摘要
Objective: To evaluate concurrent and predictive validity for low-contrast le tter acuity (L-CLA) testing as a candidate visual component for the Multiple Sc lerosis Functional Composite (MSFC). Methods: L-CLA testing was conducted in tw o MS patient cohorts. In the MSFC Validation Study, 137 participants from a Phas e III trial of inteferon beta-1a (Avonex) for relapsing-remitting MS were foll owed. A second cohort included 65 patients with secondary progressive MS who par ticipated in a substudy of the International MS Secondary Progressive Avonex Con trolled Trial (IMPACT). The total number of letters read correctly at four contr ast levels (100, 5, 1.25, and 0.6%) was correlated with Expanded Disability Sta tus Scale (EDSS), MSFC, Sickness Impact Profile, Multiple Sclerosis Quality of L ife Inventory, and brain parenchymal fraction (BPF), as determined by MRI. Resul ts: Low-and high-contrast letter acuity scores correlated with BPF at follow- up in the MSFC Validation Study (5%: r=0.40, p < 0.0001; 100%: r=0.31, p=0.000 2). L-CLA also correlated with EDSS (5%: r=-0.35, p < 0.0001; 1.25%: r=-0.2 6, p=0.0003) and MSFC (5%: r=0.47, p < 0.0001; 1.25%: r=0.45, p < 0.0001). In the IMPACT Substudy, change in L-CLA scores from baseline to year 1 predicted s ubsequent change in the EDSS from year 1 to 2 at the 5%(p=0.0142) and the 1.25 %(p=0.0038) contrast levels, after adjusting for change in MSFC scores from bas eline to year 1. Conclusions: Low-contrast letter acuity (L-CLA) scores demons trate concurrent and predictive validity in patients with relapsing-remitting a nd secondary progressive multiple sclerosis (MS). L-CLA testing provides additi onal information relevant to the MS disease process that is not entirely capture d by the Multiple Sclerosis Functional Composite.
Objective: To evaluate concurrent and predictive validity for low-contrast le tter acuity (L-CLA) testing as a candidate visual component for the Multiple Sc lerosis Functional Composite (MSFC). Methods: L-CLA testing was conducted in tw o MS patient cohorts. In the MSFC Validation Study, 137 participants from a Phas e III trial of inteferon beta-1a (Avonex) for relapsing-remitting MS were foll owed. A second cohort included 65 patients with secondary progressive MS who par ticipated in a substudy of the International MS Secondary Progressive Avonex Con trolled Trial (IMPACT). The total number of letters read correctly at four contr ast levels (100, 5, 1.25, and 0.6%) was correlated with Expanded Disability Sta tus Scale (EDSS), MSFC, Sickness Impact Profile, Multiple Sclerosis Quality of L ife Inventory, and brain parenchymal fraction (BPF), as determined by MRI. Resul ts: Low-and high-contrast letter acuity scores correlated with BPF at follow- up in the MSFC Validation Study (5%: r=0.40, p < 0.0001; 100%: r=0.31, p=0.000 2). L-CLA also correlated with EDSS (5%: r=-0.35, p < 0.0001; 1.25%: r=-0.2 6, p=0.0003) and MSFC (5%: r=0.47, p < 0.0001; 1.25%: r=0.45, p < 0.0001). In the IMPACT Substudy, change in L-CLA scores from baseline to year 1 predicted s ubsequent change in the EDSS from year 1 to 2 at the 5%(p=0.0142) and the 1.25 %(p=0.0038) contrast levels, after adjusting for change in MSFC scores from bas eline to year 1. Conclusions: Low-contrast letter acuity (L-CLA) scores demons trate concurrent and predictive validity in patients with relapsing-remitting a nd secondary progressive multiple sclerosis (MS). L-CLA testing provides additi onal information relevant to the MS disease process that is not entirely capture d by the Multiple Sclerosis Functional Composite.
