title: A multicentre phase III randomised controlled single-masked clinical trial evaluating the clinical efficacy and safety of light-masks at preventing dark-adaptation in the treatment of early diabetic macular oedema (CLEOPATRA): study protocol for a randomised controlled trial.
abstract: BACKGROUND
  This study will evaluate hypoxia, as a novel concept in the pathogenesis of diabetic macular oedema (DMO). As the oxygen demand of the eye is maximum during dark-adaptation, we hypothesize that wearing light-masks during sleep will cause regression and prevent the development and progression of DMO. The study protocol comprises both an efficacy and mechanistic evaluation to test this hypothesis.
  
  
  METHODS
  This is a phase III randomised controlled single-masked multicentre clinical trial to test the clinical efficacy of light-masks at preventing dark-adaptation in the treatment of non-central DMO. Three hundred patients with non-centre-involving DMO in at least one eye will be randomised 1:1 to light-masks and control masks (with no light) to be used during sleep at night for a period of 24 months. The primary outcome is regression of non-central oedema by assessing change in the zone of maximal retinal thickness at baseline on optical coherence tomography (SD-OCT). Secondary outcomes will evaluate the prevention of development and progression of DMO by assessing changes in retinal thickness in different regions of the macula, macular volume, refracted visual acuity and level of retinopathy. Safety parameters will include sleep disturbance. Adverse events and measures of compliance will be assessed over 24 months. Participants recruited to the mechanistic sub-study will have additional retinal oximetry, multifocal electroretinography (ERG) and microperimetry to evaluate the role of hypoxia by assessing and comparing changes induced by supplemental oxygen and the light-masks at 12 months.
  
  
  CONCLUSIONS
  The outcomes of this study will provide insight into the pathogenesis of DMO and provide evidence on whether a simple, non-invasive device in the form of a light-mask can help prevent the progression to centre-involving DMO and visual impairment in people with diabetes.
authors.affiliation: NIHR Moorfields Biomedical Research Centre, 162, City Road, London EC1V 2PD, England. senswathi@aol.com.
authors.forename: Sobha
authors.initials: S
authors.lastname: Sivaprasad
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Arden
authors.forename: A Toby
authors.initials: AT
authors.lastname: Prevost
authors.forename: Roxanne
authors.initials: R
authors.lastname: Crosby-Nwaobi
authors.forename: Helen
authors.initials: H
authors.lastname: Holmes
authors.forename: Joanna
authors.initials: J
authors.lastname: Kelly
authors.forename: Caroline
authors.initials: C
authors.lastname: Murphy
authors.forename: Gary
authors.initials: G
authors.lastname: Rubin
authors.forename: Joanna
authors.initials: J
authors.lastname: Vasconcelos
authors.forename: Philip
authors.initials: P
authors.lastname: Hykin
mesh_terms: D002985:Clinical Protocols; D003623:Dark Adaptation; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D004596:Electroretinography; D004739:England; D004867:Equipment Design; D006801:Humans; D008269:Macular Edema / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D008397:Masks; D010092:Oximetry; D010101:Oxygen Consumption; D010789:Phototherapy / Q000009:adverse effects / Q000295:instrumentation*; D011237:Predictive Value of Tests; D012107:Research Design; D016037:Single-Blind Method; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity; D058609:Visual Field Tests; D014852:Wales