Assessing hydroxychloroquine toxicity by the multifocal ERG

Twenty patients on Plaquenil treatment were evaluated for retinal toxicity using the (EOG) and the mfERG. Group 1 comprises 15 patients (30 eyes) with normal EOG. From these patients 11 (22 eyes) showed normal RRD of mfERG in area 1 and area 2. The rest four patients (8 eyes) the RRD were reduced. Six months after interruption of HC, the mfERG improved in three cases. Group 2 comprises 5 patients (10 eyes) with subnormal EOG. Four (8 eyes) of these showed a decrease of RRD of the mfERG in area 1 and 2. In the rest one (2 eyes) the RRD were normal. Six months after interruption of HC the mfERG and the EOG improved in 2 cases. These results postulate that the mfERG may be used as an alternative method, perhaps more sensitive, for the detection of the HC retinopathy and the follow up of the patients on hydroxychloroquine.