Functional vision loss

Abstract

This article discusses the recent advances regarding functional vision loss relevant to the ophthalmologist.

Functional Neurologic Symptom Disorders

“…39,40 Both eyes are involved in up to 65 percent of cases, with decreased acuity and constricted visual fields being the most common complaints. 39,40 Both eyes are involved in up to 65 percent of cases, with decreased acuity and constricted visual fields being the most common complaints.…”

“…Obstacle courses, observation of stereotypies, and optokinetic-drum testing may be employed in cases involving severe visual loss or blindness (as described in detail elsewhere 39 ). These include tests of stereopsis and "fogging" of the unaffected eye in claimed monocular visual loss, tests of tangent screen and coordination for claimed constriction of the visual fields, and binocular perimetry testing in claimed monocular field deficits.…”

Identification of functional visual field loss by automated static perimetry

“…Although long labelled ‘hysterical’, ‘psychogenic’, ‘non‐organic’, or the like, there is little evidence for causal associations with psychological stress or psychiatric disease (Thompson ; Egan ; Lim et al. ; Pula ). The more neutral designation ‘functional’ has found increasing favour and will be used here.…”

Non-organic Vision Loss in the Afghanistan and Iraq Conflicts

“…8 Conversion disorders comprise one or more altered voluntary motor or sensory functions that are not intentionally produced, not explained by other disorders, and are associated with stress or trauma; manifestations include "special sensory symptoms", including visual symptoms.…”

“…[6][7][8][9][10][11] The binocular visual field test proved useful in the evaluation of several of this series' patients complaining of monocular visual field deficits. With a true, organic monocular field loss, the patient's fellow eye will compensate for all or a portion of the defective field from the eye with the complaint on binocular visual field testing.…”