Environmental and industrial developments in radiation cataractogenesis.

PURPOSE: This review discusses recent developments in our understanding of biological and physiological mechanisms underlying radiation cataractogenesis. The areas discussed include effects of low-dose exposures to the lens including potential relevance of non-targeted effects, the development of new personal-protective equipment (PPE) and standards in clinical and nuclear settings motivated by the updated ICRP recommendations to mitigate exposures to the lens of the eye. The review also looks at evidence from the field linking cataracts in birds and mammals to low dose exposures. CONCLUSIONS: The review suggests that there is evidence that cataractogenesis is not a tissue reaction (deterministic effect) but rather is a low dose effect which shows a saturable dose response relationship similar to that seen for non-targeted effects in general. The review concludes that new research is needed to determine the dose response relationship in environmental studies where field data are contradictory and lab studies confined to rodent models for human exposure studies.

Fatty acids modulate the efficacy of lutein in cataract prevention: Assessment of oxidative and inflammatory parameters in rats.

BACKGROUND: Effects of lutein (L) and fatty acids [linoleic acid (LA), eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) and oleic acid (OA)] on oxidative stress and inflammation in cataract were assessed. METHODS: Cataract was induced in male Wistar rat pups (11 days old) by giving a single dose of sodium selenite (25 µM/kg body weight) by IP. Lutein (1.3 µmol/kg body weight) was given one day before and five days after selenite injection as a micelle with 7.5 mM LA, or 7.5 mM EPA + DHA or 7.5 mM OA. Serum and lens oxidative stress and inflammatory parameters having a bearing cataract were assessed. RESULTS: Serum and lens nitric oxide, MDA and protein carbonyls were significantly (p < 0.05) increased in cataract compared to control and experimental groups. Catalase, SOD, glutathione peroxidase and glutathione transferase activity and glutathione level in serum and lens of cataract group were significantly (p < 0.05) decreased. Serum eicosanoids (PGE2, LTB4, and LTC4) and cytokines (CRP, TNF-α, IL1-ß, and MCP-1) were significantly (p < 0.05) increased in cataract. The activity of cPLA2 and Cox-2 in cataract lens was higher (p < 0.05) compared to other groups. EP-1, NOS-2 and NF-kB expression were higher (p < 0.05) in cataract. The ratio of water insoluble to water soluble protein was increased in cataract lens. Group administered with L + EPA + DHA exhibited highest cataract prevention compared to L + LA and L + OA. Pups given lutein with EPA + DHA had the highest amount of lutein in the lens. CONCLUSIONS: The anti-cataract activity of lutein was influenced by fatty acids and found to be highest with EPA + DHA compared to LA or OA.

Assessment of Levels of Ultraviolet A Light Protection in Automobile Windshields and Side Windows.

IMPORTANCE: Ultraviolet A (UV-A) light is associated with the risks of cataract and skin cancer. OBJECTIVE: To assess the level of UV-A light protection in the front windshields and side windows of automobiles. DESIGN: In this cross-sectional study, 29 automobiles from 15 automobile manufacturers were analyzed. The outside ambient UV-A radiation, along with UV-A radiation behind the front windshield and behind the driver's side window of all automobiles, was measured. The years of the automobiles ranged from 1990 to 2014, with an average year of 2010. The automobile dealerships were located in Los Angeles, California. MAIN OUTCOMES AND MEASURES: Amount of UV-A blockage from windshields and side windows. The average percentage of front-windshield UV-A blockage was 96% (range, 95%-98% [95% CI, 95.7%-96.3%]) and was higher than the average percentage of side-window blockage, which was 71% (range, 44%-96% [95% CI, 66.4%-75.6%]). The difference between these average percentages is 25% (95% CI, 21%-30% [P < .001]). A high level of side-window UV-A blockage (>90%) was found in 4 of 29 automobiles (13.8%). CONCLUSIONS AND RELEVANCE: The level of front-windshield UV-A protection was consistently high among automobiles. The level of side-window UV-A protection was lower and highly variable. These results may in part explain the reported increased rates of cataract in left eyes and left-sided facial skin cancer. Automakers may wish to consider increasing the degree of UV-A protection in the side windows of automobiles.

[Avoidable loss of vision in a global perspective]. / Undgåeligt synstab i et globalt perspektiv.

WHO estimates that in 2010 there were 39 million blind people and 246 million living with moderate to severe vision impairment globally. 90% of the disease burden is found in developing countries, and most of it is due to preventable or treatable eye conditions. Many of these, such as uncorrected refractive errors, can be prevented with the integration of simple primary health measures. However, as a result of an ageing population, the prevalence of chronic diseases such as diabetic retinopathy and age-related macular degeneration is on the rise. This calls for more focus on specialized treatment.

Cataracts.

Cataract surgery with an intraocular lens implant is one of the most common and thought to be the most effective surgical procedure in any field of medicine. Although aging is the most common cause, other factors are also known to be associated with cataract formation. Although cataracts are the domain of ophthalmology, primary care physicians are frequently the ones to whom patients present with vision complaints. Knowledge of cataract symptoms, how to evaluate them, and a basic understanding of the surgery to correct cataracts make primary care physicians an integral part of treating this leading cause of preventable blindness.

Development and validation of a cost-utility model for Type 1 diabetes mellitus.

AIMS: To develop a health economic model to evaluate the cost-effectiveness of new interventions for Type 1 diabetes mellitus by their effects on long-term complications (measured through mean HbA1c ) while capturing the impact of treatment on hypoglycaemic events. METHODS: Through a systematic review, we identified complications associated with Type 1 diabetes mellitus and data describing the long-term incidence of these complications. An individual patient simulation model was developed and included the following complications: cardiovascular disease, peripheral neuropathy, microalbuminuria, end-stage renal disease, proliferative retinopathy, ketoacidosis, cataract, hypoglycemia and adverse birth outcomes. Risk equations were developed from published cumulative incidence data and hazard ratios for the effect of HbA1c , age and duration of diabetes. We validated the model by comparing model predictions with observed outcomes from studies used to build the model (internal validation) and from other published data (external validation). We performed illustrative analyses for typical patient cohorts and a hypothetical intervention. RESULTS: Model predictions were within 2% of expected values in the internal validation and within 8% of observed values in the external validation (percentages represent absolute differences in the cumulative incidence). CONCLUSIONS: The model utilized high-quality, recent data specific to people with Type 1 diabetes mellitus. In the model validation, results deviated less than 8% from expected values.

Multi-resolution voxel phantom modeling: a high-resolution eye model for computational dosimetry.

Voxel models of the human body are commonly used for simulating radiation dose with a Monte Carlo radiation transport code. Due to memory limitations, the voxel resolution of these computational phantoms is typically too large to accurately represent the dimensions of small features such as the eye. Recently reduced recommended dose limits to the lens of the eye, which is a radiosensitive tissue with a significant concern for cataract formation, has lent increased importance to understanding the dose to this tissue. A high-resolution eye model is constructed using physiological data for the dimensions of radiosensitive tissues, and combined with an existing set of whole-body models to form a multi-resolution voxel phantom, which is used with the MCNPX code to calculate radiation dose from various exposure types. This phantom provides an accurate representation of the radiation transport through the structures of the eye. Two alternate methods of including a high-resolution eye model within an existing whole-body model are developed. The accuracy and performance of each method is compared against existing computational phantoms.

Vision insurance, eye care visits, and vision impairment among working-age adults in the United States.

OBJECTIVES: To compare rates of eye care visits and vision impairment among working-age adults with vision insurance vs without, among the total sample of Behavioral Risk Factor Surveillance Survey respondents and among a subsample of respondents who had diagnoses of glaucoma, age-related macular degeneration (ARMD), and/or cataract. DESIGN: Using the Behavioral Risk Factor Surveillance Survey 2008 vision module data, we examined the likelihood of an eye care visit within the past year and of self reported visual impairment among 27 152 adults aged 40 to 65 years and among a subset of 3158 persons (11.6%) with glaucoma, ARMD, and/or cataract. Multivariate logistic regression models were used. RESULTS: About 40% of both the study population and the subsample with glaucoma, ARMD, and/or cataract had no vision insurance. Respondents with vision insurance were more likely than those without to have had eye care visits (general population adjusted odds ratio [AOR], 1.90 [95% CI, 1.89-1.90]; glaucoma-ARMD-cataract subsample AOR, 2.15 [95% CI, 2.13-2.17]), to have no difficulty recognizing friends across the street (general population AOR, 1.24 [95% CI, 1.22-1.26]; eye-disease subsample AOR, 1.45 [95% CI, 1.42-1.49]), and to have no difficulty reading printed matter (general population AOR, 1.34 [95% CI, 1.33-1.35]; eye-disease subsample AOR, 1.37 [95% CI, 1.34-1.39]). Respondents from the total sample who had an eye care visit were better able to recognize friends across the street (AOR, 1.07) and had no difficulty reading printed matter (AOR, 1.70), and respondents from the eye-disease subsample who had an eye care visit also were better able to recognize friends across the street (AOR, 1.71) and had no difficulty reading printed matter (AOR, 1.45). CONCLUSIONS: Lack of vision insurance impedes eye care utilization, which, in turn, may irrevocably affect vision. Vision insurance for preventive eye care should cease to be a separate insurance benefit and should be mandatory in all health plans.

Evaluation of pharmacological activities and assessment of intraocular penetration of an ayurvedic polyherbal eye drop (Itone™) in experimental models.

BACKGROUND: The polyherbal eye drop (Itone™) is a mixture of aqueous distillates of nineteen traditionally used ingredients that sum up to impart potency to the formulation and make it a useful adjunct in various ocular pathologies. However, as there have been no controlled experimental studies accounting to the above claim, therefore, the present study was designed to evaluate the polyherbal formulation (PHF) for antiangiogenic, anti-inflammatory, anticataract, antioxidant and cytotoxicity in addition to the evaluation of intraocular penetration of PHF in rabbit eyes using LC-MS/MS. MATERIALS AND METHODS: Antiangiogenic activity of the PHF was evaluated using in ovo chick chorio-allantoic membrane (CAM) assay and in vivo cautery induced corneal neovascularization assay in rats. Anticataract potential was evaluated using steroid induced cataract in developing chick embryos, sodium selenite induced cataract in rat pups and galactose induced cataract in rats. The antioxidant activity was evaluated using di-phenyl picryl hydrazyl (DPPH) radical scavenging assay. Anti-inflammatory activity was evaluated in vitro using inhibition of LTB4 formation in human WBCs and in vivo using carrageenan induced paw edema assay in rats. The cytotoxicity was evaluated against HeLa cancer cell lines using (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore evaluation of the intraocular penetration of the PHF was carried out in rabbit eyes via aqueous humor paracentesis and further analysis using LC-MS/MS. RESULTS: PHF significantly inhibited VEGF induced proliferation of new blood vessels in CAM assay and inhibited the cautery induced corneal neovascularization in rats. Additionally, PHF showed noticeable delay in the progression of cataract in the selenite and galactose induced cataract models whereby the PHF treated lenses were graded for stages II and III respectively. However, the PHF did not show any anticataract activity in the hydrocortisone induced cataract model. Moreover, PHF exhibited anti-inflammatory activity whereby it showed 39.34% inhibition of LTB4 formation and significantly inhibited carrageenan induced paw edema in rats. Eight compounds of PHF viz. camphor, casticin, curcumin-II, quercetin, rosmarinic acid, γ-terpinene, ß-pinene and dipentene exhibited transcorneal penetration in rabbit eyes. CONCLUSION: The significant antiangiogenic and anti-inflammatory activities evinced by the PHF merits further investigation for ocular neovascular and inflammatory diseases in humans.

Eye conditions and blindness in children: priorities for research, programs, and policy with a focus on childhood cataract.

The major causes of blindness in children encompass intrauterine and acquired infectious diseases, teratogens and developmental and molecular genetics, nutritional factors, the consequences of preterm birth, and tumors. A multidisciplinary approach is therefore needed. In terms of the major avoidable causes (i.e., those that can be prevented or treated) the available evidence shows that these vary in importance from country to country, as well as over time. This is because the underlying causes closely reflect socioeconomic development and the social determinants of health, as well as the provision of preventive and therapeutic programs and services from the community through to tertiary levels of care. The control of blindness in children therefore requires not only strategies that reflect the local epidemiology and the needs and priorities of communities, but also a well functioning, accessible health system which operates within an enabling and conducive policy environment. In this article we use cataract in children as an example and make the case for health financing systems that do not lead to 'catastrophic health expenditure' for affected families, and the integration of eye health for children into those elements of the health system that work closely with mothers and their children.

Dose conversion coefficients for neutron exposure to the lens of the human eye.

Dose conversion coefficients for the lens of the human eye have been calculated for neutron exposure at energies from 1 × 10(-9) to 20 MeV and several standard orientations: anterior-to-posterior, rotational and right lateral. MCNPX version 2.6.0, a Monte Carlo-based particle transport package, was used to determine the energy deposited in the lens of the eye. The human eyeball model was updated by partitioning the lens into sensitive and insensitive volumes as the anterior portion (sensitive volume) of the lens being more radiosensitive and prone to cataract formation. The updated eye model was used with the adult UF-ORNL mathematical phantom in the MCNPX transport calculations.

Recent statin use and cataract surgery.

PURPOSE: To investigate whether the statin class of drugs reduces the risk of cataract extraction. DESIGN: Case-control study. METHOD: setting: Kaiser Permanente Southern California, which provides prepaid healthcare for 3.2 million residents by 6000 physicians. patient population: Eligible patients were those who had 5+ years of continuous enrollment in 2009. Cases were 13 982 patients who underwent cataract surgery in their first eye in 2009. Controls were the 34 049 patients who had an eye examination, but did not undergo cataract surgery or have a diagnosis of cataract in their medical record. observation procedure: The primary source of data to assess cataract surgery, treatment with statins, and other risk factors is the electronic database of Kaiser Permanente. main outcome measure: Use of the statin class of drug. RESULTS: Patients who had cataract surgery were older, were more likely to be white, and appeared to have more coronary artery disease but less diabetes. The proportion of statin users appeared to be greater among those with cataract surgery (64.3%) compared to those without a diagnosis of cataract or cataract surgery (55.5%). After adjustment for age, sex, race, smoking status, diabetes, and coronary artery disease, longer-term statin use was found to be protective against cataract extraction (OR: 0.93, P = .02), while shorter-term use was associated with cataract surgery (OR: 1.11, P < .0001). Age-stratified logistic regression analysis showed that statin use of 5 years or more was protective against cataract surgery in the younger age group (50-64 years), while shorter-term use (<5 years) was associated with an increased risk of surgery in both the younger and older age groups (60+ years). CONCLUSION: The current study finds that recent longer-tem statin use was protective against cataract surgery in younger patients (50-64 years of age), while shorter-term use was associated with an increased risk of surgery. One strength of the current study is information on the large number of incident cases of cataract extraction and the electronic database on drug use. Additional studies will be needed to understand the difference in effect between longer- and shorter-term users of statins.

Analyses of cataract surgery performed by the Unified Health System in Brazil, 2006-2007.

OBJECTIVE: Estimate cataract surgical rates (CSR) for Brazil and each federal unit in 2006 and 2007 based on the number of surgeries performed by the Unified Health System to help plan a comprehensive ophthalmology network in order to eliminate cataract blindness in compliance with the target set by the World Health Organization (WHO) of 3,000 cataract surgeries per million inhabitants per year. METHODS: This descriptive study calculates CSR by using the number of cataract surgeries carried out by the Brazilian Unified Health System for each federal unit and estimates the need for cataract surgery in Brazil for 2006-2007, with official population data provided by the Brazilian Institute of Geography and Statistics. The number of cataract surgeries was compared with the WHO target. RESULTS: To reach the WHO goal for eliminating age-related cataract blindness in Brazil, 560,312 cataract surgeries in 2006 and 568,006 surgeries in 2007 needed to be done. In 2006, 179,121 cataract surgeries were done by the Unified Health System, corresponding to a CSR of 959 per million population; in 2007, 223,317 were performed, with a CSR of 1,179. With the Brazilian Council of Ophthalmology estimation of 165,000 surgeries each year by the non-public services, the CSR for Brazil would be 1,842 for 2006 and 2,051 for 2007. The proportions needed to achieve the proposed target were 38.6% in 2006 and 31.6% in 2007. CONCLUSIONS: Human resources, technical expertise, and equipment are crucial to reach the WHO goal. Brazil has enough ophthalmologists but needs improved planning and infrastructure in order to eliminate the problem, aspects that require greater financial investment and stronger political commitment.

Analyses of cataract surgery performed by the Unified Health System in Brazil, 2006-2007 / Análisis de las intervenciones quirúrgicas de cataratas efectuadas en el Sistema Único de Salud del Brasil en el 2006 y el 2007

OBJECTIVE: Estimate cataract surgical rates (CSR) for Brazil and each federal unit in 2006 and 2007 based on the number of surgeries performed by the Unified Health System to help plan a comprehensive ophthalmology network in order to eliminate cataract blindness in compliance with the target set by the World Health Organization (WHO) of 3 000 cataract surgeries per million inhabitants per year. METHODS: This descriptive study calculates CSR by using the number of cataract surgeries carried out by the Brazilian Unified Health System for each federal unit and estimates the need for cataract surgery in Brazil for 2006-2007, with official population data provided by the Brazilian Institute of Geography and Statistics. The number of cataract surgeries was compared with the WHO target. RESULTS: To reach the WHO goal for eliminating age-related cataract blindness in Brazil, 560312 cataract surgeries in 2006 and 568 006 surgeries in 2007 needed to be done. In 2006, 179121 cataract surgeries were done by the Unified Health System, corresponding to a CSR of 959 per million population; in 2007, 223317 were performed, with a CSR of 1179. With the Brazilian Council of Ophthalmology estimation of 165 000 surgeries each year by the non-public services, the CSR for Brazil would be 1842 for 2006 and 2051 for 2007. The proportions needed to achieve the proposed target were 38.6 percent in 2006 and 31.6 percent in 2007. CONCLUSIONS: Human resources, technical expertise, and equipment are crucial to reach the WHO goal. Brazil has enough ophthalmologists but needs improved planning and infrastructure in order to eliminate the problem, aspects that require greater financial investment and stronger political commitment.

OBJETIVO: Calcular las tasas de cirugía de cataratas (TCC) correspondientes al 2006 y el 2007 en todo el Brasil y en cada estado según la cantidad de intervenciones efectuadas en el Sistema Único de Salud, con el objeto de planificar una red integral de atención oftalmológica tendiente a eliminar la ceguera por cataratas, en cumplimiento de la meta fijada por la Organización Mundial de la Salud (OMS), de 3 000 intervenciones quirúrgicas de cataratas por millón de habitantes por año. MÉTODOS: En este estudio descriptivo se calculó la TCC según la cantidad de intervenciones quirúrgicas de cataratas llevadas a cabo en el Sistema Único de Salud del Brasil en cada estado, y se calculó la necesidad de intervenciones quirúrgicas de cataratas en el Brasil en el 2006 y el 2007 según los datos oficiales de la población proporcionados por el Instituto Brasileño de Geografía y Estadística. Se comparó la cantidad de intervenciones quirúrgicas de cataratas con la meta de la OMS. RESULTADOS: Para alcanzar la meta de la OMS de eliminar la ceguera producida por cataratas seniles en el Brasil, deberían haberse efectuado 560 312 intervenciones quirúrgicas de cataratas en el 2006, y 568006 en el 2007. En el 2006, se efectuaron 179 121 intervenciones quirúrgicas de cataratas en el Sistema Único de Salud, lo que representa una TCC de 959 por millón de habitantes; en el 2007, se realizaron 223317, con una TCC de 1179. Si estos datos se consideran junto con la estimación del Consejo Brasileño de Oftalmología de 165000 intervenciones quirúrgicas efectuadas cada año en los servicios no públicos, la TCC correspondiente al Brasil sería de 1842 para el 2006 y de 2 051 para el 2007. Las proporciones faltantes para lograr la meta propuesta fueron de 38,6 por ciento en el 2006 y de 31,6 por ciento en el 2007. CONCLUSIONES: Los recursos humanos, los conocimientos técnicos especializados y el equipo son esenciales para alcanzar la meta de la OMS. Brasil tiene suficientes oftalmólogos pero, para eliminar el problema, necesita una mejor planificación y más infraestructura, aspectos que requieren una mayor inversión financiera y un compromiso político más firme.

Cataracts: we have perfected the surgery, but is it time for prevention?

PURPOSE OF REVIEW: This review presents a discussion of cataract prevention, with a focus on the societal burden of untreated cataracts and pathophysiologic mechanisms of prevention. RECENT FINDINGS: Multiple studies have implicated cataract surgery and vision loss due to cataract as a major cause of disability and lost productivity. Long-term use of antioxidants such as vitamin C, lutein, and zeaxanthin have been associated with lower incidence and progression of cataracts, but prospective studies of vitamin supplementation have shown little effect. There are currently over 400 cataract-related clinical trials; one trial of a topical medication for the treatment of cataract is currently in progress. SUMMARY: Vision loss due to cataract, disability associated with cataract blindness, and the surgical treatment of this disease present a significant public health burden. Useful strategies for prevention may include public health campaigns targeted at young adults, with a focus on making healthy choices to prevent this disease.

[Availability of patients living in rural areas, to have surgical method of treatment of cataract and glaucoma].

Using modern surgical treatment on patients that live in rural areas, with cataract and glaucoma is not sufficient. There is insufficient expertise of ophthalmologists, low level of human, logistical and financial resource support for eye hospitals, low level of motivation and socio-psychological problems among patients, creating a favorable situation in Ukraine for further growth of low vision and blindness in rural areas. Institutional solutions of existing problems are proposed.

Persistence with statins and incident cataract: a population-based historical cohort study.

PURPOSE: In recent years, there is a growing body of evidence suggesting that statins may have anti-inflammatory effects; consequently, it was hypothesized that statins may have a preventive effect against cataract. METHODS: The study was carried out on a retrospective cohort of 180,291 new statin users in a large health organization in Israel. Study participants were followed between 1998 and 2007 for incident cataract or cataract extraction. RESULTS: During the study period 27,301 cataracts were diagnosed and 6,976 cataract extractions were performed among study participants. Persistence with statins was associated significantly (P < 0.001) with a reduced risk of cataract in men and women aged 45 to 74. Men aged 45-54 with a high (>80%) proportion of follow-up days covered with statins had an adjusted hazard ratio of 0.62 (95% confidence interval: 0.54-0.72), compared with patients with low persistence with statins. In elderly patients, no relationship or a positive relationship was observed. CONCLUSIONS: Persistent statin use was significantly protective for the incidence of cataract in men and women under 75 years of age.

[Eye care in Nepal]. / Opieka okulistyczna w Nepalu.

Perched on the greatest heights of the Himalayas Nepal is a small landlocked country, placed between Tibet and India. Cataract is the main cause of blindness in the Nepalese population. On the other hand, very few of us realize that this poor country has been able to develop an interesting, specific and relatively good eye care service system. The aim of this study is the complete analysis of this subject in regard to its structure, funding and training of medical personnel.