In June 1989, the largest recorded outbreak of foodborne botulism occu
rred in the United Kingdom. Twenty-seven patients were affected during
the outbreak with type B botulism. A case note review of 14 patients
admitted with this condition was performed and the neuroophthalmic fin
dings are presented. Patients with severe disease presented with a com
bination of ocular and bulbar symptoms; in mild cases dysphagia was no
ted first and visual disturbance followed within 24 hours. Clustering
of cases and bilaterality of cranial nerve signs aided in the diagnosi
s. Accommodative paresis and sixth cranial nerve palsy were frequent e
arly signs. When there was respiratory paralysis and ventilatory failu
re, it occurred within 12 hours of the onset of a third cranial nerve
palsy.