Population study is required to confirm results

EDITOR,--Cherry F Radford and colleagues' highly publicised paper concerning possible risk factors for acanthamoeba keratitis in contact lens users contains some potentially misleading comments.1 Their extrapolation of limited data into sweeping generalisations seems unhelpful in providing a rational approach to understanding of the multiplicity of factors associated with acquisition of this rare but potentially sight threatening condition. Frequent replacement of storage cases will not alone prevent acanthamoebal growth and replication if chlorine based disinfection is used, since these products do not generate sufficient active …