Higher Prevalence Of Cataract Research Articles

Oestradiol levels and superoxide dismutase activity in age-related cataract: a case-control study.

BackgroundIt has been suggested that the higher prevalence of cataract in women is caused by a withdrawal effect of oestrogen at menopause. In vitro studies have demonstrated protection of serum oestradiol (E2) against oxidative stress through upregulation of antioxidant enzymes, including superoxide dismutase (SOD). The purpose of the present study was to investigate E2 levels and SOD erythrocyte activity in patients with age-related cataract.MethodsThe studied subjects consisted of 103 patients with age-related cataract and 22 controls. Cataracts were classified as nuclear, cortical, or posterior subcapsular. Blood samples were collected and data on smoking, hormonal use, diabetes and age at menarche/menopause was obtained for all individuals. Serum oestradiol analyses were performed with radioimmunoassay (RIA) and SOD activity was measured in erythrocyte lysates.ResultsA negative correlation between age and E2 concentration was seen in a linear regression analysis. No correlation was seen between SOD activity and age or gender and no correlation between E2 levels and SOD activity was found using multiple linear regression. The mean level of E2 for all male subjects was 50.1 ± 16.3 pmol/L, significantly higher compared to 13.8 ± 11.8 pmol/L for postmenopausal women.ConclusionThe present study does not support a role for E2-induced effects on SOD in cataract formation. The findings of higher E2 levels in men than in postmenopausal women may suggest that decreased oestrogen at menopause is partially responsible for the gender-related difference in cataract prevalence. However, the latter can only be verified through prospective randomized trials using hormonal replacement therapy.

Prevalence of Age-Related Cataract and Cataract Surgery in a Chinese Adult Population: The Taizhou Eye Study.

To study the prevalence of age-related cataract (ARC), cataract surgery, and visual outcomes in a Chinese adult population in Taizhou, China. A population-based, cross-sectional study was conducted using a random cluster sampling method. We evaluated 10,234 eligible subjects 45 years or older (response rate 78.1%) in the Taizhou Eye Study. We conducted a detailed eye examination in all participants, including presenting visual acuity (PVA), best-corrected visual acuity (BCVA), slit-lamp assessment of lens opacities using the Lens Opacities Classification System III (LOCS III), and fundus examination. The standardized prevalences of cortical, nuclear, and posterior subcapsular cataract (PSC) were 28.6%, 24.3%, and 4.4%, respectively, and combined nuclear and cortical cataract was the most common cataract type (40.0%). According to the US visual impairment (VI) criteria and World Health Organization VI criteria, 40.6% and 21.8% of PSC participants had binocular VI, respectively; these values were higher than the VI rates in cortical and nuclear cataract (all P < 0.001). Of 148 patients (3.5%) who had cataract surgeries, 41.2% had PVA <20/63, and 19.6% had PVA <20/200. The main causes of poor visual outcome after cataract surgery were ocular comorbidities (41.3%), uncorrected refractive error (30.0%), surgical complications (15.0%), and posterior capsular opacification (PCO; 13.7%). The high prevalence of cataract and high rate of VI from ARC in the adult Chinese population remains a severe public health problem. Cataract surgery remains insufficient in mainland China and poor visual outcomes were frequent. Surgical complications and PCO were important avoidable causes that attributed to poor visual outcomes after cataract surgeries.

Long-Term Visual Prognosis of Peripheral Multifocal Chorioretinitis

To report on the clinical manifestations, complications, and long-term visual prognosis of patients with peripheral multifocal chorioretinitis and to search for predictors for a lower visual outcome. Retrospective consecutive observational case series. setting: Institutional. 134 eyes in 69 patients with a minimum follow-up period of 5 years. Clinical characteristics were recorded as well as the visual acuity (VA) at the onset of uveitis; after 1, 5, and 10 years; and at the end of the follow-up period. Visual acuity, clinical features and complications, required medications and surgeries. The majority of the patients were elderly women with chronic bilateral ocular involvement, who developed multiple ocular complications over time. Systemic sarcoidosis was present in 39% of patients. In addition to peripheral retinal lesions and vitritis, papillitis was present in 95% of cases. The major complications included macular edema (91%), cataract (93%), glaucoma (35%), and optic disc atrophy (25%). The treatment regimens included systemic corticosteroids and/or immunosuppressive drugs in 44% of patients, and 84% of patients required intraocular surgery. One third of the affected eyes developed VA <20/40 at 5-10 years of follow-up. VA at 1 year was the most important predictor of visual outcome at 5 and 10 years (P< .001). Peripheral multifocal chorioretinitis was associated with a high prevalence of cataract, macular edema, optic disc atrophy, and glaucoma. Despite the chronic course of the disease, multiple complications, and surgical interventions, the majority of patients achieved satisfactory long-term visual acuity.

On-Set of Cataract and Accumulation of Copper, Lead and Cadmium in Smokers of Karachi, Pakistan

Background: High prevalence of cataract especially in women, children and urban dwellers and associated blindness is a major problem of Pakistan and low and middle income countries. Prevalence of tobacco use is also very high in Pakistan. The aim of study was to identify association between cigarette smoking and development of cataract in people of Karachi and to determine effect of Lead, Cadmium and Copper in progression of Cataract Material and methods: 100 Cataract Patients including Smokers and Non-Smokers visiting LRBT Hospital. Karachi was selected randomly. After Surgical Removal, their lenses were analyzed for Cadmium, Lead and Copper Concentration by Atomic Absorption Spectrometer at Pakistan Council of Scientific and Industrial Research Results: Concentration of Cadmium, Lead and Copper were found to be significantly higher among Lenses of Smokers than Non-Smokers. Conclusion: Cataract development occurred earlier in heavy smokers with mean age 48.24 years as compared to non-smokers mean age 55.72 years along-with increased accumulation of Cadmium, Lead and Copper in their lenses. The result shows an association between Cigarette Smoking and progression of Cataract

High prevalence of cataracts in birds with pheomelanin-based colouration

The crystalline lens of the eyes of vertebrates focuses light on the retina. Therefore, maintaining the lens clear is necessary for proper visual function. However, oxidative damage to proteins of the lens leads to opacification and lens dysfunction, termed cataract. Antioxidants thus have a role in avoiding the development of cataracts through their reduction of oxidative stress, and glutathione (GSH), a key intracellular antioxidant, belongs to the primary antioxidant defence mechanism of the lens. Other physiological mechanisms that require GSH may compete with the antioxidant mechanism of the eye. Pheomelanin is a main type of melanin, the most common pigment in vertebrates, and its synthesis consumes GSH. Here, we use data on 81 bird species to test the hypothesis that species producing large amounts of pheomelanin should have diminished capacity to use GSH to protect their eyes and, as a consequence, higher prevalence of cataracts. As predicted, the proportion of pheomelanic plumage was positively associated with the proportion of individuals with cataracts across species, suggesting that production of pheomelanin may have profound fitness consequences, as birds with cataracts have limited ability to perform vital activities. This constitutes the first comparative study of cataracts in wild animals.

Simulated Visual Impairment Leads to Cognitive Slowing in Older Adults

To investigate the impact of different levels of simulated visual impairment on the cognitive test performance of older adults and to compare this with previous findings in younger adults. Cognitive performance was assessed in 30 visually normal, community-dwelling older adults (mean = 70.2 ± 3.9 years). Four standard cognitive tests were used including the Digit Symbol Substitution Test, Trail Making Tests A and B, and the Stroop Color Word Test under three visual conditions: normal baseline vision and two levels of cataract simulating filters (Vistech), which were administered in a random order. Distance high-contrast visual acuity and Pelli-Robson letter contrast sensitivity were also assessed for all three visual conditions. Simulated cataract significantly impaired performance across all cognitive test performance measures. In addition, the impact of simulated cataract was significantly greater in this older cohort than in a younger cohort previously investigated. Individual differences in contrast sensitivity better predicted cognitive test performance than did visual acuity. Visual impairment can lead to slowing of cognitive performance in older adults; these effects are greater than those observed in younger participants. This has important implications for neuropsychological testing of older populations who have a high prevalence of cataract.

A Balanced Diet?: Selenium May Offset the Effects of Methylmercury on Cataract Development

Dietary exposure to mercury from fish has been posited as a risk factor for cataracts because some reports have suggested methylmercury accumulates in the lens of the eye. But selenium from other dietary sources may offset that damage, according to a study of communities in the Amazon basin [EHP 118(11):1584–1589; Lemire et al.]. The findings, while preliminary, hint at potential public health measures in areas where methylmercury-contaminated fish are a significant part of people’s diets. With old age comes cataracts, particularly in latitudes like the Amazon, where higher ultraviolet radiation exposure and other environmental factors contribute to the clouding of the lenses in human eyes. And while surgical fixes exist for cataracts, people in isolated regions may not always have access to those options. Cataracts therefore are a major cause of blindness among older people in the Amazon. The current study involved communities that eat fish from the Tapajos River, a tributary of the Amazon. People here have among the highest reported exposures to mercury in the world. Deforestation in the region leads to the release of natural inorganic mercury from soils into surface waters, where it is methylated and eventually ends up in fish. Several hundred people voluntarily participated in the study, which entailed taking an overnight boat trip to a nearby city where participants gave blood samples and were examined by optometrists. In the end, 211 people over age 40 were included in the analysis. A third of them had age-related cataracts. Low plasma selenium and high blood mercury each were associated with a higher prevalence of cataracts (over 2 and 4 times higher, respectively). The team calculated that the people with both low plasma selenium and high blood mercury were 16 times more likely to develop cataracts than the “optimum situation” group, which had both high plasma selenium and low blood mercury. This is the first study known to associate high levels of methylmercury from fish consumption with increased occurrence of cataracts. The authors emphasize that other factors—such as differences in dietary intakes of antioxidants and vitamins—could confound their findings. Still, if the observed associations hold true in broader studies, public health interventions to alleviate cataracts in this Amazonian population must consider both the health benefits of fish consumption and the risks of the main source of dietary selenium in the region: brazil nuts, which also contain barium and strontium, heavy metals with their own hazards.

Gender inequality in vision loss and eye diseases: Evidence from the Sultanate of Oman

Purpose:The data from surveys of vision loss and monitoring of services were used to assess changes in gender inequality in Oman.Study Design:Retrospective review of data collection instruments.Materials and Method:The data sets of 12 years between 1996 and 2007 were abstracted to assess the gender equality for vision loss, eye disease prevalence, and service use. They included two surveys (1996 and 2005), Health Information from eye units (1998 and 2007), and eye screening in schools.Results:In 1996, the prevalence of bilateral blindness in ≥ 40 years of age was higher in females [Odd's Ratio (OR) = 0.36 (95% Confidence Interval (CI) 0.24 – 0.53)]. Gender differences in the prevalence of cataract [OR = 0.82 (95% CI 0.63 – 1.03)] were not significant while trachomatous trichaisis (TT) was less in males [OR = 0.33 (95% CI 0.22-0.48)]. In 2005, gender differences in the prevalence of bilateral blindness [OR = 0.97 (95% CI 0.71 – 1.34)] and TT [OR = 0.66 (95% CI 0.42- 1.04)] were not statistically significant. But males were associated with higher prevalence of cataract [OR = 1.26 (95% CI 1.00 – 1.59)]. Surgery rates for cataract, glaucoma and TT were not different by gender. More male compared to female patients with diabetic retinopathy were treated. Myopia was significantly higher in girls. Compliance of spectacle wear was higher in girls.Conclusions:Gender inequality for eye care seems to have reduced in the last 10 years in Oman. However, apart from TT and glaucoma patients the difference in service utilization by gender was not statistically significant.

Cataract and type 1 diabetes mellitus

Aims To evaluate the prevalence of cataract and the possible factors associated with cataract in young type 1 diabetes mellitus (DM). Methods 293 patients were evaluated. The association of cataract with diabetic retinopathy (DR), retinal laser treatment, hypertension, body mass index, peripheral neuropathy, lipid profile, glycemic control, serum creatinine and albuminuria was evaluated. Results Cataract was present in 19.8% ( n = 58) of the sample. Patients with cataracts were older, had a higher frequency of history of retina photocoagulation treatment, higher serum creatinine values and higher prevalence of arterial hypertension. There was a progressive increase in cataract frequency according to the number of risk factors, starting to rise with two or more. In logistic regression model cataract was associated with mild/moderate DR (odd ratio (OR) 4.28 95% CI 1.63–11.29), severe DR (OR 4.07 95% CI 1.63–10.23) and macroalbuminuria (OR 2.34 95% CI 1.06–5.16). Conclusion These data indicate a high prevalence of cataract in subjects with type 1 DM attending a general hospital in Southern Brazil and suggest that the more severe the disease process the greater is the risk of having this diabetic complication. Cataract should be suspected in young patients with two or more risk factors.

Risk factors for cataract in India: the INDEYE study

Abstract Purpose To describe the prevalence of lens opacities and to assess risk factors in older people in India. Methods People aged 60 years and older identified using random cluster‐sampling in 2 study centres in north and south India, attended an eye examination. Digital images of lens opacities were graded using the Lens Opacity Classification System III. To identify lifestyle and environmental factors associated with lens opacities, assessment of different potential risk factors was performed, with a focus on cooking fuels, tobacco and alcohol use, sunlight exposure, diet and antioxidant blood levels. Results 2821 people in north India and 3079 in south India attended an eye examination. The prevalence of any cataract was 73.6% and similar in the two centres (p=0.2). Type of cataract differed in prevalence between the centres: nuclear 60.0% in north India, 48.0% in south India; posterior subcapsular 26.5% in north India, 21.7% in south India; cortical 9.6% in north India and 12.8 % in south India. Prevalence of any cataract rose with age (54.9%, age group 60‐64 years; 90.3%, age group 70 years and older, p&lt;0.001) and was higher in women than in men (76.7%, women; 70.1%, men, p&lt;0.001). Similar patterns with age and gender were observed for each type of cataract. Among risk factors, tobacco use, exposure to cooking fuels and antioxidants levels were significantly associated with cataract (p&lt;0.001). Conclusion Cataract prevalence, especially posterior subcapsular cataract, is very high in older Indians compared to comparable age groups in western populations. Factors as tobacco use, exposure to cooking fuels and low antioxidant blood levels may in part explain the high prevalence of cataract in this population.

Prevalence and predictors of ocular manifestations of RA: is there a need for routine screening?

People with rheumatoid arthritis (RA) have an increased risk for eye problems caused by associated conditions or medication side-effects. Consequent visual impairment may increase the risk of falls or difficulties self-administering medications. The aim of the present study was to estimate the prevalence and predictors of ocular manifestations and visual impairment in a local sample of people with RA. The Visual Functioning Questionnaire (VFQ-25) was evaluated as a screening tool in people with RA. Seventy-five participants with RA attended a visual screening clinic. Demographic, medication and disease characteristics were recorded, a full ophthalmological assessment was performed by an expert ophthalmologist and the VFQ-25, Health Assessment Questionnaire and Self-administered Comorbidity Questionnaire were completed. Twenty-nine participants (38.7%) had impaired visual acuity; this was correctable by appropriate refraction in 93.1%. The prevalence of cataracts was 22.7% and this was predicted by older age and steroid use. An abnormal Schirmer's test, suggesting dry eyes, was seen in 70.7% of participants but only 12.0% were using artificial tears. Answers to the VFQ-25 suggested misinterpretation of questions as relating to disability attributed to arthritis rather than caused by visual impairment. Visual impairment does not appear to be particularly prevalent in RA, obviating the need for a screening programme. Utilization of the VFQ-25 as a screening tool in RA requires further consideration. The high prevalence of cataracts in participants on steroids emphasizes the need to prescribe the minimum required dose. The high prevalence of dry eyes suggests that a Schirmer's test should be performed regularly, with prescription of artificial tears if required.

Axial Length: A Risk Factor for Cataractogenesis

To evaluate whether eyes with longer axial lengths are associated more often with clinically significant cataracts than eyes with shorter axial lengths. Charts of consecutive patients who underwent cataract surgery by 4 resident surgeons at Los Angeles County Hospital from July 2001 through May 2002 were retrospectively reviewed. Those patients whose axial lengths were significantly different between the 2 eyes (>or=0.30 mm) and who had no pathology (other than cataracts) affecting visual acuity were included in the study. The 2 eyes in each patient were compared for preoperative best-corrected visual acuity and severity of cataracts. Thirty-four of 353 patients had interocular axial length differences of at least 0.3 mm and were included in this study. Thirty-one patients had worse, 1 had equal, and 2 had better preoperative vision in the eye with longer versus the shorter axial length. Fourteen patients had more severe, 11 had the same, and 1 had less severe posterior subcapsular cataract (PSC) in the eye with longer axial length. In 8 patients, PSC severity could not be assessed due to obscuring nuclear sclerosis. Twenty-four patients had more severe, 7 patients had equal, and 3 patients had less severe nuclear sclerosis in the longer eye. Overall, longer axial lengths correlated with worse visual acuity, posterior subcapsular cataracts, and nuclear sclerosis. Diabetic status did not affect the correlation. The correlations were stronger with greater axial length asymmetry. Eyes with longer axial lengths have a higher prevalence of cataracts.

Model of Risk of Cortical Cataract in the US Population with Exposure to Increased Ultraviolet Radiation due to Stratospheric Ozone Depletion

The authors modeled the possible consequences for US cataract incidence of increases in ultraviolet B radiation due to ozone depletion. Data on the dose-response relation between ocular exposure to ultraviolet B radiation and cortical cataract were derived from a population-based study (the Salisbury Eye Evaluation Project, Salisbury, Maryland) in which extensive data on cataract and ultraviolet radiation were collected in persons aged 65-84 years. Exposure estimates for the US population were derived using estimated ultraviolet radiation fluxes as a function of wavelength. US Census data were used to obtain the age, ethnicity, and sex distribution of the population. Predicted probabilities of cataract were derived from the age-, sex-, and ethnicity-specific ocular ultraviolet exposure data and were modeled under conditions of 5-20% ozone depletion. The analysis indicated that by 2050, the prevalence of cortical cataract will increase above expected levels by 1.3-6.9%. The authors estimate that with 5-20% ozone depletion, there will be 167,000-830,000 additional cases of cortical cataract by 2050. Because of the high prevalence of cataract in older persons, at a 2003 cost of 3,370 dollars per cataract operation, this increase could represent an excess cost of 563 million dollars to 2.8 billion dollars.

Cataract preventative role of mammalian blood meal, histidine, iron and zinc in diets for Atlantic salmon (Salmo salarL.) of different strains

In the period from winter 1996 to autumn 1999, three feeding trials were conducted to study the possible role of mammalian blood meal in preventing lens opacities in Atlantic salmon. In addition to blood meal supplemented feed, experimental diets were formulated, aiming to mimic the total concentrations of selected elements present in blood meal (BM) enriched diets; the amino acid histidine (His) and the mineral iron (Fe). In addition, these diets were supplemented with Zn. The trials included different rearing conditions, sizes and strains of Atlantic salmon; one small scale feeding experiment with pre-smolt of Strain A in fresh water (Trial 1) and two semi large trials with sub-yearling (S0s) and yearling (S1s) smolts of Strains A and B in seawater (Trials 2 and 3). The trials included duplicate or triplicate feeding groups and lasted 6–12 months. Standard commercial diets not supplemented with BM were used as controls. High prevalence of cataract developed over time in all three studies, with end point ranges as follows; Trial 1: 40–52 %; Trial 2: 51–83 %; Trial 3: 63–100%. The cataracts normally first appeared in the anterior and/or posterior cortical region and later affected the perinuclear region. In all the experiments, there was a significant cataract preventative effect of both the BM supplemented and experimental diets compared to the respective control diets. To some extent, cataract incidence was reduced, but primarily cataractogenesis was less severe in these groups. A concurrent positive effect on growth of both added BM and experimental diets was observed in the two seawater trials, probably related to maintaining vision and feed uptake ability. In one of the trials, there were significant differences in cataract susceptibility between the two strains, measured both as frequency and severity of cataractous changes. Our data suggest that elevated concentrations of dietary His and/or Fe mitigate cataract formation.

Epidemiologic study of age-related cataracts among an elderly chinese population in Shih-Pai, Taiwan

Purpose The purpose of this study was to determine the prevalence and risk factors for age-related cataracts in a metropolitan elderly Chinese population in Shihpai, Taipei, Taiwan. Design Population-based cross-sectional study. Participants A total of 2045 subjects at least 65 years of age were invited to participate, and 1361 (66.6%) participated in the survey. Methods An eye examination, including lens opacity grading, was conducted by ophthalmologists using the Lens Opacity Classification System III (LOCS III). A structured questionnaire was used for data collection. Interviewers also collected information on subjects’ blood pressure, lifestyle (cigarette smoking and alcohol intake), medical history, and waist and hip circumferences. Main outcome measures Subjects were defined as having age-related cataracts if there was any type of lens opacity with an LOCS III grade of more than 2 in one or both eyes. When both eyes of an individual had age-related cataracts, the more affected eye was used for analysis. Results Among the 1361 participants, 806 were diagnosed with age-related cataracts. The prevalence was 59.2% (95% confidence interval, 56.6%–61.8%). Women had a higher prevalence of cataracts than men (64.0% vs. 56.1%, P = 0.004). The prevalence of age-related cataracts increased with age ( P = 0.001). Nuclear opacity was the most prevalent type (38.9%), followed by cortical opacity (21.9%) and posterior subcapsular opacity (9.2%). On the basis of the final logistic regression model, after controlling for all other covariates, increased age and female gender were factors that were associated with an increased risk for all types of cataracts. Besides age and gender, the most significant risk factor for nuclear cataracts was current cigarette smoking; the significant predictors for cortical cataracts were higher systolic blood pressure, a history of cigarette smoking in the past, and history of diabetes; the significant predictor for posterior subcapsular cataracts was higher systolic blood pressure. Conclusions The increasing prevalence of age-related cataracts with age highlights the need to seek appropriate medical services and for preventative interventions. Elderly people often ignore the importance of seeking vision services and care to prevent blindness or visual impairment. These findings suggest that the elderly need to be educated regarding the importance of eye care by physicians and hygiene authorities in Taiwan.

Ultraviolet Radiation and Cataract—A Review

Senile cataract has become a serious public health problem as the elderly population is increasing worldwide. As lens with dark iris is reported to have a higher prevalence of cataract, public health concern about cataract in Asia is a bigger issue. Among factors assumed to be involved in the pathogenesis of cataract, ultraviolet radiation (UV) has received much attention in accordance with the recent problem of ozone column depletion. It has been agreed that UV induces cataract in animal and biochemical experiments. However, in epidemiological studies, such agreement has not been reached. There are many factors that should be considered and controlled when investigating the association between cataract and UV. In this review, we summarize major findings obtained so far on the relationship between UV and cataract, and we discuss important factors that may be the cause of disagreement in epidemiological studies. We also point out some of the research foci which should be clarified and propose protective measures against UV induced cataract.

Carbamylation of lens proteins: A possible factor in cataractogenesis in some tropical countries

It has been suggested that severe and repeated diarrhoea may be a major factor in cataracto-genesis in some tropical countries and account for the high prevalence of cataract in these countries. At least four effects of the diarrhoeal syndrome could lead to cataract and one of these is the high concentration of urea in the blood. Urea comes to equilibrium with cyanate and in this paper we investigate the reaction of cyanate with lens proteins and report preliminary evidence that carbamylation has occurred during cataractogenesis in Pakistan.