To determine the impact of the revised academy guidelines on screening for hydroxychloroquine retinopathy.
Retrospective, observational cohort study.
setting: Private practice of 29 doctors. study population: Total of 183 patients for follow-up and 36 patients for baseline screening. observation procedure: Review of charts, 10-2 visual fields (VFs), multifocal electroretinograms (mfERG), and spectral-domain optical coherence tomography (SD-OCT) images before and after the revised guidelines. main outcome measure: Rates of use of ancillary tests and clinical intervention, costs of screening, follow-up schedules, and comparative sensitivity of tests.
New hydroxychloroquine toxicity was found in 2 of 183 returning patients (1.1%). Dosing above 6.5 mg/kg/d was found in 28 of 219 patients (12.8%), an underestimate because patient height, weight, and daily dose were not determined in 77 (35.1%), 84 (38.4%), and 59 (26.9%), respectively. In 10 of the 28 (35.7%), the dose was reduced, in 2 (7.1%) hydroxychloroquine was stopped, but in 16 (57.1%) no action was taken. The cost of screening rose 40%/patient after the revised guidelines. Fundus autofluorescence imaging was not used. No toxicity was detected by adding mfERG or SD-OCT. In no case was a 5-year period free of follow-up recommended after baseline screening in a low-risk patient.
Detection of toxic daily dosing is a cost-effective way to reduce hydroxychloroquine toxicity, but height, weight, and daily dose were commonly not checked. The revised guidelines, emphasizing mfERG, SD-OCT, or FAF, raised screening cost without improving case detection. The recommended 5-year screening-free interval for low-risk patients after baseline examination was ignored.