title: UK Neovascular Age-Related Macular Degeneration Database. Report 6: time to retreatment after a pause in therapy. Outcomes from 92 976 intravitreal ranibizumab injections.
abstract: OBJECTIVE
  To study the time to retreatment in eyes with neovascular age-related macular degeneration (nAMD) that had been treatment-free for intervals of 3 months, 6 months, 9 months and 12 months during the maintenance phase of ranibizumab therapy within the UK National Health Service.
  
  
  METHODS
  In this multicentre national nAMD database study, structured data were collected from 14 centres (involving 12 951 eyes receiving 92 976 ranibizumab injections). Patients were treated with three fixed, monthly injections in a loading phase of treatment, followed by a pro re nata retreatment regimen in a maintenance phase. Eyes with a treatment-free interval (TFI) of 3 months, 6 months, 9 months or 12 months in the maintenance phase were identified and the time to retreatment after these TFIs was determined.
  
  
  RESULTS
  The time to retreatment for the 20th and 50th centiles was 0.58/2.54 months after a 3-month TFI, 2.07/9.62 months after a 6-month TFI, 3.69/15.84 months after a 9-month TFI and 5.90/22.49 months after a 12-month TFI. Following a TFI of 3 months, 6 months, 9 months and 12 months, 68%, 44%, 31% and 21% of eyes required retreatments after an additional 6 months of follow-up, respectively. Similarly, after 12 months of follow-up, 77%, 56%, 43% and 34% of these eyes required retreatment.
  
  
  CONCLUSIONS
  This study provides times to retreatment in eyes with nAMD that have been treatment-free for intervals of 3-12 months and demonstrates the likelihood of repeat therapy within the next year, even after a TFI of 12 months. These outcomes can help plan appropriate follow-up intervals for patients who have been treatment-free for intervals of up to 12 months.
authors.affiliation: Medical Retina Service, Hull and East Yorkshire Hospitals NHS Trust, Hull, UK.
authors.forename: Krishnappa C
authors.initials: KC
authors.lastname: Madhusudhana
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, University College London, London, UK.|Medical Retina Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.|Department of Ophthalmology, University of Washington, Seattle, Washington, USA.
authors.forename: Aaron Y
authors.initials: AY
authors.lastname: Lee
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, University College London, London, UK.|Medical Retina Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.
authors.forename: Pearse A
authors.identifier: http://orcid.org/0000-0002-9239-745X
authors.initials: PA
authors.lastname: Keane
authors.affiliation: Centre for Vascular & Vision Sciences, Queen's University, Belfast, UK.
authors.forename: Usha
authors.initials: U
authors.lastname: Chakravarthy
authors.affiliation: Medical Retina Service, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham General Hospital, Cheltenham, UK.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Johnston
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, University College London, London, UK.|Medical Retina Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Egan
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, University College London, London, UK.|Medical Retina Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.
authors.forename: Dawn
authors.initials: D
authors.lastname: Sim
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, University College London, London, UK.|Medical Retina Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.|Medical Retina Service, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham General Hospital, Cheltenham, UK.
authors.forename: Javier
authors.initials: J
authors.lastname: Zarranz-Ventura
authors.affiliation: NIHR Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, University College London, London, UK.|Medical Retina Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.
authors.forename: Adnan
authors.initials: A
authors.lastname: Tufail
authors.affiliation: Eye Clinic, St James's University Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: McKibbin
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D058449:Intravitreal Injections; D008268:Macular Degeneration / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D000069579:Ranibizumab / Q000008:administration & dosage*; D015861:Retinal Neovascularization / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D019233:Retreatment; D012189:Retrospective Studies; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014792:Visual Acuity
chemical_list: D020533:Angiogenesis Inhibitors; D042461:Vascular Endothelial Growth Factor A; D000069579:Ranibizumab
keywords: Degeneration; Macula; Neovascularisation; Retina; Treatment Medical