Does cognitive impairment influence outcomes from cataract surgery? Results from a 1-year follow-up cohort study

Vision impairment and cognitive decline among older adults: a systematic review

OBJECTIVES

There has been increasing epidemiological research examining the association between vision impairment (VI) and cognitive impairment and how poor vision may be a modifiable risk factor for cognitive decline. The objective of this systematic review is to synthesise the published literature on the association of VI with cognitive decline, cognitive impairment or dementia, to aid the development of interventions and guide public policies pertaining to the relationship between vision and cognition.

METHODS

A literature search was performed with Embase, Medline and Cochrane library databases from inception to March 2020, and included abstracts and articles published in peer-reviewed journals in English. Our inclusion criteria included publications that contained subjective/objective measures of vision and cognition, or a diagnosis of VI, cognitive impairment or dementia. Longitudinal or cross-sectional studies with ≥100 participants aged >50 years were included. The search identified 11 805 articles whose abstracts underwent screening by three teams of study authors. Data abstraction and quality assessment using the Effective Public Health Practice Project Quality Assessment Tool were performed by one author (NN). 10% of the articles underwent abstraction and appraisal by a second author (LA/VV), results were compared between both and were in agreement.

RESULTS

110 full-text articles were selected for data extraction, of which 53 were cross-sectional, 43 longitudinal and 14 were case-control studies. The mean age of participants was 73.0 years (range 50-93.1). Ninety-one (83%) of these studies reported that VI was associated with cognitive impairment.

CONCLUSION

Our systematic review indicates that a majority of studies examining the vision-cognition relationship report that VI is associated with more cognitive decline, cognitive impairment or dementia among older adults. This synthesis supports the need for additional research to understand the mechanisms underlying the association between VI and cognitive impairment and to test interventions that mitigate the cognitive consequences of VI.

Visual impairment increases the risk of dementia, especially in young males in a 12-year longitudinal follow-up study of a national cohort

We investigated the effect of visual impairment (VI) on dementia development in a national cohort. In this 12-year nationwide population-based retrospective cohort study, national data were collected from National Health Insurance Cooperation of South Korea from 2002 to 2017, comprising 799,074 subjects selected from the dementia-free cohort representative of the Korean population. Crude hazard ratios (HRs) as well as age- and sex-adjusted HRs and confidence intervals (CIs) for the development of dementia were estimated using multivariable Cox regression models. VI significantly increased the risk of dementia with a HR of 2.726 (95% CI 2.251–3.300, p < 0.0001) after adjusting for age, sex, and interaction between age, sex, and VI. HR of interaction between VI and age for dementia was 0.539 (95% CI 0.436–0.667, p < 0.0001). In the sensitivity analysis after adjustment for age, sex, household income level, BMI and other comorbidities, VI showed higher risk for all the type of dementia (p < 0.0001). In subgroup analysis of VI, young males showed the highest risk for development of dementia with a HR of 2.687 (95% CI 2.219–3.254, p < 0.0001). VI significantly increased the risk of dementia in the study cohort, and young males with VI appeared to be the most susceptible to the development of dementia.

Cataract Surgery Complexity and Surgical Complication Rates Among Medicare Beneficiaries With and Without Dementia

PURPOSE

To evaluate cataract surgery complexity and complications among US Medicare beneficiaries with and without dementia.

DESIGN

Retrospective claims-based cohort study.

PARTICIPANTS

A 20% representative sample of Medicare beneficiaries, 2006-2015.

METHODS

Dementia was identified from diagnosis codes on or prior to each beneficiary's first-eye cataract surgery. For each surgery, we identified setting, routine vs complex coding, anesthesia provider type, duration, and any postoperative hospitalization. We evaluated 30- and 90-day complication rates-return to operating room, endophthalmitis, suprachoroidal hemorrhage, retinal detachment, retinal tear, macular edema, glaucoma, or choroidal detachment-and used adjusted regression models to evaluate likelihood of surgical characteristics and complications. Complication analyses were stratified by second-eye cataract surgery within 90 days postoperatively.

RESULTS

We identified 457,128 beneficiaries undergoing first-eye cataract surgery, 23,332 (5.1%) with dementia. None of the evaluated surgical complications were more likely in dementia-diagnosed beneficiaries. There was also no difference in likelihood of nonambulatory surgery center setting, anesthesiologist provider, or postoperative hospitalization. Dementia-diagnosed beneficiaries were more likely to have surgeries coded as complex (15.6% of cases vs 8.8%, P < .0001), and surgeries exceeding 30 minutes (OR = 1.21, 95% CI = 1.17-1.25).

CONCLUSIONS

Among US Medicare beneficiaries undergoing cataract surgery, those with dementia are more likely to have "complex" surgery" lasting more than 30 minutes. However, they do not have greater likelihood of surgical complications, higher-acuity setting, advanced anesthesia care, or postoperative hospitalization. This may be influenced by case selection and may suggest missed opportunities to improve vision. Future research is needed to identify dementia patients likely to benefit from cataract surgery.

Receipt of Eye Care Services among Medicare Beneficiaries with and without Dementia

PURPOSE

To examine the relationship between dementia status and receipt of eye care among US Medicare beneficiaries.

DESIGN

Retrospective, claims-based analysis.

PARTICIPANTS

A 20% representative sample of Medicare beneficiaries who received care between January 1, 2006, and December 31, 2015.

METHODS

Dementia was identified from diagnosis codes documented in a beneficiary's first 3 years of observed Medicare enrollment. Eye care visits were identified from provider specialty codes on each encounter claim. We used multivariable Cox proportional hazards regression models with time-varying covariates to compare the likelihood of receiving eye care between beneficiaries with and without dementia. All models were adjusted for potential confounders, including demographics, urban/rural residence, systemic health (Charlson Index), and ocular comorbidities.

MAIN OUTCOME MEASURES

Hazard ratio (HR) and 95% confidence interval (CI) for (1) being seen by any eye care provider (ophthalmologist or optometrist); (2) being seen by an ophthalmologist specifically; and (3) receiving cataract surgery (among beneficiaries with ophthalmologist encounters).

RESULTS

A total of 4 451 200 beneficiaries met inclusion criteria; 3 805 718 (85.5%) received eye care during the study period, and 391 556 (8.8%) had diagnosed dementia. Some 73.4% of beneficiaries diagnosed with dementia saw an eye care provider during the study period and 55.4% saw an ophthalmologist versus 86.7% and 74.0% of beneficiaries, respectively, without dementia diagnoses. Compared with those without dementia diagnoses, beneficiaries with diagnosed dementia had lower likelihood of seeing any eye care provider (adjusted HR, 0.69; 95% CI, 0.69-0.70) and were less likely to see an ophthalmologist (adjusted HR, 0.55; 95% CI, 0.55-0.55). Among the subset of beneficiaries who did see ophthalmologists, those with diagnosed dementia were also less likely to receive cataract surgery than beneficiaries without diagnosed dementia (HR, 0.62; 95% CI, 0.62-0.63) and less likely to receive a cataract diagnosis (18% vs. 82%).

CONCLUSIONS

US Medicare beneficiaries diagnosed with dementia are less likely to receive eye care than those without diagnosed dementia. Depending on visual acuity and functional status, this may have implications for injury prevention, physical and cognitive function, and quality of life. Further work is needed to identify barriers to receiving eye care, determine eye care services and settings that provide greatest value to patients with dementia, and implement measures to improve access to appropriate eye care.

Kidney Transplant Outcomes in Recipients With Cognitive Impairment: A National Registry and Prospective Cohort Study

BACKGROUND

Cognitive impairment is common in patients with end-stage renal disease and is associated with poor outcomes on dialysis. We hypothesized that cognitive impairment might be associated with an increased risk of all-cause graft loss (ACGL) in kidney transplant (KT) recipients.

METHODS

Using the Modified Mini-Mental State (3MS) examination, we measured global cognitive function at KT hospital admission in a prospective, 2-center cohort of 864 KT candidates (August 2009 to July 2016). We estimated the association between pre-KT cognitive impairment and ACGL using Cox regression, adjusting for recipient, donor, and transplant factors.

RESULTS

In living donor KT (LDKT) recipients, the prevalence was 3.3% for mild impairment (60 ≤ 3MS < 80) and 3.3% for severe impairment (3MS < 60). In deceased donor KT (DDKT) recipients, the prevalence was 9.8% for mild impairment and 2.6% for severe impairment. The LDKT recipients with cognitive impairment had substantially higher ACGL risk than unimpaired recipients (5-year ACGL: 45.5% vs 10.6%; P < 0.01; adjusted hazard ratio [aHR] any impairment, 5.40 (95% confidence interval [CI], 1.78-16.34; P < 0.01); aHR severe impairment, 5.57 (95% CI, 1.29-24.00; P = 0.02). Similarly, DDKT recipients with severe impairment had higher ACGL risk than recipients without severe impairment (5-year ACGL, 53.0% vs 24.2%; P = 0.04); aHR severe impairment, 2.92 (95% CI, 1.13-7.50; P = 0.03).

CONCLUSIONS

Given the elevated risk of ACGL among KT recipients with cognitive impairment observed in this 2-center cohort, research efforts should explore the mechanisms of graft loss and mortality associated with cognitive impairment and identify potential interventions to improve posttransplant survival.

Effect of cataract surgery on cognitive function in elderly: Results of Fujiwara-kyo Eye Study

Purpose

To determine whether there is a significant association between prior cataract surgery and cognitive function in an elderly Japanese cohort.

Setting

Nara Medical University, Nara, Japan.

Design

The Fujiwara-kyo Eye Study was a cross-sectional epidemiological study.

Methods

The subjects were ≥ 68-years who lived in the Nara Prefecture and responded to recruitment notices. All of the subjects received comprehensive ophthalmological examinations, and answered questionnaires on their socio-demographic and medical history including prior cataract surgery. The association between prior cataract surgery and cognitive function was determined.

Results

A total of the 2764 subjects whose mean age was 76.3±4.8 years (±standard deviation) was studied. Of these, 668 individuals (24.2%) had undergone cataract surgery. Of these, 150 (5.4%) had dementia as determined by the Mini-Mental State Examination (MMSE) score ≤23, and 877 individuals (31.7%) had mild cognitive impairment (MCI; MMSE score 24–26). The subjects who had prior cataract surgery had significantly lower odds ratio (OR) of having MCI (OR = 0.78, 95% confidence interval; CI 0.64–0.96, P = 0.019) than those who had not had cataract surgery after adjusting for age, sex, body mass index, education, hypertension, diabetes, depression, and history of stroke. The OR was still lower when the visual acuity was also added to the adjusted factors (OR 0.79, 95% CI 0.64–0.97, P = 0.025). However, prior cataract surgery did not contribute significantly to the low OR for dementia.

Conclusions

Cataract surgery may play a role in reducing the risk of developing MCI independently of visual acuity but not for dementia.

Comorbidity and dementia: a mixed-method study on improving health care for people with dementia (CoDem)

Background

Among people living with dementia (PLWD) there is a high prevalence of comorbid medical conditions but little is known about the effects of comorbidity on processes and quality of care and patient needs or how services are adapting to address the particular needs of this population.

Objectives

To explore the impact of dementia on access to non-dementia services and identify ways of improving the integration of services for this population.

Design

We undertook a scoping review, cross-sectional analysis of a population cohort database, interviews with PLWD and comorbidity and their family carers and focus groups or interviews with health-care professionals (HCPs). We focused specifically on three conditions: diabetes, stroke and vision impairment (VI). The analysis was informed by theories of continuity of care and access to care.

Participants

The study included 28 community-dwelling PLWD with one of our target comorbidities, 33 family carers and 56 HCPs specialising in diabetes, stroke, VI or primary care.

Results

The scoping review (n = 76 studies or reports) found a lack of continuity in health-care systems for PLWD and comorbidity, with little integration or communication between different teams and specialities. PLWD had poorer access to services than those without dementia. Analysis of a population cohort database found that 17% of PLWD had diabetes, 18% had had a stroke and 17% had some form of VI. There has been an increase in the use of unpaid care for PLWD and comorbidity over the last decade. Our qualitative data supported the findings of the scoping review: communication was often poor, with an absence of a standardised approach to sharing information about a person’s dementia and how it might affect the management of other conditions. Although HCPs acknowledged the vital role that family carers play in managing health-care conditions of PLWD and facilitating continuity and access to care, this recognition did not translate into their routine involvement in appointments or decision-making about their family member. Although we found examples of good practice, these tended to be about the behaviour of individual practitioners rather than system-based approaches; current systems may unintentionally block access to care for PLWD. Pathways and guidelines for our three target conditions do not address the possibility of a dementia diagnosis or provide decision-making support for practitioners trying to weigh up the risks and benefits of treatment for PLWD.

Conclusions

Significant numbers of PLWD have comorbid conditions such as stroke, diabetes and VI. The presence of dementia complicates the delivery of health and social care and magnifies the difficulties that people with long-term conditions experience. Key elements of good care for PLWD and comorbidity include having the PLWD and family carer at the centre, flexibility around processes and good communication which ensures that all services are aware when someone has a diagnosis of dementia. The impact of a diagnosis of dementia on pre-existing conditions should be incorporated into guidelines and care planning. Future work needs to focus on the development and evaluation of interventions to improve continuity of care and access to services for PLWD with comorbidity.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.