[1] Univ Hosp Birmingham NHS Trust, Queen Elizabeth Hosp, Dept Otolaryngol, Birmingham, W Midlands, England
[2] Univ Hosp Birmingham NHS Trust, Queen Elizabeth Hosp, Dept Ophthalmol, Birmingham Neuroophthalmol Unit, Birmingham, W Midlands, England
[3] Univ Hosp Birmingham NHS Trust, Queen Elizabeth Hosp, Dept Pathol, Birmingham, W Midlands, England
[4] Univ Hosp Coventry NHS Trust, Dept Ophthalmol, Coventry, W Midlands, England
[5] Univ Hosp Warwickshire NHS Trust, Dept Ophthalmol, Coventry, W Midlands, England