Cataract Surgery and Cognitive Benefits in the Older Person: A Systematic Review and Meta-analysis

TOPIC

This systematic review and meta-analysis aims to clarify the association of cataract surgery with cognitive impairment and dementia.

CLINICAL RELEVANCE

The association between vision impairment and cognitive decline is well-established. However, the cognitive benefits of cataract surgery are less clear. Given the lack of cure for dementia, identifying modifiable risk factors is key in caring for patients with cognitive deficits.

METHODS

The study was conducted following Preferred Reporting Items for Systematic Review and Meta-analyses guidelines. PubMed, Embase, and Cochrane Library were searched from inception through October 11, 2022, for studies reporting the effect of cataract surgery on cognitive impairment and dementia. We pooled maximally adjusted hazard ratios (HRs) for dichotomous outcomes and ratio of means (RoM) for continuous outcomes using a random-effects model. Heterogeneity was examined using sensitivity and subgroup analyses. The quality of evidence was evaluated using the Newcastle-Ottawa scale, Cochrane risk-of-bias tool for randomized trials, and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) guidelines.

RESULTS

This review included 24 articles comprising 558 276 participants, of which 19 articles were analyzed qualitatively. The bias of studies ranged from low to moderate, and GRADE extended from very low to low. Cataract surgery was associated with a 25% reduced risk of long-term cognitive decline compared with those with uncorrected cataracts (HR, 0.75; 95% confidence interval [CI], 0.72-0.78). This cognitive benefit was seen across various cognitive outcomes and remained robust to sensitivity analyses. Participants who underwent cataract surgery showed a similar risk of long-term cognitive decline as healthy controls without cataracts (HR, 0.84; 95% CI, 0.66-1.06). Additionally, cataract surgery was associated with a 4% improvement in short-term cognitive test scores among participants with normal cognition (RoM, 0.96; 95% CI, 0.94-0.99), but no significant association was observed among participants with preexisting cognitive impairment.

DISCUSSION

Cataract surgery may be associated with a lower risk of cognitive impairment and dementia, and cataract-associated vision impairment may be a modifiable risk factor for cognitive decline. Physicians should be aware of the cognitive sequelae of cataracts and the possible benefits of surgery. The cognitive benefits of cataract surgery should be investigated further in randomized trials.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Systems modelling as an approach for eliciting the mechanisms for hip fracture recovery among older adults in a participatory stakeholder engagement setting

Introduction

Due to an aging population, the rising prevalence and incidence of hip fractures and the associated health and economic burden present a challenge to healthcare systems worldwide. Studies have shown that a complex interplay of physiological, psychological, and social factors often affects the recovery trajectories of older adults with hip fractures, often complicating the recovery process.

Methods

This research aims to actively engage stakeholders (including doctors, physiotherapists, hip fracture patients, and caregivers) using the systems modeling methodology of Group Model Building (GMB) to elicit the factors that promote or inhibit hip fracture recovery, incorporating a feedback perspective to inform system-wide interventions. Hip fracture stakeholder engagement was facilitated through the Group Model Building approach in a two-half-day workshop of 25 stakeholders. This approach combined different techniques to develop a comprehensive qualitative whole-system view model of the factors that promote or inhibit hip fracture recovery.

Results

A conceptual, qualitative model of the dynamics of hip fracture recovery was developed that draws on stakeholders' personal experiences through a moderated interaction. Stakeholders identified four domains (i.e., expectation formation, rehabilitation, affordability/availability, and resilience building) that play a significant role in the hip fracture recovery journey..

Discussion

The insight that recovery of loss of function due to hip fracture is attributed to (a) the recognition of a gap between pre-fracture physical function and current physical function; and (b) the marshaling of psychological resilience to respond promptly to a physical functional loss via uptake of rehabilitation services is supported by findings and has several policy implications.

The association of obstructive sleep apnea with blood and cerebrospinal fluid biomarkers of Alzheimer's dementia - A systematic review and meta-analysis

Alzheimer's disease (AD) is the most common type of dementia and is characterized by the aggregation of extracellular amyloid-beta and intracellular hyperphosphorylation of tau proteins. Obstructive Sleep Apnea (OSA) is associated with increased AD risk. We hypothesize that OSA is associated with higher levels of AD biomarkers. The study aims to conduct a systematic review and meta-analysis of the association between OSA and levels of blood and cerebrospinal fluid biomarkers of AD. Two authors independently searched PubMed, Embase, and Cochrane Library for studies comparing blood and cerebrospinal fluid levels of dementia biomarkers between patients with OSA and healthy controls. Meta-analyses of the standardized mean difference were conducted using random-effects models. From 18 studies with 2804 patients, meta-analysis found that cerebrospinal fluid amyloid beta-40 (SMD:-1.13, 95%CI:-1.65 to -0.60), blood total amyloid beta (SMD:0.68, 95%CI: 0.40 to 0.96), blood amyloid beta-40 (SMD:0.60, 95%CI: 0.35 to 0.85), blood amyloid beta-42 (SMD:0.80, 95%CI: 0.38 to 1.23) and blood total-tau (SMD: 0.664, 95% CI: 0.257 to 1.072, I² = 82, p<0.01, 7 studies) were significantly higher in OSA patients compared with healthy controls. These findings suggest that OSA is associated with an elevation of some biomarkers of AD.

Health Services Use and Functional Recovery Following Blunt Trauma in Older Persons - A National Multicentre Prospective Cohort Study

OBJECTIVE

Frailty is associated with morbidity and mortality in older injured patients. However, for older blunt-trauma patients, increased frailty may not manifest in longer length of stay at index admission. We hypothesized that owing to time spent in hospital from readmissions, frailty would be associated with less total time at home in the 1-year postinjury period.

DESIGN

Prospective, nationwide, multicenter cohort study.

SETTING AND PARTICIPANTS

All Singaporean residents aged ≥55 years admitted for blunt trauma with an Injury Severity Score (ISS) or New Injury Severity Score (NISS) ≥10 from March 2016 to July 2018.

METHODS

Frailty (by modified Fried criteria) was assessed at index admission, based on questions on preinjury weight loss, slowness, exhaustion, physical activity, and grip strength at the time of recruitment. Low time at home was defined as >14 hospitalized days within 1 year postinjury. The contribution of planned and unplanned readmission to time at home postinjury was explored. Functional trajectory (by Barthel Index) over 1 year was compared by frailty.

RESULTS

Of the 218 patients recruited, 125 (57.3%) were male, median age was 72 years, and 48 (22.0%) were frail. On univariate analysis, frailty [relative to nonfrail: odds ratio (OR) 3.45, 95% confidence interval (CI) 1.33-8.97, P = .01] was associated with low time at home. On multivariable analysis, after inclusion of age, gender, ISS, intensive care unit admission, and surgery at index admission, frailty (OR 5.21, 95% CI 1.77-15.34, P < .01) remained significantly associated with low time at home in the 1-year postinjury period. Unplanned readmissions were the main reason for frail participants having low time at home. Frail participants had poorer function in the 1-year postinjury period.

CONCLUSIONS AND IMPLICATIONS

In the year following blunt trauma, frail older patients experience lower time at home compared to patients who were not frail at baseline. Screening for frailty should be considered in all older blunt-trauma patients, with a view to being prioritized for postdischarge support.

Frailty and functional decline after emergency abdominal surgery in the elderly: a prospective cohort study

Background

Frailty has been associated with an increased risk of adverse postoperative outcomes in elderly patients. We examined the impact of preoperative frailty on loss of functional independence following emergency abdominal surgery in the elderly.

Methods

This prospective cohort study was performed at a tertiary hospital, enrolling patients 65 years of age and above who underwent emergency abdominal surgery from June 2016 to February 2018. Premorbid variables, perioperative characteristics and outcomes were collected. Two frailty measures were compared in this study-the Modified Fried's Frailty Criteria (mFFC) and Modified Frailty Index-11 (mFI-11). Patients were followed-up for 1 year.

Results

A total of 109 patients were prospectively recruited. At baseline, 101 (92.7%) were functionally independent, of whom seven (6.9%) had loss of independence at 1 year; 28 (25.7%) and 81 (74.3%) patients were frail and non-frail (by mFFC) respectively. On univariate analysis, age, Charlson Comorbidity Index and frailty (mFFC) (univariate OR 13.00, 95% CI 2.21-76.63, p < 0.01) were significantly associated with loss of functional independence at 1 year. However, frailty, as assessed by mFI-11, showed a weaker correlation than mFFC (univariate OR 4.42, 95% CI 0.84-23.12, p = 0.06). On multivariable analysis, only premorbid frailty (by mFFC) remained statistically significant (OR 15.63, 95% CI 2.12-111.11, p < 0.01).

Conclusions

The mFFC is useful for frailty screening amongst elderly patients undergoing emergency abdominal surgery and is a predictor for loss of functional independence at 1 year. Including the risk of loss of functional independence in perioperative discussions with patients and caregivers is important for patient-centric emergency surgical care. Early recognition of this at-risk group could help with discharge planning and priority for post-discharge support should be considered.

Investigating the functional grip strength of elderly fallers in Singapore

Background:

Static grip strength has been a reliable method for assessing the functional capacity of the individual and can be a useful marker for identifying elderly people at risk of functional deterioration leading to a fall. However, static grip strength alone may not represent the true maximum strength that an individual could exert in his/her daily life, especially if the task requires simultaneous forces from gripping and a forearm twisting action, which is termed as functional isometric grip strength. Hence, the objectives of this study were to determine the differences in the fallers’ grip strengths at static-neutral grip position and during isometric forearm pronation/supination, as well as the differences between the maximum and sustained isometric grip strengths.

Methods:

Data were analysed from 31 elderly people (11 males and 20 females) aged 70 and over. Using a custom-made hand strength measurement device, three measurements were taken: (1) grip strength in neutral forearm position; (2) grip strength during isometric forearm pronation; and (3) grip strength during isometric forearm supination.

Results:

Elderly fallers could only achieve approximately 60%–80% of the maximum normative strength. Additionally, it was found that their functional isometric grip strengths were generally weaker than their static maximal grip strength, especially during isometric supination as either maximum or sustained isometric supination grip strengths (Dominant hand: 10.6 kg and 8.5 kg, respectively (males); 6.0 kg and 4.4 kg, respectively (females)).

Conclusion:

Elderly fallers are weaker when their grip is subjected to additional torque, endurance or both. Hence, these findings have potential implications for designing better screening tools for the geriatric population.

One-year and three-year mortality prediction in adult major blunt trauma survivors: a National Retrospective Cohort Analysis

Background

Survivors of trauma are at increased risk of dying after discharge. Studies have found that age, head injury, injury severity, falls and co-morbidities predict long-term mortality. The objective of our study was to build a nomogram predictor of 1-year and 3-year mortality for major blunt trauma adult survivors of the index hospitalization.

Methods

Using data from the Singapore National Trauma Registry, 2011–2013, we analyzed adults aged 18 and over, admitted after blunt injury, with an injury severity score (ISS) of 12 or more, who survived the index hospitalization, linked to death registry data. The study population was randomly divided 60/40 into separate construction and validation datasets, with the model built in the construction dataset, then tested in the validation dataset. Multivariable logistic regression was used to analyze 1-year and 3-year mortality.

Results

Of the 3414 blunt trauma survivors, 247 (7.2%) died within 1 year, and 551 (16.1%) died within 3 years of injury. Age (OR 1.06, 95% CI 1.05–1.07, p < 0.001), male gender (OR 1.53, 95% CI 1.12–2.10, p < 0.01), low fall from 0.5 m or less (OR 3.48, 95% CI 2.06–5.87, p < 0.001), Charlson comorbidity index of 2 or more (OR 2.26, 95% CI 1.38–3.70, p < 0.01), diabetes (OR 1.31, 95% CI 1.68–2.52, p = 0.04), cancer (OR 1.76, 95% CI 0.94–3.32, p = 0.08), head and neck AIS 3 or more (OR 1.79, 95% CI 1.13–2.84, p = 0.01), length of hospitalization of 30 days or more (OR 1.99, 95% CI 1.02–3.86, p = 0.04) were predictors of 1-year mortality. This model had a c-statistic of 0.85. Similar factors were found significant for the model predictor of 3-year mortality, which had a c-statistic of 0.83. Both models were validated on the second dataset, with an overall accuracy of 0.94 and 0.84 for 1-year and 3-year mortality respectively.

Conclusions

Adult survivors of major blunt trauma can be risk-stratified at discharge for long-term support.

The Low Fall as a Surrogate Marker of Frailty Predicts Long-Term Mortality in Older Trauma Patients

Background

Frailty is associated with adverse outcomes including disability, mortality and risk of falls. Trauma registries capture a broad range of injuries. However, frail patients who fall comprise a large proportion of the injuries occurring in ageing populations and are likely to have different outcomes compared to non-frail injured patients. The effect of frail fallers on mortality is under-explored but potentially significant. Currently, many trauma registries define low falls as less than three metres, a height that is likely to include non-frailty falls. We hypothesized that the low fall from less than 0.5 metres, including same-level falls, is a surrogate marker of frailty and predicts long-term mortality in older trauma patients.

Methods

Using data from the Singapore National Trauma Registry, 2011–2013, matched till September 2014 to the death registry, we analysed adults aged over 45 admitted via the emergency department in public hospitals sustaining blunt injuries with an injury severity score (ISS) of 9 or more, excluding isolated hip fractures from same-level falls in the over 65. Patients injured by a low fall were compared to patients injured by high fall and other blunt mechanisms. Logistic regression was used to analyze 12-month mortality, controlling for mechanism of injury, ISS, revised trauma score (RTS), co-morbidities, gender, age and age-gender interaction. Different low fall height definitions, adjusting for injury regions, and analyzing the entire adult cohort were used in sensitivity analyses and did not change our findings.

Results

Of the 8111 adults in our cohort, patients who suffered low falls were more likely to die of causes unrelated to their injuries (p<0.001), compared to other blunt trauma and higher fall heights. They were at higher risk of 12-month mortality (OR 1.75, 95% CI 1.18–2.58, p = 0.005), independent of ISS, RTS, age, gender, age-gender interaction and co-morbidities. Falls that were higher than 0.5m did not show this pattern. Males were at higher risk of mortality after low falls. The effect of age on mortality started at age 55 for males, and age 70 for females, and the difference was attributable to the additional mortality in male low-fallers.

Conclusions

The low fall mechanism can optimize prediction of long-term mortality after moderate and severe injury, and may be a surrogate marker of frailty, complementing broader-based studies on aging.