title: The preferred retinal locus in macular disease: toward a consensus definition.
abstract: BACKGROUND
  Eccentric viewing in macular disease has been described for half a century. However, a clear definition of eccentric viewing and preferred retinal locus (PRL) does not exist. Here, we determine how the PRL in macular disease is defined by researchers active in this field and, based on the responses received, propose a standardized definition of the preferred retinal locus.
  
  
  METHODS
  A literature review of articles describing the PRL or eccentric viewing was performed. The first and senior authors of all identified publications were contacted and were asked to define the preferred retinal locus. Themes of responses were identified using inductive qualitative research techniques.
  
  
  RESULTS
  Frequently recurring themes related to the definition of the PRL included 1) it is a retinal area used for fixation, 2) it is task specific, 3) more than one PRL can be used, 4) it is a well-defined region of retina, and 5) the same PRL is used on repeated testing.
  
  
  CONCLUSIONS
  Based on the responses received, a consensus definition of the PRL is proposed. It is suggested that researchers define the PRL carefully in experimental reports and an instrument that images the retina is used to define the location of the PRL.
authors.affiliation: UCL Institute of Ophthalmology, London, United Kingdom. m.crossland@ucl.ac.uk
authors.forename: Michael D
authors.initials: MD
authors.lastname: Crossland
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Engel
authors.forename: Gordon E
authors.initials: GE
authors.lastname: Legge
mesh_terms: D032921:Consensus; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D012160:Retina / Q000503:physiopathology*; D012164:Retinal Diseases / Q000503:physiopathology*; D012607:Scotoma / Q000503:physiopathology*; D009626:Terminology as Topic; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests