Hydroxychloroquine Retinopathy Detected by SD-OCT but Not by mfERG, FAF, or 10-2 VF
This 38 year old woman with systemic lupus erythematosus had been taking hydroxychloroquine 400 mg/d for 22 years. She was 65 inches tall, weighed 205 pounds, and had no renal or liver disease. Her adjusted daily dose using her ideal body weight of 145 pounds was 6.1 mg/kg/d. She had macular drusen bilaterally and 20/20 visual acuity in each eye. Her cumulative dosage was 3212 gms. Her mfERG was normal, her fundus autofluorescence image showed hyperautofluorescence of the drusen without hydroxychloroquine induced changes, but her SD-OCT showed some loss of reflectance of the inner segment/ outer segment junction in a perifoveal location (yellow arrows). Her 10-2 VF was suspicious for pericentral scotomata but not conclusive. She was considered to have enough risk for toxicity that the dosage was dropped to 300 mg/d. This was an instance in which the SD-OCT was more sensitive than the mfERG and 10-2 VF for toxicity.