Weight status, abdominal adiposity, diabetes, and early age-related lens opacities

Changing Trends in the Global Burden of Cataract Over the Past 30 Years: Retrospective Data Analysis of the Global Burden of Disease Study 2019

BACKGROUND

Cataracts now account for the largest proportion of the global burden of blindness and vision loss. Understanding the changing trends in the global burden of cataracts over the past 30 years and the next 15 years is of clear significance for the prevention and control of cataracts in key populations. As far as we know, research on the future burden of cataracts is lacking.

OBJECTIVE

This study aims to assess the global burden of cataracts over the past 30 years by using age-period-cohort modeling and to estimate trends in the next 15 years.

METHODS

Data were obtained from the Global Burden of Disease Study 2019, the United Nations Development Programme, and the WHO (World Health Organization) Global Health Observatory data repository. The assessment of trends and disparities in the number and rate of disability-adjusted life years (DALYs) for cataracts from 1990 to 2019 was conducted. The association between the age-standardized DALY rate (ASDR) and the socio-demographic index (SDI), human development index (HDI), national levels of particulate matter <2.5 μm in diameter (PM2.5), and ambient ultraviolet radiation (UVR) was determined using linear regression analysis. Additionally, we used the Nordpred (Harald Fekjær and Bjørn Møller) age-period-cohort model to predict the cataract burden from 2020 to 2034.

RESULTS

Globally, the number of DALYs due to cataract increased from 3,492,604 (95% uncertainty interval [UI] 2,481,846-4,719,629) in 1990 to 6,676,281 (95% UI 4,761,210-9,006,193) in 2019. The ASDRs due to cataract decreased from 93.17 (95% UI 66.14-125.32) in 1990 to 82.94 (95% UI 59.06-111.75) in 2019, with an average annual percentage change of -0.37 (95% CI -0.44 to -0.3; P<.001). Age, female sex, air pollution, smoking, high fasting plasma glucose levels, and a high body mass index were risk factors for the burden of cataracts. SDI and HDI were negatively correlated with ASDRs of cataracts, while PM2.5 and UVR were positively associated with them. Higher DALY rates were also associated with lower SDI (R2=0.1939; P<.001), lower HDI (R2=0.2828; P<.001), national PM2.5 concentration (R2=0.1874; P<.001), and ambient UVR levels (R2=0.2354; P<.001). The prediction model suggested that the number of DALYs due to cataract will continue to rise globally, while the cataract DALY rate will continue to decrease.

CONCLUSIONS

While the ASDR of cataracts has decreased, there has been a notable increase in the number of DALYs over the past 30 years. Projections suggest that the global burden of cataracts will continue to rise over the next 15 years. To address this challenge, appropriate prevention and treatment policies must be implemented.

‏Impact of Food Habit on Cataracts Development Among Adults in Aseer Region, Saudi Arabia: A Retrospective Study

Background: Cataracts are the main cause of visual impairment among the aging population, with a high impact on patients’ quality of life. It has been suggested that the antioxidant carotenoids lutein and zeaxanthin may play a role in cataract prevention. Recently, significant evidence has associated abnormal glucose metabolism with an increased likelihood of the development of cataracts.

Aim: The current study aims to assess the relationship between nutrition and cataracts among adults in the Aseer Region, Saudi Arabia.

Methods: A retrospective study was conducted targeting all accessible patients diagnosed with cataracts at Aseer Central Hospital during the period from August 8, 2019, to March 3, 2021, and at Khamis Mushayt General Hospital during the period from June 11, 2018, to March 3, 2021. Data were collected using a pre-structured data collection sheet that covered patients’ socio-demographic data, including age, gender, education, work type, and marital status. Also, the type of cataract diagnosed for the study patients was recorded with associated risk factors of cataracts, including chronic diseases, trauma, eye surgery, and family history. The last section covered patients’ dietary habits and frequency of dietary intake. 

Results: A total of 140 patients with cataracts who fulfilled the inclusion criteria were included in the study. Patients' ages ranged from 21 to 65 years, with a mean age of 54.2 ± 12.9 years old. Additionally, 12.1% of the study patients were smokers, 44.3% were diagnosed with hypertension, and 45% were diabetic, which was type 1 diabetes mellitus (T1DM) among 36.5% and type 2 diabetes mellitus (T2DM) among 52.4%. A family history of congenital cataracts was reported among 12.9%, and 12.9% had a history of eye trauma. Moreover, 37.1% of the study patients had vegetables once per week. Eating fruits or having juice was reported as once per week among 40% of the study patients and three times per week among 20%. Finally, 31.4% take nutritional supplements or vitamins.

Conclusion: There is currently an inquiry to endorse or exclude a specific diet or dietary intake that may reduce or even prevent the development and progression of cataracts. It appears beneficial for people to have some antioxidants in their daily food.

Adiposity by Differing Measures and the Risk of Cataract in the UK Biobank: The Importance of Diabetes

Purpose

To examine the association between adiposity by differing measures and incident cataract and identify important factors contributing to the association.

Methods

Our analysis included 153,139 adults from the UK Biobank, aged 40 to 70 years at baseline (2006-2010). Cataract was ascertained using hospital inpatient, and self-reported data until the early of 2021. Anthropometric measures, body fat percentage, and glycosylated hemoglobin (HbA1c) were measured at baseline.

Results

During a median follow-up of 10.9 years, 15,255 cases of incident cataract were documented. HbA1c was an important contributor to the association between obesity and incident cataract. Obesity; defined by body mass index was associated with an increased risk of cataract (hazard ratio [HR], 1.21 95% confidence interval [CI], 1.16-1.26), and this association was attenuated but remained significant after additional adjustment for HbA1c (HR, 1.05; 95% CI, 1.00-1.10). Similar results were observed for obesity defined by waist circumference or waist-to-hip ratio. Obesity defined by fat percentage was associated with an increased risk of cataract before but not after adjustment for covariates. The association between obesity defined by body mass index and incident cataract was positively significant in individuals with normal HbA1c (HR, 1.07; 95% CI, 1.02-1.13), but inversely significant in those with prediabetes (HR, 0.80; 95% CI, 0.67-0.96) or diabetes (HR, 0.74; 95% CI, 0.61-0.89).

Conclusions

Anthropometric measurements are more predictive of cataract than bioelectrical impedance measures. Diabetes plays an important role in the association between obesity and incident cataract.

Genotype, Age, Genetic Background, and Sex Influence Epha2-Related Cataract Development in Mice

Purpose

Age-related cataract is the leading cause of blindness worldwide. Variants in the EPHA2 gene increase the disease risk, and its knockout in mice causes cataract. We investigated whether age, sex, and genetic background, risk factors for age-related cataract, and Epha2 genotype influence Epha2-related cataract development in mice.

Methods

Cataract development was monitored in Epha2+/+, Epha2+/-, and Epha2-/- mice (Epha2Gt(KST085)Byg) on C57BL/6J and FVB:C57BL/6J (50:50) backgrounds. Cellular architecture of lenses, endoplasmic reticulum (ER) stress, and redox state were determined using histological, molecular, and analytical techniques.

Results

Epha2-/- and Epha2+/- mice on C57BL/6J background developed severe cortical cataracts by 18 and 38 weeks of age, respectively, compared to development of similar cataract significantly later in Epha2-/- mice and no cataract in Epha2+/- mice in this strain on FVB background, which was previously reported. On FVB:C57BL/6J background, Epha2-/- mice developed severe cortical cataract by 38 weeks and Epha2+/- mice exhibited mild cortical cataract up to 64 weeks of age. Progression of cataract in Epha2-/- and Epha2+/- female mice on C57BL/6J and mixed background, respectively, was slower than in matched male mice. N-cadherin and β-catenin immunolabeling showed disorganized lens fiber cells and disruption of lens architecture in Epha2-/- and Epha2+/- lenses, coinciding with development of severe cataracts. EPHA2 immunolabeling showed intracellular accumulation of the mutant EPHA2-β-galactosidase fusion protein that induced a cytoprotective ER stress response and in Epha2+/- lenses was also accompanied by glutathione redox imbalance.

Conclusions

Both, Epha2-/- and Epha2+/- mice develop age-related cortical cataract; age as a function of Epha2 genotype, sex, and genetic background influence Epha2-related cataractogenesis in mice.

FACTORS ASSOCIATED WITH PREVALENT LENS OPACITIES IN CHINESE AMERICAN ADULTS: THE CHINESE AMERICAN EYE STUDY

PURPOSE

To identify risk factors associated with lens opacities in Chinese Americans.

METHODS

A cross-sectional population-based study of 4,582 Chinese Americans ≥50 years residing in Monterey Park, California. Participants completed a comprehensive clinical examination with lens assessment using the Lens Opacities Classification System II, with lens opacities defined by a grade ≥2 in either eye. Participants were considered to have nuclear-only, cortical-only, or posterior subcapsular (PSC)-only if that was the only type of opacity present in both eyes.

RESULTS

Cortical-only opacity was associated with older age, diabetes mellitus (OR 1.5, 95%CI 1.1-2.1), and family history of cataracts (OR 1.5, 95%CI 1.2-1.9). Nuclear-only opacity was associated with older age, diabetes mellitus (OR 1.4, 95%CI 1.1-1.9), greater waist-to-hip ratio (OR 1.2, 95%CI 1.1-1.4), and high-density lipoprotein (OR 1.1, 95%CI 1.02-1.2). Mixed-type opacities were associated with older age, greater waist-to-hip ratio (OR 1.3, 95%CI 1.1-1.6), and higher HbA1 c (OR 1.3, 95%CI 1.1-1.4). Taller height (OR 0.7, 95%CI 0.6-0.8), greater weight (OR 0.98, 95%CI 0.97-0.99), and higher diastolic pressure (OR 0.98, 95%CI 0.96-0.99) were protective.

CONCLUSION

CHES identified a strong, dose-response association between age and all types of prevalent lens opacities, which suggests an increasing cataract burden in Chinese Americans based on aging populations. CHES results demonstrate general consistency with previous population-based studies in regard to more sedentary lifestyle exposures (e.g., Westernized lifestyle) and prevalent cortical-only, nuclear-only, and mixed-type opacities, yet also identified further sedentary lifestyle exposures associated with prevalent lens opacities. Improved glycemic control and a more active lifestyle that minimizes factors contributing to metabolic syndrome may help reduce the burden of vision loss associated with lens opacities.

Risk factors for self-reported cataract symptoms, diagnosis, and surgery uptake among older adults in India: Findings from the WHO SAGE data

Visual impairments have a substantial impact on the well-being of older people, but their impact among older adults in low- and middle-income countries is under-researched. We examined risk factors for self-reported cataract symptoms, diagnosis, and surgery uptake in India.

Cross-sectional data from the nationally representative WHO SAGE data (2007-2008) for India were analysed. We focused on a sub-sample of 6558 adults aged 50+, applying descriptive statistics and logistic regression.

Nearly 1-in-5 respondents self-reported diagnosed cataracts, more than three-fifths (62%; n = 3879) reported cataract symptoms, and over half (51.8%) underwent surgery. Increasing age, self-reported diabetes, arthritis, low visual acuity, and moderate or severe vision problems were factors associated with self-reported diagnosed cataracts. Odds of cataract symptoms were higher with increasing age and among those with self-reported arthritis, depressive symptoms, low visual acuity, and with moderate or severe vision problems. Odds of cataract surgery were also higher with increasing age, self-reported diabetes, depressive symptoms, and among those with low visual acuity.

A public health approach of behavioural modification, well-structured national outreach eye care services, and inclusion of local basic eye care services are recommended.

Six-Year Incidence and Causes of Low Vision and Blindness in a Rural Chinese Adult Population: The Handan Eye Study

PURPOSE

To determine the six-year incidence, risk factors, and causes of visual impairment in a Chinese population.

METHODS

This was a population-based study of eye disease in Chinese adults in a rural district of Handan in China. 6,830 individuals were invited to participate in 2006 and 5,394 returned for follow-up in 2012. All participants underwent standardized eye examinations. Visual impairment was defined according to WHO criteria. The incidence of visual impairment was age- and gender-standardized to the 2010 China Census. Multivariable logistic regression analysis was used to determine risk factors for visual impairment.

RESULTS

The leading causes of visual impairment were cataract and refractive error. Based on presenting visual acuity (PVA), the six-year incidence rates of low vision and blindness were 5.2% and 0.5%, respectively. Incidence of low vision was associated with older age (p < .001), less education (p < .001), diabetes (p < .05), and lower BMI (p < .001). The incidence of blindness was associated with diabetes (p < .05). Based on best-corrected visual acuity (BCVA), the six-year incidence rates of low vision and blindness were 0.8% and 0.1%, respectively. Incidence of low vision was associated with older age (p < .001) and lower BMI (p < .05). None of these factors were associated with the incidence of blindness.

CONCLUSION

In Handan, the incidence of visual impairment was high and associated with older age, less education, diabetes, and lower BMI. The majority of cases were due to unoperated cataract and uncorrected refractive error, reflecting the need for improved eye care in this region.

High-Density Lipoprotein Cholesterol in Age-Related Ocular Diseases

There is limited understanding of the specific role of high-density lipoprotein cholesterol (HDL-C) in the development of various age-related ocular diseases, despite it being a common measurable biomarker in lipid profiles. This literature review summarizes current knowledge of the role of HDL-C, if any, in pathogenesis and progression of four age-related ocular diseases, namely age-related macular degeneration (AMD), age-related cataract, glaucoma, and diabetic retinopathy (DR), and will primarily discuss epidemiological and genetic evidence.

Body shape, fear of falling, physical performance, and falls among individuals aged 55 years and above

PURPOSE

To evaluate the relationship between waist-to-hip ratio (WHR) and fall-related outcomes in community-dwelling individuals aged 55 and above.

METHODS

Cross-sectional data obtained from the first wave of the Malaysian Elders Longitudinal Research (MELoR) study were utilized for this study. Participants aged 55 years and over were recruited using simple random sampling from the electoral rolls of three local parliamentary constituencies. Socio-demographics, falls history and medical history were obtained through home-based computer-assisted interviews while anthropometric measurements, including WHR, and physical performance were obtained during hospital-based health checks. WHR was categorized into three arbitrary categories stratified by gender.

RESULTS

Data on both falls and WHR were available for 1335 participants, mean age ± standard deviation (SD) = 68.4 ± 7.1 years. Logistic regression analyses using dummy variables revealed that individuals within the higher WHR group were significantly more likely to report a history of fall in the preceding 12 months {adjusted odds ratio (aOR) [95% confidence interval (CI)] = 1.78 (1.18-2.67)}, fear of falling [aOR (95% CI) = 1.58 (1.08-2.32)], impaired timed-up-and-go [2.14 (1.44-3.17)] and reduced functional reach [1.68 (1.18-2.38)] compared to those with lower WHR. A higher WHR remained independently associated with increased risk of falls compared to those with lower WHR after additional adjustment for fear of falling and functional performance.

CONCLUSION

Our finding suggests WHR as an independent risk factor for higher risk of fall which may indicate body shape as a potentially modifiable risk factor for falls in adults in aged 55 years and over.

Evaluating the associations between obesity and age-related cataract: a Mendelian randomization study

BACKGROUND

The obesity-cataract association has been inconsistently reported. The fat mass and obesity-related (FTO) single-nucleotide polymorphism (SNP) rs9939609 is a major SNP associated with obesity and has been used as an instrumental variable for obesity in a Mendelian randomization (MR) approach. An interaction between the FTO SNP and macronutrient intake for obesity was suggested previously.

OBJECTIVE

The aim of this study was to assess the associations between obesity and cataract, using FTO SNP rs9939609 as an instrumental variable in an MR approach, and explore interactions of this SNP with macronutrient intake in relation to risk of cataract in a population-based cohort.

METHODS

The Blue Mountains Eye Study (BMES) is a longitudinal population-based study of common eye disease. Of 3654 baseline participants of the BMES (1992-1994), 2334 (75.8% of survivors) and 1952 (76.7% of survivors) were followed 5 and 10 y later. During the 5-y follow-up, 1174 new participants were examined. Cumulative cataract was defined as the presence of cortical, nuclear, or posterior subcapsular (PSC) cataract at any visit, following the Wisconsin Cataract Grading System. Imputed dosage of the FTO SNP rs9939609 was used. Quintiles of macronutrient intake (carbohydrates, protein, fats) were derived from an FFQ. ORs and 95% CIs were estimated using multivariable-adjusted logistic regression models.

RESULTS

After multivariable adjustment, there were no associations between BMI and any cataract types in MR models using rs9939609 as an instrumental variable. However, an interaction between rs9939609 and protein intake for PSC cataract risk was suggested (P = 0.03). In analyses stratified by quintiles of protein intake, each minor allele of rs9939609 was associated with increased odds of PSC (OR: 2.14; 95% CI: 1.27, 3.60) in the lowest quintile subgroup only.

CONCLUSIONS

Obesity was not causally associated with age-related cataract. However, among persons in the lowest quintile of protein intake, obesity may be associated with PSC cataract.

Metabolic syndrome and some of its components in relation to risk of cataract extraction. A prospective cohort study of men

PURPOSE

To evaluate the relationship between metabolic syndrome and some of its components with the incidence of cataract extraction.

METHODS

A population-based prospective cohort with a total of 45 049 men, aged 45-79 years, from the Cohort of Swedish Men completed in 1997 a self-administered questionnaire concerning anthropometric measurements and lifestyle factors. The men were followed from 1 January 1998 through 31 December 2012, and the cohort was matched with registers of cataract extraction. The main outcome measure was incident cases of age-related cataract extraction.

RESULTS

Over the 15-years of follow-up, 7573 incident cases of cataract extraction were identified. After controlling for potential confounders, the association between single components of metabolic syndrome, abdominal adiposity, diabetes and hypertension and risk of cataract extraction was rate ratio (RR): 1.04; 95% confidence interval (CI): 0.99-1.10, RR: 1.77; 95% CI: 1.64-1.92 and RR: 1.06; 95% CI 1.00-1.13, respectively. The risk of cataract extraction increased with increasing numbers of metabolic syndrome components (p < 0.0001). Men aged 65 years or younger at baseline with all three components of the metabolic syndrome had a relative risk of 2.43 (95% CI: 1.95-3.01) for cataract extraction.

CONCLUSION

In this cohort of middle-aged and elderly men, metabolic syndrome with the combination of abdominal adiposity, diabetes and hypertension was associated with an increased risk for cataract extraction, especially among men aged 65 years or younger. These findings put emphasis on the importance of weight control and healthy lifestyle behaviours in order to prevent cataract.

Association between serum lipids concentration and patients with age-related cataract in China: a cross-sectional, case-control study

OBJECTIVE

Obesity and a high-fat diet have been found to be associated with an increased risk of age-related cataract (ARC). Thus, this study aimed to investigate whether serum lipid levels are associated with the incidence of ARC.

DESIGN

Cross-sectional, case-control study.

SETTING

EyeandENT Hospital of Fudan University, Shanghai, China.

PARTICIPANTS

A total of 219 ARC (male=94, female=125) subjects and 218 (male=110, female=118) normal control subjects were recruited in this study.

OUTCOME MEASURES

A detailed eye and systematic examination was performed. Serum high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG) and cholesterol (CHO) levels were measured by enzymatic colorimetry, and serum apolipoprotein A (APOA) and apoB (APOB) levels were measured by immunoturbidimetry. The subgroups were classified according to gender and types of disease (cortical, nuclear and posterior subcapsular cataract). Logistic regression analyses were performed to identify the association between serum lipid levels and ARC.

RESULTS

The serum LDL-C, TG, CHO and APOA levels were significantly higher (p<0.05) in the ARC group than in the control group. A similar result was observed when the serum lipid concentrations were compared between the ARC and control groups both in male and female subgroups. A higher proportion of individuals in the ARC group had higher LDL-C, TG, CHO and APOA levels (fold=3.45, 17.37, 3.27 and11.91, respectively; p<0.0001 in all cases) than in the control group. Results of the logistic regression analyses revealed that high LDL-C (ORs=1.897, 95% CI 0.960 to 3.678) and TG (OR=1.854, 95% CI 1.232 to 2.791) were the independent risk factors for ARC.

CONCLUSION

The serum LDL-C and TG levels were demonstrated to be independent risk factors for ARC.

Diagnosed cataracts in patients with cystic fibrosis in a United States administrative database

BACKGROUND

We estimated the incidence and prevalence of diagnosed cataracts among patients with cystic fibrosis (CF) versus the general population (GP).

METHODS

Using a large US health insurance claims database, we identified a CF cohort and a GP cohort matched with respect to age, gender, and calendar year. The prevalence and incidence of diagnosed cataract (primary outcome) for both cohorts were calculated, as well as the incidence rate ratios (IRRs).

RESULTS

The prevalence of diagnosed cataracts among patients with CF alive and enrolled in the health plan on August 31, 2012 was 4.8% versus 2.8% in the GP. The incidence in the CF cohort was higher than in the GP and increased with age in both cohorts. The adjusted IRR comparing the CF and GP cohorts was 1.5 (95% CI: 1.2-1.8).

CONCLUSIONS

The study suggests that the risk of developing cataract was higher among patients with CF than among the GP.

Comparison of Risk Factor Profiles for Primary Open-Angle Glaucoma Subtypes Defined by Pattern of Visual Field Loss: A Prospective Study

PURPOSE

We explored whether risk factor associations differed by primary open-angle glaucoma (POAG) subtypes defined by visual field (VF) loss pattern (i.e., paracentral or peripheral).

METHODS

We included 77,157 women in the Nurses' Health Study (NHS) and 42,773 men in the Health Professionals Follow-up Study (HPFS 1986-2010), and incident medical record confirmed cases of paracentral (n = 440) and peripheral (n = 865) POAG subtypes. We evaluated African heritage, glaucoma family history, body mass index (BMI), mean arterial blood pressure, diabetes mellitus, physical activity, smoking, caffeine intake, and alcohol intake. We used competing risk Cox regression analyses modeling age as the metameter and stratified by age, cohort, and event type. We sequentially identified factors with the least significant differences in associations with POAG subtypes ("stepwise down" approach with P for heterogeneity [P-het] < 0.10 as threshold).

RESULTS

Body mass index was more inversely associated with the POAG paracentral VF loss subtype than the peripheral VF loss subtype (per 10 kg/m2; hazard ratio [HR] = 0.67 [95% confidence interval (CI): 0.52, 0.86] versus HR = 0.93 [95% CI: 0.78, 1.10]; P-het = 0.03) as was smoking (per 10 pack-years; HR = 0.92 [95% CI: 0.87, 0.98] versus HR = 0.98 [95% CI: 0.94, 1.01]; P-het = 0.09). These findings were robust in sensitivity analyses using a "stepwise up" approach (identify factors that showed the most significant differences). Nonheterogeneous (P-het > 0.10) adverse associations with both POAG subtypes were observed with glaucoma family history, diabetes, African heritage, greater caffeine intake, and higher mean arterial pressure.

CONCLUSIONS

These data indicate that POAG with early paracentral VF loss has distinct as well as common determinants compared with POAG with peripheral VF loss.

The Gender-Dependent Association between Obesity and Age-Related Cataracts in Middle-Aged Korean Adults

The aim of this study was to investigate the association of central and abdominal obesity with the prevalence of cataracts in a middle-aged Korean population. This retrospective cross-sectional study was based on the data collected from the Korea National Health and Nutrition Examination Survey 2008–2009, in which 4,914 subjects were examined. Ophthalmological examinations were performed to determine the presence of a nuclear, cortical, or posterior subcapsular cataract. Both general obesity (a body mass index ≥25 kg/m²) and abdominal obesity (a waist circumference ≥90 cm for men and ≥80 cm for women) were significantly associated with the occurrence of cataracts among middle-aged women [adjusted odds ratio (aOR), 1.32; 95% confidence interval (CI), 1.03–1.69; and aOR, 1.40; 95% CI, 1.06–1.85, respectively], while abdominal obesity was significantly inversely associated with the occurrence of cataracts among middle-aged men (aOR, 0.76; 95% CI, 0.58–1.01; and aOR, 0.66; 95% CI, 0.49–0.89, respectively). We report a difference in the association between obesity and the prevalence of cataracts based on gender.

Self-reported cataracts in older adults in Ghana: sociodemographic and health related factors

BACKGROUND

Changes in function of sensory organs with increasing age have significant impact on health and wellbeing of older persons. This paper describes cataract, a chronic eye condition, self-reported among older adults in Ghana and the need for improving access to eye care services.

METHODS

This work was based on the World Health Organization's multi-country Study on global AGEing and adult health (SAGE), conducted in six countries including Ghana. SAGE Wave 1 in Ghana was conducted in 2007-2008 in a nationally representative sample of 4278 older adults, ≥ 50 years. Data were obtained on sociodemographic and health factors related to self-reported cataracts in older persons in Ghana. Data were analysed using descriptive measures (frequencies and proportions), chi-square test for associations in categorical outcome measures, and logistic regression for predictors of cataracts with SPSS version 21.

RESULTS

Overall prevalence of self-reported cataracts among 4278 older adults in Ghana was 5.4%. Prevalence was proportionately higher for women (5.9%) than men (4.7%). Reported cataracts increased with age, among urban residents, in older adults living without partners and among those with the worse life satisfaction index. Older adults in lower income groups, poorly educated or living alone had difficulty seeking vision care services. Prevalence was 8.4% among persons with diabetes, 10.4% among hypertensives and 11.4% in persons with previous history of stroke. Among older persons who had ever used alcohol or tobacco, prevalence rates of reported cataracts were 5.7% and 4.9%, respectively. Logistic regression analysis indicated that increasing age, lower income status and self-reported hypertension were significantly associated with cataract among older adults in Ghana.

CONCLUSIONS

Cataract is prevalent in older people in Ghana with approximately 1 in 20 people aged 50 years or older reporting a previous diagnosis of cataract. As cataract surgery is restorative, a public health approach on behavioural modification, well structured national outreach eye care services (for rural residents), inclusion of basic eye health services at sub-district levels, increased family support and national health insurance for older persons is indicated.

Relationship between Body Mass Index, Blood Pressure, and Visual Acuity in Residents of Esan West Local Government Area of Edo State, Nigeria

Aim. To study the relationship between body mass index (BMI) and blood pressure (BP) on visual acuity among apparently healthy residents of Ekpoma, Esan West Local Government Area of Edo State, Nigeria. Methodology. This is a cross-sectional descriptive study among 225 subjects (ages of 18–35 years) from whom BP, body weight, and height were collected. Visual acuity was measured using the Snellen chart following standard procedures of number of letters seen at 6-metre distance. The data were then analyzed using SPSS version 17. Results. The sampled population consists of 112 male and 113 female (mean age 31.72±14.2 years). Majority (180) of the respondents had normal visual acuity. However, compared with the respondents with normal BMI (R19.61±1.5; L19.67±1.70), visual acuity of underweight (R18.53±2.30; L18.53±2.70) and obese (R15.68±4.79; L17.73±1.70) were more deviated. Similarly, compared with respondent with normal BP (120–125/80–85 mmHg; R18.00±2.53; L18.07±3.11), hypotensive (R15.5±7.35; L15.00±10.20), and hypertensive (R15.01±21.25; L15.00±11.91) respondents had deviated visual acuity. Conclusion. Abnormal body weight (underweight and obese) and BP (hypotension and hypertension) have potential negative impacts on visual acuity. Based on the observed relationship between weights, BP, and visual acuity, eye examinations can be included as regular screening exercise for abnormal BMI and BP conditions.

Meta-analysis of the risk of cataract in type 2 diabetes

Background

This meta-analysis aimed to investigate the association between type 2 diabetes (T2D) and the risk of cataract.

Methods

Databases of Pubmed, Embase, and SpringerLink were retrieved for observational studies published before November 2013. The odds ratio (OR) and 95% confidence interval (CI) were used for estimating the association. All statistical analyses were performed by Stata 10.0 software.

Results

A total of 8 studies involving 20837 subjects were included in the meta-analysis. The risk of any cataract (AC) in T2D patients was higher than that in non-diabetic subjects (OR = 1.97, 95% CI: 1.45-2.67, P < 0.001). The risks of cortical cataract posterior (CC) (OR = 1.68, 95% CI: 1.47-1.91, P < 0.001) and posterior subcapsular (PSC) (OR = 1.55, 95% CI: 1.27-1.90, P < 0.001) were significantly elevated in T2D patients, while no significant association was found in nuclear sclerosis (NS) (OR = 1.36, 95% CI: 0.97-1.90, P = 0.070).

Conclusion

T2D patients had a higher risk of cataracts, excepting NS. Special attention should be paid on the ophthalmic extermination, especially for cataract in T2D patients.

Association between cataract and the degree of obesity

PURPOSE

To investigate the association between the degree of obesity and cataract.

METHODS

We examined 3248 subjects (1421 men and 1827 women) aged 50 years and older who did not have a previous cataract operation. Data were derived from the fourth Korea National Health and Nutrition Examination Survey (2009). Cataract was evaluated by using Lens Opacities Classification System III. Body mass index was categorized into four groups (underweight, <18.5 kg/m(2); normal weight, 18.5 to 22.9 kg/m(2); overweight, 23.0 to 24.9 kg/m(2); and obese, ≥25.0 kg/m(2)). Association between the degree of obesity and cataract was evaluated using logistic regression analyses with adjustments of age, the total pack-years of cigarettes smoked, the amount of pure alcohol (g) consumed per day, daily time spent in vigorous physical activity, diabetes mellitus, sunlight exposure, education level, and income.

RESULTS

Compared with the normal-weight group, the overweight group had significantly lower risk of any type of cataract (odds ratio, 0.70; 95% confidence interval, 0.50 to 0.97) in men and (odds ratio, 0.70; 95% confidence interval, 0.51 to 0.97) in women in the multiple logistic regression analyses. We could not find any unusual lifestyles or metabolic risks for explaining this low cataract prevalence in the overweight groups. However, nutrient intakes (e.g., vitamin B2, niacin, vitamin C, and vitamin A) were highest in the overweight group.

CONCLUSIONS

The overweight group had significantly lower risk of cataract formation than the normal-weight group in Korean population.

Walking and running are associated with similar reductions in cataract risk

PURPOSE

Habitual running has been associated with reduced risk of cataract development in one prospective study. The purposes of the current analyses were to provide further evidence of this potentially important benefit of vigorous exercise and to test whether moderate exercise (e.g., walking) provides as significant and equivalent reduction in cataract risk as vigorous exercise (e.g., running).

METHODS

Cox proportional hazard analyses of self-reported, physician-diagnosed incident cataracts versus baseline energy expenditure (METs) in 32,610 runners and 14,917 walkers during a 6.2-yr follow-up. Results are reported as hazard ratios (HR), percent risk reductions (100 (HR - 1)), and 95% confidence intervals (95% CI).

RESULTS

Runners and walkers reported 733 and 1074 incident cataracts during follow-up, respectively. When adjusted for sex, race, age, education, smoking, and intakes of meat, fruit, and alcohol, lower cataract risk was significantly associated with both running (HR = 0.960 per MET·h·d, 95% CI 0.935-0.986) and walking (HR = 0.918 per MET·h·d, 95% CI = 0.881-0.956), with no significant difference in the risk reduction per MET-hours per day between running and walking or between men and women. Compared with running or walking at or below guideline levels (≤1.8 MET·h·d), incident cataract risk was significantly lower for running or walking 1.8-3.6 (16.4% lower, 95% CI = 6.4%-25.3%), 3.6-5.4 (19.0% lower, 95% CI = 5.6%-30.4%), 5.4-7.2 (26.2% lower, 95% CI = 11.2%-38.7%), 7.2-9.0 (34.1% lower, 95% CI = 10.0%-51.2%), and ≥9 MET·h·d (41.6% lower, 95% CI = 19.8%-57.4%).

CONCLUSION

Moderate (walking) and vigorous (running) exercise were both significantly associated with lower cataract risk and their effects similar. Cataract risk appears to decrease linearly with increasing exercise energy expenditure through 9 MET·h·d.

Gender difference in the association of metabolic syndrome and its components with age-related cataract: the Korea National Health and Nutrition Examination Survey 2008-2010

Purpose

To explore the relationship of the metabolic syndrome (MetS) and its components with age-related cataract in a representative Korean population.

Methods

We analyzed the data from the Korea National Health and Nutrition Examination Surveys (2008–2010). A total of 11,076 adults (4,811 men and 6,265 women) aged 40 and over who completed ophthalmologic examination were evaluated. Cataract was defined as the presence of cortical, nuclear, anterior (sub)capsular or posterior subcapsular cataract, from slit-lamp examination or previous cataract surgery. MetS was defined according to the Joint Interim Statement proposed in 2009 from the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute.

Results

The prevalence of cataract and MetS in this population was 39.4% (37.1% for men and 41.6% for women) and 38.5% (37.6% for men and 39.4% for women), respectively. Cataract prevalence tended to increase with the number of MetS components in both genders (both P< 0.001). After being controlled for confounders, however, MetS was significantly associated with cataract only in women (adjusted odds ratio (aOR), 1.24; 95% confidence interval (CI), 1.02–1.50]. Reduced HDL cholesterol, elevated fasting glucose, and elevated triglycerides were also significantly associated with cataract in women (aOR, 95% CI; 1.27 (1.07–1.50), 1.23 (1.01–1.50), and 1.26 (1.04–1.52), respectively). In the subgroup analysis for cataract subtype, MetS and reduced HDL cholesterol were significantly associated with nuclear cataract in women (aOR, 95% CI; 1.25 (1.07–1.55) and 1.25 (1.03–1.52), respectively). However, such associations were not found in men.

Conclusions

Our results suggest that MetS and its components appear to be associated with age-related cataract only among Korean women, especially in nuclear cataract.

Cataract research using electronic health records

BACKGROUND

The eMERGE (electronic MEdical Records and Genomics) network, funded by the National Human Genome Research Institute, is a national consortium formed to develop, disseminate, and apply approaches to research that combine DNA biorepositories with electronic health record (EHR) systems for large-scale, high-throughput genetic research. Marshfield Clinic is one of five sites in the eMERGE network and primarily studied: 1) age-related cataract and 2) HDL-cholesterol levels. The purpose of this paper is to describe the approach to electronic evaluation of the epidemiology of cataract using the EHR for a large biobank and to assess previously identified epidemiologic risk factors in cases identified by electronic algorithms.

METHODS

Electronic algorithms were used to select individuals with cataracts in the Personalized Medicine Research Project database. These were analyzed for cataract prevalence, age at cataract, and previously identified risk factors.

RESULTS

Cataract diagnoses and surgeries, though not type of cataract, were successfully identified using electronic algorithms. Age specific prevalence of both cataract (22% compared to 17.2%) and cataract surgery (11% compared to 5.1%) were higher when compared to the Eye Diseases Prevalence Research Group. The risk factors of age, gender, diabetes, and steroid use were confirmed.

CONCLUSIONS

Using electronic health records can be a viable and efficient tool to identify cataracts for research. However, using retrospective data from this source can be confounded by historical limits on data availability, differences in the utilization of healthcare, and changes in exposures over time.

Association of body mass index with risk of age-related cataracts in a middle-aged Japanese population: the JPHC Study

OBJECTIVES

Many epidemiological studies have demonstrated that body mass index (BMI) is associated with the risk of developing age-related cataracts. These reports have suggested that high and low BMIs can affect the onset or progression of age-related visual impairment. However, few prospective studies have examined this relationship in a general Asian population. Therefore, in this study, we investigated whether BMI was associated with an increased risk of age-related cataracts by performing a 5-year prospective population-based study in a middle-aged Japanese population.

METHODS

This 5-year population-based study included 35,365 men and 40,825 women (aged 45-74 years), who were recruited into the Japan Public Health Center (JPHC)-based Prospective Study and had not reported cataracts in a baseline survey. The self-reported diagnosis of age-related cataracts was used in the analysis of this study.

RESULTS

At follow up, 1,004 men (2.84%) and 1,807 women (4.43%) reported new diagnoses of age-related cataracts. The multivariate odds ratios (ORs) for those in the lowest and the highest BMI categories, compared with a BMI category of 21.0-22.9 as a reference point (OR, 1.00), were 1.29 [95% confidence interval (CI) 0.93-1.79] and 1.15 (95% CI 0.96-1.39) in men, and 1.23 (95% CI 0.97-1.55) and 1.19 (95% CI 1.04-1.36) in women.

CONCLUSIONS

Previous studies have suggested high BMI as a risk factor of age-related cataracts for Caucasian populations in developed countries while low BMI for populations living in developing countries. In contrast to those studies, the present large-cohort study showed a U-shaped association between BMI and the incidence of cataracts in Japanese men and women.

Lifestyle strategies for the prevention of vision loss

As the baby boom generation ages, it is anticipated that half a million cases per year will be added to the 19 to 21 million Americans not living in institutions or serving in the military who have low vision or blindness. The 4 major causes of vision loss and blindness in the United States are cataract, diabetic retinopathy, glaucoma, and age-related macular degeneration. All 4 diseases involve change in the microcirculation in eye structures. Holistic approaches to health incorporate attention to individuals' lifestyle choices. Relevant research literature was reviewed to identify strategies for lifestyle modification that nurses can use to prevent or slow progression of these diseases. Prevention strategies in general are those that promote avoidance of cardiovascular disease and diabetes. Because vision loss has been shown to be associated with diminished quality of life and increased mortality, lifestyle changes that prevent or moderate the impact of these diseases are an important focus of nursing care.

Androgen deprivation therapy and cataract incidence among elderly prostate cancer patients in the United States

PURPOSE

The side-effects associated with androgen deprivation therapy (ADT) include weight gain, dyslipidemia, and insulin resistance. As cataracts have been linked to these metabolic abnormalities, an increased risk of cataract may be another adverse consequence of ADT use.

METHODS

Using data from the Surveillance, Epidemiology and End Results-Medicare database, we estimated risk of cataract associated with ADT among 65,852 prostate-cancer patients. ADT treatment was defined as at least one dose of a gonadotropin-releasing hormone agonist or orchiectomy within 6 months after prostate cancer diagnosis. The outcome measure was a first claim of cataract diagnosis identified in Medicare claim files. Cox regression was used to estimate hazard ratios (HR) for the effects of ADT treatment, controlling for confounders.

RESULTS

Gonadotropin-releasing hormone agonist use was associated with a modest increase in cataract incidence (HR 1.09, 95% confidence interval 1.06-1.12). Orchiectomy was also associated with an increased risk of cataract among men with no history of cataract prior to prostate cancer diagnosis (HR 1.26, 95% confidence interval 1.07-1.47).

CONCLUSIONS

In the first systematic investigation of the association between ADT and cataract, our results suggest an elevation in the incidence of cataract among ADT users. Further study, preferably prospective in design, is needed to provide additional evidence to support or refute these findings.

Metabolic syndrome, its components and risk of age-related cataract extraction: a case-control study in Italy

PURPOSE

We sought to explore the relationship between age-related cataract extraction and the metabolic syndrome or its various components separately and in various combinations in an Italian case-control study.

METHODS

A total of 761 cases and 1,522 controls in hospital for acute, non-neoplastic, non-ophthalmologic, non-metabolic diseases were interviewed between 1991 and 2003. Odds ratios (ORs), and their 95% confidence intervals (CIs), were computed from multiple logistic regression models, conditioned on sex, age, and study center and adjusted for education and smoking.

RESULTS

The ORs were 1.41 for a history of central obesity, 1.42 for hypertension, 1.25 for hyperlipidemia, and 1.16 for diabetes. Patients with the metabolic syndrome (defined as the simultaneous presence of central obesity and at least two other factors among hypertension, hyperlipidemia, diabetes) had an increased risk of cataract, with an OR of 2.01 (95% CI: 1.43-2.83). The ORs were 1.75 for the presence of any of two components and 2.50 for three to four components, with a linear trend in risk.

CONCLUSIONS

This study indicates that the metabolic syndrome, its components, and their combination are associated with an increased risk of cataract extraction in this Italian population.

Relation of age-related cataract with obesity and obesity genes in an Asian population

Obesity shows an inconsistent association with cataract. Causality has not been established. Polymorphisms at the fat mass- and obesity-associated (FTO) locus are associated with obesity and offer an opportunity to examine the obesity-cataract association using a mendelian randomization approach. The authors conducted a population-based study among Singaporean Malay adults (2004-2006) in which nuclear, cortical, and posterior subcapsular (PSC) cataracts were assessed and defined by slit-lamp examination using Lens Opacity Classification System III. Obesity was defined as body mass index (weight (kg)/height (m)(2)) > or =30. The study included 3,000 subjects, of whom 1,339 (44.6%) had cataract (848 (28.3%) nuclear, 939 (31.3%) cortical, and 285 (9.5%) PSC). After multivariable adjustment for age, gender, diabetes, hypertension, smoking, and education, obesity was significantly associated with cortical (odds ratio (OR) = 1.31, 95% confidence interval (CI): 1.01, 1.71) and PSC (OR = 1.60, 95% CI: 1.10, 2.32) cataracts but not nuclear cataract. FTO single nucleotide polymorphisms known to be associated with obesity in this study population were not associated with cortical or PSC cataract but were associated with nuclear cataract (OR = 1.33, 95% CI: 1.11, 1.58), even in multivariate analyses controlling additionally for body mass index, diabetes, hypertension, and smoking (OR = 1.30, 95% CI: 1.08, 1.55). These results do not support a causal association between obesity and cortical or PSC cataract. The FTO gene may be involved in the pathogenesis of nuclear cataract.

Metabolic syndrome components in relation to risk of cataract extraction: a prospective cohort study of women

OBJECTIVE

To investigate the association between metabolic syndrome and some of its components with the incidence of cataract extraction.

DESIGN

Population-based prospective cohort study.

PARTICIPANTS

A total of 35,369 women, participating in the Swedish Mammography Cohort, aged 49 to 83 years, who completed a self-administered questionnaire about anthropometric measurements and lifestyle factors in 1997.

METHODS

The women were followed from September of 1997 to October of 2005. The cohort was matched with registers of cataract extraction in the study area.

MAIN OUTCOME MEASURES

Incident surgical extraction of age-related cataract.

RESULTS

We identified 4508 incident cases of cataract extractions during 98 months of follow-up. In multivariate analysis, women with a waist circumference >or=80 cm had an 8% increased risk of cataract extraction (rate ratio [RR], 1.08; 95% confidence interval [CI], 0.99-1.17). Women with diabetes had a 43% increased risk of cataract extraction (RR, 1.43; 95% CI, 1.10-1.86), and hypertension was associated with a 12% increased risk (RR, 1.12; 95% CI, 0.99-1.26). Women with all 3 components of the metabolic syndrome (waist >or=80 cm, diabetes, and hypertension) had a 68% increased risk of cataract extraction (RR, 1.68; 95% CI, 1.40-2.02) compared with women without any of these components. Among women aged less than 65 years at baseline with all 3 components of metabolic syndrome, the risk of cataract extraction was approximately 3-fold more (RR, 2.80; CI, 1.94-4.03).

CONCLUSIONS

Metabolic syndrome and its components, abdominal adiposity, diabetes, and hypertension, seem to be associated with an increased risk for cataract extraction, especially among women aged less than 65 years.

Prospective epidemiological cohort study of reduced risk for incident cataract with vigorous physical activity and cardiorespiratory fitness during a 7-year follow-up

PURPOSE

To test whether greater vigorous physical activity (kilometers per week run) and greater cardiorespiratory fitness (10-km race performance in meters per second) reduce the incidence of clinically diagnosed cataract.

METHODS

Prospective cohort study of self-reported clinical diagnosis of cataract in nondiabetic, nonvegetarian, and nonsmoking male (n = 29,025) and female runners (n = 11,967).

RESULTS

Incident cataracts were reported by 733 (2.53%) men and 179 (1.50%) women during (mean +/- SE) 7.74 +/- 0.01 and 7.42 +/- 0.02 years of follow-up, respectively. The risk for incident cataract increased with BMI, such that the risk in men > 27.5 kg/m(2) was 88% larger than in men < 20 kg/m(2). Men's cataract risk declined significantly in relation to running distance (P = 0.01), even when adjusted for BMI. Men who ran > or = 64 km/wk had 35% lower risk for cataract than those reporting < 16 km/wk (28% lower risk when adjusted for BMI). In addition, men with greater cardiorespiratory fitness were at significantly less risk for development of cataract than were the least fit men. This result was not accounted for by adjustment for running distance or BMI. Compared with the least fit men, those who ran faster than 4.75 m/s had 50% lower risk for incident cataract (43% lower when adjusted for km/wk and BMI).

CONCLUSIONS

These data suggest that the men's cataract risk decreased in association with lower BMI, greater physical activity, and greater cardiorespiratory fitness, the latter being statistically independent of both BMI and physical activity. The study limitations include the absence of confirmation of the clinical diagnosis and the lack of specificity of the type of cataract.

Maintaining transparency: a review of the developmental physiology and pathophysiology of two avascular tissues

The lens and cornea are transparent and usually avascular. Controlling nutrient supply while maintaining transparency is a physiological challenge for both tissues. During sleep and with contact lens wear the endothelial layer of the cornea may become hypoxic, compromising its ability to maintain corneal transparency. The mechanism responsible for establishing the avascular nature of the corneal stroma is unknown. In several pathological conditions, the stroma can be invaded by abnormal, leaky vessels, leading to opacification. Several molecules that are likely to help maintain the avascular nature of the corneal stroma have been identified, although their relative contributions remain to be demonstrated. The mammalian lens is surrounded by capillaries early in life. After the fetal vasculature regresses, the lens resides in a hypoxic environment. Hypoxia is likely to be required to maintain lens transparency. The vitreous body may help to maintain the low oxygen level around the lens. The hypothesis is presented that many aspects of the aging of the lens, including increased hardening, loss of accommodation (presbyopia), and opacification of the lens nucleus, are caused by exposure to oxygen. Testing this hypothesis may lead to prevention for nuclear cataract and insight into the mechanisms of lens aging. Although they are both transparent, corneal pathology is associated with an insufficient supply of oxygen, while lens pathology may involve excessive exposure to oxygen.

Relation between cataract and metabolic syndrome and its components

PURPOSE

To estimate the prevalence of cataract in the middle-aged urban population and the relation between cataract and metabolic syndrome and metabolic syndrome components.

METHODS

The survey was carried out in Kaunas City, Lithuania, from 2001 to 2002, according to WHO MONICA study protocol. The ophthalmologic investigation was performed for 1282 respondents (573 men and 709 women) aged 35-64 years. Cataract was defined at slit lamp using LOCS III method. Metabolic syndrome was defined by ATP III criteria.

RESULTS

Cataract was found in 17.6% of men and 19.0% of women (p>0.05). Metabolic syndrome was detected in 19.5% of men and 25.7% of women (p<0.05). After distribution of persons into 10-year age groups (35-44, 45-54, 55-64), the prevalence of cataract and metabolic syndrome among men and women significantly increased with age. A relation between cataract and metabolic syndrome was found for men aged 55-64 years and for women aged 45-64 years: the prevalence of cataract in men with metabolic syndrome was 1.3 times higher (43.8% vs 32.9%; OR=1.59 [95% CI, 0.77-3.26]) and in women with metabolic syndrome 1.4 times higher (31.8% vs. 22.6%; OR=1.60 [95% CI, 1.03-2.49]) than in persons of the same age and sex without metabolic syndrome. For men aged 4-64 years cataract was significantly related to central obesity (OR=1.80 [95% CI, 1.01-3.20]) and for women aged 45-64 years cataract was significantly related to higher arterial pressure (OR=1.98 [95% CI, 1.21-3.25]), central obesity (OR=1.54 [95% CI, 1.01-2.35]), and elevated level of serum triglycerides (OR=1.86 [95% CI, 1.20-2.90]).

CONCLUSIONS

The results of this study show that the prevalence of cataract in urban women 45-64 years of age with metabolic syndrome was significantly higher than in women of this age without metabolic syndrome.

Comparison of methods to identify incident cataract in eyes of patients with neovascular maculopathy: Submacular Surgery Trials Report No. 18

PURPOSE

To describe and compare methods used to monitor development and progression of presumed vision-limiting lens opacity in study eyes of Submacular Surgery Trials (SST) patients.

DESIGN

Prospective study of patients enrolled in a set of randomized clinical trials.

PARTICIPANTS

Patients enrolled in the SST who were phakic in the study eye at the time of enrollment (n = 690). In a subset of 114 patients, lens photographs were obtained at baseline and 2 years after enrollment.

METHODS

Data collection at baseline and annual follow-up examinations included ocular history, ophthalmologic examination including the SST ophthalmologist's assessment of presence or absence of vision-limiting opacity, fundus photography, and lens photography (13 of 27 clinics only). All photographs were assessed by masked graders centrally using the Lens Opacities Classification System III (LOCS III). kappa statistics were calculated to compare LOCS III cataract classifications with fundus photograph quality and with the ophthalmologist's assessment of lens opacity, with the LOCS III classification considered the gold standard.

MAIN OUTCOME MEASURE

Incidence of cataract in study eyes.

RESULTS

Baseline lens photographs were available and graded for 312 (45%) of 690 patients with phakic study eyes; 2-year lens photographs were available for 156 (23%) of 690 initially phakic eyes. Both baseline and 2-year lens photographs were available for 114 eyes that remained phakic. Submacular surgery was associated with significant progression of nuclear color and nuclear opalescence characteristics within 2 years of enrollment. The reliability of fundus photograph quality versus cataract classification using a 4.5 LOCS III score threshold for cataract was poor to good at each time point and for all groups (kappa, 0-0.51), but sensitivity of the photograph quality score as a surrogate was low, and both positive and negative predictive values were low. Agreement between the ophthalmologists' assessments of lens opacity and the 4.5 LOCS III score threshold for cataract was good (kappa, 0.42-0.78).

CONCLUSIONS

In the SST, clinical identification of severe cataract (LOCS III scores of 4.5 or worse for nuclear opacity or nuclear color) by the examining ophthalmologist was valid based on comparison with LOCS III scores and may be an adequate method to use in similar trials.

Obesity and eye diseases

The prevalence of obesity has reached epidemic proportions in many countries. Although its impact on overall health is well documented, less is known about the ocular manifestations of obesity. Among different eye diseases, obesity has been linked with age-related cataract, glaucoma, age-related maculopathy, and diabetic retinopathy. Numerous population-based and prospective studies support an association between obesity and risk of age-related cataract. However, the nature and strength of these associations, particularly with the different cataract subtypes, remains to be determined. There is strong evidence that obesity is associated with elevated intraocular pressure, but there is no convincing data to support a more direct association between obesity and glaucomatous optic neuropathy. Studies to date have not found a consistent pattern of association between obesity and risk of age-related maculopathy or diabetic retinopathy. Thus, although obesity may be a risk factor for many ocular conditions, the present literature is inadequate to establish any convincing associations. Furthermore, whether weight loss reduces the risk of eye diseases remains unresolved. Because of the potential public health impact of obesity, there is a greater need to understand its ocular effects.

Lower intraocular oxygen tension in diabetic patients: possible contribution to decreased incidence of nuclear sclerotic cataract

PURPOSE

To report intraocular oxygen tension in eyes of diabetic and nondiabetic patients.

DESIGN

A prospective, interventional consecutive case series.

METHODS

Oxygen was measured with an optical oxygen sensor in patients who were undergoing vitrectomy. Before turning on the infusion fluid, intraocular oxygen tension was measured in two locations: adjacent to the lens and in the mid vitreous cavity.

RESULTS

Fifty eyes from 50 patients were included in the study. Twenty-one eyes were from diabetic patients and 29 eyes were from nondiabetic patients. The mean oxygen tension adjacent to the lens was significantly lower in diabetic than in nondiabetic patients (8.4 +/- 0.7 mm Hg vs 10.7 +/- 0.8 mm Hg; P < .05). Similarly, the mean oxygen tension in the center of the vitreous cavity was lower in diabetic than in nondiabetic patients (5.7 +/- 0.7 mm Hg vs 8.5 +/- 0.6 mm Hg; P < .001). In subgroup analyses, previous panretinal photocoagulation or cataract surgery did not affect oxygen levels significantly in the vitreous of diabetic or nondiabetic patients.

CONCLUSION

Eyes from diabetic patients have significantly lower intraocular oxygen tension than in eyes from nondiabetic patients. Because oxidative damage to the lens nucleus and increased intraocular oxygen tension have been associated with nuclear sclerotic cataract, these findings may help explain recent reports of an apparent protective effect of diabetes mellitus against nuclear sclerotic cataract.

Dietary carbohydrate intake and glycemic index in relation to cortical and nuclear lens opacities in the Age-Related Eye Disease Study

BACKGROUND

Little is known about the association between dietary carbohydrates and cataract in nondiabetic persons.

OBJECTIVE

The aim was to test whether recent dietary carbohydrate intakes or glycemic index (GI; a measure of carbohydrate intake quality) was associated with the presence of cortical or nuclear opacities.

DESIGN

A modified Block food-frequency questionnaire was used to obtain dietary information from 3377 participants (aged 60-80 y; 56% were women) in the Age-Related Eye Disease Study (AREDS). Lens status was evaluated by using the AREDS System for Classifying Cataracts. Associations were examined for eyes with only a single, or pure, type of lens opacity by using the generalized estimating approach to logistic regression to account for the lack of independence between the eyes of a person.

RESULTS

For participants in the highest quartile, dietary GI was associated with a higher prevalence of all pure nuclear opacities [grade >2; odds ratio (OR): 1.29; 95% CI: 1.04, 1.59; P for trend = 0.02] and moderate nuclear opacities (grade > or =4; OR: 1.43; 95% CI: 0.96, 2.14; P for trend = 0.052). The OR in a comparison of the highest with the lowest quartile of intake was 1.27 (95% CI: 0.99, 1.63; P for trend = 0.09) for cortical opacities of any severity (>0% of area opaque), and the OR increased somewhat for moderate cortical opacities (>5% of area opaque; OR: 1.71; 95% CI: 1.00, 2.95; P for trend = 0.056).

CONCLUSIONS

Results from the cross-sectional analysis of AREDS baseline data suggest that dietary glycemic quality and dietary carbohydrate quantity may be associated with prevalent nuclear and cortical opacities, respectively.

Communicating the ocular and systemic complications of obesity to patients

BACKGROUND

Obesity has become a growing worldwide epidemic that is associated with serious medical complications. Many clinicians and patients are aware of the systemic complications of obesity, but there are few providers and patients who are aware of the ocular manifestations of obesity.

METHODS

A review of the current medical literature was performed. Ocular and systemic manifestations associated with obesity are described, and a methodology for educating the optometric patient is presented.

RESULTS

There is significant morbidity and mortality associated with obesity, which is causing serious consequences to patients and an enormous economic strain on the health care system. Optometrists have a tremendous opportunity and obligation to educate their patients on the potential sight-threatening complications of obesity and encourage them to decrease their caloric intake and increase their physical activity to help alleviate this individual and collective burden.

CONCLUSIONS

Optometrists have a duty to educate and counsel their overweight and obese patients on the devastating ocular complications that could manifest as a result of obesity.

Risk factors for cataract subtypes waterclefts and retrodots: two case–control studies

Waterclefts and retrodots are independently associated with visual impairment, yet a review identified no data on risk factors.

PURPOSE

To investigate risk factors for these two human lens cataract subtypes.

METHOD

Two nested case-control studies: The host study comprised 1078 subjects (55 years) attending the Somerset and Avon Eye Study (SAES). In total, 197 watercleft cases (Oxford grade 0.2 in either eye) and 199 retrodot cases (Oxford grade 1.0 in either eye) were individually age/gender matched to controls. Detailed ophthalmic and potential risk factor data were collected, including body mass index (BMI), smoking, alcohol, diabetes, hypertension, analgesics, vitamin supplementation, nutrition, sunlight exposure, dehydration, hormonal (women), blood lipids, glucose, urea, creatinine, uric acid, and vitamin levels.

RESULTS

For waterclefts, univariable analysis identified BMI, alcohol intake, vitamin status, sunlight, urea, creatinine, and uric acid as possible risk factors. Multivariable analysis identified two independent associations. Total number of 'any' analgesics in the previous year: adjusted P<0.01 (U-shaped risk profile, unadjusted high vs medium use (=reference) OR 2.39, 95% CI 1.35-4.26 with medium use vs none (=reference) OR 0.43, 95% CI 0.26-0.72); total sunlight: adjusted P=0.03 (unadjusted highest exposure vs lowest (=reference) OR 3.25, 95% CI 1.11-9.50). For retrodots, univariable analysis identified alcohol, HRT, and lipids. Multivariable analysis identified two independent associations. Mean number of alcohol units consumed per month, adjusted P=0.02 and HDL cholesterol levels, adjusted P=0.02 (unadjusted ORs NS both).

CONCLUSION

This is the first available published information on risk factors for the human cataractous lens features waterclefts and retrodots.

Carbohydrate intake and glycemic index in relation to the odds of early cortical and nuclear lens opacities

BACKGROUND

Animal studies suggest a role for dietary carbohydrate in cataractogenesis. However, few published human studies have evaluated associations between carbohydrate nutrition and lens opacification.

OBJECTIVE

Our objective was to test the hypothesis that long-term carbohydrate intake and dietary glycemic index are associated with the odds of early cortical and nuclear opacities.

DESIGN

Subjects were 417 Boston-area members of the Nurses' Health Study cohort aged 53-73 y. Dietary information was based on an average from 5 semiquantitative food-frequency questionnaires collected over a 14-y period. Opacities were assessed by using the Lens Opacity Classification System III (LOCS III). We used eyes (n = 711) as the unit of analysis and generated odds ratios by using a generalized estimating approach to logistic regression to account for the lack of independence between the 2 eyes of each subject.

RESULTS

After multivariate adjustment, the odds of cortical opacities (LOCS III >/=1.0) among women in the highest tertile of carbohydrate intake (>/=200 g/d) was 2.46 times (95% CI: 1.30, 4.64; P for trend = 0.005) that among women in the lowest tertile (<185 g/d). This association was not affected by adjustment for dietary glycemic index, which was not associated with early cortical opacities. Carbohydrate nutrition was not associated with the odds of nuclear opacities (LOCS III >/=2.5).

CONCLUSIONS

These data suggest that carbohydrate quantity, but not carbohydrate quality, is associated with early cortical opacities, and that neither the quantity nor the quality of dietary carbohydrate affects the risk of nuclear opacities in middle-aged women.