title: A Qualitative and Quantitative Assessment of Fundus Autofluorescence Patterns in Patients With Choroideremia.
abstract: OBJECTIVE
  We set out to characterize the pattern of fundus autofluorescence (AF) loss in choroideremia (CHM) patients of varying ages and disease severity in order to determine the average rate of progression of this potential disease biomarker.
  
  
  METHODS
  Fifty consecutive CHM patients (100 eyes) attending outpatient clinics at Oxford Eye Hospital underwent analysis with the Heidelberg OCT Spectralis with autofluorescence capabilities. The area of residual AF was traced using Heidelberg Eye Explorer. Bland-Altman analysis was used to calculate the coefficient of repeatability (CR). The degree of AF loss was correlated to different ages and the pattern of residual AF constructed into color-coded maps in order to gain insight into the mechanism of disease progression.
  
  
  RESULTS
  The CR for measurement of AF area is <1%, indicating that a small change is likely to be significant. Correlation of patient age and area of residual AF produced a clinically relevant index of expected anatomic disease. Progression is 7.7% of the residual area each year (95% confidence intervals 7.0%-8.2%) and follows a logarithmic pattern with age (r = 0.95, P < 0.001). From this we derived the mean half-life of AF as 9 years. Qualitatively, the pattern of remaining AF centered on a point temporal to the fovea.
  
  
  CONCLUSIONS
  The area of residual AF in CHM can be measured reproducibly and shows a distinct pattern of loss. The measured residual area is inversely correlated to age. The ratio of the two variables may provide useful information regarding the rate of progression for any one individual at a given point in time.
authors.affiliation: Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford Biomedical Research Centre, Oxford, United Kingdom 2Oxford Eye Hospital, John Radcliffe Hospital, Oxford, United Kingdom 3Moorfields Eye Hospital-UCL Institute of Ophthalmology, National Institute for Health Research Biomedical Research Centre, London, United Kingdom.
authors.forename: Jasleen K
authors.initials: JK
authors.lastname: Jolly
authors.affiliation: Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford Biomedical Research Centre, Oxford, United Kingdom 2Oxford Eye Hospital, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Edwards
authors.affiliation: LightPear, Oxfordshire, United Kingdom.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Moules
authors.affiliation: Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford Biomedical Research Centre, Oxford, United Kingdom.
authors.forename: Markus
authors.initials: M
authors.lastname: Groppe
authors.affiliation: Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford Biomedical Research Centre, Oxford, United Kingdom 2Oxford Eye Hospital, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Downes
authors.affiliation: Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford Biomedical Research Centre, Oxford, United Kingdom 2Oxford Eye Hospital, John Radcliffe Hospital, Oxford, United Kingdom 3Moorfields Eye Hospital-UCL Institute of Ophthalmology, National Institute for Health Research Biomedical Research Centre, London, United Kingdom.
authors.forename: Robert E
authors.initials: RE
authors.lastname: MacLaren
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015794:Choroideremia / Q000175:diagnosis*; D018450:Disease Progression; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D005453:Fluorescence; D005584:Fovea Centralis / Q000000981:diagnostic imaging*; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D055815:Young Adult