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Maria A Parker, Andreas Lauer, Tim Stout, Mark E Pennesi, Paul Yang, David J Wilson, Dongseok Choi, Laura R Erker, Brandon J Lujan, Ou Tan, Pierre-Olivier Barale, Caroline Cohen, Saddek Mohand-Said, Isabelle S Audo, Jose A. Sahel, Richard G Weleber; Test-Retest Variability of Functional and Structural Parameters in patients with Usher Syndrome Type-1B (USH1B). Invest. Ophthalmol. Vis. Sci. 2018;59(9):3896.
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© ARVO (1962-2015); The Authors (2016-present)
The goal of this analysis is to determine the test re-test variability of functional and structural measures from a cohort of patients with advanced forms of retinitis pigmentosa (RP) secondary to USH1B.
Nine participants aged 22-56 years diagnosed with RP caused by MY07A mutation were enrolled in the SAR421869 (NCT01505062) gene therapy clinical trial and screened over three visits within three weeks or less. Functional visual evaluations included: best corrected visual acuity (BCVA) ETDRS letter score, kinetic perimetry (KP) isopter area (I4e, III4e, V4e, and VI4e); and central 30-degree static perimetry (SP) using a 185-loci grid (size V) and a 111-loci grid (size VI) with volumetric endpoints from hill of vision modeling (VFMA). Retinal structural changes were assessed by spectral domain optical coherence tomography (SD-OCT) and included central macular thickness (CMT), macular volume (MV) and ellipsoid zone (EZ) area. Repeatability coefficients (RC) and 95% confidence intervals (CI) were calculated for each parameter by using hierarchical mixed-effects model and bootstrapping.
The criteria for statistically significant changes were the following: BCVA (11 letter score); KP 19.29 (I4e), 90.78 (III4e), 190.37 (V4e) and 141.88 (VI4e) dg2; 30 degree HOV 0.64 (size V) and 1 (size VI) dB-sr; CMT, MV and EZ-area (22.65 μm, 0.11 mm3 and 0.14 mm2 respectively). The RCs and associated CIs are summarized in Table 1.
Test-retest variability repeatability coefficients will serve as a reference in determining whether measured changes in structural and functional outcomes are truly due to disease progression. Moreover, this information will serve to assess efficacy and safety in treatment trials involving patients with Usher Syndrome Type-1B.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
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