We thank Dr Bienfang for his valuable comments on our article. Of 4 patients who developed hydroxychloroquine sulfate toxic effects among our population of 262 patients, all of them developed visual field defects indicative of toxic effects within a mean onset of 3.5 years of treatment. All of the defects were detected within the 1-year gap between visual field tests, hence our recommendation of screening at baseline, after 2 years of initiation of therapy, and annually thereafter irrespective of the therapeutic dose of hydroxychloroquine.
Elder M, Rahman AMA. Screening for Hydroxychloroquine Toxicity—Reply. Arch Ophthalmol. 2007;125(11):1585. doi:10.1001/archopht.125.11.1585-b