title: Visual Function and Central Retinal Structure in Choroideremia.
abstract: To define the clinical phenotype of a cohort of patients affected with choroideremia.
  
  
  
  A retrospective study of patients with choroideremia included two centers. Data collected included age, visual acuity, refractive error, color vision, kinetic perimetry, optical coherence tomography (OCT), and genotype information.
  
  
  
  Sixty male participants were recruited. Genotype information was available for 58 cases, and nonsense mutations were most commonly observed. Eight novel mutations were identified including a missense mutation. The mean age at the first visit was 30.1 years (range, 5-65 years) and thirty-seven patients (61%) had more than one visit with a mean follow-up period of 10.3 years (range, 1-23 years). Visual acuity was not associated with age for patients younger than 30 years (P = 0.46) but significantly associated with age for the age group above 30 years (P < 0.0001). Central retinal thickness was significantly associated with visual acuity (P = 0.03) and with age (P = 0.0014). The extent of visual field documented by kinetic perimetry showed a negative correlation with age to tested stimuli; the smallest target used (I-4e) showed the earliest and most rapid deterioration below the age of 20 years (P = 0.0032). Color vision was abnormal in 46.7% of cases (mean age, 36.3 years; range, 18-61 years), which was associated with older age (P = 0.0039). Central OCT images were abnormal in all cases, as early as age 10 years. Outer retinal tubulations were observed in all but five patients. No genotype-phenotype correlation was observed.
  
  
  
  This comprehensive structural and functional characterization of a large cohort of patients with molecularly confirmed choroideremia indicates that certain parameters are not changing significantly with time while others are. The latter warrants a prospective natural history study, ultimately to be considered as outcome measures for interventional clinical trials.
authors.affiliation: Department of Ophthalmology and Vision Sciences The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada 2Program of Genetics and Genomic Biology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Elise
authors.initials: E
authors.lastname: Heon
authors.affiliation: Department of Ophthalmology and Vision Sciences The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Talal
authors.initials: T
authors.lastname: Alabduljalil
authors.affiliation: Department of Ophthalmology, Scheie Eye Institute, Perlman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States.
authors.forename: David B
authors.initials: DB
authors.lastname: McGuigan III
authors.affiliation: Department of Ophthalmology, Scheie Eye Institute, Perlman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States.
authors.forename: Artur V
authors.initials: AV
authors.lastname: Cideciyan
authors.affiliation: Program of Genetics and Genomic Biology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shuning
authors.initials: S
authors.lastname: Li
authors.affiliation: Clinical Research Services, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Shiyi
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Scheie Eye Institute, Perlman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States.
authors.forename: Samuel G
authors.initials: SG
authors.lastname: Jacobson
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D015794:Choroideremia / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D055253:Color Vision / Q000502:physiology; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005544:Forecasting; D005654:Fundus Oculi; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000473:pathology* / Q000503:physiopathology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity / Q000502:physiology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult