To evaluate retinal toxicity in patients treated with high-dose hydroxychloroquine (HCQ) (Plaquenil, Sanofi Pharmaceuticals) for chronic graft-versus-host disease (GVHD).

Cohort study.

Twelve patients with chronic GVHD treated with 800 mg/day HCQ between June 2005 and December 2010.

Patients in this study underwent ophthalmologic examination yearly and ancillary studies including colour vision, Amsler grid, fundus photographs, Humphrey 10-2 automated perimetry, spectral-domain optical coherence tomography (SD-OCT), and multifocal electroretinography (mfERG). Evidence of HCQ toxicity was determined by the presence of scotomas in the Amsler grid and Humphrey 10-2 automated perimetry, and confirmed by at least 1 objective test including SD-OCT or mfERG.

Of the 12 patients, 7 were male and 5 were female. Mean age was 49 years. Mean best corrected visual acuity at baseline was 20/25 and remained 20/25 at final follow-up. Median duration of HCQ treatment was 22.8 months. Median adjusted daily dosage was 11.5 mg/kg/day. Seven patients developed vortex keratopathy. No signs of pigmentary retinopathy or bull's-eye maculopathy were found in any of the patients. Three patients developed retinal toxicity with scotomas in the Amsler grid and Humphrey 10-2 automated perimetry, as well as abnormal mfERG. Retinal structure measured by SD-OCT was abnormal in 2 of the 3 patients with retinal toxicity. Colour vision measured by Ishihara plates, as well as by 100 Hue colour test, was abnormal in 2 of the 3 patients with retinal toxicity.

High-dose HCQ in patients with GVHD was associated with higher incidence and earlier development of retinal toxicity.