Association Between Cataract Extraction and Development of Dementia

Artificial Intelligence (AI) Reveals Ethnic Disparities in Cataract Detection and Treatment

INTRODUCTION

The aim of this work is to identify patients at risk of limited access to healthcare through artificial intelligence using a name-ethnicity classifier (NEC) analyzing the clinical stage of cataract at diagnosis and preoperative visual acuity.

METHODS

This retrospective, cross-sectional study includes patients seen in the cataract clinic of a tertiary care hospital between September 2017 and February 2020 with subsequent cataract surgery in at least one eye. We analyzed 4971 patients and 8542 eyes undergoing surgery.

RESULTS

The NEC identified 360 patients with names classified as 'non-German' compared to 4611 classified as 'German'. Advanced cataract (7 vs. 5%; p = 0.025) was significantly associated with group 'non-German'. Mean best-corrected visual acuity in group 'non-German' was 0.464 ± 0.406 (LogMAR), and in group 'German' was 0.420 ± 0.334 (p = 0.009). This difference remained significant after exclusion of patients with non-lenticular ocular comorbidities. Surgical time and intraoperative complications did not differ between the groups. Retrobulbar or general anesthesia was chosen significantly more frequently over topical anesthesia in group 'non-German' compared to group 'German' (24 vs. 18% respectively; p < 0.001).

CONCLUSIONS

This study shows that artificial intelligence is able to uncover health disparities between people with German compared to non-German names using NECs. Patients with non-German names, possibly facing various social barriers to healthcare access such as language barriers, have more advanced cataracts and worse visual acuity upon presentation. Artificial intelligence may prove useful for healthcare providers to discover and counteract such inequalities and establish tailored preventive measures to decrease morbidity in vulnerable population subgroups.

Association between surgery and rate of incident dementia in older adults: A population-based retrospective cohort study

BACKGROUND

The risk of incident dementia after surgery in older adults is unclear. The study objective was to examine the rate of incident dementia among older adults after elective surgery compared with a matched nonsurgical control group.

METHODS

We conducted a population-based, propensity-matched retrospective cohort study using data from linked administrative databases in Ontario, Canada. All community-dwelling individuals aged 66 years and older who underwent one of five major elective surgeries between April 1, 2007 and March 31, 2011 were included. Each surgical patient was matched 1:1 on surgical specialty of the surgeon at consultation, age, sex, fiscal year of entry, and propensity score with a patient who attended an outpatient visit with a surgeon of the same surgical specialty but did not undergo surgery. Patients were followed for up to 5 years after cohort entry for the occurrence of a new dementia diagnosis, defined from administrative data. Cause-specific hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between surgery and the hazard of incident dementia. Subgroup and sensitivity analyses were performed.

RESULTS

A total of 27,878 individuals (13,939 matched pairs) were included in the analysis. A total of 640 (4.6%) individuals in the surgical group and 965 (6.9%) individuals in the control group developed dementia over the 5-year follow-up period. Individuals who underwent surgery had a reduced rate of incident dementia compared with their matched nonsurgical controls (HR 0.88; 95% CI 0.80-0.97; p = 0.01). This association was persistent in most subgroups and after sensitivity analyses.

CONCLUSIONS

Elective surgery did not increase the rate of incident dementia when compared with matched nonsurgical controls. This could be an important consideration for patients and surgeons when elective surgery is considered.

Cataract Surgery and Chronic Kidney Disease: A Hospital-based Prospective Cohort Study

Objective Cataract and chronic kidney disease (CKD) occur with increasing frequency with age and share common risk factors including smoking, diabetes, and hypertension. We evaluated the risk of incident cataract surgery in patients with non-dialysis-dependent CKD and dialysis-dependent CKD compared to non-CKD patients, while taking into account the competing risk of death. Methods The participants included 1,839 patients from Sado General Hospital enrolled in the Project in Sado for Total Health (PROST) between June 2008 and December 2016 (54% men; mean age, 69 years). Among these patients, 50%, 44%, and 6% had non-CKD, non-dialysis-dependent CKD, and dialysis-dependent CKD, respectively. Results During a median follow-up of 5.6 years (interquartile range, 4.7-7.1), 193 participants underwent cataract surgery [18.7 (95% confidence interval (CI), 16.2-21.5)/1,000 person-years] and 425 participants died without undergoing cataract surgery [41.0 (95% CI, 37.4-45.2)/1,000 person-years]. The cumulative incidence of cataract surgery was the highest in the dialysis-dependent CKD group, followed by the non-dialysis-dependent CKD and non-CKD groups (log-rank p=0.002). After adjusting for potential confounding factors, the dialysis-dependent CKD group [hazard ratio (HR) 2.48; 95% CI 1.43-4.31], but not the non-dialysis-dependent CKD group (HR, 1.01; 95% CI 0.74-1.38), had a higher risk of cataract surgery than the non-CKD group. However, this association was no longer significant according to a competing risk analysis (sub-hazard ratio, 1.67; 95% CI 0.93-3.03). Conclusion Dialysis-dependent CKD patients were found to have an increased risk of cataract surgery; however, the association was attenuated and no longer significant when death was considered a competing risk.

Sensory Loss and Risk of Dementia

Sensory loss in olfaction, vision, and hearing is a risk factor for dementia, but the reasons for this are unclear. This review presents the neurobiological evidence linking each sensory modality to specific dementias and explores the potential mechanisms underlying this. Olfactory deficits can be linked to direct neuropathologic changes in the olfactory system due to Alzheimer disease and Parkinson disease, and may be a marker of disease severity. Visual deficits potentially increase dementia risk in a vulnerable individual by reducing resilience to dementia. Hearing deficits may indicate a susceptibility to Alzheimer disease through a variety of mechanisms. More generally, sensory impairment could be related to factors associated with resilience against dementia. Further research is needed to tease out the specific and synergistic effects of sensory impairment. Studying sensory loss in relation to neurodegenerative biomarkers is necessary to clarify the mechanisms involved. This could produce new monitoring and management strategies for people at risk of dementia.

The burden of vision loss due to cataract in China: findings from the Global Burden of Disease Study 2019

OBJECTIVE

To provide a reference for future policy and measure formulation by conducting a detailed analysis of the burden of vision loss due to cataract by year, age, and gender in China from 1990 to 2019.

METHODS

Data on the prevalence and disability-adjusted life-years (DALYs) due to cataract in China and neighboring and other G20 countries were extracted from the 2019 Global Burden of Disease (GBD) study to observe the changing trends of vision loss.

RESULTS

The number and rate of all-age prevalence and DALYs for cataract in China increased significantly from 1990 to 2019. The age-standardized DALYs rate witnessed a slowly declining trend by 10.16%. And the age-standardized prevalence increased by 14.35% over the 30-year period. Higher prevalence and DALYs were observed in female population from 1990 through 2019, with little improvement over the decades(all p < 0.001). The disease burden of cataract is higher in middle-aged and elderly people. Blindness accounted for the largest proportion of vision impairment burden caused by cataract in China. The age-standardized prevalence and DALY rate of cataract in China were lower than those in India and Pakistan, but higher than those in Russia, South Korea, North Korea, Singapore, and Japan.

CONCLUSIONS

In the past 30 years, although the age-standardized DALYs rate has decreased slightly in China, the all-age prevalence and DALYs have both increased. This study highlights the importance of reducing cataract burden by providing timely and easily accessible quality care, especially in females and the elderly population.

Causal Associations of Glaucoma and Age-Related Macular Degeneration with Cataract: A Bidirectional Two-Sample Mendelian Randomisation Study

Common age-related eye disorders include glaucoma, cataract, and age-related macular degeneration (AMD); however, little is known about their relationship with age. This study investigated the potential causal relationship between glaucoma and AMD with cataract using genetic data from multi-ethnic populations. Single-nucleotide polymorphisms (SNPs) associated with exposure to cataract were selected as instrumental variables (IVs) from genome-wide association studies using meta-analysis data from BioBank Japan and UK Biobank. A bidirectional two-sample Mendelian randomisation (MR) study was conducted to assess the causal estimates using inverse variance weighted, MR-Egger, and MR pleiotropy residual sum and outlier tests. SNPs with (p < 5.0 × 10-8) were selected as IVs for cataract, primary open-angle glaucoma, and AMD. We found no causal effects of cataract on glaucoma or AMD (all p > 0.05). Furthermore, there were no causal effects of AMD on cataract (odds ratio [OR] = 1.02, p = 0.400). However, glaucoma had a substantial causal effect on cataract (OR = 1.14, p = 0.020). Our study found no evidence for a causal relationship of cataract on glaucoma or AMD and a casual effect of AMD on cataract. Nonetheless, glaucoma demonstrates a causal link with cataract formation, indicating the need for future investigations of age-related eye diseases.

Migraine Association with Alzheimer's Disease Risk: Evidence from the UK Biobank Cohort Study and Mendelian Randomization

BACKGROUND

Epidemiological studies on the association between migraine and Alzheimer's disease (AD) risk have yielded inconsistent conclusions. We aimed to characterize the phenotypic and genetic relationships between migraine and AD.

METHODS

To investigate the association between migraine and the risk of AD by analyzing data from a large sample of 404,318 individuals who were initially free from all-cause dementia or cognitive impairment, utilizing the UK Biobank dataset. We employed Cox regression modeling and propensity score matching techniques to examine the relationship between migraine and subsequent occurrences of AD. Additionally, the study utilized Mendelian randomization (MR) analysis to identify the genetic relationship between migraine and the risk of AD.

RESULTS

Migraine patients had a significantly increased risk of developing AD, compared to non-migraine patients (adjusted hazard ratio (HR) = 2.34, 95% confidence interval (CI) = 2.01-0.74, P < 0.001). Moreover, the propensity scores matching analyses found that migraine patients had a significantly higher risk of developing AD compared to non-migraine patients (HR = 1.85, 95%CI = 1,68-2.05, P < 0.001). Additionally, the MR suggested that significant causal effects of migraine on AD risks were observed [odds ratio (OR) = 2.315; 95% confidence interval (CI) = 1.029-5.234; P = 0.002]. Moreover, no evidence supported the causal effects of AD on migraine (OR = 1.000; 95%CI = 0.999-1.006; P = 0.971).

CONCLUSION

The present study concludes that migraine patients, compared to a matched control group, exhibit an increased risk of developing AD. Moreover, migraine patients exhibit an increased predisposition of genetic susceptibility to AD. These findings hold significant clinical value for early intervention and treatment of migraines to reduce the risk of AD.

The significance of G8 and other geriatric assessments in urologic cancer management: A comprehensive review

In urologic oncology, which often involves older patients, it is important to consider how to manage their care appropriately. Geriatric assessment (GA) is a method that can address the specific needs of older cancer patients. The GA encompasses various assessment domains, but these domains exhibit variations across the literature. Some of the common items include functional ability, nutrition, comorbidities, cognitive ability, psychosocial disorders, polypharmacy, social and financial support, falls/imbalance, and vision/hearing. Despite the diversity of domains, there is limited consensus on reliable measurement methods. This review discusses the role of GA in managing urologic cancer in unique scenarios, such as those necessitating temporary or permanent urinary catheters or stomas due to urinary diversion. A comprehensive GA is time and human-resource-intensive in real-world clinical practice. Hence, simpler tools such as the Geriatric-8 (G8), capable of identifying high-risk patients requiring a detailed GA, are also under investigation in various contexts. Therefore, we conducted a systematic literature review on the G8. Our findings indicate that patients with low G8 scores encounter difficulties with stoma self-care after urinary diversion and have higher risks of urinary tract infections and ileus after radical cystectomy. The utilization of G8 as a screening tool for urologic cancer patients may facilitate the delivery of appropriate and personalized treatment and care.

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.

Associations of severe liver diseases with cataract using data from UK Biobank: a prospective cohort study

Background

Liver disease is linked to series of extrahepatic multisystem manifestations. However, little is known about the associations between liver and eye diseases, especially cataract, the global leading cause of blindness. We aimed to investigate whether severe liver diseases, including non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), viral hepatitis, and liver fibrosis and cirrhosis, were associated with an increased risk of the cataract.

Methods

A total of 326,558 participants without cataract at baseline enrolled in the UK Biobank between 2006 and 2010 were included in this prospective study. The exposures of interest were severe liver diseases (defined as hospital admission), including NAFLD, ALD, viral hepatitis and liver fibrosis and cirrhosis. The outcome was incident cataract. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). Each liver disease was first treated as a binary time-varying variable to investigate its association with cataract, and then was treated as a ternary time-varying variable to examine the recent (liver disease within 0-5 years) vs. long-term (liver disease > 5 years) state associations with the risk of cataract.

Findings

After a median follow-up of 13.3 years (interquartile range, 12.5-14.0 years), 37,064 individuals were documented as developing cataract. Higher risk of cataract was found in those with severe NAFLD (HR, 1.47; 95% CI, 1.33-1.61), ALD (HR, 1.57; 95% CI, 1.28-1.94) and liver fibrosis and cirrhosis (HR, 1.58; 95% CI, 1.35-1.85), but not in individuals with viral hepatitis when exposure was treated as a binary time-varying variable (P = 0.13). When treating exposure as a ternary time-varying variable, an association between recently diagnosed viral hepatitis and cataract was also observed (HR, 1.55; 95% CI, 1.07-2.23). Results from the combined model suggested they were independent risk factors for incident cataract. No substantial changes were found in further sensitivity analyses.

Interpretation

Severe liver diseases, including NAFLD, ALD, liver fibrosis and cirrhosis and recently diagnosed viral hepatitis, were associated with cataract. The revelation of liver-eye connection suggests the importance of ophthalmic care in the management of liver disease, and the intervention precedence of patients with liver disease in the early screening and diagnosis of cataract.

Funding

National Natural Science Foundation of China, Science and Technology Innovation Action Plan of Shanghai Science and Technology Commission, Clinical Research Plan of Shanghai Shenkang Hospital Development Center, Shanghai Municipal Key Clinical Specialty Program, the Guangdong Basic and Applied Basic Research Foundation and Shenzhen Science and Technology Program.

Associations of cataract, cataract surgery with dementia risk: A systematic review and meta-analysis of 448,140 participants

BACKGROUND

Cataract is the leading cause of blindness around the world. Previous investigations have assessed the relationship between cataract, cataract surgery and dementia risk, but their results remain controversial. Herein, we conducted a meta-analysis to evaluate the associations between cataract, cataract surgery and the risk of dementia.

METHODS

We systemically screened the literature from three electronic databases PubMed, EMBASE and CENTRAL until April 2023. The data were collected by two independent researchers. The hazard ratios (HRs) or odds ratios (ORs) from eligible studies with 95% confidence intervals (CIs) were adjusted into the risk ratios (RRs), which were pooled using the random-effects model.

RESULTS

A total of nine studies with 448,140 participants reported the associations between cataract or cataract surgery and the risk of dementia were included in this meta-analysis. The outcomes of our pooled analysis indicated that cataract was associated with an increased risk of all-cause dementia (RR = 1.24, 95% CI, 1.14-1.35, p < .00001), Alzheimer's disease (RR = 1.22, 95% CI, 1.10-1.35, p = .0002) and vascular dementia (RR = 1.29, 95% CI, 1.01-1.66, p = .04). Cataract surgery is associated with a reduction of the dementia risk (RR = 0.74, 95% CI, 0.67-0.81, p < .00001).

CONCLUSIONS

Current evidence from the existing studies supports that cataract is associated with an increased risk of dementia, and cataract surgery may be instrumental in reducing the risk of dementia in patients with cataract.

On some challenges of psychological research in late adulthood and aging

The World population is aging and, consequently, understanding late adulthood and aging processes is a major scientific priority. Research in this segment of the life is particularly challenging: the lifespan approach, necessary for thorough aging investigations, implies theoretical multidisciplinary and methodological multivariate perspectives; variability during aging is particularly high compared to previous life phases; study designs must account for specific predicaments (such as confound between age, cohort, and time of measurement; selective study participation and attrition; assumed age-invariance of measurements; retest effects). Furthermore, promising methods for data analysis develop on a daily basis, requiring continuous technical training. I will discuss some of these challenges, summarize extant potential solutions, and touch on some ethical and broader social responsibility issues.

Impact of cataract surgery on cognitive impairment in older people

OBJECTIVES

To examine the impact of cataract surgery on mild cognitive impairment (MCI) and dementia in older people.

METHODS

This prospective observational study included patients aged 75 years and older who underwent cataract surgery between 2019 and 2021. Mini-mental state examination (MMSE) and MMSE for the visually impaired (MMSE-blind) were measured to evaluate cognitive function before and 3 months after cataract surgery. MMSE score at baseline was used to categorize patients into dementia (MMSE ≤ 23) and MCI groups (23 < MMSE ≤ 27). Logistic regression models were used to estimate associations between improvement in cognitive function and other factors.

RESULTS

Of 132 patients screened for inclusion in the study, 88 met the inclusion criteria; 39 patients were assigned to the dementia group (mean age, 85.7 ± 4.2 years) and 49 to the MCI group (mean age, 84.2 ± 3.4 years). The MCI group showed significant improvement from before to after surgery in the MMSE score (25.65 ± 1.03 vs. 27.08 ± 1.99, respectively, p < 0.001) and MMSE-blind score (18.04 ± 1.14 vs. 19.41 ± 2.01, respectively, p < 0.001). Cognitive function improved significantly in the MCI group compared with the dementia group (odds ratio, 2.85; 95% confidence interval, 1.02-7.97; and p = 0.046).

CONCLUSIONS

Cataract surgery significantly increases cognitive test scores in older patients with MCI. After cataract surgery, the likelihood of improvement in cognitive function may be highly dependent on a patient's preoperative cognitive state.

Cataract Phacoemulsification in People with Dementia: Characterization and Outcomes

PURPOSE

To characterize cataract surgery in people with dementia (PWD) using a cataract surgery outcomes database.

METHODS

Demographics, medical and ocular history, surgical characteristics, and postoperative measures were analyzed for differences between PWD and non-PWD cohorts. Patient-level data were analyzed with Fisher's Exact Test, and eye-level data were analyzed with logistic regression using generalized estimating equations to account for correlation of eyes from the same individual.

RESULTS

507 eyes from 296 PWD were identified using appropriate ICD codes and cross-referenced to a cataract surgery outcomes database containing 12,949 eyes from 7,853 patients who underwent cataract phacoemulsification at a single center between January 2014 and October 2019. PWD were older (p < .001), had shorter duration cataract surgeries (p = .006), and were more likely to have mature cataract (p = .017). The rate of general anesthesia was higher in PWD (p = .005). There were no differences in complication rates between PWD and non-PWD cohorts. Both preoperative best corrected LogMAR distance visual acuity (CDVA) (p < .001) and postoperative CDVA (p < .001) were worse in PWD. CDVA significantly improved in both groups (p < .001); however, the average magnitude of improvement in CDVA was not significantly different between groups (p = .169).

CONCLUSIONS

PWD present for cataract surgery at a later age and were more likely to have mature cataracts and general anesthesia, but did not have higher rates of complication, and showed significant improvement in CDVA following surgery. These findings should be encouraging to PWD undergoing counseling for cataract surgery, and for the potential for improved function in PWD.

The Effect of Cataract Surgery on the Risk of Dementia: A Nationwide Cohort Study

BACKGROUND

An advanced age and the female sex are widely recognized risk factors for both cataract and dementia. We investigated the effect of cataract surgery on the incidence of dementia in a Korean population aged ≥ 45 years with a previous diagnosis of cataract.

METHODS

This nationwide cohort study was performed using Korean National Health Insurance Service data collected from 2006 to 2017. A total of 300,327 subjects aged ≥ 45 years with a history of cataract diagnosis but no previous diagnosis of dementia were analyzed. The relationship between cataract surgery and dementia was evaluated, applying a time-varying analysis to evaluate the hazard ratio (HR) and 95% confidence interval (CI) values according to dementia. It was calculated via a multivariable Cox regression model, with adjustments for age, sex, visual acuity (VA), ocular and systemic comorbidities, and social factors (including body mass index, income, smoking, and drinking).

RESULTS

In the multivariate analysis, the cataract surgery group showed a marginal difference in dementia development (HR 1.10 [95% CI 1.02-1.19]) because both cataract and dementia share common risk factors. However, in the subgroup analysis, men (HR 0.49 [95% CI 0.26-0.90]) and patients under 65 years of age (HR 0.88 [95% CI 0.79-0.99]) in the group with cataract surgery and good VA showed a significantly lower incidence of dementia.

CONCLUSION

Through visual improvement, together with timely surgical intervention, the procedure can alleviate the risk of dementia in visually impaired patients, especially in younger and male patients.

CircRNA 06209 inhibits cataract development by sponging miR-6848-5p and regulating ALOX15 expression

Cataract is the leading cause of blindness in the world, and there is a lack of effective treatment drugs. CircRNA plays an important part in a variety of diseases, however, the role of circRNA in cataracts remains largely unknown. In this study, we constructed a cataract model of rats and obtained the circRNAs related to cataracts by whole transcriptome sequencing and circRNA-mRNA co-expression network. To investigate the effect and mechanism of circRNA 06209 on cataracts, we performed several in vivo and in vitro experiments, including CCK8 assay, flow cytometry, dual luciferase reporter assay, RIP assay, actinomycin D assay, and Western blot analysis. We identify that a necroptosis-related circRNA, circRNA 06209, is down-regulated in cataracts. Vitro experiments showed that up-regulation of circRNA 06209 could promote cell proliferation and inhibit cell apoptosis. Vivo experiments revealed that circRNA 06209 overexpression could inhibit the development of cataracts. Mechanistically, circRNA 06209 acts as a miRNA sponge and competitively binds to miR-6848-5p to curb the inhibitory effect of miR-6848-5p on ALOX15, thereby affecting cell viability and apoptosis. This study found that circRNA 06209 plays a critical part in inhibiting cataracts through the miR-6848-5p/ALOX15 pathway, suggesting that circRNA 06209 may be a promising therapeutic target for cataracts.

Remarkable Improvements After Cataract Surgery in a Presumed "End-Stage" Glaucoma Patient: A Case Report

Predicting the visual outcome after cataract extraction can be challenging in glaucoma patients who develop cataracts. Here, we demonstrate the case of a patient with advanced glaucoma and a mild-to-moderate cataract at initial presentation, who demonstrated remarkable improvement in visual acuity following a period of controlled intraocular pressure (IOP) and the removal of a matured cataract at the time of surgery. A 64-year-old Haitian woman with severe mixed-mechanism glaucoma and hand motion vision in both eyes (OU) presented with intraocular pressures of 38 mmHg OD (oculus dexter/right eye) and 41 mmHg OS (oculus sinister/left eye) while on three IOP-lowering agents. Her medications were escalated to six IOP-lowering medications, and she underwent bilateral transscleral laser cyclophotocoagulation with both micropulse and continuous wave probes simultaneously. Postoperatively, IOPs dropped to 7 and 9 mmHg in the right and left eyes, respectively, and remained at or below target on three topical agents for the remainder of her follow-up. Contrastingly, the patient's cataract had progressed, and the decision was made to undergo cataract extraction OU sequentially. The subsequent clinical course demonstrated progressive visual improvement with 20/80 best-corrected visual acuity OU and increased independence with activities of daily living. This case illustrates the potential for visual improvement in an advanced glaucoma patient after removing a matured cataract despite limited prior expectations. Ocular comorbidities complicate but do not necessarily preclude appropriate interventions that may improve patients' vision-related quality of life.

Dementia and cataract surgery in Australia and New Zealand

BACKGROUND

Cataract surgery improves quality of life and reduces cognitive deterioration.

OBJECTIVES

This paper discusses the health implications of low vision, commonly related to cataracts, in older adults. A recent publication reported that cataract surgery reduces the risk of dementia by 30% over 10 years.

METHODS

We searched Medline from inception to January 2023. We also conducted backward and forward citation searches of included studies and set up alerts to identify studies published after the search date. We performed discussion groups with multidisciplinary experts.

RESULTS

This article provides a broad description of the importance of vision for cognitive function. We discuss access to public-funded cataract surgery in Australia and New Zealand and how this impacts population benefits.

CONCLUSIONS

We have evidence that cataract surgery can decrease the risk of dementia. This is an important topic that deserves recognition as part of an overall ageing response by policymakers and health professionals.

Objectively Measured Visual Impairment and Dementia Prevalence in Older Adults in the US

Importance

Estimates of the association between visual impairment (VI) and dementia in the US population are based on self-reported survey data or measures of visual function that are at least 15 years old. Older adults are at high risk of VI and dementia so there is a need for up-to-date national estimates based on objective assessments.

Objective

To estimate the association between VI and dementia in older US adults based on objective visual and cognitive function testing.

Design, Setting, and Participants

This secondary analysis of the 2021 National Health and Aging Trends Study (NHATS), a population-based, nationally representative panel study, included 3817 respondents 71 years and older. Data were analyzed from January to March 2023.

Intervention

In 2021, NHATS incorporated tablet-based tests of distance and near visual acuity and contrast sensitivity (CS) with habitual correction.

Main Outcomes and Measures

VI was defined as distance visual acuity more than 0.30 logMAR, near visual acuity more than 0.30 logMAR, and CS more than 1 SD below the sample mean. Dementia was defined as scoring 1.5 SDs or more below the mean in 1 or more cognitive domains, an AD8 Dementia Screening Interview Score indicating probable dementia, or diagnosed dementia. Poisson regression estimated dementia prevalence ratios adjusted for covariates.

Results

Of 2967 included participants, 1707 (weighted percentage, 55.3%) were female, and the median (IQR) age was 76.9 (77-86) years. The weighted prevalence of dementia was 12.3% (95% CI, 10.9-13.7) and increased with near VI (21.5%; 95% CI, 17.7-25.3), distance VI (mild: 19.1%; 95% CI, 13.0-25.2; moderate, severe, or blind: 32.9%; 95% CI, 24.1- 41.8), and CS impairment (25.9%; 95% CI, 20.5-31.3). Dementia prevalence was higher among participants with near VI and CS impairment than those without (near VI prevalence ratio: 1.40; 95% CI, 1.16-1.69; CS impairment prevalence ratio: 1.31; 95% CI, 1.04-1.66) and among participants with moderate to severe distance VI or blindness (prevalence ratio: 1.72; 95% CI, 1.26-2.35) after adjustment for covariates.

Conclusions and Relevance

In this survey study, all types of objectively measured VI were associated with a higher dementia prevalence. As most VI is preventable, prioritizing vision health may be important for optimizing cognitive function.

Enhancing Intermediate Vision in Patients Affected by Epiretinal Membrane Treated by Phaco-Vitrectomy

BACKGROUND

The aim of this research was to see if a refractive enhanced monofocal IOL (Eyhance IOL, IOL Abbott Medical Optics, Inc., Santa Ana, CA, USA) can provide better intermediate vision in patients undergoing phaco-vitrectomy due to cataract and epiretinal macular membrane (ERM).

METHODS

A nonrandomized prospective observational comparative study enrolled patients affected by cataract and ERM undergoing phaco-vitrectomy. A follow up of 6 months was established. Corrected and uncorrected visual acuity of both monocular and binocular types were assessed regarding intermediate and far distances. The CATQUEST 9-SF questionnaire was administered preoperatively and at the last follow-up.

RESULTS

Twenty-three eyes of twenty-three patients were enrolled, with 11 in the enhanced monofocal group. The uncorrected and corrected distance visual acuity after 6 months was not statistically different. Both monocular and binocular uncorrected intermediate visual acuity after 6 months were higher in the enhanced monofocal group (p < 0.001). The corrected intermediate visual acuity after 6 months was higher in the enhanced monofocal group (p = 0.01). The CATQUEST-9SF questionnaire showed significant differences in the variation between the preoperative condition and six-month postoperative results (p < 0.001).

CONCLUSIONS

This refractive enhanced monofocal IOL can provide better intermediate vision compared to a standard monofocal IOL in patients undergoing phaco-vitrectomy due to cataracts and ERM. Further studies are necessary to confirm these results.

The impact of sensory impairments and eye diseases on cognitive function in elderly Chinese: The mediating effects of social participation

Background

Sensory impairments and eye diseases increase the risk of cognitive decline, but little is known regarding their influence on cognitive function in elderly Chinese and the underlying mechanisms. We aimed to explore these influence mechanism from the social participation perspective.

Methods

We selected 2876 respondents aged ≥60 from the China Health and Retirement Longitudinal Study (CHARLS) conducted in 2013, 2015, and 2018. We assessed sensory impairments and eye diseases based on self-reported responses, and evaluated its relation to social participation and cognitive function by fixed-effects regression and mediation effect analysis over a five-year period.

Results

Respondents with visual impairment and cataracts had poor memory and mental status. Compared with near visual impairment, distance visual impairment was associated with a 1.7 times higher likelihood of cognitive decline (correlation coefficient (β) = -0.051; 95% confidence interval (CI) = -0.065, -0.036)). Respondents with hearing impairment had bad memory (β = -0.046; 95% CI = -0.065, -0.036), but not mental status. Social participation partially mediated the relationships of sensory impairments and cataracts with cognitive function in elderly Chinese. Individuals with sensory impairments affected by limited social participation reported a faster cognitive decline compared to those with eye disease.

Conclusions

We found that sensory impairments and eye diseases were negatively associated with cognitive function. Furthermore, sensory impairments and cataracts influence cognitive function partly via social participation. Our results have important theoretical and practical implications and suggests that early interventions for sensory impairments and eye diseases may improve the cognitive function of elderly people.

Unfulfilled Needs in the Detection, Diagnosis, Monitoring, Treatment, and Understanding of Glaucoma in Blacks Globally

Glaucoma is an ophthalmic disorder that affects a significant number of Blacks globally. A leading cause of this condition is an age-related enlargement of the lens and increased intraocular pressure. Although Blacks are affected by glaucoma at a higher rate than their Caucasian counterparts, there remains a lack of emphasis placed on the detection, diagnosis, monitoring, and treatment of glaucoma in this population. Education regarding glaucoma in the African and African American populations is essential to reducing rates of glaucoma-related visual impairment and improving treatment success. In this article, we highlight specific issues and limitations to the management of glaucoma, which affects Blacks at a higher rate. In addition, we also review the backgrounds of Blacks globally and examine historical events that have contributed to financial inequality and wealth/health disparities affecting glaucoma management. Lastly, we suggest reparations and solutions that health care professionals can use to improve glaucoma screening and management.

Relationship between Claims-Based Frailty Index and Eye Care Utilization among Medicare Beneficiaries with Glaucoma

PURPOSE

To determine differences in eye care utilization by frailty levels among Medicare beneficiaries with glaucoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Medicare fee-for-service beneficiaries over 65 years of age with glaucoma, identified using International Classification of Diseases codes before July 1, 2014.

METHODS

By using a validated claims-based frailty index (range, 0-1), beneficiaries were classified as nonfrail/prefrail (0-0.19), mildly frail (0.20-0.29), and moderate-to-severely frail (≥ 0.30). Negative binomial regression analyses were used to estimate incident rate ratios (IRRs) of eye care utilization by frailty levels between July 1, 2014, and December 31, 2016.

MAIN OUTCOME MEASURES

Current Procedural Terminology codes for eye examinations and eye care-related office visits; eye care-related inpatient and emergency department (ED) encounters; eye care-related nursing facility and home-visit encounters; visual field (VF) and retinal nerve fiber layer (RNFL) OCT tests; and selective laser trabeculoplasties (SLTs) and glaucoma surgeries.

RESULTS

Among 76 260 Medicare beneficiaries with glaucoma, the mean age was 78.9 years (standard deviation, 7.8), female beneficiaries constituted 60.5%, and 78.7% of beneficiaries self-identified as non-Hispanic White. According to a claims-based frailty index, 79.5% of beneficiaries were nonfrail/prefrail, 17.1% were mildly frail, and 3.4% were moderate-to-severely frail. Moderate-to-severely frail beneficiaries were less likely than nonfrail/prefrail beneficiaries to have outpatient encounters (IRR, 0.85, 95% confidence interval [CI], 0.83-0.88); VF tests (IRR, 0.64, 95% CI, 0.60-0.67); RNFL OCT tests (IRR, 0.77, 95% CI, 0.73-0.81); SLT (IRR, 0.74, 95% CI, 0.60-0.92); and glaucoma surgery (IRR, 0.74, 95% CI 0.55-0.99), after adjusting for age, gender, glaucoma severity, race, and socioeconomic status. Compared with nonfrail/prefrail beneficiaries, moderate-to-severely frail beneficiaries had higher rates of inpatient/ED encounters (IRR, 5.03, 95% CI, 2.36-10.71) and nursing facility/home-visit encounters (IRR, 34.89, 95% CI, 14.82-82.13).

CONCLUSIONS

Compared with nonfrail/prefrail Medicare beneficiaries with glaucoma, beneficiaries with moderate-to-severe frailty had lower rates of eye care utilization in the outpatient setting and higher rates of utilization in acute care settings. This suggests that frail patients may receive less disease monitoring and fewer interventions for their glaucoma management.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Association of cataract extraction and the risk of dementia-A systematic review and meta-analysis

Objectives

This research aims to investigate if cataract extraction lowers the risk of all-cause dementia.

Methods

Original literature on cataract surgery associated with all-cause dementia as of November 27, 2022, was searched in several commonly used databases. Manual review was used to include eligible studies. Stata software (version 16) was used to perform statistical analysis on pertinent data. Publication bias can be precisely evaluated using funnel plots and Egger's test.

Results

In the meta-analysis of 4 cohort studies with 245,299 participants. Pooled analysis indicated that cataract surgery was linked to a lower incidence of all-cause dementia (OR = 0.77, 95%CI: 0.66-0.89; I²= 54.7%; P < 0.001). Cataract surgery was linked to a lower risk of AD (OR = 0.60, 95%CI: 0.35-1.02; I²= 60.2%; P < 0.001).

Conclusions

Cataract surgery is linked to a lower incidence of all-cause dementia and Alzheimer's disease. A cataract is a reversible visual impairment. Cataract surgery may be a protective factor against the onset of all-cause dementia and can reduce the economic and family burden caused by all-cause dementia worldwide. Given the restricted pool of included studies, our findings necessitate meticulous interpretation.

Systematic review registration

http://www.crd.york.ac.uk/prospero retrieve registration details by searching CRD4202379371.

Vitreous Humor Biomarkers Reflect Pathological Changes in the Brain for Alzheimer's Disease and Chronic Traumatic Encephalopathy

BACKGROUND

Patients with eye disease have an increased risk for developing neurodegenerative disease. Neurodegenerative proteins can be measured in the eye; however, correlations between biomarker levels in eye fluid and neuropathological diagnoses have not been established.

OBJECTIVE

This exploratory, retrospective study examined vitreous humor from 41 postmortem eyes and brain tissue with neuropathological diagnoses of Alzheimer's disease (AD, n = 7), chronic traumatic encephalopathy (CTE, n = 15), both AD + CTE (n = 10), and without significant neuropathology (controls, n = 9).

METHODS

Protein biomarkers i.e., amyloid-β (Aβ 40,42), total tau (tTau), phosphorylated tau (pTau181,231), neurofilament light chain (NfL), and eotaxin-1 were quantitatively measured by immunoassay. Non-parametric tests were used to compare vitreous biomarker levels between groups. Spearman's rank correlation tests were used to correlate biomarker levels in vitreous and cortical tissue. The level of significance was set to α= 0.10.

RESULTS

In pairwise comparisons, tTau levels were significantly increased in AD and CTE groups versus controls (p = 0.08 for both) as well as AD versus AD+CTE group and CTE versus AD+CTE group (p = 0.049 for both). Vitreous NfL levels were significantly increased in low CTE (Stage I/II) versus no CTE (p = 0.096) and in low CTE versus high CTE stage (p = 0.03). Vitreous and cortical tissue levels of pTau 231 (p = 0.02, r = 0.38) and t-Tau (p = 0.04, r = -0.34) were significantly correlated.

CONCLUSION

The postmortem vitreous humor biomarker levels significantly correlate with AD and CTE pathology in corresponding brains, while vitreous NfL was correlated with the CTE staging. This exploratory study indicates that biomarkers in the vitreous humor may serve as a proxy for neuropathological disease.

Cataract, Cataract Surgery, and Risk of Incident Dementia: A Prospective Cohort Study of 300,823 Participants

BACKGROUND

Visual impairment and interventions to preserve vision may impact dementia risk. Thus, we aimed to explore the associations of cataract and cataract surgery with the risk of dementia.

METHODS

Prospective data from 300,823 individuals in the UK Biobank were used. We used multivariate Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals for associations, with healthy control subjects as a reference. The same method was used to explore the effects of surgery on dementia outcomes of patients with cataract. One-way analysis of variance was performed to examine the associations between cataract and brain morphometric measures.

RESULTS

After a mean follow-up of 8.4 years, 3226 individuals were diagnosed with dementia. The nonsurgical cataract group had increased risk of all-cause dementia (HR, 1.214; 95% CI, 1.012-1.456; p = .037) and Alzheimer's disease (HR, 1.479; 95% CI, 1.105-1.981; p = .009). However, there was no difference in dementia risk between the cataract surgery group and the healthy control group. Cataract surgery was associated with decreased risk of all-cause dementia (HR, 0.632; 95% CI, 0.421-0.947; p = .026) and Alzheimer's disease (HR, 0.399; 95% CI, 0.196-0.812; p = .011) compared with the nonsurgical group. Additionally, cataract was negatively associated with cortical volumes, aging-related subcortical volumes, and fractional anisotropy of white matter fibers.

CONCLUSIONS

Cataract patients who did not receive surgical treatment had an increased risk of dementia. However, cataract surgery could reverse the risk of dementia. Our findings on brain structures and pathways in patients with cataract also provided evidence for the mechanism. Reversible visual impairment, such as cataract, is a promising modifiable risk factor for dementia.

Symptoms and Satisfaction Levels Associated with Intraocular Lens Implants in the Monofocal and Premium IOL Patient-Reported Outcome Measure Study

PURPOSE

To develop a questionnaire with standardized questions and images about visual symptoms and satisfaction administered before and after cataract surgery with monofocal and various (premium) intraocular lenses (IOLs).

DESIGN

A prospective, observational study of cataract surgery patients completing a self-administered questionnaire preoperatively and postoperatively at 4 to 6 months.

PARTICIPANTS

Five hundred fifty-four patients with plans to undergo implantation of the same IOL in both eyes on separate occasions in 20 ophthalmology practices.

METHODS

An 86-item questionnaire with standardized images assessed the following 14 symptoms: glare, blurry vision, starbursts, hazy vision, snowballs, halos, floaters, double images, rings and spider webs, light flashes with eyes closed, distortion, light flashes with eyes open, shimmering images, and dark crescent-shaped shadows.

MAIN OUTCOME MEASURES

Symptom severity and level of symptom bother, satisfaction with vision, quality of vision, and ability to see without corrective lenses or eyeglasses.

RESULTS

Except for dark crescent-shaped shadows, the report of visual symptoms significantly decreased postoperatively. Best uncorrected binocular visual acuity improved from 0.47 (20/59 Snellen visual acuity values) ± 0.35 logarithm of the minimum angle of resolution (logMAR) preoperatively to 0.12 (20/26 Snellen visual acuity values) ± 0.12 logMAR postoperatively. Patients' ratings of intermediate vision as good to excellent improved significantly from 12% preoperatively to 71% postoperatively, and patients' ratings of distance vision improved from 8% preoperatively to 85% postoperatively. After surgery, 84% reported that they were somewhat, very, or completely satisfied with their vision. Most patients (88%) reported that they could see pretty well, very well, or perfectly well without corrective lenses after surgery.

CONCLUSIONS

The Assessment of IntraOcular Lens Implant Symptoms questionnaire can be used across a wide variety of IOLs to evaluate visual symptoms and satisfaction with a growing segment of the market, premium IOLs, that target intermediate and near vision, in addition to distance vision. Compared to patients receiving monofocal IOLs, patients receiving premium IOLs appear to be more challenging to satisfy because of their requirements for distance, intermediate, and near vision, and their desire to be free of eyeglasses postoperatively. This instrument provides a structured, uniform tool for regulators, researchers, and ophthalmologists in everyday practice to gain insights into patients' experiences.

FINANCIAL DISCLOSURE(S)

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

Beyond vision:Cataract and health status in old age, a narrative review

Cataract is a leading cause of visual impairment in old age. Lens opacification is notoriously associated with several geriatric conditions, including frailty, fall risk, depression and cognitive impairment. The association is largely attributable to visual impairment, while other mechanisms, associated with extraocular comorbidity and lifestyle, might partly explain this correlation. Available literature suggests that cataract surgery may be effective in decreasing fall risk, improving depressive symptoms and limiting the risk of cognitive impairment and dementia incidence, although intervention studies on these outcomes are still limited. In this review we also emphasize the need to move from the concept of visual acuity to functional vision, especially in the context of the geriatric patient. Research is needed regarding the effect on the cited outcomes of different cataract treatment strategies, such as systematic bilateral versus monolateral surgery and use of different intraocular lenses.

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.

Cataracts

94 million people are blind or visually impaired globally, and cataract is the most common cause of blindness worldwide. However, most cases of blindness are avoidable. Cataract is associated with decreased quality of life and reduced life expectancy. Most cases of cataract occur after birth and share ageing and oxidative stress as primary causes, although several non-modifiable and modifiable risk factors can accelerate cataract formation. In most patients, phacoemulsification with intraocular lens implantation is the preferred treatment and is highly cost-effective. There has been an increase in the use of comprehensive cataract surgical services, including diagnoses, treatment referrals, and rehabilitation. However, global inequity in surgical service quality is still a limitation. Implementation of preoperative risk assessment, risk reduction strategies, and new surgical technologies have made cataract surgery possible at an earlier stage of cataract severity with the expectation of good refractive outcomes. The main challenge is making the service that is currently available to some patients accessible to all by use of universal health coverage.

Are cognitive researchers ignoring their senses? The problem of sensory deficit in cognitive aging research

Sensory impairments are common in older adult populations and have notable impacts on aging outcomes. Relationships between sensory and cognitive functions have been clearly established, though the mechanisms underlying those relationships are not fully understood. Given the growing burden of dementia, older adults with sensory deficits are an important and growing population to study in cognitive aging research. Yet, cognitive research sometimes excludes those with uncorrected significant/severe sensory deficits and often poorly or inconsistently assesses those deficits. Observational and interventional studies that exclude participants with sensory deficits will be limited in their generalizability to the narrower subset of the older adult population without vision or hearing impairment and may be missing an opportunity to study a growing population of older adults at higher risk of cognitive impairment. Strategies exist for adapting cognitive testing instruments, and inroads could be made into collecting normative data to inform ongoing research. Bringing together psychometricians with researchers who specialize in vision and hearing impairments could launch highly innovative research on both measurement methods and cognitive disease etiology, as sensory organs provide readily accessible neuronal and vascular beds that may show pathology earlier and elucidate innovative screening opportunities for early signs of cognitive disease.

Risk Factors for Vision Loss among Nursing Home Residents: A Cross-Sectional Analysis

OBJECTIVE

Approximately 2% of older adults currently live in nursing homes. It is important that the risks for vision loss be characterized to ensure appropriate vision care is provided for nursing home patients. Our objective was to evaluate the association of age-related eye diseases (AREDs) and multimorbidities with vision loss.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

This is a cross-sectional analysis of comprehensive eye examination records for 7753 residents of 74 North Carolina nursing homes who were ≥65 years of age at time of the initial patient visit.

METHODS

Complete data on vision and associated factors were included from the standardized Centers for Medicare and Medicaid Services eye examination. We defined vision impairment and blindness respectively as best-corrected visual acuity between 20/40 and 20/200, and 20/200 or worse. Clinical diagnoses of AREDs were defined by the attending clinician. Data were extracted from electronic health records, and all analyses were conducted in SAS v 9.4. We used descriptive statistics to summarize the resident characteristics and AREDs and logistic regression analysis to examine independent risk factors for vision impairment.

RESULTS

A total of 7753 initial eye examination records with complete data were included in the analysis. Overall, 34% of the residents had normal vision, 43% had vision impairment, and 23% were blind. Among participants with various AREDs, the prevalence of vision impaired/blind ranged from 63% to 76%, while blindness ranged from 23% to 53%. We found correction of refractive error alone served to reduce vision impairment or blindness.

CONCLUSIONS AND IMPLICATIONS

Comprehensive eye examinations showed vision impairment and blindness affected 66% of nursing home residents, overall. This study substantiates the positive impact of comprehensive eye examinations to promote visual, systemic, and cognitive health and well-being and the need that eye care service be used to inform policy and practice to improve patient functioning and independence.

Observational studies in Alzheimer disease: bridging preclinical studies and clinical trials

Recent high-profile failures of Alzheimer disease treatments at the clinical trial stage have led to renewed efforts to identify and test novel interventions for Alzheimer disease and related dementias (ADRD). In this Perspective, we highlight the importance of including well-designed observational studies as part of these efforts. Observational research is an important cornerstone for gathering evidence on risk factors and causes of ADRD; this evidence can then be combined with data from preclinical studies and randomized controlled trials to inform the development of effective interventions. Observational study designs can be particularly beneficial for hypothesis generation, posing questions that are unethical or impractical for a trial setting, studying life-course associations, research in populations typically not included in trials, and public health surveillance. Here, we discuss each of these situations in the specific context of ADRD research. We also highlight novel approaches to enhance causal inference and provide a timely discussion on how observational epidemiological studies help provide a bridge between preclinical studies and successful interventions for ADRD.

Global, regional, national burden and gender disparity of cataract: findings from the global burden of disease study 2019

Background

To evaluate the global burden of cataracts by year, age, region, gender, and socioeconomic status using disability-adjusted life years (DALYs) and prevalence from the Global Burden of Disease (GBD) study 2019.

Methods

Global, regional, or national DALY numbers, crude DALY rates, and age-standardized DALY rates caused by cataracts, by year, age, and gender, were obtained from the Global Burden of Disease Study 2019. Socio-demographic Index (SDI) as a comprehensive indicator of the national or regional development status of GBD countries in 2019 was obtained from the GBD official website. Kruskal-Wallis test, linear regression, and Pearson correlation analysis were performed to explore the associations between the health burden with socioeconomic levels, Wilcoxon Signed-Rank Test was used to investigate the gender disparity.

Results

From 1990 to 2019, global DALY numbers caused by cataracts rose by 91.2%, crude rates increased by 32.2%, while age-standardized rates fell by 11.0%. Globally, age-standardized prevalence and DALYs rates of cataracts peaked in 2017 and 2000, with the prevalence rate of 1283.53 [95% uncertainty interval (UI) 1134.46–1442.93] and DALYs rate of 94.52 (95% UI 67.09–127.24) per 100,000 population, respectively. The burden was expected to decrease to 1232.33 (95% UI 942.33–1522.33) and 91.52 (95% UI 87.11–95.94) by 2050. Southeast Asia had the highest blindness rate caused by cataracts in terms of age-standardized DALY rates (99.87, 95% UI: 67.18–144.25) in 2019. Gender disparity has existed since 1990, with the female being more heavily impacted. This pattern remained with aging among different stages of vision impairments and varied through GBD super regions. Gender difference (females minus males) of age-standardized DALYs (equation: Y = -53.2*X + 50.0, P < 0.001) and prevalence rates (equation: Y = − 492.8*X + 521.6, P < 0.001) was negatively correlated with SDI in linear regression.

Conclusion

The global health of cataracts is improving but the steady growth in crude DALY rates suggested that health progress does not mean fewer demands for cataracts. Globally, older age, females, and lower socioeconomic status are associated with higher cataract burden. The findings of this study highlight the importance to make gender-sensitive health policies to manage global vision loss caused by cataracts, especially in low SDI regions.

Demand Coupling Drives Neurodegeneration: A Model of Age-Related Cognitive Decline and Dementia

The societal burden of Alzheimer's Disease (AD) and other major forms of dementia continues to grow, and multiple pharmacological agents directed towards modifying the pathological "hallmarks" of AD have yielded disappointing results. Though efforts continue towards broadening and deepening our knowledge and understanding of the mechanistic and neuropathological underpinnings of AD, our previous failures motivate a re-examination of how we conceptualize AD pathology and progression. In addition to not yielding effective treatments, the phenotypically heterogeneous biological processes that have been the primary area of focus to date have not been adequately shown to be necessary or sufficient to explain the risk and progression of AD. On the other hand, a growing body of evidence indicates that lifestyle and environment represent the ultimate level of causation for AD and age-related cognitive decline. Specifically, the decline in cognitive demands over the lifespan plays a central role in driving the structural and functional deteriorations of the brain. In the absence of adequate cognitive stimulus, physiological demand-function coupling leads to downregulation of growth, repair, and homeostatic processes, resulting in deteriorating brain tissue health, function, and capacity. In this setting, the heterogeneity of associated neuropathological tissue hallmarks then occurs as a consequence of an individual's genetic and environmental background and are best considered downstream markers of the disease process rather than specific targets for direct intervention. In this manuscript we outline the evidence for a demand-driven model of age-related cognitive decline and dementia and why it mandates a holistic approach to dementia treatment and prevention that incorporates the primary upstream role of cognitive demand.

Lens Epithelial Cell Removal in Routine Phacoemulsification: Is It Worth the Bother?

PURPOSE

To review the literature on crystalline lens epithelial cell (LEC) removal in routine phacoemulsification and determine whether it should be incorporated as part of a surgeon's standard technique.

DESIGN

Perspective.

METHODS

Expert commentary with video demonstrations on techniques of removal of LECs and associated potential complications. Discussion incorporates the importance of LEC removal, a review of techniques to prevent posterior capsular opacification (PCO), and the effects of intraocular lens design on LEC proliferation and PCO.

RESULTS

The evidence suggests that LEC removal should be routinely performed as it can be carried out safely and with considerable short- and long-term benefits for patients. With effective cleanup, there is reduced anterior capsule opacification, fibrosis, and decentration of the capsular bag as well as reduced rates of posterior capsular opacification. Techniques for removal are easy to learn, with very low complication rates, and can reduce the risk of the long-term need for technically complex procedures such as intraocular lens explantation.

CONCLUSIONS

LEC removal from both the anterior and posterior capsule is part of a continuous, incremental improvement of cataract surgery and should be introduced to ophthalmology trainees during their formative years as part of their regular cataract surgery armamentarium.

Associations of dual sensory impairment with incident mobility and ADL difficulty

BACKGROUND

There is a dearth of studies examining the associations of objectively measured dual sensory impairment (DSI) with incident mobility and activities of daily life (ADL) difficulty longitudinally.

METHODS

Cox proportional hazards models were used to examine the associations of DSI and single sensory impairment (hearing, vision) with incident mobility difficulty (many problems or inability to walk ¼ mile and/or climb 10 steps) and ADL difficulty up to six years of follow-up among 2020 participants of the Health, Aging, and Body Composition Study, a cohort of older adults aged 70-79 years from Pittsburgh, PA and Memphis, TN. Vision impairment (VI) was defined as impaired visual acuity (20/50 or worse on Bailey-Lovie distance test) and contrast sensitivity (<1.3 log units on Pelli-Robson test), and hearing impairment (HI) was defined as pure-tone average in better-hearing ear >25 decibels. Models were adjusted by age, race, sex, education, diabetes, depressive symptoms, hypertension, gait speed from 20-meter walk, global cognition score, prevalent cardiovascular disease, and body mass index.

RESULTS

There were 23% with DSI (n = 459). DSI was associated with increased risk of both incident report of mobility (hazard ratio [HR] = 2.25, 95% confidence interval [CI]: 1.47, 3.43), and ADL difficulty (HR = 2.26, 95% CI: 1.50, 3.40). Neither VI nor HI alone was associated with risk of either outcome.

CONCLUSIONS

DSI is associated with increased risk of incident mobility and ADL difficulty. Rehabilitation and adaptive environmental changes for individuals living with DSI may be important to maximize mobility and daily function.