QUININE TOXICITY: MULTIMODAL RETINAL IMAGING AND ELECTRORETINOGRAPHY FINDINGS.

PURPOSE: To report the multimodal retinal imaging and electroretinography (ERG) findings of two cases with quinine toxicity.

METHODS: Retrospective case series describing the retinal imaging and ERG findings in two patients with retinal toxicity due to remote quinine exposure. Color fundus photography, fundus autofluorescence, spectral domain optical coherence tomography, and full-field ERG findings are described.

RESULTS: Two patients with longstanding decreased vision were found to have bilateral optic disk pallor and retinal vascular attenuation indicative of chronic sequela after acute quinine toxicity. Inner retinal atrophy was identified on spectral domain optical coherence tomography, and full-field ERG was consistent with generalized inner retinal dysfunction in both patients. Fundus autofluorescence failed to demonstrate any evidence of outer retinal or retinal pigment epithelial abnormalities.

CONCLUSION: Quinine toxicity may be associated with vision loss secondary to inner retinal atrophy. We report two cases with a clear history of acute quinine exposure leading to similar retinal imaging findings and distinctive ERG abnormalities. Clinicians should be aware of this uncommon condition as ingestion history may be remote.