title: Functional Defects in Color Vision in Patients With Choroideremia.
abstract: OBJECTIVE
  To characterize defects in color vision in patients with choroideremia.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Thirty patients with choroideremia (41 eyes) and 10 age-matched male controls (19 eyes) with visual acuity of ≥6/36 attending outpatient clinics in Oxford Eye Hospital underwent color vision testing with the Farnsworth-Munsell 100 hue test, visual acuity testing, and autofluorescence imaging. To exclude changes caused by degeneration of the fovea, a subgroup of 14 patients with a visual acuity ≥6/6 was analyzed. Calculated color vision total error scores were compared between the groups and related to a range of factors using a random-effects model.
  
  
  RESULTS
  Mean color vision total error scores were 120 (95% confidence interval [CI] 92, 156) in the ≥6/6 choroideremia group, 206 (95% CI 161, 266) in the <6/6 visual acuity choroideremia group, and 47 (95% CI 32, 69) in the control group. Covariate analysis showed a significant difference in color vision total error score between the groups (P < .001 between each group).
  
  
  CONCLUSIONS
  Patients with choroideremia have a functional defect in color vision compared with age-matched controls. The color vision defect deteriorates as the degeneration encroaches on the fovea. The presence of an early functional defect in color vision provides a useful biomarker against which to assess successful gene transfer in gene therapy trials.
authors.affiliation: Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom; Oxford Biomedical Research Centre and Moorfields Eye Hospital-UCL Institute of Ophthalmology NIHR Biomedical Research Centre, London, United Kingdom. Electronic address: enquiries@eye.ox.ac.uk.
authors.forename: Jasleen K
authors.initials: JK
authors.lastname: Jolly
authors.affiliation: Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom; Oxford Biomedical Research Centre and Moorfields Eye Hospital-UCL Institute of Ophthalmology NIHR Biomedical Research Centre, London, United Kingdom.
authors.forename: Markus
authors.initials: M
authors.lastname: Groppe
authors.affiliation: Centre For Statistics In Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Birks
authors.affiliation: Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Downes
authors.affiliation: Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom; Oxford Biomedical Research Centre and Moorfields Eye Hospital-UCL Institute of Ophthalmology NIHR Biomedical Research Centre, London, United Kingdom.
authors.forename: Robert E
authors.initials: RE
authors.lastname: MacLaren
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000328:Adult; D015794:Choroideremia / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D003119:Color Perception Tests; D055253:Color Vision / Q000502:physiology; D003117:Color Vision Defects / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C081787:CHM protein, human