Cataract and cognitive impairment: a review of the literature

Alzheimer's disease pathophysiology in the Retina

The retina is an emerging CNS target for potential noninvasive diagnosis and tracking of Alzheimer's disease (AD). Studies have identified the pathological hallmarks of AD, including amyloid β-protein (Aβ) deposits and abnormal tau protein isoforms, in the retinas of AD patients and animal models. Moreover, structural and functional vascular abnormalities such as reduced blood flow, vascular Aβ deposition, and blood-retinal barrier damage, along with inflammation and neurodegeneration, have been described in retinas of patients with mild cognitive impairment and AD dementia. Histological, biochemical, and clinical studies have demonstrated that the nature and severity of AD pathologies in the retina and brain correspond. Proteomics analysis revealed a similar pattern of dysregulated proteins and biological pathways in the retina and brain of AD patients, with enhanced inflammatory and neurodegenerative processes, impaired oxidative-phosphorylation, and mitochondrial dysfunction. Notably, investigational imaging technologies can now detect AD-specific amyloid deposits, as well as vasculopathy and neurodegeneration in the retina of living AD patients, suggesting alterations at different disease stages and links to brain pathology. Current and exploratory ophthalmic imaging modalities, such as optical coherence tomography (OCT), OCT-angiography, confocal scanning laser ophthalmoscopy, and hyperspectral imaging, may offer promise in the clinical assessment of AD. However, further research is needed to deepen our understanding of AD's impact on the retina and its progression. To advance this field, future studies require replication in larger and diverse cohorts with confirmed AD biomarkers and standardized retinal imaging techniques. This will validate potential retinal biomarkers for AD, aiding in early screening and monitoring.

Epidemiologic association and shared genetic architecture between cataract and hearing difficulties among middle-aged and older adults

Age-related cataract and hearing difficulties are major sensory disorders that often co-exist in the global-wide elderly and have a tangible influence on the quality of life. However, the epidemiologic association between cataract and hearing difficulties remains unexplored, while little is known about whether the two share their genetic etiology. We first investigated the clinical association between cataract and hearing difficulties using the UK Biobank covering 502,543 individuals. Both unmatched analysis (adjusted for confounders) and a matched analysis (one control matched for each patient with cataract according to confounding factors) were undertaken and confirmed that cataract was associated with hearing difficulties (OR, 2.12; 95% CI, 1.98-2.27; OR, 2.03; 95% CI, 1.86-2.23, respectively). Furthermore, we explored and quantified the shared genetic architecture of these two complex sensory disorders at the common variant level using the bivariate causal mixture model (MiXeR) and conditional/conjunctional false discovery rate method based on the largest available genome-wide association studies of cataract (N = 585,243) and hearing difficulties (N = 323,978). Despite detecting only a negligible genetic correlation, we observe polygenic overlap between cataract and hearing difficulties and identify 6 shared loci with mixed directions of effects. Follow-up analysis of the shared loci implicates candidate genes QKI, STK17A, TYR, NSF, and TCF4 likely contribute to the pathophysiology of cataracts and hearing difficulties. In conclusion, this study demonstrates the presence of epidemiologic association between cataract and hearing difficulties and provides new insights into the shared genetic architecture of these two disorders at the common variant level.

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.

The association between cataract and incidence of cognitive impairment in older adults: A systematic review and meta-analysis

BACKGROUND

Cataract has been shown to be associated with an increased risk of cognitive impairment. However, the results of previous studies have been inconsistent. This systematic review and meta-analysis aimed to investigate the association between cataract and the incidence of cognitive impairment in older adults.

METHODS

A comprehensive search of electronic databases from inception to January 2023 was performed to identify relevant studies. Data were extracted from eligible studies and a meta-analysis was performed to calculate the pooled hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

We included 13 studies with 25 study arms involving a total of 798,694 participants. Compared with participants without cataract, those with cataract had a higher risk of developing all-cause dementia (pooled HR: 1.22; 95% CI: 1.08-1.38; I²=86%; 9 studies), Alzheimer's disease dementia (pooled HR: 1.18; 95% CI: 1.07-1.30; I²=0%; 9 studies), vascular dementia (pooled HR: 1.21; 95% CI: 1.02-1.43; I²=77%;3 studies) and mild cognitive impairment (pooled HR: 1.30; 95% CI: 1.13-1.50; I²=0%;2 studies). There was no significant association between cataract and mixed dementia (pooled HR: 1.03; 95% CI: 0.52-2.04; I²=78%;2 studies). We assessed the risk of bias of the included studies using the Newcastle-Ottawa Scale and found that most of them had a low or moderate risk of bias. The number of studies in each meta-analysis ranged from two to nine, with more studies available for all-cause dementia and Alzheimer's disease dementia than for vascular dementia and mixed dementia.

CONCLUSIONS

The findings suggest that cataract may be associated with cognitive impairment in older adults. However, the causal relationship between cataract and cognition remains unclear and requires further investigation.

Early Lifetime Substance Use and Development of Visual Impairment: Analysis of the National Survey on Drug Use and Health Data

Purpose

To investigate the association between early lifetime substance use on the development of severe visual acuity impairment or blindness on a national level.

Methods

National Survey of Drug Use and Health data was used to identify cases of substance use before 21* years of age, within the past year, and cases of self-reported blindness or visual impairment. Univariable and multivariable binary logistic regression with time-dependency was performed to evaluate odds of visual impairment influenced by 16 substances separated into three classes: prescription, non-prescription, and illicit drugs. Adjusted variables of interest included gender, marital status, race, level of education, total family income, poverty level, population density, and history of chronic disease.

Results

55,824 total responses were analyzed with 2577 (4.6%) cases of self-reported blindness or significant visual impairment. All early-use substance categories, including prescription, non-prescription, and illegal substances, were significantly associated with self-reported VI (OR 2.068, CI 1.451-2.949, p<0.001; OR 1.352, CI 1.227-1.489, p<0.001); OR 1.211, CI 1.086-1.352, p<0.001), respectively). Non-prescription substances displayed parallel significances amongst all constituents (alcohol, cigarettes, inhalants, and marijuana) (OR=1.227, CI 1.12-1.344, p<0.001; OR 1.363, CI 1.243-1.495, p<0.001; OR 1.418, CI 1.134-1.774; OR 1.388, CI 1.27-1.518, p<0.001, respectively). Univariable and multivariable analysis revealed several significant demographical and clinical adjustors.

Conclusion

Early lifetime use of all three classes of substances is associated with enhanced odds of subsequent visual impairment or blindness. Several readily available and commonly used substances have a greater risk. These findings may help clinicians and public health agencies in mitigation ventures including education, prevention, and rehabilitation efforts.

The Association Between Cataract and Cognitive Functions in Older Adults: A Longitudinal Cohort Study

BACKGROUND

The association between cataracts and cognitive functions has been reported in several studies. However, the dynamic trajectories of cognitive changes in patients with cataracts remain unelucidated.

OBJECTIVE

The aim of the study was to evaluate the dynamic trajectories of cognitive changes in patients with cataracts.

METHODS

This observational cohort study recruited 1,146 patients with age-related cataracts (ARC) from the Department of Ophthalmology, Daping Hospital, from September 2020 to November 2021. The cognitive functions of the patients were assessed using a Chinese version of the Telephone Interview of Cognitive Status-40 (TICS-40) test at baseline and 6 months of follow-up. The trajectories and the associated risk factors for the longitudinal cognitive decline during the 6-month follow-up were investigated.

RESULTS

Patients with severe ARC [median (IQR): 0 month, 24 (22, 25); 6 months, 23 (21,25)] had lower TICS-40 scores than those with non-severe ARC [0 month, 31 (24, 33), p < 0.001; 6 months, 31 (23,33), p < 0.001] and controls [0 month, 32 (28, 35), p < 0.001; 6 months, 32 (28, 35), p < 0.001] at both baseline and 6 months of follow-up. Age (OR: 1.311, 95% CI: 1.229 to 1.398) and cataract grade (OR: 5.569, 95% CI: 2.337 to 13.273) were found to be the risk factors of cognitive decline as indicated by a decrease in the TICS-40 scores.

CONCLUSION

ARC is associated with an increased risk of longitudinal cognitive decline; however, the reversibility of such declines needs to be investigated further.

Evaluation of the impact of cataract surgery on cognitive function in very elderly patients: a prospective, observational study

AIM

To evaluate the impact of cataract surgery on cognitive function in very elderly patients (≥ 85 years).

METHODS

A prospective, nonrandomized, comparative study of very elderly patients (≥ 85 years), and elderly patients (≥ 65 < 85 years) scheduled for first time cataract surgery. Cognitive function, quality of life (QoL), best corrected visual acuity (BCVA), endothelial cell count (ECC), and central corneal thickness (CCT) were assessed at 90 days before surgery (T0), at surgery (T1), and at 30 (T2) and 90 days (T3) after surgery. Macular thickness (MT) was evaluated at T2. Six-item cognitive impairment test (6CIT) was used to evaluate cognitive function while the Catquest-9SF test was used to assess QoL. The confusion assessment method (CAM) was used to evaluate the presence of delirium episodes at within 48 h from T1.

RESULTS

A total of 78 patients (very elderly n = 24, elderly n = 54) were enrolled; average age 80.3 ± 6.2 years old. Significant improvements for cognitive function, BCVA, QoL (p < 0.01) during the observational period were observed among the cohort. A greater improvement in cognitive function was observed in the very elderly patients between T1 and T2 (p = 0.02), while there was no difference in BCVA and QoL between the groups. There were no significant differences in ECC and CCT changes between the groups. No delirium episodes or significant macular abnormalities were registered.

CONCLUSIONS

Cataract surgery in very elderly patients seems to offer a greater improvement in cognitive function as compared to elderly patients, and it is associated with a significant improvement in QoL, without any incidence of postoperative delirium.

Visual Impairment, Eye Diseases, and Dementia Risk: A Systematic Review and Meta-Analysis

BACKGROUND

Visual impairment and eye diseases have been associated with dementia, though with mixed findings and often in cross-sectional studies.

OBJECTIVE

To identify prospective studies investigating associations between visual impairment or common eye diseases and risk of all-cause dementia or key dementia subtypes.

METHODS

We searched Medline, PsycINFO, and Embase from inception to January 2020. We also conducted backward and forward citation searches of included studies and set up alerts to identify studies published after the search date. Random-effects meta-analysis was used to combine adjusted estimates across studies.

RESULTS

Thirty studies met our eligibility criteria. For visual impairment, pooled estimates indicated an increased risk of all-cause dementia (37,705 participants, 3,415 cases, risk ratio [RR] = 1.38, 95%confidence interval [CI]: 1.19-1.59, I2 = 28.6%). Pooled estimates also suggested an increased dementia risk associated with cataract (6,659 participants, 1,312 cases, hazard ratio [HR] = 1.17, 95%CI 1.00-1.38, I2 = 0.0%) and diabetic retinopathy (43,658 participants, 7,060 cases, HR = 1.34, 95%CI 1.11-1.61, I2 = 63.9%), respectively. There was no evidence of an association between glaucoma (175,357 participants, 44,144 cases, HR = 0.97, 95%CI 0.90-1.04, I2 = 51.5%) or age-related macular degeneration (7,800,692 participants, >  2,559 cases, HR = 1.15, 95%CI 0.88-1.50, I2 = 91.0%) and risk of dementia, respectively.

CONCLUSION

As visual impairment, cataract, and diabetic retinopathy are associated with an increased likelihood of developing dementia, early diagnosis may help identify those at risk of dementia. Given most causes of visual impairment are treatable or preventable, the potential for dementia prevention warrants further investigation.

The Evolving Role of Ophthalmology Clinics in Screening for Early Alzheimer's Disease: A Review

Alzheimer’s disease (AD) is the leading cause of dementia, which is a growing public health concern. Although there is no curative treatment for established AD, early recognition and modification of the known risk factors can reduce both severity and the rate of progression. Currently, an early diagnosis of AD is rarely achieved, as there is no screening for AD. The cognitive decline in AD is gradual and often goes unnoticed by patients and caregivers, resulting in patients presenting at later stages of the disease. Primary care physicians (general practitioners in the UK) can administer a battery of tests for patients presenting with memory problems and cognitive impairment, however final diagnosis of AD is usually made by specialised tertiary level clinics. Recent studies suggest that in AD, visuospatial difficulties develop prior to the development of memory problems and screening for visuospatial difficulties may offer a tool to screen for early stage AD. AD and cataracts share common risk and predisposing factors, and the stage of cataract presentation for intervention has shifted dramatically with early cataract referral and surgical intervention becoming the norm. This presentation offers an ideal opportunity to administer a screening test for AD, and visuospatial tools can be administered at post-operative visits by eye clinics. Abnormal findings can be communicated to primary care physicians for further follow up and assessment, or possible interventions which modify risk factors such as diabetes, hypertension and obesity can be undertaken. We propose that eye clinics and ophthalmology facilities have a role to play in the early diagnosis of AD and reducing the burdens arising from severe dementia.

Glaucoma, but not cataracts, predicts lower verbal fluency performance: 3.8-year follow-up from the ELSA-Brasil study

Glaucoma, cataracts, and cognitive decline are most common in older ages. Although cross-sectional studies showed that these disorders are associated, follow-up studies are lacking. To investigate this issue, baseline and follow-up data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) were employed. We evaluated participants ≥ 55 years-old at follow-up without diagnosis of dementia, stroke, and other eye conditions except for glaucoma and cataracts. Cognition was evaluated using delayed word recall, verbal fluency, and trail making (version B) tests. Regression models were employed to investigate associations between glaucoma and cognition, adjusted by several confounders. Out of 3,867 participants, 379 and 118 presented cataracts and glaucoma, respectively. Only glaucoma was apredictor of lower verbal fluency (B = -0.23, 95% CI -035 to -012, p< 0.001). Other associations were not significant (ps>0.57). Our results suggest that glaucoma may be related to declining cognition.

Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Layer Thickness in Alzheimer's Disease Using Optical Coherence Tomography

Objective

To evaluate the feasibility of using optical coherence tomography (OCT) for the detection of Alzheimer's disease (AD), by measuring the thickness of the retinal nerve fiber layer (RNFL) and the ganglion cell layer and inner plexiform layer (GCL-IPL).

Material and Methods

This was a single-center, cross-sectional study. The study included 29 patients with AD (mean age ± standard deviation: 75.61 ± 6.24 years) and 29 healthy age- and sex-matched controls. All participants underwent cognitive evaluations using the Montreal Cognitive Assessment test. Measurements of the RNFL thickness, as well as GCL-IPL thickness, were obtained for all participants using OCT. Both RNFL and GCL-IPL parameters were adjusted for best-corrected visual acuity, hypertension, diabetes and dyslipidemia.

Results

The mean RNFL thickness was significantly thinner in the AD group than in the control group (85.24 and 90.68 µm, respectively, adjusted P=0.014). The superior quadrant was thinner in the AD group (adjusted P=0.033). The thicknesses did not differ significantly between groups for the other quadrants. The mean GCL-IPL thickness in the AD (68.81 µm) was significantly thinner than that in the controls (76.42 µm) (adjusted P=0.014). Overall, there was a negative correlation between age and mean RNFL; and between age and GCL-IPL thickness (r=-0.338, P=0.010 and r=-0.346, P=0.008, respectively).

Conclusion

The mean RNFL and GCL-IPL thicknesses were thinner in the AD group than in the control group. These findings suggest that RNFL and GCL-IPL thickness may be biological markers for AD.

Risk Factors for Incident Dementia Among Older Cubans

Introduction: Little is known about risk factors of dementia in Latin American countries. We aimed to identify socio–demographic, health and lifestyle risk factors of incident dementia in Cuban older adults.

Methods: Data were from 1,846 participants in the Cuban cohort of the 10/66 Dementia Research Group. Participants completed questionnaires, health examinations, and cognitive tests at baseline (2003–2006) and 4.5 years later (2007–2010). Associations between risk factors (baseline) and incident dementia (follow-up) were examined using logistic regression.

Results: Just over 9% of participants developed dementia. Overall, older age and low physical activity were associated with incident dementia. In those 65–74 years of age, depression, stroke and low physical activity were associated with incident dementia. In those ≥75 years of age, low physical activity, never eating fish, and smoking were associated with incident dementia.

Conclusions: Modifiable lifestyle factors play an important role in developing dementia in Cuban older adults. This knowledge opens up opportunities for preventive strategies.

Screening for Vision Impairments in Individuals with Dementia Living in Long-Term Care: A Scoping Review

Vision impairments are prevalent, but underdiagnosed in individuals with dementia living in long-term care (LTC). Effective screening tools could identify remediable vision problems. This scoping review was conducted to identify vision screening tests used with individuals with dementia and assesses their suitability for administration by nurses in LTC. A literature search using the Arksey and O’Malley (2005) method included research articles, conference proceedings, and dissertations. Data were included from participants over 65 years of age with a diagnosis of probable dementia. A panel of vision experts evaluated the suitability of the candidate vision tests. The search yielded 179 publications that met the inclusion criteria. Of 134 vision tests that were identified, 19 were deemed suitable for screening by nurses in LTC. Tests screened for acuity (12), visual field (1), anatomy (2), color vision (2), and general visual abilities (2). Tests were excluded because of complexity of interpretation (90), need for specialized training (83), use in research only (57), need for specialized equipment (54), not assessing visual function (44), long test duration (21), uncommonness (13), and needing an act reserved for specialists (7). Psychometric properties were not often reported for tests. Few of the tests identified had been validated for use with individuals with dementia. Based on our review, few tests were deemed suitable for use by nurses to assess this population in LTC. Identifying appropriate tools to screen vision in individuals with dementia is a necessary first step to interventions that could potentially improve functioning and quality of life.

Intraocular cataract lens replacement and light exposure potentially impact procedural learning in older adults

Procedural learning declines with age and appropriately timed light exposure can improve cognitive performance in older individuals. Because cataract reduces light transmission and is associated with cognitive decline in older adults, we explored whether lens replacement (intraocular blue-blocking [BB] or UV-only blocking) in older patients with cataracts enhances the beneficial effects of light on procedural learning. Healthy older participants (n = 16) and older patients with post-cataract surgery (n = 13 with BB or UV lens replacement) underwent a randomized within-subject crossover laboratory design with three protocols. In each protocol, 3.5 hr dim-dark adaptation was followed by 2 hr evening blue-enriched (6,500K) or non-blue-enriched light exposure (3,000K or 2,500K), 30 min dim post-light, ~8 hr sleep and 2 hr morning dim light. Procedural learning was assessed by the alternating serial reaction time task (ASRT), as part of a larger test battery. Here, ASRT performance was indexed by type of trial (random or sequence) and sequence-specific (high or low probability) measures. During evening light exposure, we observed a significant effect of the interaction of "group" versus "light condition" on the type of trial (p = .04; p = .16; unadjusted and adjusted p-values, respectively) and sequence-specific learning (p = .04; p = .16; unadjusted and adjusted p-values, respectively), whereby patients with UV lens replacement performed better than patients with BB lens or non-cataract controls, during blue-enriched light exposure. Lens replacement in patients with cataracts may potentially be associated with beneficial effects of blue light on procedural learning. Thus, optimizing spectral lens transmission in patients with cataracts may help improve specific aspects of cognitive function, such as procedural learning.

Use of ocular biomarkers as a potential tool for early diagnosis of Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide which unfortunately has no known effective cure to date. Despite many clinical trials indicating the effectiveness of preclinical treatment, a sensitive tool for screening of AD is yet to be developed. Due to multiple similarities between ocular and the brain tissue, the eye is being explored by researchers for this purpose, with utmost attention focused on the retinal tissue. Besides visual functional impairment, neuronal degeneration and apoptosis, retinal nerve fiber degeneration, increase in the cup-to-disc ratio, and retinal vascular thinning and tortuosity are the changes observed in the retinal tissue which are related to AD. Studies have shown that targeting these changes in the retina is an effective way of reducing the degeneration of retinal neuronal tissue. Similar mechanisms of neurodegeneration have been demonstrated in the brain and the eyes of AD patients. Multiple studies are underway to investigate the potential of diagnosing AD and detection of amyloid-β (Aβ) levels in the retinal tissue. Since the tissues in the anterior segment of the eye are more accessible for in vivo imaging and examination, they have more potential as screening biomarkers. This article provides a concise review of available literature on the ocular biomarkers in anterior and posterior segments of the eye including the cornea, aqueous humour (AH), crystalline lens, and retina in AD. This review will also highlight the newer technological tools available for the detection of potential biomarkers in the eye for early diagnosis of AD.

Characteristics Associated With Receiving Cataract Surgery in the US Medicare and Veterans Health Administration Populations

Importance

Considerable variation exists with respect to the profiles of patients who receive cataract surgery in the United States.

Objective

To identify patient characteristics associated with receiving cataract surgery within the US Medicare and Veterans Health Administration (VHA) populations.

Design, Setting, and Participants

In this population-based retrospective cohort study of 3 073 465 patients, Medicare and VHA patients with a cataract diagnosis between January 1, 2002, and January 1, 2012, were identified from the 2002-2012 Medicare Part B files (5% sample) and the VHA National Patient Care Database. Patient age, sex, race/ethnicity, region of residence, Charlson Comorbidity Index (CCI) scores, and comorbidities were recorded. Cataract surgery at 1 and 5 years after diagnosis was identified. Data analysis was performed from July 1, 2016, to July 1, 2017.

Main Outcomes and Measures

Odds ratios (ORs) of cataract surgery for selected patient characteristics.

Results

The study sample included 1 156 211 Medicare patients (mean [SD] age, 73.7 [7.0] years) and 1 917 254 VHA patients (mean [SD] age, 66.8 [10.2] years) with a cataract diagnosis. Of the 1 156 211 Medicare patients, 407 103 (35.2%) were 65 to 69 years old, 683 036 (59.1%) were female, and 1 012 670 (87.6%) were white. Of the 1 917 254 VHA patients, 905 455 (47.2%) were younger than 65 years, 1 852 158 (96.6%) were male, and 539 569 (28.1%) were white. A greater proportion of Medicare patients underwent cataract surgery at 1 year (Medicare: 213 589 [18.5%]; VHA: 120 196 [6.3%]) and 5 years (Medicare: 414 586 [35.9%]; VHA: 240 884 [12.6%]) after diagnosis. Factors associated with the greatest odds of surgery at 5 years were older age per 5-year increase (Medicare: OR, 1.24 [95% CI, 1.23-1.24]; VHA: OR, 1.18 [95% CI, 1.17-1.18]), residence in the southern United States vs eastern United States (Medicare: OR, 1.38 [95% CI, 1.36-1.40]; VHA: OR, 1.40 [95% CI, 1.38-1.41]), and presence of chronic pulmonary disease (Medicare: OR, 1.26 [95% CI, 1.24-1.27]; VHA: OR, 1.40 [95% CI, 1.38-1.41]). Within Medicare, female sex was associated with greater odds of surgery at 5 years (OR, 1.14; 95% CI, 1.13-1.15). Higher CCI scores (CCI score ≥3 vs 0-2) were associated with increased odds of surgery among VHA but not Medicare patients at 5 years (Medicare: OR, 0.94 [95% CI, 0.92-0.95]; VHA: OR, 1.24 [95% CI, 1.23-1.36]). Black race vs white race was associated with decreased odds of cataract surgery 5 years after diagnosis (Medicare: OR, 0.79 [95% CI, 0.78-0.81]; VHA: OR, 0.75 [95% CI, 0.73-0.76]).

Conclusions and Relevance

Within both groups, older age, residence in the southern United States, and presence of chronic pulmonary disease were associated with increased odds of cataract surgery. Findings from this study suggest that few disparities exist between the types of patients receiving cataract surgery who are in Medicare vs the VHA, although it is possible that a smaller proportion of VHA patients receive surgery compared with Medicare patients.

A Primary Care Provider's Guide to Cataract Surgery in the Very Elderly

Planning for cataract surgery and perioperative care in the very elderly requires the teamwork of the patient's primary care provider and the ophthalmologist.

Chronic Physical Conditions, Multimorbidity, and Mild Cognitive Impairment in Low- and Middle-Income Countries

OBJECTIVES

To assess the association between chronic physical conditions and multimorbidity and mild cognitive impairment (MCI) in low- and middle-income countries (LMICs).

DESIGN

Nationally representative, cross-sectional, community-based study.

SETTING

Six countries that participated in the World Health Organization Study on Global Ageing and Adult Health.

PARTICIPANTS

Individuals aged 50 and older (N=32,715; mean age 62.1 ± 15.6; 51.7% female).

MEASUREMENTS

The definition of MCI was based on the recommendations of the National Institute on Ageing and Alzheimer's Association. Ten chronic conditions were assessed (angina pectoris, arthritis, asthma, cataract, chronic lung disease, diabetes mellitus, edentulism, hearing problems, hypertension, stroke). Multivariable logistic regression analysis was conducted to assess the association between chronic physical conditions, multimorbidity (≥2 chronic conditions), and MCI.

RESULTS

The prevalence of multimorbidity was 49.8% (95% confidence interval (CI)=48.1-51.5%) and of MCI was 15.3% (95% CI=14.4-16.3%). After adjustment for potential confounders, edentulism (odds ratio (OR)=1.24), arthritis (OR=1.24), chronic lung disease (OR=1.29), cataract (OR=1.33), stroke (OR=1.94), hearing problems (OR=2.27), and multimorbidity (OR=1.40) were significantly associated with MCI. There was a gradual increase in the likelihood of MCI (1 condition: OR=1.21, 95% CI=1.03-1.42; ≥4 conditions: OR=2.07, 95% CI=1.70-2.52).

CONCLUSION

These results highlight the need to investigate the underlying mechanisms linking chronic conditions and MCI and whether prevention or treatment of chronic conditions or multimorbidity can reduce the onset of cognitive decline and subsequent dementia, especially in LMICs.

Visual Restoration after Cataract Surgery Promotes Functional and Structural Brain Recovery

Background

Visual function and brain function decline concurrently with aging. Notably, cataract patients often present with accelerated age-related decreases in brain function, but the underlying mechanisms are still unclear. Optical structures of the anterior segment of the eyes, such as the lens and cornea, can be readily reconstructed to improve refraction and vision quality. However, the effects of visual restoration on human brain function and structure remain largely unexplored.

Methods

A prospective, controlled clinical trial was conducted. Twenty-six patients with bilateral age-related cataracts (ARCs) who underwent phacoemulsification and intraocular lens implantation and 26 healthy controls without ARC, matched for age, sex, and education, were recruited. Visual functions (including visual acuity, visual evoke potential, and contrast sensitivity), the Mini-Mental State Examination and functional magnetic resonance imaging (including the fractional amplitude of low-frequency fluctuations and grey matter volume variation) were assessed for all the participants and reexamined for ARC patients after cataract surgery. This trial was registered with ClinicalTrials.gov (NCT02644720).

Findings

Compared with the healthy controls, the ARC patients presented decreased brain functionality as well as structural alterations in visual and cognitive-related brain areas preoperatively. Three months postoperatively, significant functional improvements were observed in the visual and cognitive-related brain areas of the patients. Six months postoperatively, the patients' grey matter volumes in these areas were significantly increased. Notably, both the function and structure in the visual and cognitive-related brain areas of the patients improved significantly and became comparable to those of the healthy controls 6 months postoperatively.

Interpretation

We demonstrated that ocular reconstruction can functionally and structurally reverse cataract-induced brain changes. The integrity of the eye is essential for maintaining the structure and function of the brain within and beyond the primary visual pathway.

•

Cataract patients with reduced visual function presented a simultaneous decrease in brain function and grey matter volume.

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Cataract surgery can reverse cerebral changes in both visual and cognitive-related regions associated with visual decline.

•

The integrity of the eye is essential for maintaining the structure and function of the brain.

The eyes and brain are anatomically and functionally connected. Age related cataract (ARC) is associated with structural and functional impairments of the brain. However, whether these changes are reversible after cataract surgery is largely unknown. We assessed the patients based on subjective cognitive evaluations and objective functional magnetic resonance imaging before and after surgery. Significant improvements in brain function and increases in the grey matter volumes of the visual, cognitive-related, and somatosensory brain areas were observed, demonstrating that the impaired brain function and structure of ARC patients can be reversed after restoration of visual acuity.

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.

Cognitive functions and normal tension glaucoma

Purpose:

Only a few studies have analyzed the potential link between glaucoma and cognitive function impairment. They have found controversial results. This study aims to perform quick cognitive function assessment with clock drawing test (CDT) using two different scoring systems and compare between normal tension glaucoma (NTG) and cataract patients.

Methods:

Totally, 30 NTG and 30 patients with cataracts were included in a prospective, pilot study. The predrawn circle was given, and patients were asked to draw the clock showing a time of 11:10. The test was evaluated using two methods – Freund method using a 7-point scoring scale (optimal cutoff ≤4) and Rakusa using a 4-point scoring scale (optimal cutoff ≤3). The level of significance was set at P < 0.05.

Results:

CDT result was significantly better in cataract group than in NTG group: 3.5 (2) versus 2 (2) by Freund, (P = 0.003) and 6.5 (1) versus 4.5 (2.75) by Rakusa, respectively (P = 0.004). Sixty percent (n = 18) of NTG group and 10% (n = 3) of cataract group patients completed the CDT in the specific picture manner (the short hand on 11 and the long hand between 11 and 12), (P = 0.001).

Conclusions:

Lower CDT results were seen in NTG patients according to two different scoring systems. NTG patients showed a specific manner of drawing. Further prospective studies are needed to investigate the CDT reliability as fast screening test of cognitive function impairment in glaucoma patients.

Intra-ocular lens optical changes resulting from the loading of dexamethasone

To study the optical changes on hydrogel-silicone intraocular lenses (IOLs) resulting from loading them with dexamethasone. We used prototype hydrogel(pHEMA)-silicone IOLs and loaded the matrices with an anti-inflammatory drug (dexamethasone). The optical properties we analyzed experimentally were a) modulation transfer function (MTF); b) spectral transmission; c) diopter power. These determinations were performed on drug-loaded IOLs, IOLs that had released the drug, and IOLs that had not been drug-loaded. Loading a hydrogel-silicone IOL with dexamethasone results in impairment of its optical qualities, in particular its MTF and spectral transmission, but not dioptric power. However, once the drug has been released, it almost recovers its initial optical properties.

[Cataract surgery among 50 Alzheimer's patient (55 eyes)]

OBJECTIVE

Cataract surgery for 50 Alzheimer patients (55 eyes).

METHODS

Cinquante Alzheimer's patients with 0≤MMS≤25, with bilateral disabling cataracts were included for surgery. The surgical technique is analyzed.

RESULTS AND CONCLUSION

The preoperative examination of Alzheimer's patients is time consuming and requires experience in this area, which is important to integrate into the practice of ophthalmology. The type of cataract is unusual, with a predilection for pseudoexfoliation syndrome and zonular fragility that has to be managed during surgery. The procedure may be performed under local anesthesia. Three months after surgery, Alzheimer's patients demonstrated improved visual acuity (P<0.001) with no worsening of their dementia.

Sensorineural Organs Dysfunction and Cognitive Decline: A Review Article

Vision, hearing, olfaction, and cognitive function are essential components of healthy and successful aging. Multiple studies demonstrate relationship between these conditions with cognitive function. The present article focuses on hearing loss, visual impairment, olfactory loss, and dual sensory impairments in relation to cognitive declination and neurodegenerative disorders. Sensorineural organ impairment is a predictive factor for mild cognitive impairment and neurodegenerative disorders in the elderly. We recommend early detection of sensorineural dysfunction by history, physical examination, and screening tests. Assisted device and early cognitive rehabilitation may be beneficial. Future research is warranted in order to explore advanced treatment options and method to slow progression for cognitive declination and sensorineural organ impairment.

Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study

Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA) >0.2 logarithm of the minimum angle of resolution (logMAR) units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE) score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation). The mean BCVA of the better eye was −0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = −0.10, p < 0.0001). Subjects with mild visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5–3.8, p < 0.001) after adjusting for age, sex, and length of education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment.

The Prevalence of Visual Impairment in People with Dementia (the PrOVIDe study): a cross-sectional study of people aged 60–89 years with dementia and qualitative exploration of individual, carer and professional perspectives

Background

The prevalence of visual impairment (VI) and dementia increases with age and these conditions may coexist, but few UK data exist on VI among people with dementia.

Objectives

To measure the prevalence of eye conditions causing VI in people with dementia and to identify/describe reasons for underdetection or inappropriate management.

Design

Stage 1 – cross-sectional prevalence study. Stage 2 – qualitative research exploring participant, carer and professional perspectives of eye care.

Setting

Stage 1 – 20 NHS sites in six English regions. Stage 2 – six English regions.

Participants

Stage 1 – 708 participants with dementia (aged 60–89 years): 389 lived in the community (group 1) and 319 lived in care homes (group 2). Stage 2 – 119 participants.

Interventions

Stage 1 gathered eye examination data following domiciliary sight tests complying with General Ophthalmic Services requirements and professional guidelines. Cognitive impairment was assessed using the Standardised Mini-Mental State Examination (sMMSE) test, and functional ability and behaviour were assessed using the Bristol Activities of Daily Living Scale and Cambridge Behavioural Inventory – Revised. Stage 2 involved individual interviews (36 people with dementia and 11 care workers); and separate focus groups (34 optometrists; 38 family and professional carers).

Main outcome measures.

VI defined by visual acuity (VA) worse than 6/12 or worse than 6/18 measured before and after refraction.

Results

Stage 1 – when participants wore their current spectacles, VI prevalence was 32.5% [95% confidence interval (CI) 28.7% to 36.5%] and 16.3% (95% CI 13.5% to 19.6%) for commonly used criteria for VI of VA worse than 6/12 and 6/18, respectively. Of those with VI, 44% (VA < 6/12) and 47% (VA < 6/18) were correctable with new spectacles. Almost 50% of remaining uncorrectable VI (VA < 6/12) was associated with cataract, and was, therefore, potentially remediable, and one-third was associated with macular degeneration. Uncorrected/undercorrected VI prevalence (VA < 6/12) was significantly higher in participants in care homes (odds ratio 2.19, 95% CI 1.30 to 3.73;p < 0.01) when adjusted for age, sex and sMMSE score. VA could not be measured in 2.6% of group 1 and 34.2% of group 2 participants (p < 0.01). The main eye examination elements (excluding visual fields) could be performed in > 80% of participants. There was no evidence that the management of VI in people with dementia differed from that in older people in general. Exploratory analysis suggested significant deficits in some vision-related aspects of function and behaviour in participants with VI. Stage 2 key messages – carers and care workers underestimated how much can be achieved in an eye examination. People with dementia and carers were unaware of domiciliary sight test availability. Improved communication is needed between optometrists and carers; optometrists should be informed of the person’s dementia. Tailoring eye examinations to individual needs includes allowing extra time. Optometrists wanted training and guidance about dementia. Correcting VI may improve the quality of life of people with dementia but should be weighed against the risks and burdens of undergoing examinations and cataract surgery on an individual basis.

Limitations

Sampling bias is possible owing to quota-sampling and response bias.

Conclusions

The prevalence of VI is disproportionately higher in people with dementia living in care homes. Almost 50% of presenting VI is correctable with spectacles, and more with cataract surgery. Areas for future research are the development of an eye-care pathway for people with dementia; assessment of the benefits of early cataract surgery; and research into the feasibility of specialist optometrists for older people.

Funding

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

Changes in Visual Function in the Elderly Population in the United States: 1995-2010

PURPOSE

To document recent trends in visual function among the United States population aged 70+ years and investigate how the trends can be explained by inter-temporal changes in: (1) population sociodemographic characteristics, and chronic disease prevalence, including eye diseases (compositional changes); and (2) effects of the above factors on visual function (structural changes).

METHODS

Data from the 1995 Asset and Health Dynamics among the Oldest Old (AHEAD) and the 2010 Health and Retirement Study (HRS) were merged with Medicare Part B claims in the interview years and the 2 previous years. Decomposition analysis was performed. Respondents from both studies were aged 70+ years. The outcome measure was respondent self-reported visual function on a 6-point scale (from 6 = blind to 1 = excellent).

RESULTS

Overall, visual function improved from slightly worse than good (3.14) in 1995 to slightly better than good (2.98) in 2010. A decline in adverse effects of aging on vision was found. Among the compositional changes were higher educational attainment leading to improved vision, and higher prevalence of such diseases as diabetes mellitus, which tended to lower visual function. However, compared to compositional changes, structural changes were far more important, including decreased adverse effects of aging, diabetes mellitus (when not controlling for eye diseases), and diagnosed glaucoma.

CONCLUSION

Although the US population has aged and is expected to age further, visual function improved among elderly persons, especially among persons 80+ years, likely reflecting a favorable role of structural changes identified in this study in mitigating the adverse effect of ongoing aging on vision.

Visual and Ocular Manifestations of Alzheimer's Disease and Their Use as Biomarkers for Diagnosis and Progression

Alzheimer's disease (AD) is the most common form of dementia affecting the growing aging population today, with prevalence expected to rise over the next 35 years. Clinically, patients exhibit a progressive decline in cognition, memory, and social functioning due to deposition of amyloid β (Aβ) protein and intracellular hyperphosphorylated tau protein. These pathological hallmarks of AD are measured either through neuroimaging, cerebrospinal fluid analysis, or diagnosed post-mortem. Importantly, neuropathological progression occurs in the eye as well as the brain, and multiple visual changes have been noted in both human and animal models of AD. The eye offers itself as a transparent medium to cerebral pathology and has thus potentiated the development of ocular biomarkers for AD. The use of non-invasive screening, such as retinal imaging and visual testing, may enable earlier diagnosis in the clinical setting, minimizing invasive and expensive investigations. It also potentially improves disease management and quality of life for AD patients, as an earlier diagnosis allows initiation of medication and treatment. In this review, we explore the evidence surrounding ocular changes in AD and consider the biomarkers currently in development for early diagnosis.

Higher Cognitive Function in Elderly Individuals with Previous Cataract Surgery: Cross-Sectional Association Independent of Visual Acuity in the HEIJO-KYO Cohort

Cataract surgery improves visual acuity and drastically increases the capacity for light reception to the retina. Although previous studies suggested that both light exposure and visual acuity were associated with cognitive function, the relationships between cataract surgery, visual acuity, and cognitive function have not been evaluated in large populations. In this cross-sectional study, we measured cognitive function using the Mini-Mental State Examination and best-corrected visual acuity in pseudophakic (previous cataract surgery) and phakic (no previous cataract surgery) elderly individuals. Of 945 participants (mean age 71.7 years), 166 (17.6%) had pseudophakia and 317 (33.5%) had impaired cognitive function (score ≤26). The pseudophakic group showed significantly better visual acuity than the phakic group (p = 0.003) and lower age-adjusted odds ratio (ORs) for cognitive impairment (OR 0.66; p = 0.038). Consistently, in multivariate logistic regression models, after adjusting for confounding factors, including visual acuity and socioeconomic status, ORs for cognitive impairment were significantly lower in the pseudophakic group than in the phakic group (OR 0.64; 95% confidence interval 0.43-0.96; p = 0.031). This association remained significant in sensitivity analysis, excluding participants with low cognitive score ≤23 (n = 36). In conclusion, in a general elderly population, prevalence of cognitive impairment was significantly lower in pseudophakic individuals independently of visual acuity. The association was also independent of several major causes of cognitive impairment such as aging, gender, obesity, socioeconomic status, hypertension, diabetes, sleep disturbances, depressive symptoms, and physical inactivity.

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.

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

BACKGROUND/AIMS

To assess the impact of impaired cognition on visual outcomes 1 year following cataract surgery in a cohort of older people.

METHODS

Participants aged 75 years or more with bilateral cataract and scheduled for cataract surgery were recruited consecutively. Cognition was assessed using the revised Addenbrooke's cognitive examination (ACE-R). Participants were divided into two groups: normal (ACE-R ≥88) and impaired cognition (ACE-R <88). Visual quality of life (VQOL) and logarithm of minimum angle of resolution visual acuity (VA) were assessed at baseline and 1 year following cataract surgery.

RESULTS

Of 112 participants, 48 (43%) had normal cognition and 64 (57%) had impaired cognition. One year following cataract surgery participants in both groups had significant improvements in VQOL and VA. Visual outcomes at 1 year were significantly better in participants with normal cognition than in those with impaired cognition (95% CIs for difference 0.4-7.0 and 0.02-0.1, for VQOL and VA, respectively). Regression analyses correcting for potential confounders showed a relationship between baseline cognition and VA at 1 year (R(2)=0.30, p=0.001) and a possible relationship between baseline cognition and VQOL at 1 year (R(2)=0.41, p=0.01, this became insignificant after removal of outliers).

CONCLUSIONS

Patients with impaired cognition benefit from cataract surgery, but not to the same extent as patients with normal cognition.

Comorbidity and dementia: a scoping review of the literature

BACKGROUND

Evidence suggests that amongst people with dementia there is a high prevalence of comorbid medical conditions and related complaints. The presence of dementia may complicate clinical care for other conditions and undermine a patient's ability to manage a chronic condition. The aim of this study was to scope the extent, range and nature of research activity around dementia and comorbidity.

METHODS

We undertook a scoping review including all types of research relating to the prevalence of comorbidities in people with dementia; current systems, structures and other issues relating to service organisation and delivery; patient and carer experiences; and the experiences and attitudes of service providers. We searched AMED, Cochrane Library, CINAHL, PubMed, NHS Evidence, Scopus, Google Scholar (searched 2012, Pubmed updated 2013), checked reference lists and performed citation searches on PubMed and Google Scholar (ongoing to February 2014).

RESULTS

We included 54 primary studies, eight reviews and three guidelines. Much of the available literature relates to the prevalence of comorbidities in people with dementia or issues around quality of care. Less is known about service organisation and delivery or the views and experiences of people with dementia and their family carers. There is some evidence that people with dementia did not have the same access to treatment and monitoring for conditions such as visual impairment and diabetes as those with similar comorbidities but without dementia.

CONCLUSIONS

The prevalence of comorbid conditions in people with dementia is high. Whilst current evidence suggests that people with dementia may have poorer access to services the reasons for this are not clear. There is a need for more research looking at the ways in which having dementia impacts on clinical care for other conditions and how the process of care and different services are adapting to the needs of people with dementia and comorbidity. People with dementia should be included in the debate about the management of comorbidities in older populations and there needs to be greater consideration given to including them in studies that focus on age-related healthcare issues.

Challenges for the cataract surgeon treating people with dementia: a qualitative study exploring anesthetic choices

BACKGROUND

In light of the growing number of people with dementia and age-related cataract, as well as changing anesthetic practices for cataract surgery, this study aimed to explore the experiences of cataract surgeons in managing patients with dementia and making anesthetic decisions.

METHODS

This was a qualitative study using semistructured interviews with senior cataract surgeons from two centers in England. Fourteen surgeons were interviewed, and a thematic approach informed by grounded theory was used for the analysis.

RESULTS

Choice of anesthesia for people with dementia was a central theme arising from the data. Surgeons varied in their thresholds for using general anesthesia. Decisions about suitability for local anesthesia were limited by time constraints and generally made rapidly and based on instinct; dementia was not always apparent at the point of preassessment. Surgeons used a variety of topical, sub-Tenon's, and sharp needle blocks for people with dementia. Surgeons discussed techniques to help patients tolerate local anesthesia, such as clear communication, a primary nurse, hand-holding, and support from an anesthetist. However, within our sample, some surgeons had had negative experiences of operating on people with dementia, where an incorrect judgment had been made that they could tolerate local anesthetic cataract surgery.

CONCLUSION

This study highlights the differing practices of cataract surgeons when making anesthetic choices for people with dementia and the challenges they face. In order to avoid the situation of a patient with dementia becoming distressed during awake surgery, increased time at preassessment and anesthetic support may be beneficial.

Cataract surgery is associated with a reduced risk of dementia: a nationwide population-based cohort study

BACKGROUND AND PURPOSE

Our purpose was to determine the association of cataract surgery with subsequent development of dementia in older adults with newly diagnosed cataract.

METHODS

By using data from Taiwan National Health Insurance Research Database (NHIRD), a population-based cohort study including 491 226 subjects aged 70 or older with first-time diagnosis of cataract coded from 2000 to 2009 was conducted. After matching cataract patients receiving cataract surgery with cataract patients without receiving cataract surgery for age, sex, index date, Charlson Comorbidity Index score, interval between first coding of cataract diagnosis and index date, hypertension and diabetes mellitus, 113 123 patients in each cohort were enrolled. The main outcome measure was newly diagnosed dementia coded by neurologists or psychiatrists more than 365 days after cataract surgery. Incidence rate and hazard ratio of dementia were compared between the cataract surgery and cataract diagnosis cohorts.

RESULTS

The incidence rate of dementia was 22.40 per 1000 person-years in the cataract surgery cohort and 28.87 per 1000 person-years in the cataract diagnosis cohort. The rate of dementia was significantly lower in the cataract surgery group (hazard ratio 0.77, 95% confidence interval 0.75-0.79, P < 0.001). Female gender (P < 0.001) and a shorter interval between the date of first coding of a cataract diagnosis and the date of cataract surgery (P = 0.009) were significantly associated with a lower incidence rate of dementia.

CONCLUSION

In an NHIRD cohort of Taiwanese aged 70 years and older with a diagnosis of cataract, patients undergoing cataract surgery were associated with a reduced risk of subsequent dementia compared with those without cataract surgery.

The association between diagnosed glaucoma and cataract and cognitive performance in very old people: cross-sectional findings from the newcastle 85+ study

PURPOSE

Common age-related eye diseases including glaucoma, cataract and age-related macular degeneration (AMD) have been proposed to be associated with dementia. Few studies have examined the relationship between cognition and cataract or glaucoma. We explored the association between cognition and cataract and glaucoma diagnoses in community-dwelling 85-year-olds.

METHODS

Cross-sectional analysis of data from the Newcastle 85+ Study. Diagnoses of eye disease were extracted from family practice records. Cognitive performance was assessed by the standardized mini-mental state examination (sMMSE) and the sMMSE-blind (MMblind). Relationships between glaucoma diagnosis or cataract diagnosis and lower cognition were examined using ordinal logistic regression.

RESULTS

Complete data were available for 839 participants. Of these, 36.0% (302/839) had recorded previous cataract surgery, 11.2% (94/839) untreated cataract and 7.9% (66/839) diagnosed glaucoma. Glaucoma diagnosis was associated with lower sMMSE results (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.05-2.95); but not lower MMblind (OR 1.17, 95% CI 0.65-2.12). When compared to no cataract, cataract diagnosis (treated and untreated combined) was associated with higher sMMSE (OR 0.55, 95% CI 0.38-0.79) and MMblind (OR 0.51, 95% CI 0.34-0.76). Previously treated cataract was associated with higher sMMSE (OR 0.72, 95% CI 0.59-0.88) and MMblind (OR 0.68, 95% CI 0.55-0.85). Untreated cataract was not significantly associated with sMMSE (OR 0.65, 95% CI 0.36-1.19) or MMblind (OR 0.73, 95% CI 0.39-1.36).

CONCLUSIONS

This large epidemiological study of 85-year-olds found that lower sMMSE but not MMblind was associated with glaucoma diagnosis, suggesting the association may be driven by poor vision. Cataract diagnosis was associated with higher sMMSE and MMblind. Reasons for this observation are unclear but may relate to enhanced help-seeking behavior in people with diagnosed cataract.

The assessment of cognition in visually impaired older adults

BACKGROUND

visual and cognitive impairments are common in later life. Yet there are very few cognitive screening tests for the visually impaired.

OBJECTIVE

to screen for cognitive impairment in the visually impaired.

METHODS

case-control study including 150 elderly participants with visual impairment (n = 74) and a control group without visual impairment (n = 76) using vision-independent cognitive tests and cognitive screening tests (MMSE and clock drawing tests (CDT)) which are in part vision dependent.

RESULTS

the scoring of the two groups did not differ in the vision-independent cognitive tests. Visually impaired patients performed poorer than controls in the vision-dependent items of the MMSE (T = 7.3; df: 148; P < 0.001) and in CDT (T = 3.1; df: 145; P = 0.003). No group difference was found when vision-independent items were added to MMSE and CDT. The test score gain by the use of vision-independent items correlated with the severity of visual impairment (P < 0.002).

CONCLUSION

visually impaired patients benefit from cognitive tests, which do not rely on vision. The more visually impaired the greater the benefit.

Vision and night driving abilities of elderly drivers

OBJECTIVE

In this article, we review the impact of vision on older people's night driving abilities. Driving is the preferred and primary mode of transport for older people. It is a complex activity where intact vision is seminal for road safety. Night driving requires mesopic rather than scotopic vision, because there is always some light available when driving at night. Scotopic refers to night vision, photopic refers to vision under well-lit conditions, and mesopic vision is a combination of photopic and scotopic vision in low but not quite dark lighting situations. With increasing age, mesopic vision decreases and glare sensitivity increases, even in the absence of ocular diseases. Because of the increasing number of elderly drivers, more drivers are affected by night vision difficulties. Vision tests, which accurately predict night driving ability, are therefore of great interest.

METHODS

We reviewed existing literature on age-related influences on vision and vision tests that correlate or predict night driving ability.

RESULTS

We identified several studies that investigated the relationship between vision tests and night driving. These studies found correlations between impaired mesopic vision or increased glare sensitivity and impaired night driving, but no correlation was found among other tests; for example, useful field of view or visual field. The correlation between photopic visual acuity, the most commonly used test when assessing elderly drivers, and night driving ability has not yet been fully clarified.

CONCLUSIONS

Photopic visual acuity alone is not a good predictor of night driving ability. Mesopic visual acuity and glare sensitivity seem relevant for night driving. Due to the small number of studies evaluating predictors for night driving ability, further research is needed.

A novel, multidisciplinary clinic for complex visual problems in older people

BACKGROUND

Visual symptoms in older people can be complex and inadequately explained by eye pathology alone. Psychological and neurodegenerative processes may manifest as complex visual symptoms, and thus some patients may be poorly served by a purely ophthalmic approach. We have developed a novel multidisciplinary clinic with input from neurology, ophthalmology, and psychiatric specialists. Here, we describe the patient population, disease prevalence, and potential impact of this new clinic.

METHODS

A retrospective audit of paper and electronic records from June 2010 to February 2012 and selected case reports.

RESULTS

Between June 2010 and February 2012 48 patients attended the clinic. Notes were available for 47 (98%). Mean age was 76.2 (range 48-92). The main presenting complaints were hallucinations, followed by nonspecific visual deficit, double vision, blurred vision, and visuospatial deficit. Cognitive impairment was noted in 68% (32/47) of patients, of which 16/32 (50%) were new diagnoses. We were able to give a diagnosis to 98% (46/47) of patients; of these, 74% (35/46) were new diagnoses. A total of 6% (3/47) were felt to have presentations attributable to eye pathology alone, whereas 89% (42/47) were felt to have a neuropsychiatric component. Management included referral to other clinics for continuing care in 43% (20/47) and initiation of therapy in 36% (17/47). The three case reports demonstrate cases, where our multidisciplinary approach aided diagnosis and management of patients with complex visual symptoms.

CONCLUSION

A combined clinic with neurological, ophthalmic, and psychiatric input is an effective way to diagnose and manage complex visual problems in older people.