Prevalence of lens opacities in the Barbados Eye Study

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.

The Relationship between Myopia and Obesity in Adults

PURPOSE

To investigate the relationship between myopia and obesity through direct measurements of fat content.

METHODS

A cross-sectional study used a stratified, multistage survey, the Korea National Health and Nutrition Examination Survey (2008-2010). Subjects 19 years or older (n = 10,305) were included. Participants were divided into three groups according to refractive status: myopia (spherical equivalent [SE] ≤ -1.0 diopter [D]), emmetropia (-1.0 D < SE ≤ 1.0 D), and hyperopia (SE > 1.0 D). Obesity was investigated with assessment of fat mass and body mass index or waist circumference. Fat mass was measured with whole-body dual energy x-ray absorptiometry. Body fat percentage was calculated as (total fat mass / body weight × 100).

RESULTS

Higher obesity index was found in individuals with myopic eyes after adjustment for age, sex, education level, income status, physical activity, residence, and serum vitamin D level. The significant difference in total body fat percentages among myopia, emmetropia, and hyperopia was significant in the young age group (19-39 years, p < 0.05) but not in the middle age group (40-64 years) and the old age group (≥65 years). Individuals with a higher percentage of total body fat had greater odds ratios for myopia (fourth quartile of body fat; odds ratio, 1.352; 95% confidence interval, 1.178-1.551).

CONCLUSIONS

An association was found between adiposity and myopia in relatively young adults using direct measurements of fat mass.

The Impact of Social Determinants of Health on Vision Loss From Cataracts and Cataract Surgery Utilization in the United States-A National Health Interview Survey Analysis

PURPOSE

To investigate the association of social determinants of health (SDOH) factors and cataract-related outcomes disparities.

DESIGN

Cross-sectional, with a nationally representative sample.

METHODS

We used publicly available data from the 2008, 2016, and 2017 National Health Interview Survey data sets. Outcome measures included self-reported prevalence for ever been diagnosed with cataract, vision loss secondary to cataracts, and the likelihood of undergoing cataract surgery. Survey-weighted, multivariable logistic regression models, adjusted for age, race and ethnicity, and other relevant covariates, were used to examine the association between SDOH factors and cataract-related outcomes.

RESULTS

A total of 81,551 participants were included, who were predominantly between 18 and 44 years of age (49.6%), female (51.7%), and White (74.8%). Multivariable regression models with age as a covariate showed that individuals who were not working were more likely to report having cataracts than those who were working (P < .001). Those who needed but could not afford medical care in the past year were more likely to report vision loss secondary to cataracts than their counterparts (P < .001). Uninsured participants were less likely to report undergoing cataract surgery than those with private insurance (P = .03). Individuals with higher income (poverty-income ratio: 1.00-2.99 vs <1.00) were more likely to report undergoing cataract surgery (P = .04).

CONCLUSIONS

Several SDOH factors were associated with disparities in rates of cataract-related outcomes. These findings highlight the importance of ophthalmologists screening for social risks in patients with cataract, as these social factors are important barriers for access to care.

Pseudophakia and Lens Opacities in 70-Year-Olds in Gothenburg, Sweden; Gender Differences, Impact on Self-Reported Visual Function and Validation of Self-Reported Cataract and Pseudophakia

Purpose

The study aimed at determining the prevalence and sex differences in cataract, pseudophakia, lens opacities and self-reported cataract in 70-year-old people in Gothenburg, Sweden. The purpose was also to identify correlations between lens opacities, visual acuity and subjective visual function, and to validate self-reported cataract and cataract surgery.

Patients and Methods

Population-based cross-sectional study where participants (n=1182) answered questions about self-reported diagnosis of cataract and cataract surgery. A total of 1139 subjects completed the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25), 560 subjects underwent ophthalmic examination including visual acuity and lens photography. t-test, Pearson chi-square and Mann-Whitney U-test were used for obtaining p-values. ANOVA (analysis of variances, Kruskal-Wallis, one-way) was used to compare VFQ-25 between 3 groups; no cataract, cataract and pseudophakia. To clarify the differences between specific pairs of groups post-hoc test (Bonferroni) was used after ANOVA.

Results

Self-reported cataract was more common in women than in men (27.2% vs 19.1%, p=0.001, chi-square). Cataract surgery was reported by 16.3% of women and 12.6% of men (p=0.072). Upon eye examination, the prevalence of pseudophakia was 16.9% in women compared to 10.2% in men (p=0.020). The prevalence of cataract, including pseudophakia, was 31.9% in women versus 23.8% in men (p=0.033). Significant correlations (Spearman's rho) were found between lens opacities and visual acuity. Self-reported cataract surgery showed a very high specificity and high sensitivity. The composite score from NEI VFQ-25 was lower in people with pseudophakia than in people with/without cataract (p=0.012, Kruskal-Wallis).

Conclusion

The prevalence of cataract including pseudophakia in 70-year-olds in Gothenburg is higher compared to previous studies in similar geographical areas. Also, it is more common in women than in men. The lack of significant sex differences in lens opacities may be due to cataract surgery at an earlier stage. Validation showed very good agreement between pseudophakia and self-reported cataract surgery.

Development and validation of the Iris Glare, Appearance, and Photophobia questionnaire for patients with iris defects

PURPOSE

To validate the Iris Glare, Appearance, and Photophobia (Iris GAP) questionnaire, a new symptom-based and appearance-based quality-of-life measure for patients with iris defects.

SETTING

Single tertiary glaucoma clinic in Toronto, Ontario, Canada.

DESIGN

Prospective cohort study.

METHODS

Patients with varying degrees of iris defects were enrolled. Patients completed the Iris GAP questionnaire and the glare and driving subscales of the Refractive Status and Vision Profile (RSVP) questionnaire. Test-retest reliability, defined by Cronbach α and intraclass correlation coefficients (ICCs), was evaluated with repeat testing 2 weeks later.

RESULTS

The study included 73 patients with iris defects, 68 controls with no iris defects, 77 patients with peripheral iridotomies (PIs) or transillumination defects (TIDs), and 22 patientswith surgically repaired irides (n = 22). Iris GAP scores ranged from 0 to 32 with a 97% completion rate. Iris GAP had high test-retest reliability (Cronbach α = 0.866, ICC = 0.953, P < .0005). Iris GAP scores were reliably distinguishable between patients with iris defects, repaired iris defects, and PIs and TIDs and controls (1-way analysis of variance, P < .0005). In pairwise comparisons, the major defect group had statistically significant higher scores than any of the other groups ( P < .005 for each). The control and repaired groups had the lowest scores, whereas the PI/TID group had intermediate scores. 9 patients underwent iris repair between tests and had a mean difference of 8.2 ± 6.2 points between their preoperative and postoperative scores ( P = .004). Iris GAP scores positively correlated with RSVP scores ( R2 = 0.73).

CONCLUSIONS

Iris GAP can reliably evaluate symptomatology and patient-reported appearance in patients with iris defects.

Prevalence of pseudophakia: U.S. population-based study

PURPOSE

To determine the current prevalence and trends of pseudophakia in a well-defined U.S. population, calculating values for Olmsted County, Minnesota, from 1988 through 2018.

SETTING

Mayo Clinic, Rochester, Minnesota.

DESIGN

Population-based cohort study.

METHODS

Rochester Epidemiology Project (REP) databases were used to identify all cases of pseudophakia in Olmsted County, Minnesota, between January 1, 1988, and December 31, 2018. Age- and sex-specific prevalence rates were calculated in 1988, 1998, 2008, and 2018 using REP census population estimates and mortality counts. Poisson regression analysis was used to assess changes in prevalence over time. Mortality rates were estimated by Kaplan-Meier analysis.

RESULTS

In 2018, 10 024 county residents were pseudophakic in at least 1 eye, for a total population prevalence of 6.5%. The prevalence increased 67% in the last 10 years and 590% in the last 30 years (P < .001). By 2018, 51% of residents aged 75 years and 88% of residents aged 85 years and older were pseudophakic in at least 1 eye, 53% of residents with pseudophakia aged 65 years and older were bilaterally pseudophakic, and 29% of residents with pseudophakia had lived with pseudophakia for more than 10 years. The prevalence was higher among women than men and increased with age (P < .001). Overall, pseudophakia had a lower all-cause mortality compared with the general Minnesota population (P < .001).

CONCLUSIONS

In 2018, most residents aged 75 years and older were pseudophakic in at least 1 eye. These numbers underscore the changing visual status of older adults and the large number of adults who benefit from cataract surgery.

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.

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.

The Temporal Window of Visual Processing in Aging

Purpose

Aging affects a variety of visual functions. In this study, we aim to quantitatively investigate the temporal characteristics of visual processing in aging.

Methods

Twelve younger (24.1 ± 1.6 years) and 12 older observers (58.4 ± 3.6 years) participated in the study. All participants had normal or corrected-to-normal vision. The contrast thresholds of the participants were measured using an orientation discrimination task with white external noise masks. The target-mask stimulus onset asynchronies were 16.7 ms, 33.4 ms, 50.0 ms, 83.4 ms, and ∞ (no external noise masks) in separate conditions. The signal stimulus was carefully chosen such that it was equally visible for the younger and older participants. An elaborated perceptual template model (ePTM) was fit to the data of each participant.

Results

Without masks, there was no difference in contrast thresholds between the younger and older groups (P = 0.707). With masks, contrast thresholds in the older group elevated more than those in the younger group, and the pattern of threshold elevation differed in the two groups. The ePTM fitted the data well, with the older observers having lower template gains than the younger observers (P = 3.58 × 10-6). A further analysis of the weight parameters of the temporal window revealed that the older observers had a flatter temporal window than the younger observers (P = 0.025).

Conclusions

Age-related temporal processing deficits were found in older observers with normal contrast sensitivity to the signal stimuli. The deficits were accounted for by the inferior temporal processing window of the visual system in aging.

Global and regional prevalence of age-related cataract: a comprehensive systematic review and meta-analysis

The aim of our study was to estimate regional and global cataract prevalence, its prevalence in different age groups, and the determinants of heterogeneity and its prevalence. For that, we used international databases such as PubMed, Web of Science, Scopus, Embase, and other sources of information to conduct a systematic search for all articles concerning the prevalence of age-related cataract and its types in different age groups. Of the 9922 identified articles, 45 studies with a sample size of 161,947 were included in the analysis, and most of them were from the Office for the Western Pacific Region (19 studies). Age- standardized pooled prevalence estimate (ASPPE) and 95% confidence interval (95% CI) of any cataract, cortical cataract, nuclear cataract, and posterior subcapsular (PSC) cataract were 17.20% (13.39-21.01), 8.05% (4.79-11.31), 8.22% (4.93-11.52), and 2.24% (1.41-3.07), respectively. Significant effects on heterogeneity were observed for the WHO region in the prevalence of any cataract (b: 6.30; p: 0.005) and study year in the prevalence of nuclear cataract (b: -0.66, p: 0.042). In general, the prevalence of cataract not only varies by region but also by age group, and most cases are over the age of 60 years. We examined the sources of variance in the prevalence of cataract and its different types, and identified age as a responsible factor in the prevalence of any cataract, cortical cataract, nuclear cataract, and PSC of cataract, WHO region in the prevalence of any cataract, and study year in the prevalence of nuclear cataract.

The PACAP-derived peptide MPAPO facilitates corneal wound healing by promoting corneal epithelial cell proliferation and trigeminal ganglion cell axon regeneration

It is well known that the cornea plays an important role in providing protection to the eye, but it is fragile and vulnerable. To clarify the biological effects and molecular mechanisms of the pituitary adenylate cyclase activating polypeptide (PACAP)-derived peptide MPAPO (named MPAPO) to promote corneal wound healing, we applied a mechanical method to establish a corneal injury model and analyzed the repair effects of MPAPO on corneal injury. MPAPO significantly promoted corneal wound repair in C57BL/6 mice. In addition, we established injury models of epithelial cells and trigeminal ganglion cells with H₂O₂. The results show that when the concentration of MPAPO is 1 μM, it can significantly promote the repair of injured corneal epithelial cells and the regeneration of trigeminal ganglion cell axons. MPAPO repairs epithelial cells through the promotion of GSK3β phosphorylation by binding to PAC1 and activating AKT. β-catenin escapes the phosphorylation of GSK3β and enters the nucleus to promote the expression of cyclin D1, accelerate cell cycle progression and promote cell proliferation. MPAPO promotes axonal regeneration by binding to the PAC1 receptor and activating adenylate cyclase activity, followed by the cAMP activation of protein kinase A activity and the promotion of CREB phosphorylation. Phosphorylated CREB promotes Bcl₂ expression and axonal regeneration. In conclusion, our data support the role of MPAPO to facilitate corneal wound healing by promoting corneal epithelial cell proliferation and trigeminal ganglion cell axon regeneration.

Incidence of Visually Impairing Cataracts Among Older Adults in Kenya

Importance

Half of all the cases of blindness worldwide are associated with cataract. Cataract disproportionately affects people living in low- and middle-income countries and persons of African descent.

Objective

To estimate the 6-year cumulative incidence of visually impairing cataract in adult participants in the Nakuru Eye Disease Cohort Study in Kenya.

Design, Setting, and Participants

This secondary analysis of the Nakuru Eye Disease Cohort Study was conducted from February 2016 to April 2016. This cohort comprised citizens of Nakuru, Kenya, aged 50 years or older who consented to participate in the initial or baseline survey from January 2007 to November 2008, as well as the follow-up conducted from January 2013 to March 2014. All participants at baseline (n = 4364) and follow-up (n = 2159) underwent ophthalmic examination.

Main Outcomes and Measures

Six-year cumulative incidence of visually impairing cataract, risk factors of incidence, population estimates, and required cataract surgical rates to manage incident visually impairing cataract.

Results

In total, 4364 individuals (with a mean [SD] age of 63.4 [10.5] years and with 2275 women [52.1%]) had complete eye examinations at baseline, and 2159 participants (with a mean [SD] age of 62.5 [9.3] years and with 1140 men [52.8%]) were followed up 6 years later. The 6-year cumulative incidence of visually significant cataract in either eye was 251.9 per 1000 (95% CI, 228.5-276.8), with an increase with age from 128.9 (95% CI, 107.9-153.2) per 1000 for the group aged 50 to 59 years to 624.5 (95% CI, 493.1-739.9) per 1000 for the group aged 80 years or older. This equated to an annual incidence of visually significant cataract of 45.0 per 1000 people aged 50 years or older. Multivariable analysis showed alcohol consumption (risk ratio [RR], 1.4; 95% CI, 1.1-1.8), diabetes (RR, 1.7; 95% CI, 1.3-2.3), educational level, and increasing age (RR, 3.8; 95% CI, 2.6-5.5 for those aged ≥80 years) were associated with incident visually impairing cataract. Extrapolations to all people aged 50 years or older in Kenya indicated that 148 280 (95% CI, 134 510-162 950) individuals might develop new visually impairing cataract in either eye (visual acuity <6/18 in the worse-seeing eye) and that 9540 (95% CI, 6610-13 750) might become cataract blind in both eyes (visual acuity <3/60 in better-seeing eye).

Conclusions and Relevance

Adults in Kenya appeared to have a high incidence of visually impairing cataract, making cataract a priority for blindness prevention programs in the region; surgical interventions and awareness of these services are also required.

Decomposing sensorimotor variability changes in ageing and their connection to falls in older people

The relationship between sensorimotor variability and falls in older people has not been well investigated. We developed a novel task having shared biomechanics of obstacle negotiation to quantify sensorimotor variability related to locomotion across age. We found that sensorimotor variability in foot placement increases continuously with age. We then applied sensory psychophysics to pinpoint the visual and somatosensory systems associated with sensorimotor variability. We showed increased sensory variability, specifically increased proprioceptive variability, the vital cause of more variable foot placement in older people (greater than 65 years). Notably, older participants relied more on the vision to judge their own foot’s height compared to the young, suggesting a shift in multisensory integration strategy to compensate for degenerated proprioception. We further modelled the probability of tripping-over based on the relationship between sensorimotor variability and age and found a correspondence between model prediction and community-based data. We reveal increased sensorimotor variability, modulated by sensation precision, a potentially vital mechanism of raised tripping-over and thus fall events in older people. Analysis of sensorimotor variability and its specific components may have the utility of fall risk and rehabilitation target evaluation.

Prevalence of Lens Opacities in Adult Chinese Americans: The Chinese American Eye Study (CHES)

Purpose

We determined the age- and sex-specific prevalence of posterior subcapsular (PSC), nuclear, cortical, and mixed lens opacities in a population-based sample of Chinese-American adults.

Methods

A population-based sample of Chinese-Americans 50 years and older, from 10 census tracts in Monterey Park, CA, USA, underwent a detailed interview and a comprehensive clinical examination that included assessment of different types of lens opacities by the slit-lamp–based Lens Opacities Classification System II (LOCS II). All lens changes (including pseudophakia/aphakia), PSC, nuclear, and/or cortical opacities, were evaluated and graded.

Results

Of the 5782 eligible subjects, 4582 (79.2%) Chinese Americans aged 50 years and older completed a comprehensive eye examination. Of the participants with LOCS II grading (n = 4234/4582, 92%), 3.0% had PSC opacities, 38.1% had nuclear opacities, and 23.4% had cortical opacities. The prevalence of all lens changes was 48.0% for all age groups and was higher by 10-year increasing age groups (P < 0.0001). The prevalence of visual impairment in the better-seeing eye with cortical only, nuclear only, PSC only, and mixed opacities was 3.9%, 5.0%, 14.3%, and 9.4%, respectively. A total of 454 (9.9%) individuals had undergone cataract extraction in at least one eye.

Conclusions

Chinese Americans have a high prevalence of visual impairment associated with lens opacities, and a high prevalence of nuclear opacities. Public health policies and programs designed to improve cataract detection and treatment could help reduce the burden of visual impairment in Chinese Americans.

Association of Single Nucleotide Polymorphisms in XRCC1 (194) and XPD (751) with Age-related cataract

PURPOSE

Age-related cataract (ARC) is a multifactorial disease and different risk factors, including genetic and environmental, are responsible for the development of its various types. The aim of this study was to find out a correlation, if any, between ARC and the single nucleotide polymorphisms (SNPs) in DNA repair genes XRCC1 (X-ray repair cross-complementary-1) [Arg194Trp (rs1799782)] and XPD (xerodermapigmentosa complementation group D) [Lys751Gln (rs13,181].

METHOD

The genotype at these two SNPs was analyzed in 260 subjects (125 control and 135 patients) from Southern Punjab population (Pakistan) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. Genotype at both analyzed codons was correlated either individually or in various combinations with the studied epidemiological factors known to be associated with ARC.

RESULTS

Our results indicated that both SNPs Arg194Trp in XRCC1 (P = 0.967) and Lys751Gln in XPD (P = 0.995) were not associated with ARC whether they were analyzed individually or in combined form (P > 0.05). Analysis of epidemiological factors revealed that age (P < 0.001), cast of subjects (P = 0.001), diabetes (P < 0.001), hypertension (P = 0.001), smoking habit (P = 0.01), drug abuse (P < 0.05), steroid use (P = 0.001) and body weight (P < 0.001) can influence the incidence of ARC in enrolled subjects. After applying Binary logistic regression it was found that the weight (P < 0.01), family history (P = 0.05), drug abuse (P = 0.05), smoking (P < 0.05) and steroid use (P < 0.05) has a significant association with the phenotype of the subjects. All epidemiological factors were also studied in association with various genotypic combinations of both SNPS, diabetes was the only factor that had a significant association (P < 0.001) association with ARC. Hypertension (P = 0.01), body weight (P < 0.05) and cast (P < 0.001) were found associated with ARC when epidemiological factors were individually correlated with ARC. Result of the two proportion test indicated that gender had no influence on the incidence of disease.

CONCLUSION

It is concluded that studied SNPs in XRCC1 and XPD have no association with the incidence of age related cataract in the analyzed group of subjects.

The impact of pseudophakia on vision-related quality of life in the general population - The Gutenberg Health Study

Cataract surgery is the most frequently performed surgical procedure worldwide. We aim to determine the prevalence of having implanted an artificial lens (pseudophakia) and of no lens (aphakia) and to compare visual function.

As part of the Gutenberg Health study, a population-based cross-sectional study was conducted in Germany. An ophthalmological examination including slit-lamp examination was conducted. Prevalence including 95% confidential intervals were calculated and analyses were conducted for systemic and ocular associated factors with pseudophakia using multivariable logistic regression models. Vision-related quality of life was assessed using a standardized questionnaire and Rasch transformation.

14,696 people were included. Of these, 1.55% [1.36%–1.77%] had unilateral pseudophakia and 3.08% [2.81%-3.37%] had bilateral pseudophakia. Unilateral aphakia was present in 21 people and bilateral aphakia in 2 people. Pseudophakia was independently associated with age, higher body weight and lower body height, diabetes and smoking. Vision-related quality of life values were similar for those with bilateral phakia and pseudophakia but were lower for those with unilateral pseudophakia.

The pseudophakia status is related to several cardiovascular risk factors, indicating a relationship to an aging effect that causes premature lens opacification. Bilateral pseudophakia can almost imitate the physiological condition of phakia except for the need to use glasses.

The National Eye Survey of Trinidad and Tobago (NESTT): Rationale, Objectives and Methodology

PURPOSE

This paper describes the rationale, study design and procedures of the National Eye Survey of Trinidad and Tobago (NESTT). The main objective of this survey is to obtain prevalence estimates of vision impairment and blindness for planning and policy development.

METHODS

A population-based, cross-sectional survey was undertaken using random multistage cluster sampling, with probability-proportionate-to-size methods. Eligible participants aged 5 years and older were sampled from the non-institutional population in each of 120 cluster segments. Presenting distance and near visual acuity were screened in their communities. People aged 40 years and older, and selected younger people, were invited for comprehensive clinic assessment. The interview included information on potential risk factors for vision loss, associated costs and quality of life. The examination included measurement of anthropometrics, blood glucose, refraction, ocular biometry, corneal hysteresis, and detailed assessment of the anterior and posterior segments, with photography and optical coherence tomography imaging. Adult participants were invited to donate saliva samples for DNA extraction and storage.

RESULTS

The fieldwork was conducted over 13 months in 2013-2014. A representative sample of 10,651 individuals in 3410 households within 120 cluster segments identified 9913 people who were eligible for recruitment.

CONCLUSION

The study methodology was robust and adequate to provide the first population-based estimates of the prevalence and causes of visual impairment and blindness in Trinidad and Tobago. Information was also gathered on risk factors, costs and quality of life associated with vision loss, and on normal ocular parameters for the population aged 40 years and older.

Mental Health Status and Quality of Life in Undiagnosed Glaucoma Patients: A Nationwide Population-Based Study

Glaucoma is a leading cause of irreversible vision loss. Mental health and quality of life (QoL) are important issues for patients with glaucoma because visual impairment can be related to those. Analysis of mental health status or QoL in undiagnosed glaucoma patients can be free of the bias caused by awareness of the disease itself. In this study, the association between mental health status or QoL and undiagnosed glaucoma, along with the effects of visual acuity or visual field damage was investigated. Among individuals in the Korea National Health and Nutrition Examination Survey (KNHANES) V (2010-2012), subjects 40 years or older were included. KNHANES is a cross-sectional study using a stratified, multistage, probability sampling survey. The KNHANES includes questionnaires to assess psychological health, including depression, sleep duration, psychological stress, and suicidal ideations. To evaluate QoL, the KNHANES includes the EuroQoL, which is composed of a health-status descriptive system (EuroQol 5-dimension, EQ-5D) and the EQ visual analog scale (EQ-VAS). The proportion of people reporting symptoms of "some or severe problems" in all 5 dimensions of the EuroQoL-5 instrument, including anxiety/depression, was higher in the glaucoma group than in the nonglaucoma group. The subjective health status reported by the EQ-VAS was lower in the subjects with glaucoma than in those without glaucoma. Suicidal ideation was greater in subjects with glaucoma than in those without glaucoma (P = 0.005). After adjustment for demographic factors, glaucoma subjects were more likely than those without glaucoma to have some or severe problems with anxiety/depression (odds ratio 1.77; 95% confidence interval, 1.26-2.49). Worse best corrected visual acuity was associated with more problems with a lower EQ-5D score in glaucoma subjects. Individuals who had undiagnosed glaucoma were more depressed than those without glaucoma. QoL can be affected by glaucoma, especially in patients with worse visual acuity.

Six-year incidence of visually significant age-related cataract: the Chennai eye disease incidence study

BACKGROUND

The aim of this study is to report the 6-year incidence of age-related cataract in a population-based study.

DESIGN

The design used is a population-based cohort study.

PARTICIPANTS

A cohort of 2484 phakic subjects, aged 40 years and above at baseline, from a south Indian population was included in the study.

METHODS

Bilateral phakics with visual acuity of 6/12 or better and cataract less than N2, C2 and P2 on the Lens Opacities Classification System II at baseline were included. Subjects with glaucoma and corneal or retinal diseases were excluded. Incident visually significant cataract was defined as visual acuity of less than 6/18 with a corresponding one grade or greater change in Lens Opacities Classification System II or history of having undergone cataract surgery with evidence of pseudophakia or aphakia at the 6-year follow-up.

MAIN OUTCOME MEASURES

Six-year incidence of visually significant cataract and associated risk factors data were collected.

RESULTS

Incident visually significant cataract at 6 years was seen in 158 subjects (6.36%, 95% CI: 5.40-7.32, phakics:pseudophakics/aphakics 70:88). Incidence was higher in the rural cohort as compared with the urban cohort (P < 0.001). Incidence increased with age and was highest in the ≥70 years age group (odds ratio (OR):31.23, 95% CI: 15.20-64.16, P < 0.001). Other associated risk factors included illiteracy (OR 1.75, 95% CI: 1.17-2.61, P = 0.007) and smoking (OR 1.77, 95% CI: 1.08-2.88, P = 0.02).

CONCLUSIONS

A significant proportion of the population developed visually significant age-related cataract at 6 years. Incident visually significant cataract was significantly greater for the rural cohort between 50 and 69 years old.

Outcomes of phacoemulsification in patients with chronic ocular graft-versus-host disease

PURPOSE

The purpose of this study was to evaluate the outcomes of phacoemulsification in patients with ocular graft-versus-host disease (GVHD).

METHODS

The occurrence of cataracts, cataract surgery, and its outcomes were analyzed in the medical records of 229 patients (458 eyes) with ocular GVHD. Outcome measures included pre- and postoperative corrected distance visual acuity (CDVA) and the rate of postoperative complications.

RESULTS

Of the 458 eyes evaluated, 58 were pseudophakic; from the 400 phakic eyes, 238 (59 %) presented with cataracts and 62 (26 %) underwent cataract surgery. Analysis of postoperative complications and visual outcomes at 1 month was performed in 51 eyes in which detailed surgical and immediate postoperative records were available. Preoperatively, the mean CDVA was 0.67 ± 0.57 LogMAR (Snellen 20/93), improving postoperatively to 0.17 ± 0.18 (Snellen 20/29) at 1 month (P < 0.0001), and to 0.13 ± 0.14 (Snellen 20/26) by the final follow-up visit (P < 0.0001). Postoperative complications included corneal epithelial defects (8 %), filamentary keratitis (6 %), worsening of corneal epitheliopathy (16 %), posterior capsular opacification (18 %), and cystoid macular edema (4 %). A corrected distance visual acuity of 20/30 or better was achieved in 87 % of the eyes; suboptimal CDVA improvement was attributable to severe ocular surface disease, pre-existing advanced glaucoma, and prior macular surgery.

CONCLUSIONS

Phacoemulsification in patients with chronic ocular GVHD is a safe and efficacious procedure resulting in significant visual improvement. Overall, postoperative adverse events responded well to timely management.

Cataractogenic potential of quetiapine versus risperidone in the long-term treatment of patients with schizophrenia or schizoaffective disorder: a randomized, open-label, ophthalmologist-masked, flexible-dose, non-inferiority trial

Clinical observations indicate no cataractogenic potential for quetiapine, in contrast to studies in laboratory animals. This randomized, non-inferiority study compared changes in lens opacity during long-term treatment with quetiapine versus risperidone. Patients with schizophrenia or schizoaffective disorder participated in the 2-year, randomized, multicentre, open-label, ophthalmologist-masked, flexible-dose, parallel-group study. Two ophthalmologists examined each patient 6-monthly for presence of nuclear opalescence (N) and cortical (C) or posterior subcapsular opacification (P), according to the lens opacities classification system II. 1098 patients were randomized to treatment. Mean doses were 386.3 mg/day quetiapine and 3.2 mg/day risperidone. Estimated absolute risk differences in cataractogenic events for quetiapine versus risperidone over 2 years were -0.035 (C), -0.012 (N) and -0.017 (P), with upper margins of confidence intervals within the non-inferiority margin of 10%. In post hoc analysis, risk of any lens opacification event was significantly lower for quetiapine than risperidone (6 and 16 events, respectively; risk difference: -0.058; P = 0.035). Efficacy and other safety assessments were in agreement with known profiles of these medications. Quetiapine was non-inferior to risperidone for changes in lens opacity grade in patients with schizophrenia or schizoaffective disorder, indicating that quetiapine does not have clinically significant cataractogenic potential during long-term treatment.

Gender and cataract--the role of estrogen

There is evidence from epidemiologic data that cataract is more common in women than men. This is not solely due to a higher rate of cataract extraction in women, as is the case in the western world, but several population-based studies show that females have a higher prevalence of lens opacities, especially cortical. There is no firm evidence that lifestyle-related factors are the cause of this gender discrepancy. Focus has therefore been directed towards the role of estrogen in cataract formation. Although data on endogenous and exogenous estrogen involvement in cataractogenesis are conflicting, some studies have indicated that hormone therapy may decrease the risk of cataract and thus be protective. It has been hypothesized that the decrease in estrogen at menopause cause increased risk of cataract in women, i.e. not strictly the concentration of estrogen, but more the withdrawal effect. Estrogens are known to exert several anti-aging effects that may explain the longer lifespan in women, including metabolically beneficial effects, neuroprotection, preservation of telomeres and anti-oxidative properties. Since oxidative stress is considered important in cataractogenesis, studies have investigated the effects of estrogens on lens epithelial cells in culture or in animal models. Several investigators have found protection by physiological concentrations of 17β-estradiol against oxidative stress induced by H2O2 in cultured lens epithelial cells. Although both main types of estrogen receptors, ERα and ERβ, have been demonstrated in lens epithelium, most studies so far indicate that the estrogen-mediated protection in the lens is exerted through non-genomic, i.e. receptor-independent mechanisms, possibly through phosphorylation of extracellular signal-regulated kinase (ERK1/ERK2), a member of the mitogen-activated protein kinase (MAPK)-signaling pathway. Further studies are needed, both epidemiologic as to the role of hormone therapies, and laboratory studies regarding molecular estrogen-mediated mechanisms, in order to comprehend the role of estrogens on cataract formation.

Prevalence of and risk factors for age-related and anterior polar cataracts in a Korean population

Objective

To investigate the potential risk factors associated with nuclear, cortical, posterior subcapsular, and anterior polar cataracts (APC) in the Korean population.

Research Design and Methods

This was a population-based, cross-sectional study of 7992 adults (over 40 years of age) from the data of the fourth annual Korea National Health and Nutrition Examination Survey, performed from 2007 to 2009. The presence of lens opacity was examined by slit-lamp biomicroscopy and evaluated according to LOCS II standard photographs. The subtype of cataract present, including nuclear, cortical, posterior subcapsular, and anterior polar cataracts, was noted. 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 age, sex, health examination, and medical history.

Results

The prevalence of nuclear, cortical, and posterior subcapsular cataract increased gradually with increasing age. However, the prevalence of APC peaked in the 50- to 59-year-old subjects. All types of cataract except for APCs were more prevalent in women. Oral steroid use was associated with a lower risk of APC.

Conclusions

These findings showed the unique characteristics of APC in the Korean population.

Prevalence of and factors associated with lens opacities in a Korean adult population with and without diabetes: the 2008-2009 Korea National Health and Nutrition Examination Survey

Objective

We examined the prevalence of and factors associated with lens opacities in a Korean adult population with and without diabetes.

Research Design and Methods

Among the 11,163 adults (≥19 years old) from the fourth Korea National Health and Nutrition Examination Survey in 2008–2009, the data from laboratory tests, nutritional surveys, and slit-lamp examinations of 10,248 persons (4,397 men, 5,851 women) were examined. Cataract was defined as the presence of any nuclear, cortical, subcapsular, or mixed cataract in at least one eye, using the Lens Opacities Classification System III.

Results

The weighted prevalence of cataracts were 23.5% [95% confidence interval (CI), 21.7–25.4] in a Korean adult population (19–39 years old, 1.8% [1.3–2.5], 40–64 years old, 25.2% [22.5–28.1],≥65 years old, 87.8% [85.4–89.9])and 54.7% [50.1–59.2] in a diabetic population(19–39 years old, 11.6% [4.5–26.5], 40–64 years old, 41.1% [35.4–47.0], ≥65 years old, 88.3% [83.5–91.8]). In a logistic regression analysis, age, myopia, and the presence of diabetes were independent risk factors. For young (age 19–39 years) and middle aged (age 40–65 years) adults with diabetes, the OR of having a lens opacity is 5.04 [1.41–17.98] and 1.47 [1.11–1.94], respectively, as those without diabetes, whereas for adults aged 65 and older, there was no difference in the prevalence of cataract.

Conclusions

According to these national survey data, ∼ 24% of Korean adults and ∼ 55% of people with diabetes have cataracts. The presence of diabetes was independently associated with cataracts in young and middle aged adults.

Cataracts among adults aged 30 to 49 years: a 10-year study from 1995 to 2004 in Korea

Purpose

To investigate the long-term characteristics of cataracts among adults aged 30 to 49 years in Korean over a span of 10 years.

Methods

Subjects between the ages of 30 to 49 years who underwent cataract surgery at St. Mary's Hospital from 1995 to 2004 (n = 976) were included. Patients with a history of ocular trauma, uveitis, other ocular or systemic diseases, and congenital cataracts were excluded. Additional information including type of lens opacity, urban/rural region, and pre- and postoperative visual acuities were analyzed. Lens opacity grading was conducted using Lens Opacity Classification System III. The Cochran-Armitage proportion trend test was used to analyze vision changes with the passage of time.

Results

Among the patients who had undergone cataract surgeries, 8.8% (976 / 11,111) met the inclusion criteria. The mean age was 41.7 ± 5.45 years. Gender breakdown of the patient population included 79.0% male and 21.0% female. In terms of home environment, 60.9% were from an urban region and 39.1% from a rural region. Opacity type included anterior polar (AP), posterior subcapsular (PSC), AP and PSC, cortical, and nuclear in 35.7%, 35.1%, 7.0%, 6.0%, and 5.4% of patients, respectively. At a 2-month postoperative follow-up appointment, 92.7% of patients showed a best-corrected visual acuity of more than 20 / 40.

Conclusions

Predominance of AP and PSC opacities as well as male patients was observed in this study population.

The chinese american eye study: design and methods

PURPOSE

To summarize the study design, operational strategies and procedures of the Chinese American Eye Study (CHES), a population-based assessment of the prevalence of visual impairment, ocular disease, and visual functioning in Chinese Americans.

METHODS

This population-based, cross-sectional study included 4570 Chinese participants aged 50 years and older, residing in the city of Monterey Park, California. Each eligible participant completed a detailed interview and eye examination. The interview included an assessment of demographic, behavioral and ocular risk factors and health-related and vision-related quality of life. The eye examination included measurements of visual acuity, intraocular pressure, visual fields, fundus and optic disc photography, a detailed anterior and posterior segment examination, and measurements of blood pressure, glycosylated hemoglobin levels, and blood glucose levels.

RESULTS

The objectives of the CHES are to obtain prevalence estimates of visual impairment, refractive error, diabetic retinopathy, open-angle and angle-closure glaucoma, lens opacities, and age-related macular degeneration in Chinese Americans. In addition, outcomes include effect estimates for risk factors associated with eye diseases. Lastly, CHES will investigate the genetic determinants of myopia and glaucoma.

CONCLUSION

The CHES will provide information about the prevalence and risk factors of ocular diseases in one of the fastest growing minority groups in the United States.

Cataract prevalence and prevention in Europe: a literature review

This literature review is aimed at the evaluation of the potential for cataract prevention in Europe. It was performed using PubMed with Mesh and free-text terms. Studies included were (i) performed on a population of Caucasian origin at an age range of 40-95 years, (ii) cataract was clinically verified, (iii) drug record of prescriptions, their indication, a record of every diagnosis, dosage and quantity of prescribed medicine were available, (iv) sample size >300 and (v) published between 1990 and 2009. The results of 29 articles were reviewed. Former [3.75 (2.26-6.21)] or current smoking [2.34 (1.07-5.15)], diabetes of duration >10 years [2.72 (1.72-4.28)], asthma or chronic bronchitis [2.04 (1.04-3.81)], and cardiovascular disease [1.96 (1.22-3.14)] increased the risk of cataract. Cataract was more common in patients taking chlorpromazine during ≥90 days with a dosage ≥300 mg [8.8 (3.1-25.1)] and corticosteroids >5 years [3.25 (1.39-7.58)] in a daily dose >1600 mg [1.69 (1.17-2.43)]. Intake of a multivitamin/mineral formulation [2.00 (1.35-2.98)] or corticosteroids [2.12 (1.93-2.33)] also increased the risk of cataract. Corticosteroids applied orally [3.25 (1.39-7.58)], parenteral [1.56 (1.34-1.82)] or inhalational [1.58 (1.46-1.71)] lead to cataract more frequently than those applied topically: nasal [1.33 (1.21-1.45)], ear [1.31 (1.19-1.45)] or skin [1.43 (1.36-1.50)]. Outpatient cataract surgery was negatively associated with total cataract surgery costs, and chlorpromazine, corticosteroids and multivitamin/mineral formation increase the risk of posterior subcapsular cataract dependent on dose, treatment application and duration. This review presented a comprehensive overview of specific and general cataract risk factors and an update on most recent experimental studies and randomized control trials directed at cataract prevention.

Racial differences in lens opacity incidence and progression: the Salisbury Eye Evaluation (SEE) study

PURPOSE

To evaluate racial differences in nuclear and cortical lens opacity incidence and progression over a 2-year period in an older American population.

METHODS

Prospective population-based cohort study of a multiethnic population of 2520 people (26% African-American and 74% Caucasian), 65 to 84 years of age, living in Salisbury, Maryland. Data at baseline included race, education level, past steroid use, smoking status, alcohol status, sunlight exposure, and history of hypertension and diabetes. Lens photographs were taken at baseline and at 2-year follow-up and were graded using the Wilmer grading scheme. Multiple logistic regression models were used to examine the independent associations between race, as well as other risk factors, and incidence and progression of cortical and nuclear opacities.

RESULTS

AFRICAN-AMERICANS HAD LOWER RATES OF NUCLEAR OPACITY INCIDENCE (ODDS RATIO [OR]: 0.52; 95% Confidence Interval [CI]: 0.35-0.76) and nuclear opacity progression (OR: 0.60; 95% CI: 0.38-0.92) compared with Caucasians. African-Americans had higher rates of cortical opacity incidence (OR: 1.90; 95% CI: 1.21-2.98) and cortical opacity progression (OR: 1.72; 95% CI: 1.21-2.45) compared with Caucasians. Additionally, nuclear opacity incidence was associated with age, female sex, and current smoking status. Nuclear progression was associated with past smoking and current smoking. Cortical opacity incidence was associated with female sex, Ultraviolet-B exposure, and a history of diabetes. Cortical opacity progression was associated with current smoking status.

CONCLUSIONS

Differences by race in the type of cataract incidence and progression, even adjusting for personal and environmental risk factors, deserve further exploration.

Socioeconomic disparities in cataract surgery

PURPOSE OF REVIEW

As the elderly population continues to grow in the USA, an understanding of the increasing burden of cataract is pivotal. This review seeks to iterate the presence of this burden and to understand it better in the context of race, sex, and socioeconomic factors.

RECENT FINDINGS

Although there have been multiple prevalence studies addressing the cataract burden in the USA, updated literature that directly elucidates the above issues has been sparse. Recent data support previous findings that the cataract burden among women is greater than that of men, likely predominantly due to greater longevity. With regard to race, there appears to be a slightly increased burden among Whites, although this increase may show regional variability and change over the next few decades, especially as the presently young Hispanic population continues to age and grow. It is likely that the significant divider responsible for unmet cataract surgery is socioeconomic, due to such factors as insurance coverage, income, and barriers to access such as transportation, service accessibility, and awareness. These latter barriers of income and access appear to be identical to those identified in developing countries.

SUMMARY

The cataract burden in the USA is significant and is expected to continue to grow. Further studies are warranted to help us better understand barriers to access, particularly with regard to race and socioeconomic factors. Local efforts to address education and logistical barriers as well as nationwide policy efforts to address insurance coverage appear to be a crucial factor in surmounting an ongoing but treatable chronic disease.

Biomass stoves and lens opacity and cataract in Nepalese women

PURPOSE

Cataract is the most prevalent cause of blindness in Nepal. Several epidemiologic studies have associated cataracts with use of biomass cookstoves. These studies, however, have had limitations, including potential control selection bias and limited adjustment for possible confounding. This study, in Pokhara City, in an area of Nepal where biomass cookstoves are widely used without direct venting of the smoke to the outdoors, focuses on preclinical measures of opacity while avoiding selection bias and taking into account comprehensive data on potential confounding factors.

METHODS

Using a cross-sectional study design, severity of lenticular damage, judged on the LOCS (Lens Opacities Classification System) III scales, was investigated in women (n = 143), aged 20 to 65 years, without previously diagnosed cataract. Linear and logistic regression analyses were used to examine the relationships with stove type and length of use. Clinically significant cataract, used in the logistic regression models, was defined as a LOCS III score ≥2.

RESULTS

Using gas cookstoves as the reference group, logistic regression analysis for nuclear cataract showed evidence of relationships with stove type: for biomass stoves, the odds ratio was 2.58 (95% confidence interval, 1.22 to 5.46); and for kerosene stoves, the odds ratio was 5.18 (95% confidence interval, 0.88 to 30.38). Similar results were found for nuclear color (LOCS III score ≥2), but no association was found with cortical cataracts. Supporting a relationship between biomass stoves and nuclear cataract was a trend with years of exposure to biomass cookstoves (p = 0.01). Linear regression analyses did not show clear evidence of an association between lenticular damage and stove types. Biomass fuel used for heating was not associated with any form of opacity.

CONCLUSIONS

This study provides support for associations of biomass and kerosene cookstoves with nuclear opacity and change in nuclear color. The novel associations with kerosene cookstove use deserve further investigation.

Association of IFN-g+874(T/A) polymorphism with female patients of age-related cataracts

Aim:

Exposure to UV light is the major risk factor in the development of age-related cataract (ARC). UV filters produced during tryptophan catabolism maintain the transparency of the lens and protect retina from photo damage. Indoleamine 2, 3-dioxygenase (IDO), the first rate-limiting enzyme in the tryptophan catabolism, is up regulated by interferon-gamma (IFN-g) which harbors single nucleotide polymorphisms (SNPs). The T allele of SNP at +874 position of the IFN-g is known to be associated with the up regulation of IDO than the allele A. Hence, we attempted to study the IFN-g+874(T/A) polymorphism for its association with ARCs.

Materials and Methods:

A total of 680 cataract cases [199 nuclear (NC), 175 cortical (CC), 174 posterior subcapsular (PSC), and 132 mixed types (MT)] and 210 healthy controls were genotyped for +874(T/A) polymorphism using amplification refractory mutation system-polymerase chain reaction on 2% agarose gel stained with ethidium bromide.

Results:

There was increased risk for CC and PSC when the patients happened to be females, with low body mass index and with early onset. Considering the IFN-g polymorphism, a high risk was observed for CC and PSC in female patients of AA genotype with significant protection for those with TT genotypes.

Conclusion:

Present results indicate that +874(T/A) polymorphism may be considered as one of the biomarkers to distinguish between the CC and PSC types of cataracts for risk estimations. The study appears to be the first of its kind reporting an association of IFN-g+874(T/A) polymorphism with ARCs.

NASCA report 2: Longitudinal study of relationship of exposure to space radiation and risk of lens opacity

The NASA Study of Cataract in Astronauts (NASCA) was designed to measure the impact of exposure to space radiation on progression rates of cortical, nuclear, and posterior subcapsular cataract in U.S. astronauts who have flown in space and comparison groups of astronauts who had not flown in space, and subjects with a history of military aviation. We present our analyses of 5 years of data with an average of 3.8 exams per subject. All subjects had digital lens images with the Nidek EAS 1000 Lens Imaging System. Because of high variability and skewness of opacity measures, nonparametric methods were used to test for association between rates of opacification and space radiation exposure. First, median regression was used to collapse longitudinal data into robust estimates of progression rates (opacity severity compare to time for each eye of each subject). To quantify and test for a radiation effect, median regression with the dependent variable being the maximum of the two slopes (OD and OS) per subject was then used, adjusting for the confounding variables of age, nutritional, and sun-exposure histories. Median regression showed evidence of an association between the rate of cortical progression in the worse eye with radiation dose and age. The estimated median progression rate from space radiation being 0.25 ± 0.13% lens area/Sv/year (P = 0.062). We found no relationship between radiation exposure and progression of aggregate area of posterior subcapsular cataract or nuclear progression rates. However, longer follow-up may be needed to further understand any impact of space radiation on progression rates for posterior subcapsular cataracts and nuclear cataracts, and to characterize changes to visual acuity.

Prevalence and associations of cataract in a rural Chinese adult population: the Handan Eye Study

BACKGROUND

Cataract remains the leading cause of blindness and visual impairment in the world and in China. However, data on the prevalence of cataract based on standardized lens grading protocols from mainland China are limited. This paper estimated the age- and gender-specific prevalence and risk factor for cataract

METHODS

In a population-based Chinese sample, participants underwent a comprehensive ophthalmic examination, including assessment of cortical, nuclear, posterior subcapsular (PSC) and mixed lens opacities from slit-lamp grading using the Lens Opacities Classification System III.

RESULTS

Of the 7,557 eligible subjects, 6,830 took part in the study (90.4% response rate), and 6,544 participants (95.8%, mean age 52.0 ± 11.8 years) had lens data for analyses. The prevalence of any cataract surgery in at least one eye was 0.8% (95% confidence interval [CI], 0.62, 1.06), with similar rates between men and women. The overall prevalence of any cataract or cataract surgery was 20.8% (95% CI, 19.8, 21.8), higher in women than in men after adjusting for age (23.6% vs 17.6%; OR: 1.78; 95% CI: 1.54-2.07). When distinct lens opacity was categorized in each eye as cortical, nuclear, PSC or mixed, based on one randomly selected eye, cortical cataract was the most common distinct subtype (12.3%), followed by mixed (3.2%), nuclear (1.7%), and PSC (0.2%) cataract. The prevalence of all lens opacities increased with age (P < 0.001). After excluding other causes for visual impairment, the proportion of people with best corrected visual acuity <20/60 was 21% among those with PSC, and 12% among those with mixed opacities in the better-seeing eye. In multivariable logistic regression models, myopia was associated with all cataract types, while higher fasting plasma glucose and diabetes were only associated with PSC cataract.

CONCLUSIONS

Cataract affects 20% of the population aged 30 years and older living in rural China, with cortical cataract the most common subtype. Risk factors for cataract include myopia and diabetes.

Lens opacities in Valencia, Spain

PURPOSE

To evaluate the most common lens opacities in Valencia (Spain), analyzed by gender, grade, and type of cataracts. The results are compared with other studies performed at other geographical latitudes and on different races.

METHODS

A total of 1951 eyes of patients diagnosed with cataracts, aged between 30 and 96 years, were evaluated in accordance with age, gender, type and degree of the cataract, bilaterality, and symmetry of this disease. Lens Opacities Classification System III was used to classify the cataract and the degree was graded as mild or moderate to advanced.

RESULTS

The most common type of cataract is corticonuclear in the elderly and subcapsular in younger subjects. The most common are nuclear (28.4%) followed by cortical (6.2%), if combined cataracts are ruled out. There is a greater incidence of cortical cataracts in women (70%) and subcapsular cataracts in men (70%).

CONCLUSIONS

The results suggest the existence of a gender factor in cataract formation and coincide with those obtained in similar studies performed in areas at a similar latitude (40º N) and with different race population. The geographical location (intensity and length of exposure to solar radiation) seems to be a determining factor in the formation of a specific type of cataract, more than race, although there are other factors that contribute in the formation of a specific type of cataract.

Risk factors for cortical, nuclear, posterior subcapsular, and mixed lens opacities: the Los Angeles Latino Eye Study

PURPOSE

To identify sociodemographic and biological risk factors associated with having cortical, nuclear, posterior subcapsular (PSC), and mixed lens opacities.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

A total of 5945 Latinos aged ≥ 40 years from 6 census tracts in Los Angeles, California.

METHODS

Participants underwent an interview and detailed eye examination, including best-corrected visual acuity and slit-lamp assessment of lens opacities using the Lens Opacities Classification System II. Univariate and stepwise logistic regression analyses were used to identify independent risk factors associated with each type of lens opacity.

MAIN OUTCOME MEASURES

Odds ratios for sociodemographic and biological risk factors associated with cortical only, nuclear only, PSC only, and mixed lens opacities.

RESULTS

Of the 5945 participants with gradable lenses, 468 had cortical only lens opacities, 217 had nuclear only lens opacities, 27 had PSC only opacities, and 364 had mixed lens opacities. Older age, higher hemoglobin A(1c), and history of diabetes mellitus were independent risk factors for cortical only lens opacities. Older age, smoking, and myopic refractive error were independent risk factors for nuclear only lens opacities. Higher systolic blood pressure and history of diabetes were independent risk factors for PSC lens opacities. Older age, myopic refractive error, history of diabetes, higher systolic blood pressure, female gender, and presence of large drusen were independent risk factors for mixed lens opacities.

CONCLUSIONS

The modifiable and non-modifiable risk factors identified in this study provide insight into the mechanisms related to the development of lens opacification. Improved glycemic control, smoking cessation and prevention, and blood pressure control may help to reduce the risk of having lens opacities and their associated vision loss.

Prevalence of common ocular morbidities in adult population of aligarh

AIMS AND OBJECTIVES

To determine the prevalence of common ocular morbidities (cataract, refractive errors, glaucoma, and corneal opacities) and their demographic and sociocultural correlates.

SETTINGS AND DESIGN

The present cross-sectional study was conducted in the field practice areas of the Department of Community Medicine, JNMC, AMU, Aligarh, for a period of one year, from September 2005 to August 2006.

MATERIALS AND METHODS

Systematic random sampling was done to select the required sample size. All adults aged 20 years and above in the selected households were interviewed and screened using a 6/9 illiterate 'E' chart. Those who could not read the 'E' chart were referred to the respective health training center for a complete eye examination by an ophthalmologist.

STATISTICAL ANALYSIS

Chi- square test.

RESULTS

The prevalence of visual impairment, low vision, and blindness, based on presenting visual acuity was 13.0, 7.8, and 5.3%, respectively. The prevalence of cataract was 21.7%. Bilateral cataract was present in 16.9% of the population. Cataract was significantly associated with age, education, and fuel use. The prevalence of myopia, hypermetropia, and astigmatism was 11.5, 9.8, and 3.7%, respectively. Glaucoma was diagnosed in six patients, giving a prevalence rate of 0.9%. All the six patients of glaucoma were aged above 40 years. The prevalence of corneal opacity was 4.2%.

CONCLUSION

There is a high prevalence of treatable or preventable morbidities such as cataract, refractive errors, and corneal opacity.

Prevalence of cataract in an older population in India: the India study of age-related eye disease

Purpose

To describe the prevalence of cataract in older people in 2 areas of north and south India.

Design

Population-based, cross-sectional study.

Participants

Randomly sampled villages were enumerated to identify people aged ≥60 years. Of 7518 enumerated people, 78% participated in a hospital-based ophthalmic examination.

Methods

The examination included visual acuity measurement, dilatation, and anterior and posterior segment examination. Digital images of the lens were taken and graded by type and severity of opacity using the Lens Opacity Classification System III (LOCS III).

Main Outcome Measures

Age- and gender-standardized prevalence of cataract and 95% confidence intervals (CIs). We defined type of cataract based on the LOCS III grade in the worse eye of: ≥4 for nuclear cataract, ≥3 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Any unoperated cataract was based on these criteria or ungradable dense opacities. Any cataract was defined as any unoperated or operated cataract.

Results

The prevalence of unoperated cataract in people aged ≥60 was 58% in north India (95% CI, 56–60) and 53% (95% CI, 51–55) in south India (P = 0.01). Nuclear cataract was the most common type: 48% (95% CI, 46–50) in north India and 38% (95% CI, 37–40) in south India (P<0.0001); corresponding figures for PSC were 21% (95% CI, 20–23) and 17% (95% CI, 16–19; P = 0.003), respectively, and for cortical cataract 7.6% (95% CI, 7–9) and 10.2% (95% CI, 9–11; P<0.004). Bilateral aphakia/pseudophakia was slightly higher in the south (15.5%) than in the north (13.2%; P<0.03). The prevalence of any cataracts was similar in north (73.8%) and south India (71.8%). The prevalence of unoperated cataract increased with age and was higher in women than men (odds ratio [OR], 1.8). Aphakia/pseudophakia was also more common in women, either unilateral (OR, 1.2; P<0.02) or bilateral (OR, 1.3; P<0.002).

Conclusions

We found high rates of unoperated cataract in older people in north and south India. Posterior subcapsular cataract was more common than in western studies. Women had higher rates of cataract, which was not explained by differential access to surgery.

Financial Disclosure(s)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Five-year incidence of age-related cataract and cataract surgery in the adult population of greater Beijing: the Beijing Eye Study

PURPOSE

To estimate the 5-year incidence of cataract and cataract surgery in an adult Chinese population.

DESIGN

Population-based study.

PARTICIPANTS

The Beijing Eye Study 2006 included 3251 (73.2%) subjects (≥45 years) of 4439 subjects who participated in the 2001 survey and returned for re-examination.

METHODS

Nuclear, cortical, and posterior subcapsular lens opacities were assessed based on standardized slit-lamp-based photographs and retroilluminated photographs of the lens using a modification of the grading score of the Age-Related Eye Disease Study.

MAIN OUTCOME MEASURES

Incidence of any type of cataract and of cataract surgery.

RESULTS

The 5-year incidence of nuclear cataract was 5.98% (95% confidence intervals [CI], 5.96%-6.00%), that of cortical cataract was 11.14% (95% CI, 11.12%-11.17%), that of posterior subcapsular cataract was 5.47% (95% CI, 5.45%-5.48%), and that of cataract surgery was 2.01% (95% CI, 2.00%-2.02%). The incidence of any cataract (16.82%; 95% CI, 16.79%-16.86%) was significantly associated with higher age (P<0.001) and female gender (P<0.001). It was not significantly associated with the area of habitation (P = 0.78), smoking (P = 0.95), or alcohol consumption (P = 0.12). Differentiation into the 3 cataract types revealed that the incidence of nuclear cataract additionally was associated with rural region (P<0.001) and smoking (P<0.001). The incidence of cortical cataract additionally was associated with nonsmoking (P = 0.02). The incidence of cataract surgery was significantly (P<0.001) associated with age only.

CONCLUSIONS

As in white persons, the age-adjusted incidence of all types of cataract types increased with age and it was associated with female gender. When compared with data in the literature, the incidence rates of all cataract types did not vary markedly between Chinese in greater Beijing and white persons. In contrast, the incidence of cataract surgery was considerably lower in this Chinese population.

Oxidative damage and the prevention of age-related cataracts

PURPOSE

Cataracts are often considered to be an unavoidable consequence of aging. Oxidative damage is a major cause or consequence of cortical and nuclear cataracts, the most common types of age-related cataracts.

METHODS

In this review, we consider the different risk factors, natural history and etiology of each of the 3 major types of age-related cataract, as well as the potential sources of oxidative injury to the lens and the mechanisms that protect against these insults. The evidence linking different oxidative stresses to the different types of cataracts is critically evaluated.

RESULTS

We conclude from this analysis that the evidence for a causal role of oxidation is strong for nuclear, but substantially lower for cortical and posterior subcapsular cataracts. The preponderance of evidence suggests that exposure to increased levels of molecular oxygen accelerates the age-related opacification of the lens nucleus, leading to nuclear cataract. Factors in the eye that maintain low oxygen partial pressure around the lens are, therefore, important in protecting the lens from nuclear cataract.

CONCLUSIONS

Maintaining or restoring the low oxygen partial pressure around that lens should decrease or prevent nuclear cataracts.

A randomized, double-masked, placebo-controlled clinical trial of multivitamin supplementation for age-related lens opacities. Clinical trial of nutritional supplements and age-related cataract report no. 3

OBJECTIVE

To evaluate the effect of a multivitamin/mineral supplement on development or progression of age-related lens opacities.

DESIGN

Randomized, double-masked, single center, placebo-controlled clinical trial.

PARTICIPANTS

One thousand twenty participants, 55 to 75 years old and with early or no cataract, were randomly assigned to a daily tablet of a multivitamin/mineral formulation or a placebo.

METHODS

Baseline and annual lens photographs were graded for severity of lens opacities according to a modification of the Age-Related Eye Disease Study system for classifying cataracts.

MAIN OUTCOME MEASURES

The primary outcome was a prespecified increase from baseline in nuclear, cortical, or posterior subcapsular cataract (PSC) opacity grades or cataract surgery. Secondary outcomes included an increase in type-specific opacity grades, cataract surgery, and visual acuity (VA) loss from baseline > or =15 letters.

RESULTS

Participants were observed for an average of 9.0+/-2.4 years. There was a decrease in total lens events in participants assigned to the multivitamin/mineral formulation compared with those assigned to the placebo (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.68-0.98; P = 0.03). Nuclear events were significantly less common (HR, 0.66; 95% CI, 0.50-0.88; P = 0.004) and PSC events significantly more common (HR, 2.00; 95% CI, 1.35-2.98; P<0.001) in participants taking the multivitamin/mineral formulation than in those assigned to the placebo. No statistically significant treatment effects were seen for cortical opacities, moderate VA loss, or cataract surgery.

CONCLUSIONS

Lens events were less common in participants who took the multivitamin/mineral formulation, but treatment had opposite effects on the development or progression of nuclear and PSC opacities, the 2 most visually important opacity subtypes.