how is sleep affected in the blind? (version 1)
Research type
Research Study
Full title
How is sleep affected in the blind: how does eye disease affect the architecture of sleep
IRAS ID
271166
Contact name
Vincent Walsh
Contact email
Sponsor organisation
University College London (UCL)
Clinicaltrials.gov Identifier
Z6364106/2020/08/80, UCL Data Protection Registration number
Duration of Study in the UK
2 years, 2 months, 1 days
Research summary
This project aims to investigate the link between eye disease and sleep disturbances. Because sleep is critical for our mental and physical health, sleep disruption is detrimental to well-being in the blind and visually impaired. Evidence suggests that sleep disturbances in the blind are linked to damage to a class of cells called intrinsically photosensitive retinal ganglion cells (ipRGC), which detect changes in ambient light and pass this information to the master clock in the brain. Damage to these cells prevents accurate information about day and night getting to the clock. As a result, sleep is disrupted because it's the onset and offset of sleep timing that is set by the body clock. We hypothesise that sleep dysfunction will be more prevalent in those with eye diseases where the ipRGC's are damaged e.g. Glaucoma, than in those with eye diseases in which ipRGC's remain intact e.g. Retinitis Pigmentosa.
In addition to the main research question, we will measure how the COVID-19 associated lockdowns have been affecting sleep. Humans are extremely sensitive to changes in circadian timing, especially if there is a lack of daylight exposure or a change to sleep-wake regimes.Sleep disruption during the lockdown has been Widely reported and It is unclear if this affects different populations disproportionately, e.g., in the blind. To test this we will administer the Pittsburgh sleep quality index (PSQI), a highly validated, retrospective self-report questionnaire that assesses sleep quality.
During the course of the study, participants will first be identified by primary care givers at Moorfields Eye Hospital (MEH) and Guys and St Thomas's foundation Trust (GST). During a normal eye health check-up, a measurement of the population of IpRGC in the retina is taken and, if a participant meets the inclusion criteria, they will be invited to talk to a member of the research team. After seeking informed consent, The participants will be required to answer a series of questionnaires including the retrospective sleep quality questionnaire to assess how sleep may have changed because of COVID-19 related lockdown conditions. We will only ask whether sleep has changed in the last six months and no other medical information related to COVID-19. The primary care team will be notified of a participants involvement in the study and then an estimation of the damage to ipRGC in the blind participants will be attributed an anonymized participant I.D code and shared with the research team. The Blind participants will then be matched to sighted controls. All participants will be given a sleep headset, which records electrical brain activity, to wear for 2 weeks while they sleep at home. The headsets are not medical devices, they are standard recording equipment commonly used in home-based sleep research. They will also be asked to wear a wrist device (acti-watch), which records daily light exposure and activity, continuously during this time. The acti-watches are not medical devices, they are standard recording devices used to record periods of rest and activity that have been used for many decades in sleep research. We will use statistical and machine learning techniques such as Hidden Markov models (HMM’s), on the data to determine the link between eye damage, light exposure and sleep-circadian dysfunction. Hmm’s are a common machine learning approach in sleep research and the algorithms have been developed by the research team in free open programming languages python and R. At the end of each individual trial, the participant will receive a non-clinical sleep report that may inform behavioural change to improve sleep quality. For example, we may suggest regulating sleep and wake times to help stabilise circadian rhythms and therefore improve sleep. This work will inform chrono-medicine interventions for chronic sleep-circadian dysfunction in the visually impaired by informing pre-emptive interventions in high-risk groups such as those with eye diseases such as glaucoma who will likely develop sleep problems as the severity of the disease progresses.
REC name
London - Central Research Ethics Committee
REC reference
22/PR/0236
Date of REC Opinion
19 Apr 2022
REC opinion
Further Information Favourable Opinion