Observational cohort study of 100 patients presenting with functional visual loss: clinical characteristics and comparison with other functional neurologic disorders

Mitchell Lawlor; Brandon Huynh; Kate Humphreys; Lola Ogunbowale; Michael D Kopelman; Gordon Terence Plant

doi:10.1016/j.jcjo.2024.02.018

Observational cohort study of 100 patients presenting with functional visual loss: clinical characteristics and comparison with other functional neurologic disorders

Can J Ophthalmol. 2024 Apr 2:S0008-4182(24)00063-2. doi: 10.1016/j.jcjo.2024.02.018. Online ahead of print.

Authors

Mitchell Lawlor¹, Brandon Huynh², Kate Humphreys³, Lola Ogunbowale⁴, Michael D Kopelman⁵, Gordon Terence Plant⁶

Affiliations

¹ Save Sight Institute, Sydney, Australia; Faculty of Medicine and Health, University of Sydney, Sydney, Australia; Department of Ophthalmology, Sydney Eye Hospital, Sydney, Australia.
² Department of Ophthalmology, Sydney Eye Hospital, Sydney, Australia. Electronic address: b.huynh@live.com.
³ Cleveland Clinic London Hospital, London, United Kingdom; Department of Neuropsychiatry and Memory Disorders, St. Thomas Hospital, London, United Kingdom.
⁴ Department of Neuro-Ophthalmology, Moorfields Eye Hospital, London, United Kingdom.
⁵ Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, United Kingdom.
⁶ Department of Brain Repair and Rehabilitation, University College London, London, United Kingdom.

PMID: 38580217
DOI: 10.1016/j.jcjo.2024.02.018

Abstract

Objective: Recent research has helped to develop a more detailed understanding of many functional neurologic disorders. The aim of this study was to increase our knowledge of functional visual loss and to compare the findings with those of other functional syndromes.

Design: Prospective and retrospective observational cohort study.

Methods: This study took place at neuro-ophthalmology clinics at 3 major hospitals in London, United Kingdom, over a 12-month period. The study population consisted of 157 participants, 100 with functional visual loss, 21 pathologic control subjects with organic visual loss, and 36 healthy nonpathologic control subjects. All participants had their diagnosis confirmed with a full neuro-ophthalmic examination, neuroimaging, and visual electrophysiology. A full assessment of all participants' medical history was obtained from their general practitioner, and all participants completed a series of questionnaires assessing relevant associations.

Results: Data were obtained on 157 participants, 100 with functional visual loss, 21 pathologic control subjects with organic visual loss, and 36 healthy nonpathologic control subjects. Participants with functional visual loss were typically female (74%) with a mean age at vision loss of 40.0 ± 16 years. Sixty-four percent of participants had bilateral vision loss; the remainder, unilateral loss. Twenty-six percent of the total cohort had organic visual loss with functional overlay. Fifty percent of participants with functional visual loss had a preexisting psychiatric diagnosis, the most common being a depressive disorder. Sixty-two percent of participants had an ocular history, and 87% had a previously diagnosed medical illness, most commonly neurologic (45%). Thirty-five percent of participants self-reported at least 1 additional functional symptom.

Conclusions: Our population of functional visual loss subjects shares many similarities with the majority of patients with other functional neurologic disorders. They are generally young and female and have a greater than expected rate of psychiatric, medical, and coexisting ocular conditions. We found increased rates of precipitating stressors, clinical depression, and organic eye problems in subjects with functional visual loss.