Impaired Contrast Sensitivity Research Articles

Hazard warning modalities and timing thresholds for older drivers with impaired vision

PurposeWe examined collision warning systems with different modalities and timing thresholds, assessing their impact on responses to pedestrian hazards by drivers with impaired contrast sensitivity (ICS). MethodsSeventeen ICS (70–84 y, median CS 1.35 log units) and 17 normal vision (NV: 68–73 y, median CS 1.95) participants completed 6 city drives in a simulator with 3 bimodal warnings: visual-auditory, visual-directional-tactile, and visual-non-directional-tactile. Each modality had one drive with early and one with late warnings, triggered at 3.5 s and 2 s time-to-collision, respectively. ResultsICS participants triggered more early (43 vs 37 %) and late warnings (12 vs 6 %) than NV participants and had more collisions (3 vs 0 %). Early warnings reduced time to fixate hazards (late 1.9 vs early 1.2 s, p < 0.001), brake response times (2.8 vs 1.8 s, p < 0.001) and collision rates (1.2 vs 0.02 %). With late warnings, ICS participants took 0.7 s longer to brake than NV (p < 0.001) and had an 11 % collision rate (vs 0.7 % with early warnings). Non-directional-tactile warnings yielded the lowest collision rates for ICS participants (4 vs auditory 12 vs directional-tactile 15.2 %) in late warning scenarios. All ICS participants preferred early warnings. ConclusionsWhile early warnings improved hazard responses and reduced collisions for ICS participants, late warnings did not, resulting in high collision rates. In contrast, both early and late warnings were helpful for NV drivers. Non-directional-tactile warnings were the most effective in reducing collisions. The findings provide insights relevant to the development of hazard warnings tailored for drivers with impaired vision.

Association between vision impairment and increased prevalence of falls in older US adults.

Vision impairment (VI) is associated with falls in older adults. However, past studies have relied on geographically constrained samples with limited generalizability or self-reports of visual difficulty. To date, there have not been nationally representative studies on the association of objective measures of visual function and falls outcomes. We used cross-sectional data from Round 11 of National Health and Aging Trends Study (NHATS), a nationally representative panel study of age-eligible Medicare beneficiaries (N = 2951). We performed Poisson regression to calculate the prevalence and prevalence ratio (PR) of >1 fall in the past year, any fall in the past month, fear of falling (FoF), and activity limitation due to FoF as a function of distance visual acuity, near visual acuity, and contrast sensitivity. Models were adjusted for demographic and health covariates and were weighted to make nationally representative parameter estimates. The weighted proportion of participants with VI was 27.6% (95% CI, 25.4%-29.9%). Individuals with any VI had a higher prevalence of falls compared with those without VI (18.5% vs. 14.1%, PR = 1.25, 95% CI 1.02-1.53). Specifically, contrast sensitivity impairment was associated with a higher prevalence of recurrent falls (20.8% vs. 14.7%; PR = 1.30, 95% CI 1.01-1.67) and recent falls (17.1% vs. 9.9%; PR = 1.40, 95% CI 1.01-1.94). This relationship existed even independent of near and distance visual acuity. Distance and near visual acuity were not significantly associated with falls. Having any VI was also associated with a higher prevalence of FoF (38.4% vs. 30.5%, PR = 1.17, 95% CI 1.02-1.34). The prevalence of falls is associated with poor contrast sensitivity but not with near or distance visual acuity. Findings suggest greater collaboration between geriatricians and eye care providers may be warranted to assess and address fall risk in older adults with VI.

Limited restoration of contrast sensitivity with training after V1 damage in humans.

Stroke damage to the primary visual cortex (V1) causes severe visual deficits, which benefit from perceptual retraining. However, whereas training with high-contrast stimuli can locally restore orientation and motion direction discrimination abilities at trained locations, it only partially restores luminance contrast sensitivity (CS). Recent work revealed that high-contrast discrimination abilities may be preserved in the blind field of some patients early after stroke. Here, we asked if CS for orientation and direction discrimination is similarly preserved inside the blind field, to what extent, and whether it could benefit from a visual training intervention. Thirteen subacute patients (<3 months post-V1-stroke) and 12 chronic patients (>6 months post-V1-stroke) were pre-tested, then trained to discriminate either orientation or motion direction of Gabor patches of progressively lower contrasts as their performance improved. At baseline, more subacute than chronic participants could correctly discriminate the orientation of high-contrast Gabors in their blind field, but all failed to perform this task at lower contrasts, even when 10Hz flicker or motion direction were added. Training improved CS in a greater portion of subacute than chronic participants, but no-one attained normal CS, even when stimuli contained flicker or motion. We conclude that, unlike the near-complete training-induced restoration of high-contrast orientation and motion direction discrimination abilities, V1 damage in adulthood may severely limit the residual visual system's ability to regain normal CS. Our results support the notion that CS involves different neural substrates and computations than those required for orientation and direction discrimination in V1-damaged visual systems.Significance statement Stroke-induced V1 damage in adult humans induces a rapid and severe impairment of contrast sensitivity for orientation and motion direction discrimination in the affected hemifield, although discrimination of high-contrast stimuli can persist for several months. Adaptive training with Gabor patches of progressively lower contrasts improves contrast sensitivity for both orientation and motion discriminations in the blind-field of subacute (<3 months post-stroke) and chronic (>6 months post-stroke) participants; however, it fails to restore normal contrast sensitivity. Nonetheless, more subacute than chronic stroke participants benefit from such training, particularly when discriminating the orientation of static, non-flickering targets. Thus, contrast sensitivity appears critically dependent on processing within V1, with perceptual training displaying limited potential to fully restore it after V1 damage.

COVID-19 Testing and Vaccination Among US Older Adults with Vision Impairment: The National Health and Aging Trends Study 2021

ABSTRACT Purpose To examine the associations between vision impairment (VI) and COVID-19 testing and vaccination services in older US adults. Methods This cross-sectional study assessed data from adults ≥ 65 years who participated in the National Health and Aging Trends Study (year 2021), a nationally representative sample of Medicare beneficiaries. Exposure: Distance VI (<20/40), near VI (<20/40), contrast sensitivity impairment (CSI) (<1.55 logCS), and any VI (distance, near, or CSI). Outcomes: Self-reported COVID-19 testing and vaccination. Results Of 2,822 older adults, the majority were female (weighted; 55%) and White (82%), and 32% had any VI. In fully-adjusted regression analyses, older adults with any VI had similar COVID-19 vaccination rates to adults without any VI (OR:0.77, 95% CI:0.54–1.09), but had lower odds of COVID-19 testing (OR:0.82, 95% CI:0.68–0.97). Older adults with distance (OR:0.47, 95% CI:0.22–0.99) and near (OR:0.68, 95% CI:0.47–0.99) VI were less likely to be vaccinated for COVID-19, while those with CSI were less likely to test for COVID-19 (OR:0.76, 95% CI:0.61–0.95), as compared to peers without respective impairments. The remaining associations were not significant (p > .05). Conclusions and Relevance These findings highlight inequities in the COVID-19 pandemic response for people with vision disability and emphasize the need for equitable prioritization of accessibility of healthcare services for all Americans.

Assessment of Safety, Efficacy and Predictability of a Trifocal Intraocular Lens. Performance of PanOptix Trifocal Versus Monofocal IOL

Purpose. To evaluate the performance and the visual outcomes of Acrysof PanOptix trifocal IOL in terms of safety, efficacy, predictability and assessment of the quality of vision after implantation as regards; contrast sensitivity and ocular aberrations. Methods. A prospective interventional non randomized study that included forty eyes of twenty one patients with senile cataract. All surgeries were carried out between September 2019 and January 2020. Patients underwent phacoemulsification for cataract removal with IOL implantation. They were divided into two groups; group(A) included twenty eyes of eleven patients who were implanted with AcrySof IQ PanOptix trifocal IOL Model TFNT00. While group (B) included twenty eyes of ten patients who were implanted with monofocal AcrySof IOLs as a control group. Results. There were 21 subjects enrolled in our study. Mean age was 56.6 ± 6.9 years in group (A) and 62.8 ± 7.1 years in group (B),(range 50–70).We found statistical significant difference between both groups with group A showing better post operative uncorrected distance, intermediate, near, and best corrected near visual acuity . Group (B) showed statistically significant better post operative contrast sensitivity compared to group (A). Conclusion: In this study, Acrysof PanOptix trifocal IOL showed excellent safety, efficacy, predictability and spectacle independence at all distances, This prospective interventional non-randomized study showed excellent safety, efficacy and predictability of the PanOptix IOL with higher spectacle independence, slightly impaired contrast sensitivity without affecting daily activities. However, contrast sensitivity was compromised in comparison to the monofocal group and high order aberrations (coma, trefoil) were noted to be higher affecting the quality of vision but not the daily activities of the patient.

NEW MEASURES AND POPULATION PREVALENCE OF VISION IMPAIRMENT IN NHATS

Abstract The National Health and Aging Trends Study (NHATS) is a nationally representative panel study of older U.S. adults that in 2021 (Round 11) added to its annual protocol a suite of objective visual function measures consisting of distance visual acuity, near visual acuity, and contrast sensitivity tests. These measures were developed to approximate clinical gold-standard tests, while allowing for administration on a tablet in participants’ homes. The tests were found to have good agreement with clinical gold-standards based on their limits of agreement, correlations, and lack of systematic bias between tests. In the initial 2021 fielding of the NHATS visual function measures, 27.8% (25.5%-30.1%) of U.S. adults over age 70 had one or more visual impairment (VI) (distance VI: 10.3% [8.9%-11.7%]; near VI: 22.3% [20.3%-24.3%]; contrast sensitivity impairment: 10.0% [8.5%-11.4%]), and the prevalence was highest among those who were older, had less education, lower income, and were of Hispanic ethnicity and non-White race. Additionally, the adjusted prevalence ratio for dementia was significantly higher among those with each type of VI compared to those with normal vision (moderate/severe distance VI=1.72 [1.26-2.35]; any near VI=1.40 [1.16-1.69]-; contrast sensitivity impairment =1.31 [1.04-1.66]). Since few other national studies of older adults include objective visual function measures, NHATS now serves as a vital resource for the study of vision epidemiology and the impact of VI and blindness on later-life health outcomes and trajectories.

VISION LOSS AND FOOD INSECURITY IN THE NATIONAL HEALTH AND AGING TRENDS STUDY

Abstract Adults with vision impairment (VI) may be at a greater risk of experiencing food insecurity due to economic hardships and difficulty with daily activities. However, the relationship is not well understood. We examined the cross-sectional associations between VI and food insecurity in older community-dwelling US adults among 2,815 National Health and Aging Trends Study participants. VI was measured on categorical (distance acuity VI [&amp;gt; 20/40], near acuity VI [&amp;gt; 20/40], contrast sensitivity impairment [CSI] [&amp;lt;1.55], and any VI (distance, near, or CSI)) and continuous scales (distance and near acuity [per 0.1 logMAR], and contrast sensitivity [per 0.1 logCS units]). Food insecurity was classified based on functional limitations, lack of social support, and/or financial limitations. Overall, older adults with any VI had higher prevalence rates of food insecurity than adults without VI (4.56% vs. 1.90%). In fully-adjusted models, older adults with any VI had double the odds of food insecurity than their peers (OR=2.13, 95% CI: 1.25–3.62). Although no associations were found when assessing other vision measures categorically, continuous scales showed strong associations; worse distance (OR=5.00, 95% CI: 1.85–13.48) and near acuity (OR=2.56, 95% CI: 1.05–6.21, per 0.1 logMAR), and worse CS (OR=2.57, 95% CI: 1.11–5.94, per 0.1 logCS units) were associated with higher odds of food insecurity. These results suggest that older Americans with VI have a higher likelihood of food insecurity, and highlight a need to examine strategies, such as more disability-inclusive policies impacting food access, to improve accessibility and reduce these inequities.

CONCURRENT VISION AND HEARING IMPAIRMENTS, SOCIAL ISOLATION, DEPRESSION, AND ANXIETY: FINDINGS FROM THE NHATS

Abstract Sensory impairments are contributors to poor health for older adults, and the likelihood of having more than one sensory impairment increases with age. There has been little research on population-level associations of visual and hearing function with social and mental health. This study examined the associations between objectively measured hearing and vision impairment, social isolation, depression, and anxiety among older US adults. Using nationally representative data from the 2021 National Health and Aging Trends Study, we conducted cross-sectional analysis among adults aged &amp;gt;70 (n=2,520). Visual impairment (VI) was defined as distance (&amp;lt;20/40), near (&amp;lt;20/40), and/or contrast sensitivity (&amp;gt;1SD below mean) impairment. Hearing impairment (HI) was defined as a better ear pure-tone average &amp;gt;25 decibel hearing level. Respondents with VI and HI were identified as having dual sensory impairment (DSI). Social isolation was assessed by living arrangement, core network size, religious attendance, and social participation. Depressive and anxiety symptoms were measured with the PHQ-2 and GAD-2, respectively. Weighted sample characteristics showed that 25.53% of older adults had DSI. Logistic regression analyses revealed that, compared to those without HI or VI, older adults with DSI were more likely to report social isolation (OR=1.71, 95% CI=1.12-2.60), have depression (OR=4.57, 95% CI=2.34-8.92), and anxiety (OR=2.65, 95% CI=1.36-5.17). Associations with DSI were stronger than for single impairments. All models controlled for age, gender, education, race/ethnicity, marital status, number of chronic conditions. Findings suggested that older adults experiencing DSI are at greater risk of having social isolation and emotional distress.

Correlation of contrast sensitivity with ganglion cell/inner plexiform layer thickness and damage location in glaucoma with varying severity.

To investigate the correlation of contrast sensitivity with macular region ganglion cell/inner plexiform layer (GC/IPL) thickness and damage location in open-angle glaucoma (OAG) of varying severity. Cross-sectional study with 106 patients (203 eyes) who had OAG. Contrast sensitivity of each eye evaluated by quick contrast sensitivity function test based on intelligent algorithm. The GC/IPL thickness measured with optical coherence tomography; six sectors were delineated for localization of damage area. All eyes were grouped by the healthy macular sector and divided into pre-perimetric, early, moderate, and advanced stages, according to severity of visual field impairment. Mean GC/IPL thickness in the entire macular region and each sector were correlated with parameters that reflected contrast sensitivity (p < 0.01). The structure-function correlations were stronger nasally compared with temporally, and superiorly compared with inferiorly. Eyes with normal structure in inferior temporal sector had less visual field (p' = 0.024) and macular damage (p' = 0.034) compared with eyes that had healthy superior nasal sector; there was no difference in contrast sensitivity (p = 0.898). The structure-function correlations were significant in early, moderate, and advanced glaucoma (p < 0.05) but not in pre-perimetric glaucoma (p = 0.116). GC/IPL thinning in all sectors of the macular region in OAG was correlated with contrast sensitivity impairment, whereas the inferior temporal sector was least affected. Contrast sensitivity was supported as a severity evaluation indicator of early, moderate, and advanced glaucoma, but not of pre-perimetric glaucoma.

Visual resolution under photopic and mesopic conditions in patients with Sjögren's syndrome.

To focus on different visual resolution tasks under photopic and mesopic conditions in Sjögren's syndrome patients compared to age-matched healthy controls. The visual resolution measurements included high and low visual acuities and contrast sensitivity functions. These tests were conducted under photopic and then mesopic conditions. Twenty-one Sjögren's syndrome patients and 21 aged-matched healthy volunteers completed all the measurements in this study. Sjögren's syndrome patients have greater impairment in contrast sensitivity than standardized visual acuity. This reduction was significant under the mesopic condition. Also, Sjögren's syndrome patients treated with pilocarpine suffer more than patients without pilocarpine treatment under low light conditions. Sjögren's syndrome patients shows greater impairment in different visual resolution tasks due to dry eye symptoms.

Does in-vehicle automation help individuals with Parkinson's disease? A preliminary analysis.

PD is a progressive neurodegenerative disorder that affects, according to the ICF, body systems (cognitive, visual, and motor), and functions (e.g., decreased executive functions, decreased visual acuity, impaired contrast sensitivity, decreased coordination)-all which impact driving performance, an instrumental activity of daily living in the domain of "Activity" and "Participation" according to the ICF. Although there is strong evidence of impaired driving performance in PD, few studies have explored the real-world benefits of in-vehicle automation technologies, such as in-vehicle information systems (IVIS) and advanced driver assistance systems (ADAS), for drivers with PD. These technologies hold potential to alleviate driving impairments, reduce errors, and improve overall performance, allowing individuals with PD to maintain their mobility and independence more safely and for longer periods. This preliminary study aimed to fill the gap in the literature by examining the impact of IVIS and ADAS on driving safety, as indicated by the number of driving errors made by people with PD in an on-road study. Forty-five adults with diagnosed PD drove a 2019 Toyota Camry equipped with IVIS and ADAS features (Toyota Safety Sense 2.0) on a route containing highway and suburban roads. Participants drove half of the route with the IVIS and ADAS systems activated and the other half with the systems deactivated. The results suggest that systems that assume control of the driving task, such as adaptive cruise control, were most effective in reducing driving errors. Furthermore, individual differences in cognitive abilities, particularly memory, were significantly correlated with the total number of driving errors when the systems were deactivated, but no significant correlations were present when the systems were activated. Physical capability factors, such as rigidity and bradykinesia, were not significantly correlated with driving error. Taken together, these results show that in-vehicle driver automation systems can benefit drivers with PD and diminish the impact of individual differences in driver cognitive ability.

The relationship between visual function and physical performance in the Study of Muscle, Mobility and Aging (SOMMA).

The relationship of types of visual function to different aspects of physical function, especially strength and coordination, has been understudied, but delineation of these relationships could suggest potentially modifiable targets prior to the onset of disability. Cross-sectional analysis of visual function (self-reported eyesight and eye disease, visual acuity, contrast sensitivity) and physical function tests in 877 older adults (mean age 76.36±5.01 years, 59.2% women, and 13.3% Black race). Separate linear regression models were constructed for short physical performance battery (SPPB), expanded SPPB (eSPPB), their components (gait speed, chair stand, balance, narrow walk), stair climb, four-square step, leg extension peak power and strength, and grip strength. In adjusted models, worse acuity, worse contrast sensitivity, and self-reported poor vision were significantly associated with worse performance on the eSPPB and four-square step test. Worse contrast sensitivity, but not acuity, was significantly associated with shorter balance times, slower chair stand pace, longer stair climb time, and worse SPPB score. Associations of worse acuity and contrast sensitivity with weaker leg extension power, leg strength, and grip strength were attenuated by covariate adjustment. Self-reported macular degeneration, but not cataract or glaucoma, was associated with worse performance on SPPB, eSPPB, balance, stair climb, and four-square step tests in adjusted models. Worse contrast sensitivity and macular degeneration remained associated with worse SPPB and balance after controlling for visual acuity and self-reported eyesight. Poor contrast sensitivity was more strongly associated with worse physical performance than acuity, especially for complex tasks that dynamically challenge coordination and balance. Future studies should examine if older adults with contrast sensitivity impairment would benefit from targeted intervention to decrease their risk of disability.

Visual Dysfunction in Parkinson's Disease.

Non-motor symptoms in Parkinson's disease (PD) include ocular, visuoperceptive, and visuospatial impairments, which can occur as a result of the underlying neurodegenerative process. Ocular impairments can affect various aspects of vision and eye movement. Thus, patients can show dry eyes, blepharospasm, reduced blink rate, saccadic eye movement abnormalities, smooth pursuit deficits, and impaired voluntary and reflexive eye movements. Furthermore, visuoperceptive impairments affect the ability to perceive and recognize visual stimuli accurately, including impaired contrast sensitivity and reduced visual acuity, color discrimination, and object recognition. Visuospatial impairments are also remarkable, including difficulties perceiving and interpreting spatial relationships between objects and difficulties judging distances or navigating through the environment. Moreover, PD patients can present visuospatial attention problems, with difficulties attending to visual stimuli in a spatially organized manner. Moreover, PD patients also show perceptual disturbances affecting their ability to interpret and determine meaning from visual stimuli. And, for instance, visual hallucinations are common in PD patients. Nevertheless, the neurobiological bases of visual-related disorders in PD are complex and not fully understood. This review intends to provide a comprehensive description of visual disturbances in PD, from sensory to perceptual alterations, addressing their neuroanatomical, functional, and neurochemical correlates. Structural changes, particularly in posterior cortical regions, are described, as well as functional alterations, both in cortical and subcortical regions, which are shown in relation to specific neuropsychological results. Similarly, although the involvement of different neurotransmitter systems is controversial, data about neurochemical alterations related to visual impairments are presented, especially dopaminergic, cholinergic, and serotoninergic systems.

When do contrast sensitivity impairments (or enhancements) depend on spatial frequency? Two ways to avoid spurious interactions.

When do contrast sensitivity impairments (or enhancements) depend on spatial frequency? Two ways to avoid spurious interactions.

Characterization of vision in pediatric retinoblastoma survivors beyond visual acuity

Retinoblastoma (RB) and its associated treatments can significantly impact visual acuity. However, little is known regarding other measures of vision, such as contrast sensitivity or saccades. The aim of this study was to describe contrast sensitivity and saccades in children treated for retinoblastoma. This cross-sectional study included children aged 5-17 years who had completed treatment for RB. Visual acuity, saccades via fixation analysis, and contrast sensitivity by Cardiff contrast sensitivity were assessed, and multivariable linear regression was performed. Eleven children were enrolled (mean age, 10.7 ± 3.9 years). Treatment included enucleation (8 children [73%]) and chemotherapy (10 [91%]). Of the 11, one participant was unable to complete testing of saccades, and another was unable to complete contrast sensitivity testing. Decreased saccade parameters (velocity, latency, or accuracy) and impaired contrast sensitivity were observed in all 10 participants who underwent visual testing. Multivariable analysis revealed that worse logMAR visual acuity (B, -4.54 [-6.8, -2.2]; P = 0.004) and bilateral disease (B, -3.9 [-6.4, -1.4]; P = 0.009) were associated with worse contrast sensitivity. Germline disease was associated with decreased vertical saccade accuracy (P = 0.02). Decreased contrast sensitivity and impaired saccades were universally observed in this cohort of RB survivors. Comprehensive visual evaluation should be considered for all RB survivors to provide optimal rehabilitative services for these patients.

Association between contrast sensitivity function and structural damage in primary open-angle glaucoma

AimsTo evaluate the association between contrast sensitivity function (CSF) and glaucomatous structural damage in primary open-angle glaucoma (POAG).MethodsA cross-sectional study was performed with 103 patients (103 eyes) aged 25–50 years...

Central Visual Attention in Primary Open-angle Glaucoma

SIGNIFICANCE To better understand the implication of a potential cognitive change in glaucoma, patients were stimulated in central visual areas considered functionally normal to discard an effect due to the loss of vision during an attentional task. The outcome might improve the follow-up on the impact of the pathology. PURPOSE This study aimed to evaluate the effect of primary open-angle glaucoma on the visual attention system by recording responses of behavioral and oculomotor strategies. METHODS We included 20 individuals with primary open-angle glaucoma (62.1 ± 7.2 years old), 18 age-matched control subjects (58.4 ± 7.2 years old), and 20 young control subjects (25.7 ± 3.5 years old). The procedure consisted of visual (eye-tracking recordings) and manual detection of a target. All participants had to detect a square with a vertical bar within distractors (squares, triangles, and circles with a horizontal or vertical bar) of identical size of 1.6 × 1.6° visual angle. The shapes were displayed concentrically on a radius of 5° of visual angle. All participants were tested to ensure that their visual field sensitivity was normal within ±5° central vision. RESULTS In responding manually, glaucoma participants were slower than age-matched control subjects (1723 ± 488 vs. 1263 ± 385 milliseconds; P &lt; .01). Eye-tracking recordings showed that glaucoma participants found the target within the same time frame as age-matched control subjects. Compared with the young group, the scanpath length and average fixation duration on distractors were significantly longer for the glaucoma patients (+235 pixels, +104 milliseconds) and the age-matched control participants (+120 pixels, +39 milliseconds). Impaired contrast sensitivity was correlated with longer response time, longer scanpath, and longer fixation on distractors. CONCLUSIONS Glaucoma affects the manual response times in a visual attention task, but patients can visually detect the target as quickly as age-matched control subjects. Different clinical factors predicted the performances. The age of the patients was associated with longer scanpath. The visual field loss (mean deviation) was linked with longer visual response time. The loss of contrast sensitivity predicted the behavioral change on fixation duration to the distractors, global response time, visual response time, and scanpath length.

Using Objective Vision Measures to Explore the Association of Vision Impairment With Cognition Among Older Adults in the United States

To evaluate the association between vision impairment (VI) and cognitive function using objective measures. Cross-sectional analysis with a nationally representative sample. The association between VI and dementia was investigated in a US population-based, nationally representative sample of Medicare beneficiaries, the National Health and Aging Trends Study (NHATS), a nationally representative sample of Medicare beneficiaries aged ≥65 years, using objective vision measures. Exposures included distance VI (>20/40), near VI (>20/40), contrast sensitivity impairment (CSI) (<1.55), any objective VI (distance and near visual acuity, or contrast), and self-reported VI. The main outcome measure was dementia status defined based on survey reports, interviews, and cognitive tests. A total of 3026 adults were included in this study; the majority were female (55%) and White (82%). The weighted prevalence rates were 10% for distance VI, 22% for near VI, 22% for CSI, 34% for any objective VI, and 7% for self-reported VI. Across all measures of VI, dementia was more than twice as prevalent in adults with VI compared to their peers without (P < .001 for all). In adjusted models, all measures of VI were associated with higher odds of dementia (distance VI: OR 1.74, 95% CI 1.24-2.44; near VI: OR 1.68, 95% CI 1.29-2.18; CSI: OR 1.95, 95% CI 1.45-2.62; any objective VI: OR 1.83, 95% CI 1.43-2.35; self-reported VI: OR 1.86, 95% CI 1.20-2.89). In a nationally representative sample of older US adults, VI was associated with increased odds of dementia. These results suggest that maintaining good vision and eye health may help preserve cognitive function in older age, although more research is needed to investigate the potential benefits of interventions that focus on vision and eye health on cognitive outcomes.

Visual and cognitive functioning among older adults with low vision before vision rehabilitation: A pilot study.

The occurrence of age-related vision changes is inevitable. However, some of these changes can become pathological. Research indicates that vision and hearing loss is correlated with age-related cognitive decline, and with a higher risk of developing dementia due to Alzheimer's disease. Low vision rehabilitation could possibly be a protective factor against cognitive decline, as it provides the clients with compensatory strategies to overcome their visual deficits. The aim of this pilot study was to assess correlations between visual and cognitive functions in older adults referred for low vision rehabilitation. We hypothesized that more severe impairment of visual acuity and contrast sensitivity would be correlated with more advanced levels of cognitive impairment. The second objective was to examine which of these correlations would remain significant once established variables that influence cognition are statistically removed (e.g., age, education). Thirty-eight older adults (age range: 66-97 years old) with a visual impairment (acuity <20/70) were recruited before the onset of their low vision rehabilitation. They underwent vision (reading acuity, reading speed, contrast sensitivity), hearing (audiogram, speech-in-noise perception) and cognitive (global cognition, memory, executive functions) testing, and demographic information was obtained. Correlations among global cognition and visual aid use, memory and reading speed, memory and contrast sensitivity, memory, and visual aid use, and between executive functions and contrast sensitivity were significant. Correlations between contrast sensitivity and memory, as well as between global cognition and visual aid use remained significant after controlling for age and education. The present study is relevant to clinicians who are assessing the cognitive status of older adults, such as neuropsychologists, because it highlights the importance of considering low vision when administering neuropsychological tests, especially to persons who have not yet received rehabilitation for their visual impairment.

Population Prevalence of Vision Impairment in US Adults 71 Years and Older

Existing estimates of the prevalence of vision impairment (VI) in the United States are based on self-reported survey data or measures of visual function that are at least 14 years old. Older adults are at high risk for VI and blindness. There is a need for up-to-date, objectively measured, national epidemiological estimates. To present updated national epidemiological estimates of VI and blindness in older US adults based on objective visual function testing. This survey study presents a secondary data analysis of the 2021 National Health and Aging Trends Study (NHATS), a population-based, nationally representative panel study of Medicare beneficiaries 65 years and older. NHATS includes community-dwelling older adults or their proxies who complete in-person interviews; annual follow-up interviews are conducted regardless of residential status. Round 11 NHATS data were collected from June to November 2021, and data were analyzed in August 2022. In 2021, NHATS incorporated tablet-based tests of distance and near visual acuity and contrast sensitivity with habitual correction. National prevalence of impairment in presenting distance visual acuity (>0.30 logMAR, Snellen equivalent worse than 20/40), presenting near visual acuity (>0.30 logMAR, Snellen equivalent worse than 20/40), and contrast sensitivity (>1 SD below the sample mean). Prevalence estimates stratified by age and socioeconomic and demographic data were calculated. In the 2021 round 11 NHATS sample, there were 3817 respondents. After excluding respondents who did not complete the sample person interview (n = 429) and those with missing vision data (n = 362), there were 3026 participants. Of these, 29.5% (95% CI, 27.3%-31.8%) were 71 to 74 years old, and 55.2% (95% CI, 52.8%-57.6%) were female respondents. The prevalence of VI in US adults 71 years and older was 27.8% (95% CI, 25.5%-30.1%). Distance and near visual acuity and contrast sensitivity impairments were prevalent in 10.3% (95% CI, 8.9%-11.7%), 22.3% (95% CI, 20.3%-24.3%), and 10.0% (95% CI, 8.5%-11.4%), respectively. Older age, less education, and lower income were associated with all types of VI. A higher prevalence of near visual acuity and contrast sensitivity impairments was associated with non-White race and Hispanic ethnicity. More than 1 in 4 US adults 71 years and older had VI in 2021, higher than prior estimates. Differences in the prevalence of VI by socioeconomic and demographic factors were observed. These data could inform public health planning.