Cataract subtype risk factors identified from the Korea National Health and Nutrition Examination survey 2008-2010

Characterization of mechanical stress in the occurrence of cortical opacification in age-related cataracts using three-dimensional finite element model of the human lens and RNA-seq

Cataract is the leading cause of blindness across the world. Age-related cataract (ARC) is the most common type of cataract, but its pathogenesis is not fully understood. Using three-dimensional finite element modeling combining experimental biotechnology, our study demonstrates that external forces during accommodation cause mechanical stress predominantly in lens cortex, basically matching the localization of opacities in cortical ARCs. We identified the cellular senescence and upregulation of PIEZO1 mRNA in HLECs under mechanical stretch. This mechano-induced senescence in HLECs might be mediated by PIEZO1-related pathways, portraying a potential biomechanical cause of cortical ARCs. Our study updates the fundamental insight towards cataractogenesis, paving the way for further exploration of ARCs pathogenesis and nonsurgical treatment.

Association between cataract and fatty liver diseases from a nationwide cross-sectional study in South Korea

This study examined the link between fatty liver disease (FLD) and cataracts, as previous research has suggested that FLD may contribute to metabolic syndrome, systemic inflammation, and potentially cataracts. We studied a nationwide cross-sectional cohort of the Fifth Korean National Health and Nutrition Examination Survey 2010-2011. FLD was defined as nonalcoholic FLD (NAFLD) and metabolic dysfunction-associated FLD (MAFLD). Multinomial logistic regression was utilized to investigate the relationship between cataracts and FLD after adjustment for potential confounders. Participants with cataracts had higher liver fibrosis scores, including the NAFLD fibrosis score (NFS; P < 0.001), fibrosis-4 index (FIB4; P < 0.001), and fatty liver index (FLI; P = 0.001). NAFLD was not associated with a higher odds ratio (OR) for cataracts in the fully adjusted model (OR = 1.23, P = 0.058). MAFLD was significantly associated with a higher OR (OR = 1.34, P = 0.006). After adjusting for all factors, the severity of FLD was linked to an increased risk of cataracts, with significant linear trends (P values for linear trends of NFS, FIB4, and FLI < 0.05). After adjusting for well-known cataract risk factors, MAFLD was significantly associated with cataracts. Our analysis suggests that FLD may serve as an independent risk factor for cataracts.

A Population-based Study of the Prevalence of Cataract and Its Relationship with Smoking in the Northwest of Iran: The Azar Cohort Eye Study

PURPOSE

The purpose of the to determine the prevalence of cataract and study the relationship of smoking and other potential risk factors with visually significant cataract.

METHODS

This is a cross-sectional study based on the Azar cohort databases including 11,208 participants aged 35-70 years of the general population. According to the questionnaire, participants were divided into five groups in terms of smoking. Eye examinations were performed in two steps. The first step was performed by an optometrist, and in the second step, participants with poor red reflex or visual acuity of <8/10 were examined by an ophthalmologist for diagnosing cataract.

RESULTS

Of the participants, 4992 (44.5%) were male and 6216 (55.5%) were female, with a mean age of 50.1 ± 9.27 years. The prevalence of visually significant cataract was 7.2%. The frequency of ex-smoking in the male and female population in the cataract group was significantly higher than that in the noncataract group (male: P = 0.008, female: P = 0.01), but after adjustment for age and education level, lost its significance (male odds ratio [OR] = 1.1 [0.8-1.5], P = 0.4; female OR = 1.5 [0.5-4], P = 0.3).

CONCLUSION

There is no association between cigarette smoking in different doses and the history of smoking with cataracts but other factors such as aging, education level, and underlying diseases including diabetes mellitus, hypertension, and myopia have statistically significant association with visually significant cataract.

The Risk of Major Depressive Disorder Due to Cataracts among the Korean Elderly Population: Results from the Korea National Health and Nutrition Examination Survey (KNHANES) in 2016 and 2018

Cataracts and major depressive disorder (MDD) both have high prevalence, representing for major health burdens globally. In this study, we examined the risk of MDD due to cataracts. Data from the 2016 to 2018 Korea National Health and Nutrition Examination Survey (KNHANES) were used, including 4122 participants. Logistic regression analysis was performed to evaluate the odds ratio for MDD in association with cataracts. Controlled variables were age, gender, smoking, dyslipidemia and mobility. Subgroup analysis was performed with stratification by gender. The results reveal that cataracts are significantly correlated with MDD. Elderly people with cataracts were found to be more likely to develop MDD compared to those without cataracts (adjusted odds ratio: 1.654; 95% CI = 1.197-2.286). In subgroup analysis, men (adjusted odds ratio: 2.631; 95% CI = 1.247-5.551) were found to be more likely to develop MDD than women (adjusted odds ratio: 1.510; 95% CI = 1.061-2.150). Cataracts may be a risk factor for MDD in the elderly, especially among the male population.

Better oral hygiene is associated with a reduced risk of cataract: A nationwide cohort study

Objective

To investigate the association of oral health status and oral hygiene behaviors with cataract occurrence longitudinally.

Materials and methods

Based on the National Health Screening cohort database of Korea, participants who underwent oral health screening by dentists in 2003 were included. Cataract was defined as two or more claims of disease classification for the International Classification of Diseases-10 (E10.34, E11.34, E12.34, E13.34, E14.34, H25, and H26) with cataract specific treatment or surgery procedure claim codes. The occurrence of cataract was analyzed with Cox proportional hazard model according to the presence of periodontitis and oral health examination findings, including missing teeth, caries, tooth brushing, and dental scaling.

Results

Overall, 103,619 subjects were included. During a median follow-up of 12.2 years, cataract developed in 12,114 (11.7%) participants. Poor oral health status such as the presence of periodontitis (adjusted hazard ratio [HR] 1.08, 95% CI [confidence interval] 0.99-1.17, p = 0.088) and increased number of missing teeth (adjusted HR = 1.74, 95% CI = 1.55-1.96, p < 0.001) was associated with the increased cataract risk. Better oral hygiene behaviors such as increased frequency of tooth brushing (adjusted HR = 0.84, 95% CI = 0.79-0.88, p < 0.001) and performed dental scaling within 1 year (adjusted HR = 0.90, 95% CI = 0.86-0.94, p < 0.001) were negatively associated with cataract occurrence.

Conclusion

Periodontitis and increased number of missing teeth may increase the risk of cataract. However, maintaining good oral hygiene through tooth brushing and dental scaling may reduce the risk of future cataract occurrence. Further studies should be performed to confirm the association between chronic oral inflammation and cataract.

Five-year change in refractive error and its risk factors: results from the Gutenberg Health Study

BACKGROUND/AIMS

To examine the 5-year change in refractive error in phakic eyes and its risk factors in the general population.

METHODS

The Gutenberg Health Study (GHS) is a population-based cohort study including 15 010 participants from Germany aged 35-74 years at baseline examination (2007-2012). After 5 years, a follow-up examination was carried out (83% participation). 5-year change of spherical equivalent (SE) was computed as difference between follow-up and baseline objective refraction. Linear and logistic regression analysis were conducted analysing potential risk factors. Only phakic eyes at follow-up examination were included.

RESULTS

Right eyes of 10 175 subjects were included. An age-related shift of refractive error was identified, namely -0.12 D for age 35-44 years, 0.25 D for age 45-54 years, 0.25 D for age 55-64 years and 0.12 D for age 65-74 years during the 5-year follow-up. Smokers had a hyperopic shift (OR=1.31; p<0.001), while baseline SE (OR=0.89 per dioptre; p<0.001) and female sex (OR=1.49; p<0.001) were linked with a myopic shift. Education, occupation and other cardiovascular parameters were not associated with change in refractive error.

CONCLUSIONS

The GHS demonstrates a parabolic shift in refractive error with a myopic shift at age 35-44 years, followed by a hyperopic shift at age 45-64 years which decreases at higher age. Smoking is associated with a hyperopic shift whereas female sex and myopic baseline SE is associated with a myopic shift. Educational level and occupation were not linked to a change in refractive error at age 35-74 years.

Ambient Air Pollution and Age-Related Eye Disease: A Systematic Review and Meta-Analysis

Purpose

To compare the burden of age-related eye diseases among adults exposed to higher versus lower levels of ambient air pollutants.

Methods

MEDLINE, EMBASE, and Scopus were searched for relevant articles until September 30, 2021. Inclusion criteria included studies of adults, aged 40+ years, that provided measures of association between the air pollutants (nitrogen dioxide, carbon monoxide [CO], sulfur dioxide, ozone [O3], particulate matter [PM] less than 2.5 µm in diameter [PM2.5], and PM less than 10 µm in diameter [PM10]) and the age-related eye disease outcomes of glaucoma, age-related macular degeneration (AMD), or cataract. Pooled odds ratio (OR) estimates and 95% confidence intervals (CIs) were calculated using a random-effects meta-analysis model. PROSPERO registration ID: CRD42021250078.

Results

A total of eight studies were included in the review. Consistent evidence for an association was found between PM2.5 and glaucoma, with four of four studies reporting a positive association. The pooled OR for each 10-µg/m3 increase of PM2.5 on glaucoma was 1.18 (95% CI, 0.95-1.47). Consistent evidence was also found for O3 and cataract, with three of three studies reporting an inverse association. Two of two studies reported a null association between PM2.5 and cataract, while one of one studies reported a positive association between PM10 and cataract. One of one studies reported a positive relationship between CO and AMD. Other relationships were less consistent between studies.

Conclusions

Current evidence suggests there may be an association between some air pollutants and cataract, AMD, and glaucoma.

Prevalence and 11-Year Incidence of Cataract and Cataract Surgery and the Effects of Socio-Demographic and Lifestyle Factors

Purpose

To assess the impact of cataract in ageing population by evaluating the prevalence, incidence, and background factors of cataract and cataract surgery.

Patients and Methods

Two health examination surveys representing Finnish population in 2000 and 2011 included 7380 and 5930 participants aged 30 years or older with cataract status known. An 11-year follow-up included 4840 persons who participated in both the surveys. The data include information on physician-made diagnoses, socio-demographic factors, and lifestyle factors based on self-reported assessment. Cataract diagnoses and surgeries recorded in the Finnish Care Register for Health Care were linked to the survey data. Cataract patients were compared to those without cataract using logistic regression. Differences in cataract surgery age were evaluated using linear regression. Univariable and multivariable models were included.

Results

During 2000-2011, the prevalence of cataract increased from 8.8% to 13.6% and cataract surgery from 5.7% to 8.9% in a representative sample of the Finnish adult population. Cataract and cataract surgery were associated with age, smoking, and high alcohol consumption. Cataract was also associated with female gender and low income in 2000, but this association declined during the 11 years. Smoking and high alcohol consumption were associated with younger surgery age.

Conclusion

The prevalence of cataract and cataract surgery is increasing with the ageing of the population. The increase in cataract surgery is likely also reflecting the improvements in eye care. The possibility to equally use health-care services throughout a country can reduce the impact of socio-demographic status. Healthy lifestyle delays the development of cataract, whereas smoking and high alcohol consumption are associated with earlier cataract development. Therefore, the availability of cataract services and promotion of healthy lifestyle will be the key to prevent the detrimental effects of cataract on patients and the society in countries where the population is rapidly ageing.

Association between age-related cataract and blepharoptosis in Korean adults: a population-based study

Cataract and blepharoptosis are both commonly encountered ophthalmic problems in older adults. Since they share similar risk factors, it is plausible that there may be an association between the two conditions. We examined data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2010–2012 to determine if there is an association between age-related cataract and blepharoptosis. Multivariable adjusted logistic regression analysis was conducted to examine the odds ratio (OR) and 95% confidence interval (CI) for association of each specific type of cataract with presence of blepharoptosis. Of the 10,387 eligible participants, 4782 (46.0%) had cataract and 1419 (15.8%) had blepharoptosis. There were more participants with blepharoptosis in the cataract group, compared with those in the no cataract group. After adjusting for potential confounders, participants with blepharoptosis had a higher risk of total cataract (OR: 1.557, 95% CI 1.201–2.019) and nuclear subtype cataract (OR: 1.305, 95% CI 1.050–1.620). Blepharoptosis was associated with significantly higher odds of cataract in obese participants when compared with non-obese participants (p for interaction = 0.0236). Our study revealed a positive association between age-related cataract and blepharoptosis; it suggests that thorough ophthalmic assessment is needed when assessing patients who are planning cataract or blepharoptosis surgery.

[Prevalence and detection rate of senile cataract in individuals with cardiovascular diseases]

OBJECTIVE

To determine the prevalence of senile cataracts and its detection rate among the population at the age of 40 and older with diseases of the cardiovascular system.

MATERIAL AND METHODS

This observational cross-sectional study was based on the information extracted from electronic health records (EHR) of patients aged 40-99 years assigned for medical services to a city polyclinic.

RESULTS

Among the population with essential hypertension (EH) senile cataract occurs with the frequency of 10.4±0.3% (95% CI 9.8-10.9%) of cases, in patients with cerebrovascular diseases (CVD) - 17.1±0.2% (95% CI 16.6-17.5%) of cases, with varicose veins of the lower extremities - 19.9±0.2% (95% CI 19.4-20.3%) of cases, with ischemic heart disease (IHD) - 15.8±0.2% (95% CI 15.4-16.2%) of cases. At the same time, senile cataract is associated with an increase in the likelihood of its detection in patients with hypertension by 6.8 times (OR 6.57; 95% CI 5.89-7.74), with CVD by 5 times (OR 5.02; 95% CI 4.64-5.44), with varicose veins by 3.7 times (OR 3.70; 95% CI 3.34-4.10), with IHD by 3.5 times (OR 3.53; 95% CI 3.20-3.90). Female gender is associated with an increased likelihood of developing senile cataracts in the presence of EH by 1.4 times (OR 1.420; 95% CI 1.299-1.553), in the presence of CVD by 1.2 times (OR 1.199; 95% CI 1.066-1.348), in the presence of varicose veins by 1.4 times (OR 1.355; 95% CI 1.064-1.725), in the presence of IHD by 1.5 times (OR 1.476; 95% CI 1.298-1.679). The detection rate of senile cataract is highest at the ages of 70-79 years, amounting to 18.1% of cases with hypertension, 24.0% of cases with CVD, 29.2% of cases with varicose veins, and 33.7% of cases with ischemic heart disease.

CONCLUSION

Target population groups have been identified for more effective screening studies in order to detect senile cataracts among them.

Prevalence of chronic disease in older adults in multitier eye-care facilities in South India: Electronic medical records-driven big data analytics report

Purpose:

To study the prevalence of systemic conditions in older adults, either self-reported or discovered during routine eye examinations, at multitier eye-care facilities over the past decade, and to explore their association with vision and common ocular disorders, including cataract, glaucoma, and retinopathy.

Methods:

Retrospective review of a large data set compiled from the electronic medical records of patients older than 60 years who presented to an eye facility of a multitier ophthalmology network located in 200 different geographical locations that included urban and rural eye-care centers spread across four states in India over a 10-year period.

Results:

618,096 subjects aged 60 or older were identified as visiting an eye facility over the 10-year study period. The mean age of the study individuals was 67·28 (±6·14) years. A majority of older adults (66·96%) reported being free of systemic illnesses. Patients from lower socioeconomic status had a lower prevalence of chronic systemic disease, but the presenting vision was poorer. Hypertension (21·62%) and diabetes (18·77%) were the most commonly reported chronic conditions in patients who had concomitant systemic illness with visual concerns.

Conclusion:

The prevalence of chronic systemic illnesses in older adults presenting to multitier eye-care facilities is relatively low, except in those with diabetic retinopathy. These observations suggest a need to include active screening for common chronic diseases in standalone eye-care facilities to achieve a more accurate assessment of chronic disease burden in the older population.

Age- and Sex-Standardized Prevalence of Age-Related Cataract and Its Determinants; Tehran Geriatric Eye Study (TGES)

PURPOSE

To determine the prevalence of cataract and its relationship with some determinants in individuals above 60 years.

METHODS

Of 3792 subjects that were invited, 3310 participated in the study (response rate = 87.31%). All subjects underwent full optometric, slit lamp, and fundoscopic examinations. Then, their lenses were evaluated according to the World Health Organization cataract grading system after pupil dilation.

RESULTS

Age- and sex-standardized prevalence with 95% confidence interval (CI) of nuclear, cortical, posterior subcapsular cataracts (PSC), any type cataract, and all lens change was 53.09% (49.80 to 56.35), 23.02% (20.87 to 25.32), 5.57% (4.62 to 6.70), 58.78% (55.65 to 61.83), and 72.49% (70.14 to 74.71), respectively. Any type, nuclear, cortical, and PSC cataracts, had a positive association with age and an inverse association with education. Moreover, the prevalence of cortical and PSC cataract had an inverse association with economic status. Among all variables, age was the strongest determinant for cataract and its subtype.

CONCLUSION

This study found a higher prevalence of cataract compared to some previous studies such that about two-thirds of the geriatric population had cataract in the past or at the time of the study. Considering the association of cataract with variables such as economic status and education level, it seems that training and increased awareness and knowledge of the elderly population regarding the importance of eye care by physicians plays an important role in reducing the burden of cataract.

Hypertension and Hypercholesterolemia are Associated with Cataract Development in Patients with Type 2 Diabetes

INTRODUCTION

Patients with diabetes have up to five times higher incidence of cataract, mainly at a younger age, and cataract in these patients progresses more rapidly than senile cataract, especially in eyes affected with sight-threatening diabetic retinopathy (DR).

AIM

This study aimed to investigate the risk factors associated with cataract development in patients with type 2 diabetes (T2DM).

METHODS

This case-control cross-sectional study included 90 T2DM (56M/34F). Metabolic risk factors glycated hemoglobin (HbA₁c), total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides were determined using routine laboratory methods. Blood pressure was measured with a mercury sphygmomanometer after a 10-min resting period. Lens opacity was graded according to the Lens Opacity Classification System version III (LOCS III).

RESULTS

According to the LOCS III, patients were divided into two groups: group 1-patients with clear crystalline lens, and group 2-patients with initial cataract. Compared to patients with a clear crystalline lens, those with initial cataract had longer diabetes duration (p = 0.002), higher HbA₁c (p = 0.037), higher total cholesterol (p = 0.029), higher diastolic blood pressure (DBP) (p = 0.014), and lower creatinine clearance (p = 0.017). Cataract was positively associated with diabetes duration (p = 0.001), HbA₁c (p = 0.035), LDL cholesterol (p = 0.042), and DBP (p = 0.009), while negatively with creatinine clearance (p = 0.005). Logistic regression analysis showed that the influence of DBP (AOR = 1.06, p = 0.014) and creatinine clearance (AOR = 2.93, p = 0.045) on cataract development remained significant even after adjustment for diabetes duration and HbA₁c.

CONCLUSIONS

Diabetes duration and various metabolic risk factors, particularly poor glycemic control, hypercholesterolemia, DBP, and diabetic nephropathy's coexistence, are associated with cataract development in T2DM.

Gender Prediction for a Multiethnic Population via Deep Learning Across Different Retinal Fundus Photograph Fields: Retrospective Cross-sectional Study

Background

Deep learning algorithms have been built for the detection of systemic and eye diseases based on fundus photographs. The retina possesses features that can be affected by gender differences, and the extent to which these features are captured via photography differs depending on the retinal image field.

Objective

We aimed to compare deep learning algorithms’ performance in predicting gender based on different fields of fundus photographs (optic disc–centered, macula-centered, and peripheral fields).

Methods

This retrospective cross-sectional study included 172,170 fundus photographs of 9956 adults aged ≥40 years from the Singapore Epidemiology of Eye Diseases Study. Optic disc–centered, macula-centered, and peripheral field fundus images were included in this study as input data for a deep learning model for gender prediction. Performance was estimated at the individual level and image level. Receiver operating characteristic curves for binary classification were calculated.

Results

The deep learning algorithms predicted gender with an area under the receiver operating characteristic curve (AUC) of 0.94 at the individual level and an AUC of 0.87 at the image level. Across the three image field types, the best performance was seen when using optic disc–centered field images (younger subgroups: AUC=0.91; older subgroups: AUC=0.86), and algorithms that used peripheral field images had the lowest performance (younger subgroups: AUC=0.85; older subgroups: AUC=0.76). Across the three ethnic subgroups, algorithm performance was lowest in the Indian subgroup (AUC=0.88) compared to that in the Malay (AUC=0.91) and Chinese (AUC=0.91) subgroups when the algorithms were tested on optic disc–centered images. Algorithms’ performance in gender prediction at the image level was better in younger subgroups (aged <65 years; AUC=0.89) than in older subgroups (aged ≥65 years; AUC=0.82).

Conclusions

We confirmed that gender among the Asian population can be predicted with fundus photographs by using deep learning, and our algorithms’ performance in terms of gender prediction differed according to the field of fundus photographs, age subgroups, and ethnic groups. Our work provides a further understanding of using deep learning models for the prediction of gender-related diseases. Further validation of our findings is still needed.

Decomposition of Economic Inequality in Cataract Surgery Using Oaxaca Blinder Decomposition: Tehran Geriatric Eye Study (TGES)

Purpose: The aim of this study was to investigate economic inequality in cataract surgery and to decompose it into its determinants using Oaxaca-Blinder decomposition.Methods: The Tehran Geriatric Eye Study is a population-based cross-sjal study that was done on individuals above 60 years using stratified cluster random sampling. All subjects underwent full optometric, slit lamp, and fundoscopic examinations. Then, after pupil dilation, the history of cataract surgery, including PC and AC IOL, was determined.Results: The age and sex-standardized prevalence of cataract surgery was 33.51% (95% CI: 31.45 to 35.62). Cataract surgery had a significant positive association with age (OR: 14.06; p < .001 for >80 vs 60-64 years) and a significant inverse association with education level (OR: 0.55, p: 0.006 for college education vs being illiterate) and economic status (OR: 0.64, p: 0.003 for rich vs poor). A significant difference was found in cataract surgery between the rich and poor (26.22%) disfavoring the poor (p < .001). The explained and unexplained portions comprised 95.99% and 4.01% of the difference (p < .001 and p = .336, respectively). Among study variables, age (p < .001), education (p = .003), economic status (p = .002), insurance (p = .011), and eye examination (p < .001) were significant determinants of inequality in the explained portion.Conclusion: There was a marked difference in the prevalence of cataract surgery between the rich and poor that was mostly caused by the explained portion. Age, economic status, and education had the largest effects on increasing the inequality and history of eye examination by an ophthalmologist and insurance coverage had the largest effects on reducing this inequality.

Hyperglycemia and Hypo-HDL-cholesterolemia Are Primary Risk Factors for Age-related Cataract, and a Korean-style Balanced Diet has a Negative Association, based on the Korean Genome and Epidemiology Study

BACKGROUND

The prevalence of cataracts is steadily increasing among the middle-aged and elderly worldwide. We hypothesized that adults aged > 50 years with age-related cataracts (ARCs) have an association with metabolic syndrome (MS) and its components, and MS has interactions with different dietary patterns and lifestyles that affect ARC risk. We examined the hypothesis using the Korean Genome and Epidemiology Study (KoGES; a large-scale hospital-based cohort study), which collected data between 2004-2013.

METHODS

Participants ≥ 50 years old were classified as cases (1,972 ARC patients) and controls (38,290 healthy controls) based on a diagnosis of cataract by a physician. MS and its components were defined using WHO definitions for Asians. Dietary consumption was evaluated using a validated semi-quantitative food frequency questionnaire (SQFFQ), which contained 106 foods, and dietary patterns were analyzed by principal component analysis. After adjusting for potential covariates, logistic regression was used to investigate associations between MS and its components and between dietary patterns and a positive cataract history.

RESULTS

ARC had a positive association with MS after 1.32-fold adjusting for age, sex, residence area, body mass index, and energy intake. Plasma glucose and HbA1c concentrations exhibited an increased ARC risk in the participants with MS by 1.50- and 1.92-fold and without MS by 1.35 and 1.88-fold, respectively. Serum high-density lipoprotein (HDL) concentrations were negatively associated with ARC risk only in the MS patients, but not without MS. However, blood pressure, abdominal obesity, and serum triglyceride concentrations did not associate with ARC risk regardless of MS. High intake of a Korean-balanced diet (KBD) containing fermented food exhibited a negative association with ARC risk (OR = 0.81) only in the MS group. The fat and coffee intake had a negative association with ARC only in the non-MS group. Current- and former-smokers were positively associated with ARC risk.

CONCLUSION

Persons who have hyperglycemia and low-HDL-cholesterolemia had increased susceptibility of ARC prevalence. A KBD with a proper amount of fat (≥ 15%) is recommended, and smoking should be prohibited.

Association between Skin Cancer and Systemic and Ocular Comorbidities in South Korea

Background: In this study, we investigated the associations between various systemic and ocular comorbidities and skin cancer, in a nationwide cohort of South Koreans. Method: We reviewed the data of 1,103,302 individuals in the South Korean National Health Insurance Service-National Sample Cohort database from 2002 to 2015. Of these, 1202 individuals diagnosed with skin cancer from 2004 were included in the study group. The control group was matched in a 1:5 ratio based on propensity scores. Results: The prevalence rates of melanoma and non-melanoma skin cancer increased from 2004 to 2015. Multivariate logistic regression analysis revealed that, among the various systemic conditions, hypertension was significantly associated with skin cancer, while among ocular comorbidities, macular degeneration showed a significant association with skin cancer. Conclusions: This is the first study to demonstrate associations between skin cancer and various systemic and ocular comorbidities. The results suggest that hypertension and macular degeneration may increase the risk of skin cancer development, or vice versa. Further studies are needed to evaluate the causal relationships between these conditions.

Polygenetic-Risk Scores Related to Crystallin Metabolism Are Associated with Age-Related Cataract Formation and Interact with Hyperglycemia, Hypertension, Western-Style Diet, and Na Intake

Age-related cataract (ARC) development is associated with loss of crystalline lens transparency related to interactions between genetic and environmental factors. We hypothesized that polygenetic risk scores (PRS) of the selected genetic variants among the ARC-related genes might reveal significant genetic impacts on ARC risk, and the PRS might have gene-gene and gene-lifestyle interactions. We examined the hypothesis in 1972 and 39,095 subjects aged ≥50 years with and without ARC, respectively, in a large-scale hospital-based cohort study conducted from 2004 to 2013. Single nucleotide polymorphisms (SNPs) of the genes related to ARC risk were identified, and polygenetic risk scores (PRS) were generated based on the results of a generalized multifactor dimensionality reduction analysis. Lifestyle interactions with PRS were evaluated. The PRS derived from the best model included the following six SNPs related to crystallin metabolism: ULK4_rs1417380362, CRYAB_rs2070894, ACCN1_rs55785344, SSTR2_rs879419608, PTN_rs322348, and ICA1_rs200053781. The risk of ARC in the high-PRS group was 2.47-fold higher than in the low-PRS group after adjusting for confounders. Age, blood pressure, and glycemia interacted with PRS to influence the risk of ARC: the incidence of ARC was much higher in the elderly (≥65 years) and individuals with hypertension or hyperglycemia. The impact of PRS on ARC risk was greatest in middle-aged individuals with hypertension or hyperglycemia. Na, coffee, and a Western-style diet intake also interacted with PRS to influence ARC risk. ARC risk was higher in the high-PRS group than in the low-PRS group, and high Na intake, Western-style diet, and low coffee intake elevated its risk. In conclusion, ARC risk had a positive association with PRS related to crystallin metabolism. The genetic impact was greatest among those with high Na intake or hypertension. These results can be applied to precision nutrition interventions to prevent ARC.

Hypertension is the Prominent Risk Factor in Cataract Patients

Background and objectives: The purpose of this study is to determine the impact of the most prominent cardiovascular and metabolic risk factors in patients undergoing cataract surgery. Materials and Methods: The study included 812 consecutive patients undergoing unilateral, uneventful cataract surgery by means of phacoemulsification, at the 2nd Department of Ophthalmology, Medical School, Aristotle University of Thessaloniki, Greece, during a calendar year. Patients were assessed for the type of cataract and the presence of three diseases, under pharmacological treatment, that have been reported as risk factors for the development of cataract (arterial hypertension, diabetes mellitus, and dyslipidemia). Results: There was a statistically significant difference between the types of cataract and individual risk factors (p < 0.001). Hypertension was the most frequentrisk factor, ranging from 43.8% in patients with subcapsular cataracts, 24.3% in patients with nuclear cataracts, 28.6% in patients with cortical cataracts, and 27.6% in patients with mixed type cataracts. There was a statistically significant difference as to the total number of risk factors per cataract type (p < 0.001); almost all patients with subcapsular cataracts had at least one risk factor (98.4%) while this percentage was 90.5% for patients with mixed cataracts, 85.7% for patients with cortical cataracts, and78.6% for patients with nuclear cataracts. Conclusions: Diabetes mellitus did not have a large incidence in our sample as a single risk factor, while hypertension did. This finding raises the importance of early detection of hypertension, a cardiovascular condition that typically progresses undetected for a number of years.

Income and Education are Independently Associated with Visual Impairment: The Korean National Health and Nutrition Examination Survey 2010-2012

Purpose: To investigate the association of visual impairment (VI) with socioeconomic status, including the highest educational level and household income when other confounding variables were adjusted. Methods: The Korean National Health and Nutrition Examination Survey 2010-2012 data were analyzed. The final analyses included a total of 16,905 subjects with their demographic, socioeconomic, and health data. The socioeconomic data included the household income and the highest educational level. Household income was categorized into quartiles. The educational attainment was categorized as ≤ elementary school, middle school, high school, and ≥ university. VI was defined when the distance-corrected VA was worse than 0.32 (20/63 Snellen) in the better-seeing eye according to the definition of the World Health Organization. Four multiple logistic regression models were used to determine the odds ratio (OR) and 95% confidence interval (CI) between VI and household income or between VI and the highest educational level, by adjusting for several confounding variables. Results: The prevalence of VI was 5.0% (844 subjects). Multiple logistic regression analyses indicated that the adjusted OR was 1.729 (95% CI: 1.108-2.697) for developing VI in subjects with ≤ elementary school as their highest education level compared to those with ≥ university education. Also, the adjusted OR of subjects in the first quartile of household income was 1.502 (95% CI: 1.061-2.127) for developing VI compared to those in the fourth quartile of household income. Conclusions: The present study showed that household income and education were independently associated with VI even after adjusting for significant confounding variables.

Comparison of medical comorbidity between patients with primary angle-closure glaucoma and a control cohort: a population-based study from Taiwan

OBJECTIVE

To determine the prevalence and risk of systemic comorbidities in primary angle-closure glaucoma in Taiwan population.

METHODS

We included 3322 primary angle-closure glaucoma (PACG) subjects and randomly selected patients without PACG from the Taiwan National Health Insurance Research Database and frequency matched four of them (n=13 288) to each PACG patient, based on age and sex. The univariable and multivariable unconditional logistic regression models were used to estimate the effect of comorbidities on the risk of PACG as indicated by the OR with 95% CI.

RESULTS

The mean age of the PACG group was 65.2±12.7 years, and 61.1% of the patients were female. The risk of PACG was greater for patients with the comorbidities of hyperlipidaemia (ORs: 1.11), headaches (ORs: 1.13), liver diseases (ORs: 1.14), peptic ulcers (ORs: 1.10) and cataract (ORs: 3.80). For the male group, diabetes (ORs: 1.19), liver diseases (ORs: 1.29) and cataract (ORs: 4.30) were significantly associated with increasing PACG risk. For the female group, hyperlipidaemia (ORs: 1.13), headaches (ORs: 1.15), peptic ulcers (ORs: 1.14) and cataract (ORs: 3.54) were significantly associated with increasing PACG risk. For the age group of 64 years and younger, patients with comorbidity of hyperlipidaemia (ORs: 1.20), peptic ulcers (ORs: 1.21) and cataract (ORs: 5.91) were significantly associated with increasing PACG risk. For the age group of 65 years and older, patients with cataract were significantly associated with increasing PACG risk (ORs: 5.07).

CONCLUSIONS

Clinicians should be aware of slightly increased PACG risk in the subjects with the medical comorbidities of hyperlipidaemia, headaches, liver diseases and peptic ulcers. However, cataract is the strongest risk factor of PACG.

[Effect of different clear corneal incision sites on surgery efficacy and anterior segment parameters in patients undergoing phacoemulsification]

OBJECTIVE

To determine the safe distance range of clear corneal incision (CCI) from the corneal limbus and how different CCI sites affect surgery efficacy and anterior segment parameters in patients undergoing phacoemulsification.

METHODS

This retrospective case-control study was conducted in 44 patients (44 eyes) undergoing phacoemulsification and IOL implantation. The patients were divided into two groups with CCI distances ranging from 1 mm to 1.5 mm (group A, n= 22) and from 0.5 mm to 1.0 mm (group B, n= 22). The visual acuity, surgically induced astigmatism (SIA), corneal aberration, and anterior segment parameters were analyzed.

RESULTS

Compared with the preoperative data, all the patients showed significant improvements in the postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), anterior chamber depth (ACD), and anterior chamber angle (ACA) after the surgery (P &lt; 0.05). No significant differences were found between the two groups in postoperative UCVA, BCVA, SIA, total corneal aberration RMS, lower- and higher-order aberration RMS, spherical aberration (Z₄⁰), horizontal three leaf clover (Z₃³), vertical three leaf clover(Z₃^-3), horizontal coma(Z₃¹), vertical coma(Z₃^-1), ACD, ACA, anterior chamber volume, or central corneal thickness (P&gt;0.05).

CONCLUSIONS

Phacoemulsification is an effective therapy for cataract with a CCI distance range either of 1-1.5 mm or 0.5-1.0 mm. These two CCI distance ranges produce no significant differences in the visual quality following phacoemulsification, indicating that a CCI distance range of 0.5-1.5 mm can be safe for phacoemulsification.

Cataract frequency and subtypes involved in workers assessed for their solar radiation exposure: a systematic review

Cataract is currently the primary cause of blindness worldwide, and one of its main risk factors is solar ultraviolet radiation exposure. According to the localization of lens opacities, three main subtypes of cataract are recognized: nuclear, cortical and posterior subcapsular cataract. One of the main determinants of individual long-term solar radiation exposure is outdoor work. We systematically reviewed scientific literature from the last 20 years to update the recent development of research on the risk of cataract in outdoor workers and on the specific subtypes involved, also investigating the methods applied to evaluate the occupational risk. A total of 15 studies were included in the review, of which 12 showed a positive association. The studies confirm the relationship of long-term occupational solar radiation exposure with cortical cataract and give new support for nuclear cataract, although no substantial new data were available to support a relation with the posterior subcapsular subtype. In most of the studies, the exposure assessment was not adequate to support a representative evaluation of the ocular risk; however, outdoor work is clearly a relevant risk factor for cataract. Further research providing a better evaluation of the relation between solar radiation exposure levels and lens damage in workers is needed and aimed to establish adequate occupational exposure limits and better preventive measures, studying also their effectiveness.

Risk factors of presenile nuclear cataract in health screening study

Background

To identify risk factors for the development of presenile nuclear cataract in health screening test.

Methods

The cross sectional study included a total of 532 eyes of 266 participants aged 30 to 49 years of Samsung Medical Center from February 2013 to April 2015. Presence of nuclear cataract was defined when the log MAR visual acuity with correction was greater than or equal to 0.2 and one or more of the following were met: Pentacam Nuclear Staging (PNS) grading score ≥ 1, average value of nuclear density ≥ 15%, maximum value of nuclear density ≥ 30%. Possible risk factors were obtained from blood tests and questionnaires of a health screening test of Samsung Medical Center. Association between nuclear cataract and risk factors was investigated using univariate and multivariate logistic regression analysis by generalized estimating equation (GEE) models.

Results

Five factors were significantly associated with presenile nuclear cataract: current smoking [odds ratio (OR) = 2.80, 95% confidence interval (CI), 1.10–7.12, p = 0.0310], non-exercise and high amount of daily physical exercise (OR = 3.99, 95% CI, 1.27–12.52, p = 0.0178; OR = 2.92, 95% CI, 1.38–6.22, p = 0.0053), asthma (OR = 8.93, 95% CI, 1.12–71.15, p = 0.0386), tuberculosis (OR = 4.28, 95% CI, 1.36–13.50, p = 0.0131), and higher total iron binding capacity (OR = 1.01, 95% CI, 1.00–1.02, p = 0.0059).

Conclusions

Presenile nuclear cataract is related to current smoking, non-exercise or high amount of physical exercise, asthma, tuberculosis, and iron deficiency status. The association of non-exercise group and presenile nuclear cataract seems to be related to co-morbidity. Patients with asthma, tuberculosis, or iron deficiency anemia are recommended to receive frequent ophthalmic examination to detect cataract.

Electronic supplementary material

The online version of this article (10.1186/s12886-018-0928-6) contains supplementary material, which is available to authorized users.

Solar Radiation Exposure and Outdoor Work: An Underestimated Occupational Risk

A considerably high number of outdoor workers worldwide are constantly exposed for the majority of their working life to solar radiation (SR); this exposure is known to induce various adverse health effects, mainly related to its ultraviolet (UV) component. The skin and the eye are the principal target organs for both acute and long-term exposure. Actinic keratosis, non-melanoma skin cancers, and malignant melanoma are the main long-term adverse skin effects, whereas in the eye pterygium, cataracts, and according to an increasing body of evidence, macular degeneration may be induced. Despite this, SR exposure risk is currently undervalued, if not neglected, as an occupational risk factor for outdoor workers. SR exposure is influenced by various environmental and individual factors, and occupation is one of the most relevant. For a better understanding of this risk and for the development of more effective prevention strategies, one of the main problems is the lack of available and adequate methods to estimate SR worker exposure, especially long-term exposure. The main aims of this review were to provide a comprehensive overview of SR exposure risk of outdoor workers, including the UV exposure levels and the main methods recently proposed for short-term and cumulative exposure, and to provide an update of knowledge on the main adverse eye and skin effects. Finally, we also outline here preventive interventions to reduce occupational risk.

Development of diabetic retinopathy after cataract surgery

This study explored whether cataract surgery precipitates diabetic retinopathy (DR) development in diabetic patients without previous DR. Patients with the diagnosis of type II diabetes but without DR were selected from the Longitudinal Health Insurance Database 2000. Patients who received cataract surgery between January 1, 2000, and December 31, 2010, were included in the case group, and the control group was matched to the case group by age, sex, and index year. The postoperative incidence rates of nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), and diabetic macular edema (DME) were the main outcomes studied and were adjusted by age, sex, comorbidities, and statin, fibrate, angiotensin-converting-enzyme inhibitor (ACEI), oral hypoglycemic agents (OHA), and insulin use. In our cohort, patients who had dyslipidemia and used statins were more likely to undergo cataract surgery. Among diabetic patients without previous DR, patients receiving cataract surgery had a higher risk of NDPR development (adjusted hazard ratio = 1.48, 95% confidence interval = 1.15–1.91). No statistical difference was observed in PDR or DME development between operative and nonoperative groups. In additional stratified analyses, female sex, older age, comorbidities, surgery within 5 years, statin, ACEI, OHA, and insulin use increased the risk of NPDR development. In an adjusted Cox regression model, cataract surgery, OHA and insulin use were found to be risk factors for NPDR development. Cataract surgery with complications increased post-operative risks for NPDR were even higher, and the significant influence from cataract surgery persisted 5 years after surgery.

Unexpected potential protective associations between outdoor air pollution and cataracts

Air pollution is one of the biggest public health issues, and the eye is continuously exposed to multiple outdoor air pollution. However, to date, no large-scale study has assessed the relationship between air pollutants and cataracts. We investigated associations between outdoor air pollution and cataracts in the Korean population. A population-based cross-sectional study was performed using data from the Korea National Health and Nutrition Examination Survey, including 18,622 adults more than 40 years of age. The presence of cataracts and their subtypes were evaluated by ophthalmologists. Air pollution data (levels of particulate matter, ozone, nitrogen dioxide, and sulfur dioxide) for the 2 years prior to the ocular examinations were collected from national monitoring stations. The associations of multiple air pollutants with cataracts were assessed by multivariate logistic regression analyses. Sociodemographic factors and previously known risk factors for cataracts were controlled as covariates (model 1 included sociodemographic factors, sun exposure, and behavioral factors, while model 2 further included clinical factors). Higher ozone concentrations were protectively associated with overall cataract which included all subtypes [single pollutant model: 0.003 ppm increase-model 1 (OR 0.89, p = 0.014), model 2 (OR 0.87, p = 0.011); multi-pollutant model: 0.003 ppm increase-model 1 (OR 0.80, p = 0.002), model 2 (OR 0.87, p = 0.002)]. Especially, higher ozone concentrations showed deeply protective association with nuclear cataract subtype [0.003 ppm increase-single pollutant model: model 2 (OR 0.84, p = 0.006), multi-pollutant model: model 2 (OR 0.73, p < 0.001)]. Higher tropospheric ozone concentrations showed protective associations with overall cataract and nuclear cataract subtype in the Korean population.

Prevalence of Self-Reported Diagnosed Cataract and Associated Risk Factors among Elderly South Africans

This paper estimates the prevalence of self-reported cataract and associated risk factors among individuals aged ≥50 years in South Africa. Data from a nationally-representative cross-sectional Study on Global AGEing and Adult Health (SAGE) (N = 3646) conducted in South Africa from 2007–2008 was analyzed. The primary outcome was self-reported cataract, and exposures included socio-demographics, self-reported co-morbidities, and behavioral factors. Linearized multivariate logistic regression models were used. The weighted prevalence of self-reported diagnosed cataract was 4.4% (95%CI: 3.4–5.8). Prevalence was greater among individuals with advancing age (10.2%), higher quality of life (QoL) (5.9%), education (5.2%), and wealth (5.8%) than their counterparts. Prevalence was also higher among individuals with depression (17.5%), diabetes (13.3%), hypertension (9.1%), and stroke (8.4%) compared to those without these conditions, with the exception of obesity (4.2%). In the final multivariate model, the odds of self-reported cataract were: 4.14 times higher among people ≥70 years than 50 to 59 year olds (95%CI: 2.28–7.50); 2.48 times higher in urban than rural residents (95%CI: 1.25–4.92); 5.16, 2.99, and 1.97 times higher for individuals with depression (95%CI: 1.92–13.86), hypertension (95%CI: 1.60–5.59), and diabetes (95%CI: 1.07–3.61), compared to those without these conditions.

Multiple deprivation, vision loss, and ophthalmic disease in adults: global perspectives

The association between socioeconomic position and morbidity and mortality has long been recognized. We evaluate the evidence for an association between multiple aspects of deprivation and ocular health in a global context. This is a systematic review of studies that evaluated deprivation in the adult population in the context of the major acquired causes of visual loss such as cataract, diabetic eye disease, glaucoma, age-related macular degeneration, and ocular trauma. The search strategy identified relevant studies reported between 1946 and August 2016, with randomized control trials, case-control, cohort, and cross-sectional study designs being selected for inclusion. The studies identified in this review from across the world demonstrate the extent to which the common themes such as low educational attainment and low income may be associated with increased incidence of various sight-threatening conditions and may adversely affect access to specialist assessment and delivery of treatment. Health inequality may always persist, but an increased recognition of the importance of the various impacts of deprivation may empower policy makers to target limited resources to the most vulnerable groups in order to deliver the greatest benefit.

Age-Related Cataract Is Associated with Elevated Serum Immunoglobulin E Levels in the South Korean Population: A Cross-Sectional Study

Background

Previous research has suggested that immunoglobulin E (IgE)-mediated events lead to several chronic diseases. We investigated the association between allergic conditions and age-related cataracts in the South Korean adult population.

Methods

A cross-sectional study was performed using data obtained from 1,170 participants aged 40 years or older who were enrolled in the Korean National Health and Nutrition Examination Survey 2010. Multivariable logistic regression was used to examine the relationship between age-related cataracts and allergic conditions, including total serum IgE and allergen-specific serum IgE levels, after adjustment for potential confounders (age, sex, alcohol consumption, smoking, sun exposure, blood pressure, plasma glucose and cholesterol levels, as well as histories of asthma, atopic dermatitis, and rheumatoid arthritis).

Results

After adjusting for potential confounders, the odds ratio (OR) for age-related cataract was greater in participants with higher total serum IgE levels (OR = 1.37; P = 0.044). In particular, increased IgE levels were significantly associated with nuclear cataract (OR = 1.42; P = 0.032). However, allergen-specific serum IgE levels did not differ significantly between groups. In the trend analysis, no significant relationship was observed between serum IgE and any type of age-related cataract.

Conclusion

Increased total serum IgE level is independently associated with age-related cataracts after adjustment for confounding factors.

A pilot exome-wide association study of age-related cataract in Koreans

Age-related cataract (ARC) is the most common cause of visual impairment and blindness worldwide. A previous study reported that genetic factors could explain approximately 50% of the heritability of cataract. However, a genetic predisposition to ARC and the contributing factors have not yet been elucidated in the Korean population. In this study, we assessed the influence of genetic polymorphisms on the risk of ARC in Koreans, including 156 cataract cases and 138 healthy adults. We conducted an exome-wide association study using Illumina Human Exome-12v1.2 platform to screen 244,770 single nucleotide polymorphisms (SNPs). No SNPs reached exome-wide significance level of association (P < 1×10⁻⁶). B3GNT4 rs7136356 showed the most significant association with ARC (P = 6.54×10⁻⁵). Two loci (MUC16 and P2RY2) among the top 20 ARC-associated SNPs were recognized as probably linked to cataractogenesis. Functions of these genes were potentially related to regulating dehydration or homeostasis of the eyes, and showed a potential association with dry eye disease. This finding suggests that mucin- and dry eye disease-related genes may play a significant role in cataractogenesis. Our study provides insight into the genetic predisposition of ARC in Koreans. Additional studies with larger sample sizes are required to confirm the results of this study.

Cinnamaldehyde Attenuates Cataractogenesis via Restoration of Hypertension and Oxidative Stress in Fructose-Fed Hypertensive rats

OBJECTIVES

Several studies have revealed that systemic hypertension is strongly associated with cataractogenesis. However, the pathophysiology and treatment is often unclear. In this study, we evaluated the anti-cataractogenic effect of cinnamaldehyde (CA), a natural organic compound, in rats with fructose-induced hypertension.

METHODS

The rats were divided into six groups. For six weeks, the normal group received a suspension of 0.5% carboxy methyl cellulose (10 mL/kg/day, p.o.) while five other groups received a 10% (w/v) fructose solution in their drinking water to induce hypertension. By the end of the third week hypertension had been induced in all the animals receiving fructose. From the beginning of the fourth week to the end of the sixth week, one of those five groups (control) continued to receive only 10% (w/v) fructose solution, one group (standard) received ramipril (1 mg/kg/day, p.o.) plus 10% (w/v) fructose solution, and three groups (experimental) received CA at doses of 20, 30, and 40 mg/kg/day p.o., plus 10% (w/v) fructose solution. Blood pressure was measured weekly using a non-invasive blood pressure apparatus. After six weeks, the animals were sacrificed, and the anti-cataractogenic effects on the eye lenses were evaluated.

RESULTS

Administration of fructose elevated both the systolic and the diastolic blood pressures, which were significantly reduced by CA at all dose levels. In the control group, a significant increase in the malonaldehyde (MDA) level and decreases in the total protein, Ca(2+)adenosine triphosphate (ATP)ase activity, glutathione peroxidase, catalase, superoxide dismutase and glutathione levels, as compared to the normal group, were observed. Administration of CA at all doses significantly restored the enzymatic, non-enzymatic, antioxidants, total protein, and Ca(2+)ATPase levels, but decreased the MDA level, as compared to the control group.

CONCLUSION

The present study revealed that CA modulated the antioxidant parameters of the serum and lens homogenates in hypertension-induced cataractogenic animals.

Cataract and Cataract Surgery: Nationwide Prevalence and Clinical Determinants

This study aimed to investigate the prevalence and clinical determinants of cataract and cataract surgery in Korean population. The 2008-2012 Korean National Health and Nutrition Examination Survey was analyzed, which included 20,419 participants aged ≥ 40 years. The survey is a multistage, probability-cluster survey, which can produce nationally representative estimates. Prevalence of cataract and cataract surgery was estimated. Clinical determinants for those were investigated using logistic regression analyses (LRAs). The prevalence of cataract was 42.28% (95% confidence interval [CI], 40.67-43.89); 40.82% (95% CI, 38.97-42.66) for men and 43.62% (95% CI, 41.91-45.33) for women (P = 0.606). The prevalence of cataract surgery was 7.75% (95% CI, 7.30-8.20); 6.38% (95% CI, 5.80-6.96) for men and 9.01% (95% CI, 8.41-9.61) for women (P < 0.001). Cataract was associated with older age (P < 0.001), men (P = 0.032), lower household income (P = 0.031), lower education (P < 0.001), hypertension (P < 0.001), and diabetes mellitus (DM) (P < 0.001). Cataract surgery was consistently associated with older age, occupation, DM, asthma, and anemia in two LRAs, which compared participants with cataract surgery to those without cataract surgery and those having a cataract but without any cataract surgery, respectively. Hypertension, arthritis, and dyslipidemia were associated with cataract surgery at least in one of these LRAs. These results suggest that there are 9.4 million individuals with cataract and 1.7 million individuals with cataract surgery in Korea. Further studies are warranted to reveal the causality and its possible mechanism of developing/exacerbating cataract in novel determinants (i.e., anemia, asthma, and arthritic conditions) as well as well-known determinants.

An Overview of Ophthalmologic Survey Methodology in the 2008-2015 Korean National Health and Nutrition Examination Surveys

The Korea National Health and Nutrition Examination Survey (KNHANES) is a national program designed to assess the health and nutritional status of the noninstitutionalized population of South Korea. The KNHANES was initiated in 1998 and has been conducted annually since 2007. Starting in the latter half of 2008, ophthalmologic examinations were included in the survey in order to investigate the prevalence and risk factors of common eye diseases such as visual impairment, refractive errors, strabismus, blepharoptosis, cataract, pterygium, diabetic retinopathy, age-related macular degeneration, glaucoma, dry eye disease, and color vision deficiency. The measurements included in the ophthalmic questionnaire and examination methods were modified in the KNHANES IV, V, and VI. In this article, we provide detailed information about the methodology of the ophthalmic examinations in KNHANES in order to aid in further investigations related to major eye diseases in South Korea.

Factors Associated with Cataract in Korea: A Community Health Survey 2008-2012

PURPOSE

To investigate sociodemographic factors, health behaviors, and comorbidities associated with cataracts in a large, nationally representative Korean sample.

MATERIALS AND METHODS

This cross-sectional study included 715554 adults aged 40 years or older who participated in the 2008-2012 Community Health Survey. Significant risk factors were identified using multivariate logistic regression analysis for self-reported cataract, and a nomogram for analysis of cataract risk was generated.

RESULTS

Roughly 11% of participants (n=88464) reported being diagnosed with cataracts by a doctor. Age was the most important independent risk factor [adjusted odds ratio (aOR)=1.11, 99% confidence interval (CI), 1.11-1.11 for each increasing year]. Significant comorbidities with descending order of effect size (aOR, 99% CI), included diabetes mellitus (1.78, 1.71-1.85), osteoporosis (1.62, 1.56-1.69), arthritis (1.54, 1.48-1.59), hepatitis B infection (1.46, 1.31-1.63), atopic dermatitis (1.50, 1.33-1.69), angina (1.46, 1.35-1.57), allergic rhinitis (1.45, 1.36-1.55), dyslipidemia (1.38, 1.31-1.45), asthma (1.35, 1.26-1.44), and hypertension (1.23, 1.19-1.28). Subjects who sleep less than 6 hours/day were more likely to have cataract than subjects who sleep more than 9 hours/day as a reference group (aOR=1.22, 99% CI, 1.11-1.34).

CONCLUSION

While the most important cataract risk factor was age, the ten comorbidities mentioned above were also significant risk factors. Interestingly, longer duration of sleep was associated with a protective effect against cataract development.

Association between metabolic syndrome and age-related cataract

AIM

To determine the effect of metabolic syndrome on age-related cataract formation.

METHODS

We analyzed data for 2852 subjects [41.8% men and 58.2% women; mean (±SD) age, 52.9±13.9y], taken from the Korea National Health and Nutrition Examination Survey 2008. Metabolic syndrome was diagnosed by criteria proposed by the Joint Interim Societies. Cataract was diagnosed by using the Lens Opacities Classification System III. The association between metabolic syndrome and cataract was determined using age-adjusted and multivariable logistic regression analyses.

RESULTS

In multivariable analyses, men with metabolic syndrome had a 64% increased risk of nuclear cataract [odds ratio (OR), 1.64; 95% confidence interval (CI), 1.12-2.39]. Women with metabolic syndrome had a 56% increased risk of cortical cataract (OR, 1.56; 95% CI, 1.06-2.30). Men and women with metabolic syndrome had a 46% (OR, 1.46; 95% CI, 1.01-2.12) and 49% (OR, 1.49; 95% CI, 1.07-2.08) increased risk of any cataract, respectively. The prevalence of nuclear and any cataract significantly increased with an increasing number of disturbed metabolic components in men, and prevalence of all types of cataracts increased in women. Men using hypoglycemic medication had an increased risk of nuclear (OR, 2.62; 95% CI, 1.41-4.86) and any (OR, 2.27; 95% CI, 1.14-4.51) cataract, and women using antidyslipidemia medication had an increased risk of cortical (OR, 2.18; 95% CI, 1.12-4.24) and any (OR, 2.21; 95% CI, 1.14-4.26) cataract.

CONCLUSION

Metabolic syndrome and its components, such as abdominal obesity, high blood pressure, and impaired fasting glucose, are associated with age-related cataract formation in the Korean population.

Childbearing May Increase the Risk of Nondiabetic Cataract in Chinese Women's Old Age

Backgrounds. Ocular changes may arise during pregnancy and after childbirth, but very few studies have reported the association between childbearing and cataract among older adults. Methods. 14,292 individuals aged 60+ years were recruited in Xiamen, China, in 2013. Physician-diagnosed cataract and diabetes status were assessed by a self-reported questionnaire. Childbearing status was measured by number of children (NOC). Structural equation modeling (SEM) analysis was conducted to examine the relationships among NOC, diabetes, and cataract. Gender-specific logistic models regressing nondiabetic cataract on NOC were performed by adjusting some covariates. Results. 14,119 participants had complete data, of whom 5.01% suffered from cataract, with higher prevalence in women than men (6.41% versus 3.51%). Estimates of SEM models for women suggested that both NOC and diabetes were risk factors for cataract and that no correlation existed between NOC and diabetes. Women who had one or more children faced roughly 2–4 times higher risk of nondiabetic cataract than their childless counterparts (OR [95% CI] = 3.88 [1.24, 17.71], 3.21 [1.04, 14.52], 4.32 [1.42, 19.44], 4.41 [1.46, 19.74], and 3.98 [1.28, 18.10] for having 1, 2, 3, 4-5, and 6 or more children, resp.). Conclusions. Childbearing may increase the risk of nondiabetic cataract in Chinese women's older age.

Hypertension and risk of cataract: a meta-analysis

Background

Cataract is the major cause of blindness across the world. Many epidemiologic studies indicated that hypertension might play an important role in the development of cataract, while others not. We therefore conducted this meta-analysis to determine the relationship between risk of cataract and hypertension.

Methods

Retrieved studies on the association of hypertension with cataract risk were collected from PubMed, Web of Science and the Cochrane Library during June 2014 and were included into the final analysis according to the definite inclusion criteria. Odds ratio (OR) or risk ratio (RR) were pooled with 95% confidence interval (CI) to evaluate the relationship between hypertension and cataract risk. Subgroup analyses were carried out on the basis of cataract type, race and whether studies were adjusted for main components of metabolic syndrome (MS).

Results

The final meta-analysis included 25 studies (9 cohort, 5 case-control and 11 cross-sectional) from 23 articles. The pooled results showed that cataract risk in populations with hypertension significantly increased among cohort studies (RR 1.08; 95% CI: 1.05–1.12) and case-control or cross-sectional studies (OR 1.28; 95% CI: 1.12–1.45). This association was proved to be true among both Mongolians and Caucasians, and the significance was not altered by the adjustment of main components of MS. Subgroup analysis on cataract types indicated that an increased incidence of posterior subcapsular cataract (PSC) resulted among cohort studies (RR 1.22; 95% CI: 1.03–1.46) and cross-sectional/case-control studies (OR 1.23; 95% CI: 1.09–1.39). No association of hypertension with risk of nuclear cataract was found.

Conclusions

The present meta-analysis suggests that hypertension increases the risk of cataract, especially PSC. Further efforts should be made to explore the potential biological mechanisms.