[1] UCL, Ctr Nanotechnol & Regenerat Med, Div Surg & Intervent Sci, London, England
[2] UCL, London Ctr Nanotechnol, London, England
[3] Royal Free Hampstead NHS Trust Hosp, London, England
[4] Univ Zurich Hosp, Dept Ophthalmol, CH-8091 Zurich, Switzerland