Affiliations

• ¹ Department of Health Services Research, University of Liverpool, Liverpool, UK.
• ² Department of Biostatistics, University of Liverpool, Liverpool, UK.
• ³ Clinical Trials Research Unit, University of Liverpool, Liverpool, UK.
• ⁴ School of Health Sciences, University of Nottingham, Nottingham, UK.
• ⁵ Department of Orthoptics, Salford Royal NHS Foundation Trust, Manchester, UK.
• ⁶ Nursing Midwifery and Allied Health Professions Research Unit, Glasgow Caledonian University, Glasgow, UK.
• ⁷ Department of Orthoptics, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
• ⁸ Department of Orthoptics, Oxford University Hospitals NHS Trust, Oxford, UK.
• ⁹ Eye Clinic Impact Team, Royal National Institute for the Blind, Birmingham, UK.
• ¹⁰ Department of Ophthalmology, Aintree University Hospital NHS Foundation Trust, Liverpool, UK.
• ¹¹ Department of Elderly Care, Warrington and Halton Hospitals NHS Foundation Trust, Warrington, UK.
• ¹² Division of Health and Social Care, King's College, London, UK.