Comparison of different screening methods for chloroquine/hydroxychloroquine retinopathy: multifocal electroretinography, color vision, perimetry, ophthalmoscopy, and fluorescein angiography

To compare various screening methods for the early diagnosis of retinal dysfunction in patients with long-term chloroquine (CQ) and hydroxychloroquine (HCQ) treatment. Twenty patients with long-term CQ/HCQ treatment underwent ophthalmologic evaluation including visual acuity testing, ophthalmoscopy, fluorescein angiography, color vision tests, visual field and multifocal electroretinography (mfERG). In 14 patients, retinal dysfunction was indicated in the mfERG (reduced amplitudes and/or delayed implicit times) in the parafoveal area. Towards the periphery, the function was normal or only moderately reduced. Ophthalmoscopy and fluorescein angiography identified pathologic retinal changes in seven of these 14 patients. Six patients had normal mfERG, ophthalmoscopy, and fluorescein angiography. Results of color vision and visual field testing were variable even in patients with morphologic alterations. The use of mfERG may detect retinal dysfunction in a considerable number of eyes with normal ophthalmocopy and fluorescein angiography. The higher variability of color vision and visual field testing results suggests the use of mfERG as primary screening tool for retinal dysfunction in long-term CQ/HCQ treatment.