Vision Impairment and Subjective Cognitive Decline-Related Functional Limitations - United States, 2015-2017

Accurate identification of individuals with subjective cognitive decline using 3D regional fractal dimensions on structural magnetic resonance imaging

BACKGROUND AND OBJECTIVE

Accurate identification of individuals with subjective cognitive decline (SCD) is crucial for early intervention and prevention of neurodegenerative diseases. Fractal dimensionality (FD) has emerged as a robust and replicable measure, surpassing traditional geometric metrics, in characterizing the intricate fractal geometrical properties of brain structure. Nevertheless, the effectiveness of FD in identifying individuals with SCD remains largely unclear. A 3D regional FD method can be suggested to characterize and quantify the spatial complexity of the precise gray matter, providing insights into cognitive aging and aiding in the automated identification of individuals with SCD.

METHODS

This study introduces a novel integer ratio based 3D box-counting fractal analysis (IRBCFA) to quantify regional fractal dimensions (FDs) in structural magnetic resonance imaging (MRI) data. The innovative method overcomes limitations of conventional box-counting techniques by accommodating arbitrary box sizes, thereby enhancing the precision of FD estimation in small, yet neurologically significant, brain regions.

RESULTS

The application of IRBCFA to two publicly available datasets, OASIS-3 and ADNI, consisting of 520 and 180 subjects, respectively. The method identified discriminative regions of interest (ROIs) predominantly within the limbic system, fronto-parietal region, occipito-temporal region, and basal ganglia-thalamus region. These ROIs exhibited significant correlations with cognitive functions, including executive functioning, memory, social cognition, and sensory perception, suggesting their potential as neuroimaging markers for SCD. The identification model trained on these ROIs demonstrated exceptional performance achieving over 93 % accuracy on the discovery dataset and exceeding 87 % on the independent testing dataset. Furthermore, an exchange experiment between datasets revealed a substantial overlap in discriminative ROIs, highlighting the robustness of our method across diverse populations.

CONCLUSION

Our findings indicate that IRBCFA can serve as a valuable tool for quantifying the spatial complexity of gray matter, providing insights into cognitive aging and aiding in the automated identification of individuals with SCD. The demonstrated generalizability and robustness of this method position it as a promising tool for neurodegenerative disease research and offer potential for clinical applications.

Gardening and subjective cognitive decline: a cross-sectional study and mediation analyses of 136,748 adults aged 45+ years

BACKGROUND

Given the benefits of gardening for physical and psychological health, we explored whether gardening was associated with lower risks of subjective cognitive decline (SCD), a precursor of dementia, and SCD-related functional limitations.

METHODS

Included in this cross-sectional study were 136,748 participants aged 45 + years old from the Behavioral Risk Factor Surveillance System 2019 survey, who were then categorized into three groups according to self-reported exercise status: non-exercisers, gardeners, and other exercisers. SCD was assessed via a questionnaire, and SCD-related functional limitations were referred to as having difficulties in engaging in household or social activities due to SCD. The odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the associations of gardening with SCD and SCD-related functional limitations, adjusted for age, sex, socioeconomic status, lifestyle factors, and health status. Mediation analyses were conducted to examine whether the observed association between gardening and SCD was mediated by energy expenditure (MET-hours/week), depression status, and consumption of fruits and vegetables.

RESULTS

Overall, 11.1% and 5.4% of participants self-reported experiencing SCD and SCD-related functional limitations, respectively. The adjusted OR for gardeners vs. non-exercisers, was 0.72 (95% CI 0.62-0.83) for SCD and 0.57 (95% CI 0.44-0.73) for SCD-related functional limitations. The observed association between gardening and SCD was explained by higher energy expenditure (39.0%), lower likelihood of having depression (21.5%), and higher consumption of fruits and vegetables (3.4%) (P<0.05 for all). Similar patterns were observed for SCD-related functional limitations.

CONCLUSION

In this nationally representative sample, gardening was associated with better cognitive status, which may be mainly attributed to better depression status and energy expenditure.

Structural neuroimaging changes associated with subjective cognitive decline from a clinical sample

BACKGROUND

Alzheimer's disease (AD) is characterized by progressive deterioration of cognitive functions. Some individuals with subjective cognitive decline (SCD) are in the early phase of the disease and subsequently progress through the AD continuum. Although neuroimaging biomarkers could be used for the accurate and early diagnosis of preclinical AD, the findings in SCD samples have been heterogeneous. This study established the morphological differences in brain magnetic resonance imaging (MRI) findings between individuals with SCD and those without cognitive impairment based on a clinical sample of patients defined according to SCD-Initiative recommendations. Moreover, we investigated baseline structural changes in the brains of participants who remained stable or progressed to mild cognitive impairment or dementia.

METHODS

This study included 309 participants with SCD and 43 healthy controls (HCs) with high-quality brain MRI at baseline. Among the 99 subjects in the SCD group who were followed clinically, 32 progressed (SCDp) and 67 remained stable (SCDnp). A voxel-wise statistical comparison of gray and white matter (WM) volume was performed between the HC and SCD groups and between the HC, SCDp, and SCDnp groups. XTRACT ATLAS was used to define the anatomical location of WM tract damage. Region-of-interest (ROI) analyses were performed to determine brain volumetric differences. White matter lesion (WML) burden was established in each group.

RESULTS

Voxel-based morphometry (VBM) analysis revealed that the SCD group exhibited gray matter atrophy in the middle frontal gyri, superior orbital gyri, superior frontal gyri, right rectal gyrus, whole occipital lobule, and both thalami and precunei. Meanwhile, ROI analysis revealed decreased volume in the left rectal gyrus, bilateral medial orbital gyri, middle frontal gyri, superior frontal gyri, calcarine fissure, and left thalamus. The SCDp group exhibited greater hippocampal atrophy (p < 0.001) than the SCDnp and HC groups on ROI analyses. On VBM analysis, however, the SCDp group exhibited increased hippocampal atrophy only when compared to the SCDnp group (p < 0.001). The SCD group demonstrated lower WM volume in the uncinate fasciculus, cingulum, inferior fronto-occipital fasciculus, anterior thalamic radiation, and callosum forceps than the HC group. However, no significant differences in WML number (p = 0.345) or volume (p = 0.156) were observed between the SCD and HC groups.

CONCLUSIONS

The SCD group showed brain atrophy mainly in the frontal and occipital lobes. However, only the SCDp group demonstrated atrophy in the medial temporal lobe at baseline. Structural damage in the brain regions was anatomically connected, which may contribute to early memory decline.

Effect of visual impairment on subjective cognitive decline in older adults: a cross-sectional study in China

OBJECTIVE

People with visual impairment have more functional limitations associated with subjective cognitive decline (SCD), and those with SCD are extremely susceptible to transitioning to irreversible cognitive impairment. This study aimed to explore if visual impairment is a significant predictor of SCD compared with other socioeconomic and health factors associated with SCD.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

The investigation aimed to assess the factors influencing SCD among 428 participants aged 60 and above in Zhaoyuan, China.

PRIMARY OUTCOME MEASURES

The primary outcome variable was SCD, measured by the Chinese version of SCD questionnaire. Multiple logistic regression and propensity score matching (PSM) were used to analyse the influence of visual impairment on the subjective cognition of the elderly.32.2% of the elderly were experiencing SCD. Older adults with SCD showed a higher prevalence of visual impairment (72.5%) than the elderly without SCD (58.6%) (P=0.006). Multivariate logistic regression analysis showed that bad self-reported health status, lack of physical exercise and visual impairment were the risk factors for SCD in older adults, while more than 9 years of education was a protective factor. In addition, PSM model showed that after eliminating the dominant biases caused by the individual observable heterogeneity of older adults with and without visual impairment, the risk of SCD in the elderly with visual impairment was increased by 13.6%-14.5% and the difference was statistically significant (P<0.05).

CONCLUSIONS

It was found that older adults experiencing visual impairments are at an elevated risk of developing SCD compared with their counterparts without such impairments. Additionally, visual impairment remains a significant risk factor for SCD in the elderly, even adjusting for potential biases arising from individual observable heterogeneity.

Association between previous cataract surgery and cognition among middle-aged and older Chinese: the China health and retirement longitudinal study (CHARLS)

BACKGROUND

Cataract is the primary cause of blindness globally, and surgery offers the only method by which to remove cataracts. We aimed to examine whether previous cataract surgery is associated with cognitive function.

METHODS

Our study included 13,824 participants. Data from the baseline of the China Health and Retirement Longitudinal Study (CHARLS) were used. The participants were categorized into two groups: with and without previous cataract surgery. Weighted multiple linear regression was used to obtain the β and 95% confidence intervals (CI).

RESULTS

The participants who had previous cataract surgery (n = 261) scored lower in cognition, including both memory and mental state, than those without previous cataract surgery. After adjusting for socioeconomic factors and metabolic measures, a negative association was evident between previous cataract surgery and cognition (β = -0.647, 95% CI: -1.244, - 0.049). Furthermore, the participants who were older and female demonstrated a decline in cognition, while living in cities and having higher levels education were associated with higher cognition.

CONCLUSIONS

Better cognitive function was associated with less previous cataract surgery or cataract occurrence. This suggests that a period of vision loss due to cataract leads to cognitive decline, however further studies are need to dissect the impact of vision loss and cataract surgery on cognitive decline.

Vision impairment, hearing impairment and functional Limitations of subjective cognitive decline: a population-based study

BACKGROUND

The association between sensory impairment including vision impairment (VI), hearing impairment (HI), dual impairment (DI) and the functional limitations of SCD (SCD-related FL) are still unclear in middle-aged and older people.

METHODS

162,083 participants from BRFSS in 2019 to 2020 was used in this cross-sectional study. After adjusting the weights, multiple logistic regression was used to study the relationship between sensory impairment and SCD or SCD-related FL. In addition, we performed subgroup analysis on the basis of interaction between sensory impairment and covariates.

RESULTS

Participants who reported sensory impairment were more likely to report SCD or SCD-related FL compared to those without sensory impairment (p < 0.001). The association between dual impairment and SCD-related FL was the strongest, the adjusted odds ratios (aORs) and 95% confidence interval (95% CI) were [HI, 2.88 (2.41, 3.43); VI, 3.15(2.61, 3.81); DI, 6.78(5.43, 8.47)] respectively. In addition, subgroup analysis showed that men with sensory impairment were more likely to report SCD-related FL than women, the aORs and 95% CI were [HI, 3.15(2.48, 3.99) vs2.69(2.09, 3.46); VI,3.67(2.79, 4.83) vs. 2.86(2.22, 3.70); DI, 9.07(6.67, 12.35) vs. 5.03(3.72, 6.81)] respectively. The subject of married with dual impairment had a stronger association with SCD-related FL than unmarried subjects the aOR and 95% CI was [9.58(6.69, 13.71) vs. 5.33(4.14, 6.87)].

CONCLUSIONS

Sensory impairment was strongly associated with SCD and SCD-related FL. Individuals with dual impairment had the greatest possibility to reported SCD-related FL, and the association was stronger for men or married subjects than other subjects.

The Associations Between Cataracts and Alzheimer's Disease: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

The relationship between cataracts and Alzheimer's disease (AD) has been reported in recent observational studies. However, it is still unclear whether a causal effect of cataracts on AD or reverse causation exists.

OBJECTIVE

To explore the association between cataracts and AD genetically, we performed a bidirectional two-sample Mendelian randomization study.

METHODS

We obtained genetic instrumental variables related to cataracts and AD from recently published genome-wide association studies (GWASs). SNP-outcome associations for AD were obtained from a GWAS with 111,326 cases and 677,663 controls. SNP-outcome associations for cataracts were drawn from two sources: a GWAS with 67,844 cases and 517,399 controls and the FinnGen consortium (42,843 cases and 262,698 controls). Inverse variance weighted (IVW) was used as the primary method for Mendelian randomization (MR) analyses.

RESULTS

No genetic evidence suggested that cataracts were associated with the risk of AD (IVW odds ratio =1.04, 95% confidence interval: 0.98-1.10, p=0.199). In contrast, an effect of genetically determined AD on a decreased risk of cataract was observed with suggestive evidence (IVW odds ratio =0.96, 95% confidence interval: 0.93-0.99, p=0.004). However, this result might be distorted by survival bias.

CONCLUSION

Genetically determined cataracts were not related to AD, as demonstrated by our study. In contrast, there was suggestive evidence that AD might prevent cataract development, but there might be potential survival bias. To define the exact association between the two diseases, more prospective research and studies on the pathogenesis are needed.

Cognitive dysfunction and the 25-item National Eye Institute Visual Function Questionnaire

Introduction

Visual function and cognitive impairment are interrelated; however, little is known about the impact of modifying treatable vision impairment on the development of cognitive dysfunction. This study examines the relationship between cognition and self-reported visual function using the National Eye Institute's Visual Function Questionnaire (NEI VFQ).

Methods

Participants completed the NEI VFQ 25-Item questionnaire as well as the Mini-Mental State Examination (MMSE). Additionally, all participants were assigned a consensus clinical diagnosis based on established criteria. We used a general linear model and analysis of variance approach to compare means between multiple groups.

Results

A significant association between overall composite score on the NEI VFQ and total MMSE score was revealed (P = 0.04). On average, for every 1-point increase in MMSE score, the overall composite score increased by 0.40 units (95% confidence interval: 0.03-0.77).

Discussion

Reduced visual function should raise concerns about cognitive decline and prompt additional assessment.

Health Care Access and Use Among Adults With and Without Vision Impairment: Behavioral Risk Factor Surveillance System, 2018

INTRODUCTION

Adults with vision impairment may have unique needs when accessing health care to maintain good health. Our study examined the relationship between vision status and access to and use of health care.

METHODS

We analyzed data on adults aged 18 years or older who participated in the 2018 Behavioral Risk Factor Surveillance System. Vision impairment was identified by a yes response to the question "Are you blind or do you have serious difficulty seeing, even when wearing glasses?" Survey questions assessed health care access over the past year (having health insurance coverage, a usual health care provider, or unmet health care needs because of cost) and use of health care during that period (routine checkup and dental visit). We estimated age-adjusted prevalence of our outcomes of interest and used bivariate analyses to compare estimates of the outcomes by vision impairment status.

RESULTS

The prevalence of self-reported vision impairment was 5.3%. Compared with adults without impaired vision, adults with vision impairment had a lower prevalence of having health insurance coverage (80.6% vs 87.6%), a usual health care provider (71.9% vs 75.7%), or a dental visit in the past year (52.9% vs 67.2%) and a higher prevalence of having an unmet health care need in the past year because of cost (29.2% vs 12.6%).

CONCLUSION

Adults with vision impairment reported lower access to and use of health care than those without. Further research can better identify and understand barriers to care to improve access to and use of health care among this population.

Self-Reported Vision Impairment and Psychological Distress in U.S. Adults

PURPOSE

Examine the relationship between vision impairment and psychological distress in adults ≥18 years.

METHODS

Using the 2016-2017 cross-sectional, U.S. National Health Interview Survey, we analyzed self-reported data (n = 57,644) on: Kessler psychological distress scores; general vision impairment (GVI), defined as difficulty seeing even when wearing glasses or contacts; and visual function impairment (VFI), measured using six visual function questions. Multinomial logistic regression was used to estimate adjusted odds ratios (aOR) for mild/moderate and serious psychological distress, by GVI and VFI status, and identify predictors of psychological distress among those with GVI or VFI.

RESULTS

Among adults, 10.6% (95% CI: 10.2, 11.0) had GVI; 11.6% (CI: 11.1, 12.0) had VFI. One in four adults with GVI had psychological distress (14.9% [CI: 13.8, 16.0] reported mild/moderate and 11.2% [CI: 10.2, 12.3] reported serious). Individuals with GVI, versus those without, had higher odds of mild/moderate (aOR = 2.24; CI: 2.00, 2.52) and serious (aOR = 3.41; CI: 2.96, 3.93) psychological distress; VFI had similar findings. Among adults with GVI, odds of serious psychological distress were higher for those aged 18-39 (aOR = 4.46; CI: 2.89, 6.90) or 40-64 (aOR = 6.09; CI: 4.33, 8.57) versus ≥65 years; smokers (aOR = 2.45; CI: 1.88, 3.18) versus non-smokers; physically inactive (aOR = 1.61; CI: 1.22, 2.11) versus active; and with arthritis (aOR = 2.18; CI: 1.66, 2.87) or chronic obstructive pulmonary disease (aOR = 1.65; CI: 1.15, 2.37) versus without.

CONCLUSION

Adults with self-reported vision impairment had higher odds of psychological distress. These findings may inform screening interventions to address psychological distress, particularly among younger working-age adults vision impairment.

Implementation of PROMIS® in an Optometry Clinic

PURPOSE

The full utility of general health Patient-Reported Outcomes Measurement Information System® (PROMIS) surveys in the eye care setting has not been previously demonstrated. This report demonstrates the feasibility of implementing PROMIS in an eye care clinic.

PATIENTS AND METHODS

Over 2 months, general health and functioning PROMIS surveys were offered to all patients in an optometric clinic in Rochester, NY. Demographic and clinical variables were recorded along with percent completion and time to completion of the survey.

RESULTS

Across 651 patients, 258 chose to attempt PROMIS. Patients with low visual acuity were less likely to attempt the survey (p=0.049), and younger patients were more likely to complete the survey (p=0.025); no other patient characteristics were found to differ between those who did and did not participate in, nor complete, PROMIS. A total of 193 patients completed the survey (74.8%) in a mean time of 6.36 minutes (range = [1.43, 51.92] minutes; standard deviation = 5.62 minutes). Time to completion did not vary significantly across any groups.

CONCLUSION

Our relatively high completion rate among those who attempted PROMIS indicates that PROMIS surveys are feasible to implement in an optometry clinic. While most patients completed the survey in little time, the large range of time to completion may indicate that some patients had difficulty completing the survey. Furthermore, the significant difference in visual acuity between those who participated in the survey and those who did not highlights the need to address the way PROMIS is delivered in order to foster greater inclusion.

Association between Vision Impairment and Physical Quality of Life Assessed Using National Surveillance Data

SIGNIFICANCE

Physically unhealthy days assessments in national health surveillance datasets represent a useful metric for quantifying quality-of-life differences in those with and without vision impairment. Disproportionately poorer physical health in the visually impaired population provides further rationale for the inclusion of vision care in multidisciplinary approaches to chronic disease management.

PURPOSE

This study aimed to assess the association between vision impairment and health-related quality of life using data from the Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System.

METHODS

Data from each of the 50 states were extracted from the 2017 Behavioral Risk Factor Surveillance System data set. Self-report of difficulty seeing was used to categorize visually impaired versus nonvisually impaired populations. Self-report number of physically unhealthy days in the previous 30 days was used to quantify quality of life. The number of unhealthy days was calculated for the visually impaired and nonvisually impaired cohorts for each state. The ratio of the number of physically unhealthy days in the visually impaired versus nonvisually impaired population was calculated for each state and for different age cohorts.

RESULTS

Mean numbers of physically unhealthy days among persons with and without severe vision impairment across all states were 10.63 and 3.68 days, respectively, and demonstrated considerable geographic variability. Mean ratios of physically unhealthy healthy days in the visually impaired versus the nonvisually impaired population were 2.91 in the 18- to 39-year-old cohort, 2.87 in the 40- to 64-year-old cohort, and 2.16 in the ≥65-year-old cohort.

CONCLUSIONS

National surveillance data demonstrate a greater number of physically unhealthy days in the visually impaired population, indicating a need to improve our understanding of causes that lead to reduced physical health among those with vision impairment. Additional research is needed to better understand how individuals perceive vision as part of their overall health.

Effects of a Physical Therapy Intervention to Improve the Quality of Life of Visually Impaired People: Development of an Audio–Tactile Exercise Protocol

Introduction: The purpose of this study was to develop and implement an audio–tactile protocol for therapeutic intervention in individuals with visual impairments. Methods: The Physiotherapy Protocol for People with Visual Impairment (PP-PVI) was developed following five steps: physiotherapy evaluation, linguistic selection, protocol design, linguistic adequation for visually impaired, and linguistic adequation for English language. Three adolescents and three young adults with visual impairments participated in this longitudinal study and performed the protocol of therapeutic exercises twice a week for 12 months while being evaluated with respect to their quality of life before and after. The quality of life was evaluated using the 36-item Short Form Health Survey (SF-36). Results: The median score for all domains of the quality of life questionnaire improved after PP-PVI, with the exception of the body pain domain, which remained unchanged. Discussion: The PP-PVI was shown to be an important method of therapeutic intervention, and it was easy to understand and apply in persons with visual impairments. Implications for practitioners: The exercises of the PP-PVI facilitate the development of several physical and functional capabilities that are important to the independence of individuals with visual impairments.

Screening for intrinsic capacity impairments as markers of increased risk of frailty and disability in the context of integrated care for older people: Secondary analysis of MAPT

AIM

This longitudinal secondary analysis of the Multidomain Alzheimer Preventive Trial (MAPT) aimed to test whether the Integrated Care for Older People (ICOPE) Step 1 screening tool is able to identify people at risk of developing frailty and disability in basic (ADL) and instrumental (IADL) activities of daily living among community-dwelling older adults.

PARTICIPANTS AND SETTING

Seven hundred and fifty-nine (n = 759) non-demented participants of the MAPT aged 70-89 years were assessed in memory clinics in France between 2008 and 2013.

METHODS

We measured six intrinsic capacity (IC) impairments, adapted from the ICOPE screening tool. We used Cox models to estimate the adjusted hazard ratios of incident frailty and IADL/ADL disability. Incident frailty was defined by Fried's phenotype, and incident disability was measured according to Lawton and Katz for IADLs and ADLs.

RESULTS

Limited mobility (HR= 2.97, 95%CI= 1.85-4.76), depressive symptoms (HR= 2.07, 95%CI= 1.03-4.19), and visual impairment (HR= 1.70, 95%CI 1.01-2.86) were associated with a higher incidence of frailty over 5 years. Each additional IC condition demonstrated a positive association with a higher risk of incident frailty, IADL, ADL disability, with risk increased by 47%, 27%, and 23% over 5 years, respectively.

CONCLUSION

Screening for IC impairments identifies older adults at higher risk of incident frailty and incident IADL/ADL disability. It is relevant to screen for these impairments together because the risk of frailty and disability increases with each additional one. ClinicalTrials.gov identifier: NCT00672685.

Voxelwise Meta-Analysis of Gray Matter Abnormalities in Mild Cognitive Impairment and Subjective Cognitive Decline Using Activation Likelihood Estimation

Background: Voxel-based morphometry studies have not yielded consistent results among patients with mild cognitive impairment (MCI) and subjective cognitive decline (SCD). Objective: Therefore, we aimed to conduct a meta-analysis of gray matter (GM) abnormalities acquired from these studies to determine their respective neuroanatomical changes. Methods: We systematically searched for voxel-based whole-brain morphometry studies that compared MCI or SCD subjects with healthy controls in PubMed, Web of Science, and EMBASE databases. We used the coordinate-based method of activation likelihood estimation to determine GM changes in SCD, MCI, and MCI sub-groups (amnestic MCI and non-amnestic MCI). Results: A total of 45 studies were included in our meta-analysis. In the MCI group, we found structural atrophy of the bilateral hippocampus, parahippocampal gyrus (PHG), amygdala, right lateral globus pallidus, right insula, and left middle temporal gyrus. The aMCI group exhibited GM atrophy in the bilateral hippocampus, PHG, and amygdala. The naMCI group presented with structural atrophy in the right putamen, right insula, right precentral gyrus, left medial/superior frontal gyrus, and left anterior cingulate. The right lingual gyrus, right cuneus, and left medial frontal gyrus were atrophic GM regions in the SCD group. Conclusion: Our meta-analysis identified unique patterns of neuroanatomical alternations in both the MCI and SCD group. Structural changes in SCD patients provide new evidence for the notion that subtle impairment of visual function, perception, and cognition may be related to early signs of cognitive impairment. In addition, our findings provide a foundation for future targeted interventions at different stages of preclinical Alzheimer’s disease.

Cohort Profile: The Ganka-Ekigaku Network (GEN), a Network of Japanese Ophthalmological Epidemiology Studies

PURPOSE

Japan has been known as a super-aged society, and ageing is a well-known risk factor for blinding eye diseases. However, epidemiological studies in ophthalmology are still scarce in Japan, and the sizes of the cohorts are relatively small. "Ganka-Ekigaku Network" (GEN, an acronym for the epidemiological network in ophthalmology in Japanese) is established to develop a capacity to boost each epidemiological study and enrich a potential inter-study collaboration to identify risk factors of visual impairment in aged society.

METHODS

We reviewed cohort studies in Japan with the inclusion criteria as: (1) at least n = 1000 at baseline, (2) multiple modalities of ophthalmic data, and (3) diagnosis reviewed by ophthalmologist(s), and (4) ophthalmologists are involved in the investigators group. As of January 2020, GEN includes 4 individual Japanese epidemiological studies namely, Hisayama study, Yamagata Study (Funagata), Tsuruoka Metabolomics Cohort study, and the Nagahama Prospective Genome Cohort for Comprehensive Human Bioscience.

RESULTS

GEN includes approximately 25,000 Japanese participants. The baseline surveys started from 1998 to 2012, and since then the data has been prospectively collected approximately every 5 years. A variety of ophthalmic measurements and other factors have been collected in each study in GEN: ophthalmic measurements (fundus photography, optical coherence tomography, etc.), systemic conditions (laboratory data, etc.), and others (DNA, etc.).

CONCLUSION

GEN is an open platform for observational ophthalmic epidemiological studies to share standardized methodologies. While each study in GEN pursues specific and original research questions, standardization of the methods will enable us to conduct reliable meta-analysis/pooled data analyses.

Influence of Distance and Near Visual Impairment on Self-Reported Near Visual Functioning in a Multinational Study

PURPOSE

To assess the influence of distance and near visual impairment on self-reported near visual functioning (VF) in a multinational study.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Participants aged 35 years or older were selected randomly with cluster sampling at 7 sites: rural sites in Nepal (Kaski) and India (Madurai), a semirural site in China (Shunyi), semiurban sites in South Africa (Durban) and Niger (Dosso), and urban sites in the United States (Los Angeles) and China (Guangzhou).

METHODS

Binocular presenting distance and near visual acuity (VA) were measured with a logarithm of the minimum angle of resolution tumbling E chart at 4 m and 40 cm, respectively. A 12-item near VF questionnaire interview was administered by trained local interviewers, with responses scored from 100 to 0 as visual disability increased. Multiple linear regression was used to investigate the association of age, gender, education, and VA with overall eyesight, difficulty with activities, and social functioning subscale scores.

MAIN OUTCOME MEASURES

Visual functioning subscale scores.

RESULTS

The study sample consisted of 6851 questionnaire respondents. The VF subscale scores decreased significantly with worse distance and near VA, and even mildly impaired VA could result in reduced VF. Lower VF subscale scores were associated with older age at 4 sites, female gender at 3 sites, and greater education at 2 sites. The influence of near VA was greater than distance VA at 3 sites, and at 1 site, distance VA was more influential than near VA. With study site included in the regression modeling, lower scores for the overall eyesight subscale (compared with the Shunyi reference site) were found in Guangzhou, Kaski, and Durban; lower difficulty in activities scores were found in Kaski and Durban, but better scores were found in Guangzhou and Madurai; and social functioning scores were lower in Kaski, Durban, and Dosso.

CONCLUSIONS

Along the entire VA spectrum, lower levels of distance and near VA led to significant reductions in VF subscale scores, with wide variation both within and between study sites. The impact of near vision on VF should receive greater emphasis with further investigation in various socioeconomic and cultural settings.

Neuroprotective and vision-protective effect of preserving ATP levels by AMPK activator

Progression of blinding diseases, such as age-related macular degeneration, is accelerated by light exposure. However, no particular intervention is applied to the photostress. Here, we report neuroprotective effects of the adenosine monophosphate (AMP)-activated protein kinase (AMPK) activator, 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR), on light-induced visual function impairment, photoreceptor disorders and death in mice. Increase in retinal ATP levels in response to photostress was transient, because oxygen consumption rate (OCR) and cytochrome c oxidase (CcO) activity were reduced under photostress. However, AICAR treatment preserved OCR, CcO activity, and high levels of retinal ATP after light exposure. AMPK knockdown in the photoreceptor-derived cell line revealed that AMPK targeted CcO activity. Further, our data indicated that photostress reduced mitochondrial respiratory function and ATP levels, while AICAR treatment promoted neuronal survival and retained visual function, stabilizing ATP levels through preserved CcO activity. The current study has provided proof of concept for providing cells with sufficient energy to promote cell survival in the presence of cellular stress. This is in contrast to the previous reports which primarily investigated therapeutic approaches to suppress stress signals. Hence, stabilization of the ATP supply may serve as a novel therapeutic approach to support tissue survival under stress and prevent neurodegeneration.