Rare Optic Neuropathy in a Jamaican Couple Linked to Cassava Root Consumption

Abstract

We report central visual loss with selective papillomacular bundle damage in a Jamaican couple, husband and wife, with long-term cassava root consumption. The two cases presented independently with gradual central visual loss. Examination revealed bilateral temporal pallor of the optic nerve head and automated static perimetry demonstrated a central or caecocentral scotoma in each patient. Optical coherence tomography findings are described. The only mutual risk factor, reported independently, was long-term cassava consumption. Cessation of cassava intake and vitamin supplementation resulted in partial recovery of visual function. As thiocyanate levels in urine were not measured, the aetiology in these patients is not definitively confirmed, but chronic cassava consumption should be considered in similar cases as a rare cause of potentially reversible optic neuropathy.

A differential loss of nerve fiber layer thickness and retinal ganglion cell complex in toxic and nutritional optic neuropathy

“…We also published 2 cases of toxic optic neuropathy due to cassava consumption in a couple in 2018. 8 Similar to those two patients, the patients presented here were all found to have a decline in visual acuity and color vision, with central or ceco-central scotomas. Most notably however, all patients demonstrated diffuse loss of the retinal ganglion cell complex with only minimal loss of the nerve fiber layer.…”