Peripheral cone disease.

Peripheral cone disease is characterized by an absent cone function as measured by the ERG but a normal or slightly affected colour vision. The authors examined 20 cases. The most striking fact was the high incidence of myopia and the presence of nystagmus; on the basis of this finding the authors suggest that at least some cases of peripheral cone disease are due to myopic choroido-retinal degeneration (in French: "choroïdose myopique").