title: Test-Retest Variability of Functional and Structural Parameters in Patients with Stargardt Disease Participating in the SAR422459 Gene Therapy Trial.
abstract: OBJECTIVE
  The goal of this analysis was to determine the test-retest variability of functional and structural measures from a cohort of patients with advanced forms of Stargardt Disease (STGD) participating in the SAR422459 (NCT01367444) gene therapy clinical trial.
  
  
  METHODS
  Twenty-two participants, aged 24 to 66, diagnosed with advanced forms of STGD, with at least one pathogenicABCA4mutation on each chromosome participating in the SAR422459 (NCT01367444) gene therapy clinical trial, were screened over three visits within 3 weeks or less. Functional visual evaluations included: best-corrected visual acuity (BCVA) Early Treatment Diabetic Retinopathy Study (ETDRS) letter score, semiautomated kinetic perimetry (SKP) using isopters I4e, III4e, and V4e, hill of vision (HOV) calculated from static visual fields (SVF) by using a 184n point centrally condensed grid with the stimulus size V test target. Retinal structural changes such as central macular thickness and macular volume were assessed by spectral-domain optical coherence tomography (SD-OCT). Repeatability coefficients (RC) and 95% confidential intervals (CI) were calculated for each parameter using a hierarchical mixed-effects model and bootstrapping.
  
  
  RESULTS
  Criteria for statistically significant changes for various parameters were found to be the following: BCVA letter score (8 letters), SKP isopters I4e, III4e, and V4e (3478.85; 2488.02 and 2622.46 deg2, respectively), SVF full volume HOV (VTOT,14.62 dB-sr), central macular thickness, and macular volume (4.27 μm and 0.15 mm3, respectively).
  
  
  CONCLUSIONS
  This analysis provides important information necessary to determine if significant changes are occurring in structural and functional assessments commonly used to measure disease progression in this cohort of patients with STGD. Moreover, this information is useful for future trials assessing safety and efficacy of treatments in STGD.
  
  
  CONCLUSIONS
  Determination of variability of functional and structural measures in participants with advanced stages of the STGD is necessary to assess efficacy and safety in treatment trials involving STGD patients.
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Parker
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA ; OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Dongseok
authors.initials: D
authors.lastname: Choi
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Laura R
authors.initials: LR
authors.lastname: Erker
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Pennesi
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Yang
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Elvira N
authors.initials: EN
authors.lastname: Chegarnov
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Steinkamp
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Schlechter
authors.affiliation: Univ. Lille, Inserm UMR-S 1172, CHU Lille - Biochemistry and Molecular Biology Department - UF Génopathies -F-59000 Lille, France.
authors.forename: Claire-Marie
authors.initials: CM
authors.lastname: Dhaenens
authors.affiliation: Sorbornne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, Paris, France.
authors.forename: Saddek
authors.initials: S
authors.lastname: Mohand-Said
authors.affiliation: Sorbornne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, Paris, France ; Institute of Ophthalmology, University College of London, London, UK.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Audo
authors.affiliation: Sorbornne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, Paris, France ; Institute of Ophthalmology, University College of London, London, UK ; Fondation Ophtalmologique Adolphe de Rothschild, Paris, France.
authors.forename: Jose
authors.initials: J
authors.lastname: Sahel
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Weleber
authors.affiliation: Oregon Health & Science University, Casey Eye Institute, Portland, OR, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Wilson
keywords: OCT; Stargardt Disease; kinetic perimetry; static perimetry; test variability; visual acuity