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.

AB035.The link between cognitive impairment and drusen quantity in age-related macular degeneration

Background:Age-related macular degeneration(AMD)is a common cause of severe vision impairment in populations over 50 years old.It is characterized by drusen;the accumulation of waste between the retinal pigment epithelium and Bruch’s membrane.Drusen have been identified in the eyes of Alzheimer’s patients,post-mortem.Further,beta-amyloid,best known as a pathological component of the senile plaques in Alzheimer’s disease,has been identified as a component of drusen in AMD.Researchers have also demonstrated an increased prevalence of cognitive impairment in individuals with AMD.The current study uses optical coherence tomography(OCT)and a cognitive assessment to investigate the potential use of drusen as a biomarker of cognitive impairment.The overall number of drusen detectable on the OCT scans of individuals who exhibit mild cognitive impairment is compared to the number of drusen detectable on the OCT scans of individuals who do not exhibit mild cognitive impairment.Methods:To date,10 participants(nine women)aged 74 to 95 years with a diagnosis of AMD and/or drusen have been recruited.The Optos®OCT/SLO imaging system was used to take cross-sectional images of the retina.The images were then manually graded by two trained graders to determine the number of drusen present along the retina.The Montreal Cognitive Assessment(MoCA)was used to assess overall cognitive status.Results:Of the 10 participants,three passed the full MoCA(i.e.scored at or above 26 out of 30 possible points)and seven did not pass,scoring positive for mild cognitive impairment(Mpass=27.33,SDpass=0.58;Mfail=21.86,SDfail=2.55).Preliminary analyses have demonstrated that individuals who pass the MoCA seem to have fewer drusen present overall(Mdn=35)compared to those who score positive for cognitive impairment(Mdn=63).However,a Mann-Whitney U test revealed that these findings are not significant;U=5,P=0.27.Conclusions:The results agree with previous literature demonstrating an increased prevalence of mild cognitive impairment in individuals with AMD.The larger average number of drusen found in individuals who score positive for cognitive impairment points to a difference in retinal abnormalities based on cognitive status.Beyond sample size,the insignificance of the difference between groups at this stage can be explained by the number of individuals who failed the MoCA who have wet AMD(n=5).The wet AMD makes grading of drusen on OCT scans more difficult due to scarring and warping of the retina.This could result in an under-representation of the number of drusen.Data collection is still underway,and an accurate depiction is expected with a larger sample size.Researchers have also suggested the importance of peripherally located drusen and its link to cognitive impairment,therefore,future analysis will consider this as well.

AB034. Knowledge and understanding of eye disease among older adults with vision impairment

Background:By 2026,projections indicate that 1/5 Canadians will be over the age of 65.This shift in demographics will be accompanied by an increase in age-related eye disease.Survey studies have reported vision loss as a major medical concern among older adults,but there is little information on older adults’awareness and knowledge of age-related eye diseases.A lack of knowledge can lead to missed or delayed treatment and/or lifestyle modification.This study aims to assess the knowledge and understanding older adults have of their own eye disease and its prognosis.Methods:Participants over the age of 50 with a visual impairment were recruited from the MAB-Mackay Rehabilitation Centre,the Low Vision Self-Help Association(LVSHA)of the West Island and through word of mouth.Visual acuity and contrast sensitivity were measured using the ETDRS charts and Mars Charts,respectively.Optical coherence tomography(OCT)/scanning laser ophthalmoscopy was used to take cross-sectional images of participant retinas.Participants were asked to name their visual diagnoses and describe them in their own words.Participant diagnoses were compared to diagnoses determined by an optometrist or ophthalmologist.Results:To date,this study has recruited 26 participants(7M,19F)over the age of 50 years(range,51-95 years).Many participants(73%)were able to name their visual diagnoses,articulate their symptoms,and discuss their treatment and prognosis.The majority of these individuals(67%)were clients of the MAB-Mackay or participants in the LVSHA.Of the 27%(4M,4F)who were unclear or had misunderstood their diagnoses,half were participants in a low vision support group,but they had multiple visual diagnoses and it was the congenital or trauma-related visual impairments acquired before joining the MAB-Mackay or LVSHA that remained unclear.The other 4 individuals who misunderstood their diagnoses were not involved with any low vision or rehabilitation organizations.Conclusions:Visual impairment is sometimes dismissed as part of aging.A lack of awareness and knowledge can lead to missed or delayed treatment and/or lifestyle modifications.The preliminary results of this study demonstrate the important role organizations like the MAB-Mackay and LVSHA play in education and adaptation to low vision for older adults.Individuals with a better understanding of their own diagnoses are more likely to follow through with doctor-recommendations and have successful treatment or slowed progression.

AB099.Cognitive impairment and age-related macular degeneration:a possible genetic link

Background:The number of older adults affected by age-related macular degeneration(AMD)and early cognitive changes is on the rise.Recent studies have shown a high co-occurrence of these conditions.This,along with shared risk factors and similar histopathology suggests they may share genetic risk factors as well.The goal of this study was to explore the possibility of known AMD SNPs contributing to the co-morbidity.Methods:Participants(AMD and controls)aged 70 years or older with no known neurological or cognitive impairments were recruited for this study.Visual function was evaluated using ETDRS visual acuity,Mars Contrast sensitivity and the scanning laser ophthalmoscope.Cognitive status was measured using the Mini-Mental State Exam(MMSE)and the Montreal Cognitive Assessment(MoCA).Genotyping was conducted using a panel of AMD single nucleotide polymorphisms(SNPs).Analysis was focused on the CFH Y402H and ARMS2 A69S SNPs due their association with drusen and evidence of their association with cognitive impairment.Results:According to the MMSE,two participants from the AMD group(N=21)and none from the control group(N=18)scored positive for cognitive impairment.The MoCA indicated 33.3%of the AMD group and 27.7%of the control group had MCI.There were no significant differences between MoCA scores based on the carrier versus non-carrier status of either the CFH or ARMS SNPs.The SNP in FADS1(rs174547)that was part of the original panel,but not in the analysis,was found in a large number of participants.All those who scored positive for MCI were homozygous carriers of the FADS1 SNP.Conclusions:Although more people from the AMD group scored positive for MCI,scores between groups were significantly different.The AMD and control groups did differ on which cognitive domains they had difficulty with,indicating those with AMD and MCI may be at a higher risk of converting to AD.There were no significant differences on cognitive scores between CFH and ARMS2 SNP carriers and non-carriers.The FADS1 SNP,not originally intended to be part of this study,will be included in future analyses to explore the possibility of a founder effect and a potential link to mild cognitive impairment(MCI).

AB105.Database of retinal images in visually impaired individuals:drusen and age-related macular degeneration(AMD)

Background:With a large portion of older adults living longer,the number of individuals diagnosed with low vision is increasing.The use of optical coherence tomography/scanning laser ophthalmoscope(OCT/SLO)to diagnose retinal disease has become common place in the last 10 years,yet currently there are no OCT/SLO databases for pathological vision.Our aim is to develop a clinical database of individuals who have drusen(i.e.,lipid deposits found under the retina),or have been diagnosed with age-related macular degeneration(AMD),with information as to how the structure of the diseased retina changes over time,as well as measures of visual and cognitive functional performance.Methods:Fundus photographs and retinal scans will be taken using the same model of optos OCT/SLO located in three test sites(MAB-Mackay Rehabilitation Centre,School of Optometry Clinic at the University of Montreal,and the Lighthouse Institute,New York,USA).For each individual entry in the database,demographic and diagnosis information will be available.All OCT/SLO images will be graded according to the Age-related Eye Disease Study standard,in addition to number and size of drusen,severity of geographic atrophy,severity of pigment mottling and presence of choroidal neovascularization.Retinal topography and Raster scans from the OCT/SLO will provide a cross-sectional look at affected retinas.Fixation stability will be recorded using the SLO function,and present four different tasks that are designed to reproduce typical tasks of daily vision,with each task lasting for 10 seconds.The tasks are cross fixation,face recognition,visual search,and reading.These tasks in addition to the retinal scans will be used to determine the eccentricity of a preferred retinal locus from the anatomical fovea,and can be used as an outcome measure for clinical interventions in visually impaired patients.Results:The database will be available to professors training eye-care practitioners and rehabilitation specialists as a teaching tool.Students will be able to familiarize themselves with the retina and a variety of AMD-related pathologies before they start working with patients.The database will also be accessible by researchers interested in studying AMD from basic science to epidemiology,to investigate how drusen and AMD impact visual and cognitive functional performance.Conclusions:The common infrastructure is easily accessible to all VHRN members on request.The database will also be accessible online in 2018(see http://cvl.concordia.ca for more information).