Functional visual loss: I. A true psuchiatric disorder?

Abstract

SYNOPSISA review of the literature describing patients with functional visual loss reveals that a significant proportion of them do not manifest psychiatric disease as defined by current nomenclature. Apparently, these individuals are highly suggestible and do not necessarily have psychological pathology. The ramifications of this finding are discussed.

Medically unexplained visual loss in adult patients

“…In common with other authors, we have found that at least 60% of our patients do not appear to have any psychiatric morbidity that might account for their symptoms. 16 This does not fit with the conversion or hysterical model of unexplained medical symptoms. We may have underestimated the prevalence of psychiatric morbidity as our criterion was whether the patients were receiving or had received anxiolytics or psychotropic medication or had been under the care of a psychiatrist in the recent past.…”

“…16,17 Evidence of suggestibility can sometimes be seen on examination. For example, by suggesting that the earlier plates of the Ishihara pseudoisochromatic test were more difficult than the later plates, three patients could be induced to read the last six plates correctly but not the first contrast plate.…”

Psychogenic Blindness: A Rare Presentation

“…8 Of 42 patients with psychogenic or feigned visual complaints assessed by a psychiatrist in the series reported by Kathol et al, 22 (52%) were found to have psychiatric syndromes. 9 In the above mentioned case a comorbid moderate depressive episode with panic attacks were found , which definitely required psychiatric intervention for symptom relief. However the findings of one case cannot be generalized to all cases of NOVL/Psychogenic blindness.…”

“…However, the cornerstone of management for psychogenic or feigned visual complaints remains reassurance by a concerned physician that there is no brain or eye disease. 7 The natural history of non-organic visual loss should be explained and the expectation of complete visual recovery should be expressed. Use of placebo treatments such as eye drops, orthoptic exercises or spectacles are not recommended as they will only serve to undermine the reassurance.…”

“…Use of placebo treatments such as eye drops, orthoptic exercises or spectacles are not recommended as they will only serve to undermine the reassurance. 7 To the contrary some authors believe that offering an eyeglass with lenses having negligible optical strength allows patients to extract themselves from psychogenic blindness without embarrassment. 8 Terms such as 'pretending' should be avoided, and punitive measures should be actively discouraged.…”