Hydroxychloroquine Toxicity - Missed By Failure of Clinician to Recognize Field Changes

A series of 10-2 visual fields of the left eye of a 78 year old woman with rheumatoid arthritis taking 400 mg/d of hydroxychloroquine for 15 years. She was 5 feet tall and weighed 100 pounds. Her daily dose was 8.8 mg/kg/d. No visual fields were available before 2008, when she already showed signs of a paracentral scotoma. These fields were erroneously interpreted as normal by her ophthalmologist each year. In 2012 the error was detected by the author in doing research and medical record chart review. The responsible clinician was contacted, agreed that toxicity was present, and the patient was taken off hydroxychloroquine.