Ocular quinine toxicity.

A case of ocular quinine toxicity is described which showed the typical acute visual loss and subsequent recovery. Vermiform motion of the pupil was noted 48 hours after overdose. This acute effect has not been reported before. Although acute systemic intoxication may respond to removal of quinine from the gut and circulation, there is no evidence that any treatment affects the visual prognosis. The action of quinine on the retina is unknown. We suggest it may block cholinergic neurotransmission in the inner synaptic layer.