Multifocal electroretinography evaluation for early detection of retinal dysfunction in patients taking hydroxychloroquine.

PURPOSE

To evaluate macular function using multifocal electroretinography (mfERG) in a cohort of asymptomatic patients taking hydroxychloroquine and a patient with maculopathy secondary to hydroxychloroquine treatment.

METHODS

mfERG recordings were obtained for both eyes of 11 patients taking hydroxychloroquine without clinical signs of toxicity and 1 patient with toxic maculopathy. Initially, the classic m-sequence paradigm for the first-order kernel (103 hexagons; 2.7 candela x seconds/m2 peak luminance) was recorded. After that, another special stimulation mode was applied, which emphasized second-order adaptational effects (modulated multifocal flashes with interleaved global flashes, MF0F0 paradigm).

RESULTS

The patient with toxic maculopathy and one patient without toxicity had multiple areas of decreased retinal responses bilaterally (classic m-sequence). The patient with toxicity and another three patients without toxicity presented with multiple areas of decreased retinal function in both eyes with the second-order component of the MF0F0 paradigm. Repeated recordings of 1 patient 8 months after the initial recording demonstrated evidence for reproducibility of the second-order adaptive effects.

CONCLUSION

Clinically asymptomatic patients receiving hydroxychloroquine treatment can have substantial local decreases in their retinal function, as reflected by the changes in mfERG recordings, possibly indicating a preclinical stage of drug-related toxicity.