AB033.The impact of visual impairment on the Montreal Cognitive Assessment

Background:Cognitive assessments,such as the Montreal Cognitive Assessment(MoCA),use components that assume intact sensory abilities,however,adults show concomitant decreases in visual acuity with increasing age.Scores on cognitive assessments are typically lower for individuals with visual impairments compared to individuals with normal/corrected to normal vision.But it is not clear if lowers scores on cognitive assessments are due to the assessments relying on visual stimuli,or if individuals with visual impairments are actually more likely to have cognitive impairments.Therefore we simulated visual impairments,i.e.,reduced visual acuity and contrast sensitivity,in young healthy adults to determine how this impacts their scores on a measure of cognitive ability,i.e.,the MoCA.Methods:Participants(n=19)completed one of the three version of the MoCA under three conditions(20/20,simulated 20/80,simulated 20/200).The MoCA was administered following the clinical protocols.Only participants that scored>26(i.e.,normal cognitive function)at 20/20 were included in the analysis.For comparison,we included MoCA data from a sample of older adults with normal vision(n=19,Mage=74,Acuity M=0.04 logMAR,SD=0.16)or visual impairment(n=19,Mage=79,Acuity M=0.35 logMAR,SD=0.3).Results:Acuity of participants at 20/20(M=0.06 LogMAR,SD=0.1),simulated 20/80(M=0.63,SD=0.18)and simulated 20/200(M=0.88,SD=0.19)showed that the participants experienced simulated acuity loss with the goggles.For the MoCA scores,we found a main effect of acuity(F=16.22,P<0.001,η2=0.375,BF10=5,618).Planned post hoc comparisons showed a significant difference between scores with a 20/20 acuity(M=27.26,SD=0.93)and 20/80(M=24.74,SD=1.66,t=5.62,ptukey<0.001,d=1.88),and between 20/20 and 20/200(M=25.63,SD=1.46,t=3.63,ptukey=0.002,Cohen’s d=1.33).However,no difference was observed between 20/80 and 20/200(t=−1.99,ptukey=0.125,d=0.572).The MoCA scores in older adults with normal vision(M=27.32,SD=2.41)and with visual impairment(M=26.68,SD=2.52),did not differ significantly(t36=−0.787,P=0.436,d=0.26,BF10=0.4).Conclusions:Our findings show that simulated reductions in visual acuity and contrast sensitivity lead to lower scores on measures of cognitive ability,specifically the MoCA.However,it appears that older adults with actual visual impairments may have developed compensatory strategies to adapt to this loss in visual acuity as there were no significant differences in scores of older adults with and without visual impairments.Therefore,we would recommend that when assessing an individual with visual impairments to conduct the cognitive test by re-scoring it without the visual components,e.g.,the MoCA Blind,to magnify the visual components,or to substitue the visual component when possible using auditory alternatives,e.g.,the oral trail making task.

AB104.Validation of the international reading speed texts in a Canadian sample

Background:The International Reading Speed Texts(IReST)were developed in Europe as a standardized measure to assess continuous reading in normally sighted and visually impaired individuals.The IReST is used throughout the United States and Canada to assess reading speed;however,the normative values may not be valid in North America(NA).Additionally there are no normative values for individuals with visual impairments.The aim of this study was to validate the IReSTs in a normally sighted English-speaking NA sample with and without a simulated reduction in visual acuity.Methods:Fifty undergraduate students from Concordia University participated in this study.Participants were systematically assigned to a counterbalanced order of testing conditions and were asked to read all 10 IReSTs aloud.The normal and impaired vision conditions were counterbalanced such that the first set of five IReSTs were read with either the participants normal/corrected-to-normal vision or with a simulated 20/80 visual impairment.Results:Multiple two-sample dependent t-tests using a Holm-Bonferroni correction for multiple comparisons were used to compare the IReST values(means and standard deviations)to the current sample;the results showed statistically significant differences between the current samples mean reading speed and the values provided by the IReSTs.In all cases,P were equal to or less than 0.005.Mean difference scores ranged from 14.87 to 30.05 wpm,with 95%confidence intervals ranging from 4.82 to 43.32.Measures of effect size using bias corrected Hedge’s g*ranged from 0.83 to 1.32,with 95%confidence intervals ranging from 0.25 to 1.93.Multiple two-sample dependent t-tests using a Holm-Bonferroni correction for multiple comparisons were used to compare the mean reading speed in wpm of the normal and impaired vision conditions;the results showed statistically significant differences between the mean reading speeds of the normal vision condition and the simulated impairment condition on the IReSTs.In all cases,the P were less than 0.001.Mean difference scores ranged from 25.44 to 41.8 wpm,with 95%confidence intervals ranging from 21.66 to 46.Measures of effect size using bias corrected Hedge’s g*ranged from 2.74 to 3.81,with 95%confidence intervals ranging from 1.97 to 4.74.Further Bayesian analyses revealed BF10 factors ranging from 1.277×107 to 7.334×1011,indicating decisive evidence for the research.Conclusions:There are statistically significant differences in reading speed between the NA English sample and the normative values established by the IReST;such that reading speeds of the NA English sample are slower than the normative values of the IReST.Additionally,participants in the simulated impairment condition read the IReSTs significantly slower than the normal vision condition.