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The Impact of Optic Nerve Disorders on Sleep Wake / SARAH STEVENSON

Swansea University Author: SARAH STEVENSON

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DOI (Published version): 10.23889/SUthesis.65368

Abstract

Background: Sleep is mediated by photic input from photosensitive retinal ganglion cells via the optic nerves which form part of the retinohypothalamic tract to the suprachiasmatic nuclei, which act as an endogenous circadian pacemaker. Previous studies have shown increased circadian dysfunction in...

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Published: Swansea, Wales, UK 2023
Institution: Swansea University
Degree level: Doctoral
Degree name: M.D
Supervisor: John, Ann and Hutchings, Hayley (Swansea University); Downes, Susan M. and Foster, Russell G. (University of Oxford)
URI: https://cronfa.swan.ac.uk/Record/cronfa65368
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Abstract: Background: Sleep is mediated by photic input from photosensitive retinal ganglion cells via the optic nerves which form part of the retinohypothalamic tract to the suprachiasmatic nuclei, which act as an endogenous circadian pacemaker. Previous studies have shown increased circadian dysfunction in ocular disorders and blindness; however, no large-scale studies demonstrating the impact of optic nerve disorders (OND) on sleep have been performed. Hypothesis: It was hypothesised that individuals with OND would have poorer sleep quality and timing than individuals with normal visual function. Aims: The aim of this research was to investigate the nature of the relationship between OND and sleep quality and timing. Methods: A general literature review of the physiology of normal and abnormal human sleep and OND was undertaken. A systematic review of published research specific to sleep in OND was also carried out. An observational study of sleep quality and timing in OND based on the SOMNUS study was conducted. In the prospective component of this study, participants were recruited from ophthalmology clinics and completed standardised questionnaires including the Pittsburgh Sleep Quality Index (PSQI); the Epworth Sleepiness Scale (ESS); The Morningness-Eveningness Questionnaire (MEQ) to evaluate chronotype; the SF-36 Questionnaire to evaluate quality of life (QOL); and the Hospital Anxiety and Depression Scale (HADS) to assess mood. A pool of normally sighted control subjects was also recruited. In the retrospective component, data from patients with autoimmune and demyelinating optic neuropathies was descriptively analysed. Summary of Findings: In the prospective study, 122 participants with OND were compared to 302 control participants. Poor sleep was present in 65.6% of individuals with OND and in 39.7% of controls (p<0.0001). Sleep timing was worse in OND (p=0.02). Daytime sleepiness (ESS), chronotype and anxiety were comparable between groups, but HADS depression score was worse in OND (p=0.04). QOL scores for all parameters except for emotional wellbeing were worse in OND (p<0.05). Data were retrospectively analysed from 34 participants with neuromyelitis optica spectrum disorder, which revealed prevalence of poor sleep in the presence of depression, sphincter dysfunction, pain, psychiatric medication and glucocorticoid use. Conclusions: In the prospective component of this study, participants with OND had poorer sleep quality and timing than those with normal visual function. In the retrospective component, subjects with autoimmune and demyelinating OND had systemic associations which may contribute to poor sleep. This supports the consideration of sleep quality and timing in the holistic management of patients with OND.
Keywords: Optic nerve disorder, neuromyelitis optica spectrum disorder, retinal ganglion cell, sleep wake, sleep quality, sleep timing, circadian rhythm, melatonin, mood, quality of life
College: Faculty of Medicine, Health and Life Sciences
Funders: Wellcome Trust, National Institute for Health Research (NIHR); University of Oxford Sleep and Circadian Neuroscience Institute; NIHR Thames Valley and South Midlands Clinical Research Network Fellowship; Eye Research Group Oxford.

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