood levels predicted later retinopathy (1) . However, in a recent case-control study, the blood level was not associated with retinopathy(2). The inconsistency may arise from dose adjustment over the years and the timing of blood level testing.