Medically unexplained visual loss in a specialist clinic: a retrospective case-control comparison

To compare the clinical and demographic characteristics of adult patients with nonorganic or medically unexplained visual loss (MUVL) to those with other common conditions presenting to a neuro-ophthalmology clinic.

Case-control design: a retrospective review of medical notes on a consecutive case series of 49 patients assessed at the King's College Hospital neuro-ophthalmology clinic with unexplained visual loss and matched with the next assessed patient identified from clinic records. Patients presented post-symptom onset with a mean clinical course of 30 months (SD=67 months) and standard clinical examination used to confirm diagnoses, alongside ancillary investigations if required.

Seventy-two percent (n=36) of MUVL patients were female. In comparison with patients with organic visual disorders, MUVL cases presented with significantly higher rates of bilateral (cf. unilateral) visual impairment (41%, n=20), premorbid psychiatric (27%, n=13) as well as functional (24%, n=12) diagnoses and psychotropic medication usage (22%, n=11). Medically unexplained cases were significantly more likely to report preceding psychological stress (n=9; 18%).

Medically unexplained visual impairment may be regarded as part of the spectrum of medically unexplained disorders seen in the general hospital setting. Research is needed to determine long-term outcomes and effective tailored interventions.