Incidence and correction of vision impairment among elderly population in southern urban China

Associations Between Self-Reported Visual Difficulty, Age of Onset, and Cognitive Function Trajectories Among Chinese Older Adults

Objectives: This study examined the association between self-reported visual difficulty and age-related cognitive declines among older Chinese adults and how the timing of visual difficulty onset plays a role in cognitive trajectories. Methods: Data were drawn from the 2011-2018 wave of the China Health and Retirement Longitudinal Study, involving 9974 respondents aged 60 years or older (mean age 65.44 years, range 60-101 years). Results: At baseline, 14.16% respondents had self-reported visual difficulty. Growth curve models showed that Chinese older adults with visual difficulty experienced a faster decline in cognitive function compared to those without visual difficulty (β = -0.02, p < .01). Older adults who began experiencing visual difficulty between 61 and 75 years of age had steeper cognitive declines compared to those with earlier or later onset (β = -0.05, p < .01). Discussion: Older adults with self-reported visual difficulty experience faster rates of cognitive decline. Future research should explore potential factors that underlie the association between onset timing of visual difficulty and cognitive function.

Six-Year Incidence of Visual Impairment in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Diseases Study

Purpose

To examine the 6-year incidence of visual impairment (VI) and identify risk factors associated with VI in a multiethnic Asian population.

Design

Prospective, population-based, cohort study.

Participants

Adults aged ≥ 40 years were recruited from the Singapore Epidemiology of Eye Diseases cohort study at baseline. Eligible subjects were re-examined after 6 years. Subjects included in the final analysis had a mean age of 56.1 ± 8.9 years, and 2801 (50.5%) were female.

Methods

All participants underwent standardized examination and interviewer-administered questionnaire at baseline. Incidences were standardized to the Singapore Population Census 2010. A Poisson binomial regression model was used to evaluate the associations between baseline factors and incident presenting VI.

Main Outcome Measures

Incident presenting VI was assessed at the 6-year follow-up visit. Visual impairment (presenting visual acuity < 20/40), low vision (presenting visual acuity < 20/40 but ≥ 20/200), and blindness (presenting visual acuity < 20/200) were defined based on United States definition.

Results

A total of 5551 subjects (2188 Chinese, 1837 Indians, and 1526 Malays) were evaluated, of whom 514 developed incident presenting VI over 6 years. Malays had a higher incidence of low vision and blindness (13.0%; 0.6%) than Indians (7.0%; 0.1%) and Chinese (7.7%; 0.2%). Among Malay individuals with VI at baseline, 52.8% remained visually impaired after 6 years, which was considerably higher than Chinese (32.4%) and Indians (37.2%). Older age (per decade; relative risk [RR] = 1.59), a history of cardiovascular disease (RR = 1.38), current smoking (RR = 1.31), smaller housing type (1- to 2-room public flat; RR = 2.01), and no formal education (RR = 1.63) at baseline were associated with a higher risk of incident VI (all P ≤ 0.027). Older age (> 60 years) contributed the highest population attributable risk to incident VI (27.1%), followed by lower monthly income (Singapore dollar < $2000; 26.4%) and smaller housing type (24.7%). Overall, undercorrected refractive error (49.1%) and cataract (82.6%) were leading causes for low vision and blindness, respectively. This was consistently observed across the 3 ethnicities.

Conclusions

In this multiethnic Asian population, Malays had a higher VI incidence compared to Indians and Chinese. Leading causes of VI are mostly treatable, suggesting that more efforts are needed to further mitigate preventable visual loss.

Financial Disclosures

The authors have no proprietary or commercial interest in any materials discussed in this article.

Incidence, causes and risk factors of vision loss in rural Southern China: 6-year follow-up of the Yangxi Eye Study

PURPOSE

To report the 6-year incidence, causes and risk factors for vision loss (visual impairment (VI) and blindness), among elderly adults in rural southern China.

METHODS

Population-based, cohort study. Initiated in 2014, the study recruited participants aged 50 and older using random cluster sampling from Yangxi County. All eligible participants were invited to attend interviews and comprehensive eye examinations at the 6-year follow-up between November 2020 and March 2021. The WHO categories of vision loss were used to define incident cases of VI (3/60≤VA <6/12), moderate-to-severe VI (MSVI) (3/60≤VA<6/18) and blindness (VA <3/60) in the better-seeing eye.

RESULTS

Among the 5825 baseline participants, 3187 (64.4%) of 4946 surviving subjects participated in the 6-year follow-up. Based on presenting and best-corrected VA, respectively, the crude incidence rate of blindness was 0.8% (95% CI 0.5% to 1.1%) vs 0.3% (95% CI 0.1% to 0.5%), for MSVI 6.7% (95% CI 5.7% to 7.6%) vs 4.6% (95% CI 3.8% to 5.4%) and for any VI 16.1% (95% CI 14.5% to 17.6%) vs 12.9% (95% CI 11.6% to 14.1%). Cataract (48.3%) and refractive errors (44.4%) were the most common causes of vision loss. Factors significantly associated with greater incident vision loss were older age, female sex, less education, living alone and longer axial length (all p<0.05).

CONCLUSIONS

Substantial work is still required to reduce avoidable vision loss in rural China. Screening outreach and efforts to improve awareness which target the poorer and less educated are urgently needed to reduce the growing unmet need for eye care due to ageing.

Epidemiology, health policy and public health implications of visual impairment and age-related eye diseases in mainland China

The prevalence of visual impairment (VI) and age-related eye diseases has increased dramatically with the growing aging population in mainland China. However, there is limited comprehensive evidence on the progress of ophthalmic epidemiological research in mainland China to enhance our awareness of the prevention of eye diseases to inform public health policy. Here, we conducted a literature review of the population-based epidemiology of VI and age-related eye diseases in mainland China from the 1st of January 1946 to the 20th of October 2021. No language restrictions were applied. There was significant demographic and geographic variation in the epidemic of VI and age-related eye diseases. There are several factors known to be correlated to VI and age-related eye diseases, including age, gender, family history, lifestyle, biological factors, and environmental exposures; however, evidence relating to genetic predisposition remains unclear. In addition, posterior segment eye diseases, including age-related macular degeneration and diabetic retinopathy, are amongst the major causes of irreversible visual impairments in the senile Chinese population. There remains a significant prevention gap, with only a few individuals showing awareness and achieving optimal medical care with regards to age-related eye diseases. Multiple challenges and obstacles need to be overcome, including the accelerated aging of the Chinese population, the lack of structured care delivery in many underdeveloped regions, and unequal access to care. Despite the progress to date, there are few well-conducted multi-center population-based studies following a single protocol in mainland China, which findings can hopefully provide valuable cues for governmental decision-making and assist in addressing and halting the incidence of VI and age-related eye diseases in China.

Estimating need and coverage for five priority assistive products: a systematic review of global population-based research

INTRODUCTION

To improve access to assistive products (APs) globally, data must be available to inform evidence-based decision-making, policy development and evaluation, and market-shaping interventions.

METHODS

This systematic review was undertaken to identify studies presenting population-based estimates of need and coverage for five APs (hearing aids, limb prostheses, wheelchairs, glasses and personal digital assistants) grouped by four functional domains (hearing, mobility, vision and cognition).

RESULTS

Data including 656 AP access indicators were extracted from 207 studies, most of which (n=199, 96%) were cross-sectional, either collecting primary (n=167) or using secondary (n=32) data. There was considerable heterogeneity in assessment approaches used and how AP indicators were reported; over half (n=110) used a combination of clinical and self-reported assessment data. Of 35 studies reporting AP use out of all people with functional difficulty in the corresponding functional domains, the proportions ranged from 4.5% to 47.0% for hearing aids, from 0.9% to 17.6% for mobility devices, and from 0.1% to 86.6% for near and distance glasses. Studies reporting AP need indicators demonstrated >60% unmet need for each of the five APs in most settings.

CONCLUSION

Variation in definitions of indicators of AP access have likely led to overestimates/underestimates of need and coverage, particularly, where the relationship between functioning difficulty and the need for an AP is complex. This review demonstrates high unmet need for APs globally, due in part to disparate data across this sector, and emphasises the need to standardise AP data collection and reporting strategies to provide a comparable evidence base to improve access to APs.

Vision impairment, vision correction, and cognitive decline among middle-aged and older Chinese: results from the China health and retirement longitudinal study

OBJECTIVES

To investigate the associations between vision impairment (VI), vision correction (VC), and cognitive function.

METHOD

We included 20,677 participants aged ≥45 years from the China Health and Retirement Longitudinal Study (2011-2015). Participants were grouped into no VI, distance VI (DVI) only, near VI (NVI) only, or both distance and near VI (DNVI), and VI(+)/VC(-), VI(+)/VC(+), VI(-)/VC(-), or VI(-)/VC(+) further at baseline. Cognitive function at baseline and subsequently every two years was applied as a dependent variable in a generalized estimating equation model.

RESULTS

DVI only, NVI only, and DNVI had significantly worse cognitive function over time than no VI (all p < .05). DNVI had significantly worse cognitive function over time than DVI only and NVI only (all p < .001). VI(+)/VC(+), VI(-)/VC(-), and VI(-)/VC(+) had significantly better cognitive function over time than VI(+)/VC(-) (all p < .05). VI(-)/VC(+) had significantly better cognitive function over time than VI(+)/VC(+) and VI(-)/VC(-) (all p < .05).

CONCLUSION

Cognitive function was worse in middle-aged and older Chinese with VI, especially in those with DNVI. VC was associated with better cognitive function over time regardless of the status of vision.

Visual trajectories and risk of physical and cognitive impairment among older Chinese adults

BACKGROUND/OBJECTIVES

To identify visual trajectories and examine their relationships with physical and cognitive function in older Chinese adults.

DESIGN

Population-based longitudinal study.

SETTING

The Chinese Longitudinal Healthy Longevity Survey.

PARTICIPANTS

A total of 16,151 participants aged ≥65 years.

MEASUREMENTS

Visual, physical (including activities of daily living [ADL] and instrumental ADL [IADL]), and cognitive function were assessed at baseline and subsequently every 3 years. ADI disability and IADL disability were defined as needing any help in any item of the Katz scale and a modified Lawton's scale, respectively. Cognitive impairment was defined as a Chinese version of the Mini-Mental State Examination score below 24. A group-based trajectory model was used to determine visual trajectories adjusted for age, sex, and education. Associations of visual trajectories with ADL disability, IADL disability, and cognitive impairment were evaluated using generalized estimating equation models adjusted for potential confounders.

RESULTS

This study identified three distinct visual trajectories, including no decline (32.4%), moderate decline (48.3%), and progressive decline (19.3%) during the follow-up period. Compared with the no decline trajectory, both the moderate decline (ADL disability: OR = 2.75, 95% CI: 2.30-3.28; IADL disability: OR = 3.01, 95% CI: 2.74-3.31; cognitive impairment: OR = 3.37, 95% CI: 3.02-3.76) and the progressive decline (ADL disability: OR = 8.50, 95% CI: 6.55-11.02; IADL disability: OR = 12.96, 95% CI: 9.95-16.87; cognitive impairment: OR = 10.84, 95% CI: 8.89-13.23) trajectories were significantly associated with an increased risk of functional impairment. Compared with the moderate decline trajectory, the progressive decline trajectory was significantly associated with an increased risk of ADL disability (OR = 3.09, 95% CI: 2.46-3.89), IADL disability (OR = 4.30, 95% CI: 3.29-5.61), and cognitive impairment (OR = 3.22, 95% CI:2.63-3.93).

CONCLUSION

Older Chinese adults exhibit three distinct visual trajectories and those with decline trajectories in vision have an increased risk of functional impairment than those with a trajectory of no decline in vision.

Self-reported vision impairment, vision correction, and depressive symptoms among middle-aged and older Chinese: Findings from the China health and retirement longitudinal study

OBJECTIVE

To investigate associations between vision impairment (VI), vision correction (VC) and depressive symptoms among middle-aged and older Chinese.

METHODS

22 203 participants aged ≥45 years from China Health and Retirement Longitudinal Study 2011 to 2015 were divided into four self-reported VI categories: no VI, distance VI (DVI) only, near VI (NVI) only, and both distance and near VI (DNVI); and four self-reported VI/VC subgroups: VI(+)/VC(-), VI(+)/VC(+), VI(-)/VC(-) and VI(-)/VC(+). Depressive symptoms were evaluated by 10-item Center for Epidemiological Studies Depression Scale (CESD-10).

RESULTS

Compared with no VI, DVI only (OR = 2.12, 95% CI: 1.95, 2.31), NVI only (OR = 1.51, 95% CI: 1.39, 1.63) and DNVI (OR = 2.75, 95% CI: 2.47, 3.07) were associated with higher odds of depressive symptoms. Compared with VI(+)/VC(-), VI(+)/VC(+) (OR = 0.91, 95% CI: 0.83, 0.98), VI (-)/VC(-) (OR = 0.50, 95% CI: 0.48, 0.53) and VI(-)/VC(+) (OR = 0.49, 95% CI: 0.47, 0.54) were associated with lower odds of depressive symptoms. Compared with no VI at baseline, baseline DNVI was significantly associated with higher odds of depressive symptoms after two (OR = 1.48, 95% CI: 1.16, 1.88) and four (OR = 1.32, 95% CI: 1.04, 1.68) years. Baseline depressive symptoms were significantly associated with higher odds of VI after two (OR = 1.53, 95% CI: 1.34, 1.74) and four (OR = 1.54, 95% CI: 1.34, 1.76) years.

CONCLUSION

Adults with DNVI were more likely to report depressive symptoms in the future and those with depressive symptoms were more likely to report VI in the future. VC might be a protective factor for preventing depressive symptoms among adults with VI.