Diagnosis and management of medically unexplained visual loss: One clinician's perspective

First, some comments about terminology. Visual loss without organic basis is variously termed hysterical, malingering, factitious, nonorganic, nonphysiologic, functional, psychogenic, and medically unexplained. I avoid the term hysterical because it has been used specifically as a psychiatric diagnosis and has an implicit gender bias. Malingering imputes motives that are difficult to demonstrate objectively. I reserve factitious for conditions actively cause by the patient, for example corneal injury as the result of the purposeful use of ocular irritants, or by someone else, sometimes called Munchausen by proxy. Nonorganic and nonphysiologic are acceptable terms, but they define by being opposites. Functional is widely used in the neuro-ophthalmic literature but has other meanings and uses, for example functional amblyopia (the reversible component, as opposed to organic amblyopia) or functional disability (loss of a function). In Dorland's Illustrated Medical Dictionary, the definition of “functional” is “affecting the function but not the structure.”