Abstract
Purpose:
To evaluate the effectiveness of the multifocal electroretinogram (mfERG) in detecting hydroxychloroquine/chloroquine induced retinopathy in comparison to diagnosis by an expert panel consensus, which acts as a reference standard representative of the clinical setting.
Methods:
A retrospective chart review of 165 patients on hydroxychloroquine or chloroquine therapy referred to the University of Ottawa Eye Institute between 2007 and 2011 for multifocal ERG was undertaken. All mfERG tests were interpreted by an experienced clinical electrophysiologist. An expert panel independently assessed patients for the development of retinal toxicity using the composite results of serial clinical exams, visual field testing (Humphrey 10-2), and time- or spectral-domain optical coherence tomography (OCT). Comparison was then made between the assessment of toxicity based on the expert panel findings, and the interpretation of the mfERG results.
Results:
The expert panel assessment identified a total of 31 of 162 (19.1%) patients who developed some evidence of retinal toxicity during follow-up. In 29.0% of the cases, the mfERG detected retinopathy prior to the reference test, suggesting higher sensitivity. In another 54.8% of cases, the mfERG confirmed the retinal toxicity previously detected by the reference test. The mfERG had false negative detection in 16.1% of cases. Of the 131 patients in whom no retinopathy was detected by the reference test, 70.2% were confirmed by mfERG. In the other 29.8%, the mfERG revealed some level of retinopathy, which suggests either false positive detection or higher sensitivity.
Conclusions:
Our results demonstrate the utility of mfERG in screening for hydroxychloroquine/chloroquine induced retinopathy. The mfERG may be more sensitive for the early detection of retinal changes associated with these medications, as compared to the current standard of clinical examination and automated perimetry.
Keywords: 688 retina •
509 electroretinography: clinical