Research - Eyes
Genetic and Dietary Factors Influencing the Progression of Nuclear Cataract
Ekaterina Yonova-Doing, MSc Zoe A. Forkin, BSc Pirro G. Hysi, MD, PhD Katie M. Williams, MPhil, FRCOphth Tim D. Spector, MD, PhD, Clare E. Gilbert, FRCOphth, MD Christopher J. Hammond, MD, FRCOphth
To determine the heritability of nuclear cataract progression and to explore prospectively the effect of dietary micronutrients on the progression of nuclear cataract.
Prospective cohort study.
Cross-sectional nuclear cataract and dietary measurements were available for 2054 white female twins from the TwinsUK cohort. Follow-up cataract measurements were available for 324 of the twins (151 monozygotic and 173 dizygotic twins).
MethodsNuclear cataract was measured using a quantitative measure of nuclear density obtained from digital Scheimpflug images. Dietary data were available from EPIC food frequency questionnaires. Heritability was modeled using maximum likelihood structural equation twin modeling. Association between nuclear cataract change and micronutrients was investigated using linear and multinomial regression analysis. The mean interval between baseline and follow-up examination was 9.4 years.
Main Outcome MeasuresNuclear cataract progression.
The best-fitting model estimated that the heritability of nuclear cataract progression was 35% (95% confidence interval [CI], 13–54), and individual environmental factors explained the remaining 65% (95% CI, 46–87) of variance. Dietary vitamin C was protective against both nuclear cataract at baseline and nuclear cataract progression (β = −0.0002, P = 0.01 and β = −0.001, P = 0.03, respectively), whereas manganese and intake of micronutrient supplements were protective against nuclear cataract at baseline only (β = −0.009, P = 0.03 and β = −0.03, P = 0.01, respectively).
Genetic factors explained 35% of the variation in progression of nuclear cataract over a 10-year period. Environmental factors accounted for the remaining variance, and in particular, dietary vitamin C protected against cataract progression assessed approximately 10 years after baseline.
Source : Opthalmology
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Gelam honey potentiates ex vivo corneal keratocytes proliferation with desirable phenotype expression
- Alia Md Yusof,
- Norzana Abd Ghafar
- Taty Anna Kamarudin,
- Chua Kien Hui and
- Yasmin Anum Mohd Yusof
This study aimed to evaluate the effects of Gelam honey on corneal keratocytes proliferative capacity and phenotypic characterization via MTT assay, gene expression and immunocytochemistry.
Corneal keratocytes from New Zealand white rabbits were cultured in basal medium (BM) and serum enriched medium (BMS). Serial dilutions of Gelam honey (GH) were added to both media and cells were cultured until passage 1. MTT assay was performed on corneal keratocytes in both media to ascertain the optimal dose of GH that produced maximum proliferation.
Gelam honey at the concentration of 0.0015 % in both media showed the highest proliferative capacity with no morphological changes compared to their respective controls. The gene expression of aldehyde dehydrogenase (ALDH), a marker for quiescent keratocytes and vimentin, a marker for fibroblast, were higher in the GH enriched groups. The alpha smooth muscle actin (α-SMA) expression, marker for myofibroblast, was lower in GH treated groups compared to the controls. Immunocytochemistry results were in accordance to the gene expression analyses.
Gelam honey at a concentration of 0.0015 % promotes ex vivo corneal keratocytes proliferation while retaining desirable phenotype expression. The results serve as a basis for the development of Gelam honey as a potential natural product in promoting corneal wound healing.
Source : BMC Complementary and Alternative Medicine
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Association Between Vitamin D Status and Age-Related Macular Degeneration by Genetic Risk
Amy E. Millen, PhD1; Kristin J. Meyers, PhD, MPH2; Zhe Liu, MS2; Corinne D. Engelman, PhD3; Robert B. Wallace, MD4; Erin S. LeBlanc, PhD5; Lesley F. Tinker, PhD6; Sudha K. Iyengar, PhD7; Jennifer G. Robinson, MD8; Gloria E. Sarto, MD, PhD9; Julie A. Mares, PhD2
Importance Deficient 25-hydroxyvitamin D (25[OH]D) concentrations have been associated with increased odds of age-related macular degeneration (AMD).
Objective To examine whether this association is modified by genetic risk for AMD and whether there is an association between AMD and single-nucleotide polymorphisms of genes involved in vitamin D transport, metabolism, and genomic function.
Design, Setting, and Participants Postmenopausal women (N = 913) who were participants of the Carotenoids in Age-Related Eye Disease Study (CAREDS) (aged 54 to <75 years) with available serum 25(OH)D concentrations (assessed October 1, 1993, to December 31, 1998), genetic data, and measures of AMD (n = 142) assessed at CAREDS baseline from May 14, 2001, through January 31, 2004, were studied.
Main Outcomes and Measures Prevalent early or late AMD was determined from graded, stereoscopic fundus photographs. Logistic regression was used to estimate odds ratios (ORs) and 95% CIs for AMD by the joint effects of 25(OH)D (<12, ≥12 to <20, ≥20 to <30, and ≥30 ng/mL) and risk genotype (noncarrier, 1 risk allele, or 2 risk alleles). The referent group was noncarriers with adequate vitamin D status (≥30 ng/mL). Joint effect ORs were adjusted for age, smoking, iris pigmentation, self-reported cardiovascular disease, self-reported diabetes status, and hormone use. Additive and multiplicative interactions were assessed using the synergy index (SI) and an interaction term, respectively. To examine the association between AMD and variants in vitamin D–related genes, age-adjusted ORs and 95% CIs were estimated using logistic regression.
Results Among the 913 women, 550 had adequate levels of vitamin D (≥20 ng/mL), 275 had inadequate levels (≥12 to <20 mg/mL), and 88 had deficient levels (<12 ng/mL). A 6.7-fold increased odds of AMD (95% CI, 1.6-28.2) was observed among women with deficient vitamin D status (25[OH]D <12 ng/mL) and 2 risk alleles for CFH Y402H (SI for additive interaction, 1.4; 95% CI, 1.1-1.7; P for multiplicative interaction = .25). Significant additive (SI, 1.4; 95% CI, 1.1-1.7) and multiplicative interactions (P = .02) were observed for deficient women with 2 high-risk CFI (rs10033900) alleles (OR, 6.3; 95% CI, 1.6-24.2). The odds of AMD did not differ by genotype of candidate vitamin D genes.
Conclusions and Relevance In this study, the odds of AMD were highest in those with deficient vitamin D status and 2 risk alleles for the CFH and CFI genotypes, suggesting a synergistic effect between vitamin D status and complement cascade protein function. Limited sample size led to wide CIs. Findings may be due to chance or explained by residual confounding.
Source : JAMA Opthal.
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Acupuncture Therapy Is More Effective Than Artificial Tears for Dry Eye Syndrome: Evidence Based on a Meta-Analysis
Lei Yang,1 Zongguo Yang,2 Hong Yu,1 and Hui Song1
1Aerospace Center Hospital, Beijing 100049, China
2Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
Background. The efficacy of acupuncture in dry eye syndrome patients remains controversial. Methods. Pubmed, Ovid, Cochrane libraries, CNKI, Wanfang, and CQVIP databases were electronically searched until October 1, 2014. Outcomes including tear break-up time (BUT), Schirmer I test (SIT), and cornea fluorescein staining (CFS) were analyzed. A meta-analysis was performed using both fixed- and random-effects models based on heterogeneity across studies. Results. Seven studies were included in this study; 198 and 185 patients were randomly treated with acupuncture and artificial tears, respectively. The overall BUT of patients in acupuncture group was significantly longer than that of the artificial tears group after treatment (P<0.00001). The SIT was significantly higher in the acupuncture group than that in the artificial tears group after treatment (P=0.001). The CFS of patients in acupuncture group was significantly improved compared to that in artificial group (P<0.0001). Conclusions. Acupuncture therapy is effective for the dry eye patients, partly better than artificial tear treatment.
Source : Journal eCAM
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Fourier-Domain Optical Coherence Tomography for Monitoring the Lower Tear Meniscus in Dry Eye after Acupuncture Treatment
Tong Lin,1 Lan Gong,1 Xiaoxu Liu,2 and Xiaopeng Ma3
1Department of Ophthalmology, Eye & ENT Hospital of Fudan University, No. 83 Fenyang Road, Shanghai 200031, China
2Shanghai University of Traditional Chinese Medicine, No. 1200 Cailun Road, Shanghai 201203, China
3Shanghai Research Institute of Acupuncture and Meridian, No. 650 Wanping South Road, Shanghai 200030, China
Dry eye is highly prevalent and has a significant impact on quality of life. Acupuncture was found to be effective to treat dry eye. However, little was known about the effect of acupuncture on different subtypes of dry eye. The objective of this study was to investigate the applicability of tear meniscus assessment by Fourier-domain optical coherence tomography in the evaluation of acupuncture treatment response in dry eye patients and to explore the effect of acupuncture on different subtypes of dry eye compared with artificial tear treatment. A total of 108 dry eye patients were randomized into acupuncture or artificial tear group. Each group was divided into three subgroups including lipid tear deficiency (LTD), Sjögren syndrome dry eye (SSDE), and non-Sjögren syndrome dry eye (Non-SSDE) for data analysis. After 4-week treatment, the low tear meniscus parameters including tear meniscus height (TMH), tear meniscus depth (TMD), and tear meniscus area (TMA) in the acupuncture group increased significantly for the LTD and Non-SSDE subgroups compared with both the baseline and the control groups (all P values < 0.05), but not for the SSDE. Acupuncture provided a measurable improvement of the tear meniscus dimensions for the Non-SSDE and LTD patients, but not for the SSDE patients.
Source : eCAM
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Scientists Study Effects of Sunlight to Reduce Number of Nearsighted Kids
Despite what many parents may think, kids who spend a lot of time reading or squinting at tiny electronic screens aren't more likely to become nearsighted than kids who don’t. However, that risk is only reduced if the child spends plenty of quality time outside.
The “outdoor effect” on nearsightedness, or myopia, is a longstanding observation backed by both scientific and anecdotal evidence. It’s so compelling that some nations in Asia, which have among the highest myopia rates in the world, have increased the amount of daily outdoor time for children in the hopes of reducing the need for glasses.
But so far, no one has defined exactly what it is about being outside that seems to offer a protective effect against the condition, which causes distant objects to appear blurry.
“Data suggest that a child who is genetically predisposed to myopia are three times less likely to need glasses if they spend more than 14 hours a week outdoors,” says optometrist Donald Mutti, OD, PhD, of The Ohio State University College of Optometry. “But we don’t really know what makes outdoor time so special. If we knew, we could change how we approach myopia.”
Supported by a pilot grant from Ohio State’s Center for Clinical and Translational Science (CCTS), Mutti is now focusing his research on the variables he feels have the most potential: invisible ultraviolet B rays (UVB) and vitamin D, and visible bright light and dopamine.
“Between the ages of five and nine, a child’s eye is still growing. Sometimes this growth causes the distance between the lens and retina to lengthen, leading to nearsightedness,” explained Mutti. “We think these different types of outdoor light may help preserve the proper shape and length of the eye during that growth period.”
UVB and Vitamin D
UVB light is invisible to the human eye, but triggers several cellular functions in the body, including the production of vitamin D. Vitamin D is thought to support the function of the smooth muscle tissue found around the lens in the eye. This muscle not only helps focus light on the retina, but may also maintain the proper eye shape and length between the lens and the retina, something that can become distorted during the rapid growth of a child’s eye.
Some studies, including one by Mutti, show that people with myopia have lower blood levels of vitamin D – indicating that they have spent less time outdoors, with possible negative effects on the eye.
However, the data are difficult to interpret because vitamin D levels are hard to measure and change dramatically from season to season. While people usually get most of their UVB exposure during the summer, vitamin D levels don’t spike until the fall – something that could make study results less accurate if not taken into consideration.
In order to develop a protocol for measuring vitamin D levels, Mutti is conducting a study in which participants are wearing monitors that detect exposure to UV and visible light. Levels of vitamin D are also being measured via blood and saliva samples.
“We don’t know if vitamin D is simply a proxy for measuring outdoor time, or if it is actually exerting a biological effect on how the eye works and develops,” said Mutti. “The current study will validate the way we measure vitamin D, so that we can more accurately figure out what role it really plays in large-scale studies.”
Visible bright light and dopamine
There’s another part of sunlight that could help prevent myopia: exposure to visible bright light. Even on a cloudy day, visible light outdoors is at least 10 times brighter than the light indoors.
When exposed to outdoor light, specialized cells in the retina help control how big or little the pupil dilates to let more or less light in. The cells connect to others that release dopamine – an important neurotransmitter in the eye and brain. Previous research suggests that dopamine also slows down the growth of the eye, but there isn’t technology currently available that can measure dopamine release in the eye directly.
However, thanks to another CCTS-funded researcher, Andrew Hartwick, OD, PhD, there is a way to measure the activity of these specialized cells by looking at how the pupil reacts to light. Mutti thinks he can use Hartwick’s procedure – developed as an early detection test for glaucoma - as a stand in for measuring dopamine release.
“Dr. Hartwick developed a protocol that measures how much these specialized retinal cells contribute to pupil responses to blue and red light,” said Mutti. “Our initial research suggests that the pupil responds more if these cells have been exposed to a lot of sunlight in the previous few days. That could serve as a proxy for how much dopamine the eye has been producing.”
Last week, Mutti and his research team presented their results at the American Academy of Optometry annual meeting, including some of their early findings from studies looking at what happens to the pupil after visible light exposure.
These data and other ongoing studies will help Mutti develop rock-solid methodologies that he hopes can ultimately be used in large scale clinical trials – and help get the answers that so many scientists and parents would like to know.
“I think the research we are doing now will help us finally solve the mystery of the outdoor effect, and maybe help some people avoid a lifetime of wearing glasses,” said Mutti. “In the meantime, I tell parents don’t worry about reading, get their kids outside, but don’t forget sunglasses and sunscreen.”
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Source : Newswise
Do Nutritional Supplements Have a Role in Age Macular Degeneration Prevention?
Maria D. Pinazo-Durán,1,2 Francisco Gómez-Ulla,3,4,5 Luis Arias,6,7 Javier Araiz,8 Ricardo Casaroli-Marano,9 Roberto Gallego-Pinazo,10 Jose J. García-Medina,11,12 Maria Isabel López-Gálvez,13,14 Lucía Manzanas,15,16 Anna Salas,17 Miguel Zapata,18 Manuel Diaz-Llopis,19,20 and Alfredo García-Layana21
Purpose. To review the proposed pathogenic mechanisms of age macular degeneration (AMD), as well as the role of antioxidants (AOX) and omega-3 fatty acids (ω-3) supplements in AMD prevention. Materials and Methods. Current knowledge on the cellular/molecular mechanisms of AMD and the epidemiologic/experimental studies on the effects of AOX and ω-3 were addressed all together with the scientific evidence and the personal opinion of professionals involved in the Retina Group of the OFTARED (Spain). Results. High dietary intakes of ω-3 and macular pigments lutein/zeaxanthin are associated with lower risk of prevalence and incidence in AMD. The Age-Related Eye Disease study (AREDS) showed a beneficial effect of high doses of vitamins C, E, beta-carotene, and zinc/copper in reducing the rate of progression to advanced AMD in patients with intermediate AMD or with one-sided late AMD. The AREDS-2 study has shown that lutein and zeaxanthin may substitute beta-carotene because of its potential relationship with increased lung cancer incidence. Conclusion. Research has proved that elder people with poor diets, especially with low AOX and ω-3 micronutrients intake and subsequently having low plasmatic levels, are more prone to developing AMD. Micronutrient supplementation enhances antioxidant defense and healthy eyes and might prevent/retard/modify AMD.
Source: Journal Opthalmology
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Eating for Eye Health Can Be Beneficial
Eating healthy can affect more than what the scale says. According to experts at the University of Alabama at Birmingham (UAB), it is possible to aid eye health through nutrition and supplements.Research by the National Eye Institute (NEI) has shown that high levels of antioxidants and zinc, in the form of a nutritional supplement tablet, reduced the risk of advanced age-related macular degeneration (AMD).
“AMD is the leading cause of blindness in older adults,” said Cynthia Owsley, Ph.D., professor and vice chair for clinical research in the Department of Ophthalmology. “These dietary supplements are not a cure for AMD, but they do reduce one’s risk of progressing to the most serious form of the disease.”
UAB School of Optometry Professor Leo Semes, O.D., talked about the importance of diet to eye health.
“You are what you eat; it’s trite but it’s true,” Semes said. “It’s been shown that certain habits like eating a high-fat diet are associated with, but not causative, in AMD.”
One food that has long been connected with improving vision is carrots, but Semes said carrots alone will not accomplish significant gains in eye health.
“The basis for this belief is that carrots are high in beta-carotene,” Semes said. “But beta-carotene alone is not going to be protective enough. There’s also a tangential relationship that a lack of vitamin-A, a cousin of beta-carotene, is implicated in poor darkness adaptation.”
Seeing well when moving from light to dark declines with age.
Semes serves on the American Optometric Association Health and Nutrition Committee, which developed a list of specific foods and nutrients that have been found to be beneficial to eye health.
• Fruits and vegetables – Vitamin C can help minimize cataracts and AMD
• Fleshy fish (tuna or salmon) and lean meats – Fatty acids protect against AMD
• Red meats and whole grains – Zinc deficiency can lead to cataracts
• Vegetable oil – Vitamin E can slow progression of AMD
Source : Newswise
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One year study on the integrative intervention of acupressure and interactive multimedia for visual health in school children
- a School of Nursing, National Taipei University of Nursing and Health Sciences, No. 365, Minte Road, Taipei, Taiwan, ROC
- b Department of Applied Mathematics, Chung-Yuan Christian University, No. 200, Chungpei Road, Chung-Li City, Taoyuan, Taiwan, ROC
- c School of Nursing, Yuanpei University, No. 306, Yuanpei Street, Hsinchu, Taiwan, ROC
This study used a larger sample size, added a long-term observation of the effect of intervention, and provided an integrated intervention of acupressure and interactive multimedia of visual health instruction for school children. The short- and long-term effects of the interventions were then evaluated by visual health knowledge, visual acuity, and refractive error.
A repeated pretest–posttest controlled trial was used with two experimental groups and one control group.
Four elementary schools in northern Taiwan.
287 School children with visual impairment in fourth grade were recruited.
One experimental group received the integrative intervention of acupressure and interactive multimedia of visual health instruction (ACIMU), and another received auricular acupressure (AC) alone; whereas a control group received no intervention. Two 10-week interventions were separately given in the fall and spring semesters. The short- and long-term effects of the interventions were then evaluated by visual health knowledge, visual acuity, and refractive error.
During the school year the visual health knowledge was significantly higher in the ACIMU group than the control group (p < 0.001). A significant difference in the changing visual acuity was in the three groups (p < 0.001), with the improvement in the ACIMU group. No difference in the refractive error was found between any two groups (p > 0.05).
This study demonstrated that a long-term period of acupressure is required to improve school children's visual health. School children receiving the intervention of acupressure combined with interactive multimedia had better improvement of visual health and related knowledge than others. Further study is suggested in which visual health and preventative needs can be established for early childhood.
Source : Complementary Therapies in Medicine
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Vitamin D could combat the effects of ageing in eyes
Researchers funded by the Biotechnology and Biological Sciences Research Council (BBSRC) have found that vitamin D reduces the effects of ageing in mouse eyes and improves the vision of older mice significantly. The researchers hope that this might mean that vitamin D supplements could provide a simple and effective way to combat age-related eye diseases, such as macular degeneration (AMD), in people.
The research was carried out by a team from the Institute of Ophthalmology at University College London and is published in the current issue of the journal Neurobiology of Ageing.
Professor Glen Jeffery, who led the work, explains "In the back of the eyes of mammals, like mice and humans, is a layer of tissue called the retina. Cells in the retina detect light as it comes into the eyes and then send messages to the brain, which is how we see. This is a demanding job, and the retina actually requires proportionally more energy than any other tissue in the body, so it has to have a good supply of blood. However, with ageing the high energy demand produces debris and there is progressive inflammation even in normal animals. In humans this can result in a decline of up to 30% in the numbers of light receptive cells in the eye by the time we are 70 and so lead to poorer vision."
The researchers found that when old mice were given vitamin D for just six weeks, inflammation was reduced, the debris partially removed, and tests showed that their vision was improved.
The researchers identified two changes taking place in the eyes of the mice that they think accounted for this improvement. Firstly, the number of potentially damaging cells, called macrophages, were reduced considerably in the eyes of the mice given vitamin D. Macrophages are an important component of our immune systems where they work to fight off infections. However in combating threats to the aged body they can sometimes bring about damage and inflammation. Giving mice vitamin D not only led to reduced numbers of macrophages in the eye, but also triggered the remaining macrophages to change to a different configuration. Rather than damaging the eye the researchers think that in their new configuration macrophages actively worked to reduce inflammation and clear up debris.
The second change the researchers saw in the eyes of mice given vitamin D was a reduction in deposits of a toxic molecule called amyloid beta that accumulates with age. Inflammation and the accumulation of amyloid beta are known to contribute, in humans, to an increased risk of age-related macular degeneration (AMD), the largest cause of blindness in people over 50 in the developed world. The researchers think that, based on their findings in mice, giving vitamin D supplements to people who are at risk of AMD might be a simple way of helping to prevent the disease.
Professor Jeffery said "When we gave older mice the vitamin D we found that deposits of amyloid beta were reduced in their eyes and the mice showed an associated improvement of vision. People might have heard of amyloid beta as being linked to Alzheimer's disease and new evidence suggests that vitamin D could have a role in reducing its build up in the brain. So, when we saw this effect in the eyes as well, we immediately wondered where else these deposits might be being reduced."
Professor Jeffery and his team then went on to study some of the blood vessels of their mice. They found that the mice that had been given the vitamin D supplement also had significantly less amyloid beta built up in their blood vessels, including in the aorta.
Professor Jeffery continues "Finding that amyloid deposits were reduced in the blood vessels of mice that had been given vitamin D supplements suggests that vitamin D could be useful in helping to prevent a range of age-related health problems, from deteriorating vision to heart disease."
Professor Jeffery thinks that this link between vitamin D and a range of age-related diseases might be linked to our evolutionary history. For much of human history our ancestors lived in Africa, probably without clothes, and so were exposed to strong sunlight all year round. This would have triggered vitamin D production in the skin. Humans have only moved to less sunny parts of the world and adopted clothing relatively recently and so might not be well adapted to reduced exposure to the sun. Secondly, life expectancy in the developed world has increased greatly over the past few centuries, so reduced exposure to vitamin D is now coupled with exceptionally long lifespan.
Professor Jeffery said "Researchers need to run full clinical trials in humans before we can say confidently that older people should start taking vitamin D supplements, but there is growing evidence that many of us in the Western world are deficient in vitamin D and this could be having significant health implications."
Professor Douglas Kell, BBSRC Chief Executive said "Many people are living to an unprecedented old age in the developed world. All too often though, a long life does not mean a healthy one and the lives of many older people are blighted by ill health as parts of their bodies start to malfunction.
"If we are to have any hope of ensuring that more people can enjoy a healthy, productive retirement then we must learn more about the changes that take place as animals age. This research shows how close study of one part of the body can lead scientists to discover new knowledge that is more widely applicable. By studying the fundamental biology of one organ scientists can begin to draw links between a number of diseases in the hope of developing preventive strategies."
Source : BBSRC via Vitamin D rejuvenates aging eyes by reducing inflammation, clearing amyloid beta and improving visual function. By Lee V, Rekhi E, Kam JH, Jeffery G. is available online at: www.ncbi.nlm.nih.gov/pubmed/22217419
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Antioxidant May Prevent, Even Cure, Cataracts and Other Degenerative Eye Disorders
Researchers at Missouri University of Science and Technology are working with an antioxidant that could prevent or cure cataracts, macular degeneration and other degenerative eye disorders. The research group, headed by Dr. Nuran Ercal, the Richard K. Vitek/Foundation for Chemical Research Endowed Chair in Biochemistry and professor of chemistry at Missouri S&T, is studying eye drops prepared with the antioxidant N-acetylcysteine amide (NACA) as a treatment for these eye conditions.
Ercal says NACA is an improvement over another experimental treatment, the antioxidant N-acetylcysteine (NAC), because it passes more easily across cell membranes, allowing the medication to be used in lower doses.
“NACA’s characteristics as a drug were improved over NAC by neutralizing the carboxylic group of NAC, which makes the NACA pass cellular membranes easily,” says Ercal. “And because NACA can be administered at a lower dose, the drug has a greater therapeutic index and lowers the risk of side effects traditionally associated with NAC.
“NACA is also an excellent source of glutathione, a cell’s main antioxidant power, which is diminished during degenerative eye disorders,” she adds.
Vision loss from age-related eye disorders affects more than 30 million people in the United States and is expected to double in the coming decades, Ercal says.
In addition, more than $9 billion is spent annually in the U.S. on cataract surgery alone. The total annual cost of all services related to vision problems exceeds $20 billion, she says.
“NACA eye drops could drastically reduce these costs and represent an alternative to costly surgery, while greatly improving the quality of life for those afflicted,” says Ercal.
Ercal and her team have been testing NACA on HIV-related problems, lead poisoning and other toxicities for 10 years. About four years ago they began testing it on eye disorders.
Ercal recently received a $378,000 three-year research grant from the National Eye Institute of the National Institutes of Health. The preliminary data submitted for the funding was based on research by her former Ph.D. student, Joshua Carey.
Carey’s dissertation involved preliminary studies of the effects of NACA to slow down cataract growth on rats that had been given L-buthionine-S,R-sulfoximine (BSO), a solution that causes cataracts to form. “The NACA solution prevented cataracts from forming,” says Ercal. “Our research will build on Josh’s research, to see if NACA can actually reverse the degeneration as well.”
Ercal, who is also an M.D., says further testing will help establish appropriate dosage and frequency, as well as possible side effects and other factors. She says successful results using animal subjects may eventually support the viability of human usage.
Source : Newswise
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Healthy Diet May Reduce Cataracts in Women
Women who eat foods rich in a variety of vitamins and minerals appear to have a lower risk of developing cataracts, according to a large population study.
The study looked at dietary intakes for more than 1,800 postmenopausal women and found that those who ate the overall healthiest dietshad a 37% lower risk of nuclear cataracts, the most common type of age-related eye lens opacity, said Julie A. Mares, PhD, of the department of ophthalmology and visual sciences at the University of Wisconsin Madison, and colleagues.
Higher prevalence of cataracts in women was also associated with other modifiable factors such as smoking and obesity, and with nonmodifiable factors such as brown eyes, myopia, and high pulse pressure, Mares and colleagues wrote in the June issue of the Archives of Ophthalmology.
The women in the cohort were enrolled in the Carotenoids in Age-Related Eye Disease Study (CAREDS), an ancillary study of the Women's Health Initiative (WHI). They had filled out food frequency questionnaires at enrollment between 1994 and 1998, which assessed their overall intake of a variety of foods including fruits and vegetables. The multivariate-adjusted odds ratio for nuclear cataracts between the high versus low quintile of women for overall diet scores was 0.63 (95% CI 0.43 to 0.91), according to Mares.
"Diet was the strongest risk factor related to reduced risk of nuclear cataract in this sample of postmenopausal women," the authors noted. "Lifestyle improvements that include healthy diets, smoking cessation, and avoiding obesity may substantively lower the need for and economic burden of cataract surgery in aging American women."
The authors cited several aspects of diet that may lower risk for nuclear cataract by lowering oxidative stress or systemic inflammation (which can lead to oxidative stress). In previous studies, having adequate or high intakes or blood levels of lutein and zeaxanthin and the use of multivitamin supplements have been most consistently related to lower risk for cataracts, they noted.
Only one other study has looked at the overall impact of a healthy diet on cataract occurrence, and that study found that 10-year adherence to the 1990 dietary guidelines for Americans was associated with lower risk for early nuclear lens opacities, the researchers wrote.
To further investigate the relationship between overall diet and cataract formation, the investigators looked at a subset of women enrolled in CAREDS. Participants in CAREDS all had self-reported intakes of lutein plus zeaxanthin that were either higher than the 78th percentile or lower than the 28th percentile as assessed at baseline enrollment into the WHI. WHI enrollees ranged in age from 50 to 79 at baseline.
Mares and colleagues enrolled a total of 1,808postmenopausalwomen living in Iowa, Wisconsin, and Oregon who had been in both CAREDS and the WHI. Exclusion criteria included unreliable diet data, history of trauma to both eyes, reported cataract extraction before age 40, missing or ungradable nuclear lens photographs, and missing covariate data.
Estimates of basic daily food and nutrient intake were made from responses to a food frequency questionnaire given at baseline (1994-1998). Adherence to the 1990 dietary guidelines for Americans and the 1992 food guide pyramid was estimated by the 1995 Healthy Eating Index (HEI-1995) scores, which were adapted to the WHI questionnaire. HEI scores were updated in 2005 to reflect new dietary guidelines that not only included the consumption of food groups but also increased intake of foods within those groups (e.g., dark green leafy vegetables).
As part of the CAREDS study, the women underwent lens photography and eye examinations between 2001 and 2004. Both eyes were examined with slitlamp biomicroscopy. After pupils were dilated, a single nonstereoscopic photograph was taken of each eye. Severity of nuclear sclerosis was determined in eyes that had not previously undergone cataract extraction.
The primary outcome was presence of a nuclear cataract, defined as a nuclear sclerosis severity score of 4 or greater in the worse eye and/or a history of cataract extraction in either eye. A secondary outcome was nuclear sclerosis, defined as a severity score of 4 or greater, in women who had at least one natural lens for which lens photographs were gradable.
Nuclear cataract was found in 454 of 1577 women who had lenses in at least one eye. An additional 282 of the 1,808 women reported cataract extractions in either eye. Overall, 736 women (41%) either had nuclear cataracts evident from lens photographs or reported having a cataract extracted.
After adjustment for other risk factors, being in the third to fifth quintiles for the HEI-1995 score (having HEI-1995 scores >68) was associated with 37% lower odds for nuclear cataract. The association remained significant after adjusting for smoking, body mass index, supplement use, and physical activity, according to the researchers.
This association did not appear to be related to any single part of a healthy diet. Taking vitamins and other supplements was not associated with decreased risk for nuclear cataracts.
The authors noted that their own previous work showed that prevalence of nuclear cataract in this sample was associated with diets high in fat and speculated that this might reflect the possibility that dietary fat intake is a marker for diet poor in a wide variety of micronutrients.
"Indeed, dietary fat intake was highly correlated with the HEI-1995 score (r=0.7; P<0.001), and adjusting associations for dietary fat attenuated the odds ratio more than adjusting for any other nutrient (multivariate OR=0.86; 95% CI 0.54 to 1.37)," they said.
The authors noted several limitations to their study, including whether the 1995 Healthy Eating Index to the questionnaire adequately captures the protective aspects of foods,the possibility that the findings may theoretically represent poor diets that occur as a result of having nuclear cataracts, or comorbid conditions associated with them. In addition, some risk factors were not measured, such as lead exposure, or may have been unknown. Also, some misclassification of nuclear cataracts among those previously extracted may have occurred.
Source : Medical News
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Estrogen Replacement Linked to Cataract Risk
Women who receive hormone replacement therapy (HRT) to counter the drop in estrogen levels after menopause are more likely to suffer from cataracts, a new Swedish study found.
Compared with women who never had HRT, the risk of needing cataract surgery was 14% higher among those who received HRT at any point their lives (RR 1.14; 95% CI 1.07 to 1.21) and 18% higher for women currently taking hormones (RR 1.18; 95% CI 1.10 to 1.26), according to the report published online March 1 in Ophthalmology.
Women undergoing HRT who reported drinking more than one alcoholic drink per day were at 42% higher risk of cataracts (RR 1.42; 95% CI 1.11 to 1.80).
"A longer duration of HRT usage was associated with an increased risk of cataract extraction," Birgitta Ejdervik Lindblad, MD, of Sundsvall in Sweden, and colleagues wrote.
"Higher intake of alcohol seemed to potentiate the harmful effect of HRT on cataract development. If other studies confirm this association, an increased rate of cataract extraction should be added to the list of potential negative outcomes associated with HRT."
Naturally occurring (endogenous) estrogen is thought to protect the eyes from cataracts, and estrogen receptors have been found on the lens, the part of the eye damaged by cataracts.
"Prevalence of cataract is higher in postmenopausal women compared with men of equivalent age," the authors wrote. "This may be related to hormonal differences between women and men and suggests a possible role for estrogen in cataract development."
Exogenous estrogens, such as those used for HRT, have been associated with increases in C-reactive protein levels, which have been linked to cataract development. "Exogenous estrogen in form of HRT is not to be regarded as a physiological substitution and could have other effects on the lens," the authors wrote.
Lindblad and colleagues conducted an eight-year prospective study of more than 30,000 postmenopausal Swedish women, whom they followed from September 1997 through October 2005. The women initially completed a questionnaire about hormone status, HRT, and lifestyle factors. Researchers later compared these records with registers of cataract extraction.
During the study, 4,324 of the women had cataracts surgically removed. Although the length of HRT therapy and drinking more than one alcoholic drink per day were associated with risk of cataracts, smoking was not.
The authors cautioned that the vast majority of women shared the same ethnicity and had equal access to healthcare, so the results may only be applicable to the Swedish population.
The study was also limited by a lack of data on the type of estrogen therapy the women received and the type of cataract they developed. Nor did the study account for sunlight exposure, a risk factor for cataracts.
The authors noted that their results differed from previous American studies that found that HRT lowered a woman's risk of cataracts or had no influence, depending on the type of cataract.
However, they wrote that estrogen types and treatment regimens differ among countries, so comparison between the studies is difficult.
Source : Med Page Today
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SSRIs Linked to Cataracts
Use of selective serotonin reuptake inhibitor (SSRI) antidepressants may be associated with cataract risk among older adults, a large population study from Canada found.
In a nested case-control study involving more than 200,000 residents of Quebec, current users of SSRIs ages 65 and older carried a 15% greater relative risk of cataracts (95% CI 0.08 to 1.23) compared with nonusers -- even after adjustment for blood pressure, other medication use, and gender, reported Mahyar Etminan, PharmD, MSc, of the University of British Columbia in Vancouver, and colleagues.
These findings are the first to support the ocular risk seen with SSRIs in an animal model, the researchers wrote in the June issue of Ophthalmology.
If the relationship is proven to be causal, roughly 22,000 cataract cases in the U.S. each year could be attributed to SSRI use, Etminan's group estimated. According to background information in the study, 10% of U.S. residents are taking antidepressants, mostly SSRIs and newer selective serotonin-norepinephrine reuptake inhibitors (SNRIs).
Serotonin receptors are found in the lens of the eye. In animal studies, serotonin has been shown to play a role in opacification of the lens and formation of cortical cataracts, the researchers noted.
Older-generation antidepressants, particularly amitriptyline (Elavil), have also been associated with increased risk of cataracts, but it wasn't clear whether the newer-generation of receptor-selective antidepressants would have the same effect, Etminan's group wrote.
Using the linked administrative databases of the universal healthcare plan in Quebec province, the researchers searched within a cohort of residents who had received coronary revascularization between 1995 and 2004. From this cohort, the study included all 18,784 adults ages 65 and older diagnosed with a first cataract along with 187,840 matched controls.
Those who received a diagnosis of cataracts while on SSRI therapy had been on the drugs for an average of nearly two years (656 days) before their cataract diagnosis.
Whereas use of an SSRI within 30 days of the cataract diagnosis did appear to have a significant effect, any past use did not (adjusted rate ratio 1.06, 95% CI 0.97 to 1.17).
The only significant impact of past use was with sertraline (Zoloft), which was associated with a 19% elevated risk of cataract (95% CI 1% to 41%). However, current use of this drug within 30 days of cataract diagnosis showed no significant effect on cataract risk (adjusted RR 1.06, 95% CI 0.92 to 1.22).
Among the available SSRIs, the risk of cataracts was most elevated among those on fluvoxamine (Luvox) with a 39% higher rate ratio compared with controls (95% CI 7% versus 80%).
Close behind it was the SNRI venlafaxine (Effexor) with a 33% elevated relative risk of cataract compared with nonuse (95% CI 1.14 to 1.55).
Other SSRIs citalopram (Celexa) and fluoxetine (Prozac) showed a tendency toward a 13% elevation in cataract risk with current use and paroxetine (Paxil), a tendency toward a 7% elevation, but none were statistically significant.
In an analysis considering only cataract cases actually treated with outpatient surgery, the results were generally similar, except that paroxetine became significantly associated with cataracts (adjusted RR 1.23, 95% CI 1.05 to 1.45).
The results "may suggest the importance of selectivity of serotonin receptors in the formation of cataracts," Etminan's group wrote in the paper.
However, the researchers cautioned that it's possible that the lack of association of certain SSRIs with cataracts may simply have reflected lack of power in the study for individual drugs.
"Whether the catarogenic effects of SSRIs are a class effect or are limited to specific agents must be investigated further," they concluded.
Limitations of the study included its design; using an administrative database, which made it impossible to check for confounders and risk factors for cataracts such as smoking; as well the use of the International Classification of Diseases, ninth revision, codes for cataracts, which may not necessarily confirm cataract surgery had taken place.
Source : Med Page Today
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“Vitamin D Status and Early Age-Related Macular Degeneration in Postmenopausal Women”
Authors: A.E. Millen, R. Voland, S.A. Sondel, N. Parekh, et al. for the CAREDS Study Group
Higher blood levels of vitamin D may be associated with a decreased risk of developing age-related macular degeneration (AMD) in women, says new research.
According to findings published in the Archives of Ophthalmology, the highest average intakes of vitamin D from food and supplements (15.1 micrograms per day) were associated with a 59 percent decrease in the risk of developing early AMD, compared with the lowest average intakes (7.9 micrograms per day).
“This is the second study to present an association between AMD status and 25(OH)D, and our data support the previous observation that vitamin D status may potentially protect against development of AMD,” wrote the authors, led by Amy Millen, PhD, from the University at Buffalo, New York.
“More studies are needed to verify this association prospectively as well as to better understand the potential interaction between vitamin D status and genetic and lifestyle factors with respect to risk of early AMD,” they added.
As the name suggests, age-related macular degeneration (AMD) is a degenerative retinal disease that causes central vision loss and leaves only peripheral vision.
Despite the fact that approximately 25 to 30 million people worldwide are affected by AMD, awareness of the condition is low, says AMD Alliance International. And as Baby Boomers age, the Alliance expects incidence to be on the rise and triple by 2025.
The macula is a yellow spot of about five millimeters diameter on the retina. As we age, levels of the pigments in the macula decrease naturally, thereby increasing the risk of AMD. The yellow color is due to the content of the carotenoids lutein and zeaxanthin, which we derive from the diet.
Millen and her co-workers analyzed blood levels of vitamin D – measured as 25- hydroxyvitamin D (25(OH)D), the non-active 'storage' form of the vitamin – in 1,313 women aged between 50 and 79. “Serum 25(OH)D is the preferred biomarker for vitamin D status, as it reflects vitamin D exposure from both oral sources and sunlight,” explained the researchers.
Vitamin D refers to two biologically inactive precursors - D3, also known as cholecalciferol, and D2, also known as ergocalciferol. Both D3 and D2 precursors are transformed in the liver and kidneys into 25(OH)D, and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active form that is tightly controlled by the body.
According to the study’s findings, the top food sources of vitamin D for the women were milk, fish, fortified margarine and fortified cereal.
Results showed that no overall relationship was found between vitamin D and any form of AMD, but when the researchers limited their analysis to women younger than 75, they found that higher 25(OH)D levels were associated with a significant decreased risk of early AMD.
“The inverse association between early AMD and 25(OH)D in women younger than 75 years was not explained by dietary intake of lutein plus zeaxanthin or polyunsaturated fat,” they added.
On the other hand, higher vitamin D levels were associated with a borderline statistically significant increased risk in women over 75.
Is it biologically plausible?
Commenting on the potential mechanism, Dr Millen and her co-workers note that inflammation is reported to be involved in the development of AMD, and that vitamin D has anti-inflammatory activity. As such the sunshine vitamin “may suppress the cascade of destructive inflammation that occurs at the level of the retinal pigment epithelium–choroid interface in early stages of AMD”, they added.
The study was supported by the National Institutes of Health and by Research to Prevent Blindness. It was part of the Carotenoids and Age-Related Eye Disease Study, an ancillary study of the Women’s Health Initiative.
Source: Nutraingredients via Archives of Ophthalmology 2011, Volume 129, Number 4, Pages 481-489
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Vaccinium myrtillus (Bilberry) Extracts Reduce Angiogenesis In Vitro and In Vivo
Nozomu Matsunaga1, Yuichi Chikaraishi1, Masamitsu Shimazawa1, Shigeru Yokota2 and Hideaki Hara1
1Department of Biofunctional Evaluation, Molecular Pharmacology, Gifu Pharmaceutical University, 5-6-1 Mitahora-higashi, Gifu 502-8585 and 2Wakasa Seikatsu Co. Ltd, 22 Naginataboko-cho, Shijo-Karasuma, Shimogyo-ku, Kyoto 600-8008, Japan
Vaccinium myrtillus (Bilberry) extracts (VME) were tested foreffects on angiogenesis in vitro and in vivo. VME (0.3–30µg ml–1) and GM6001 (0.1–100 µM; a matrixmetalloproteinase inhibitor) concentration-dependently inhibitedboth tube formation and migration of human umbilical vein endothelialcells (HUVECs) induced by vascular endothelial growth factor-A(VEGF-A). In addition, VME inhibited VEGF-A-induced proliferationof HUVECs. VME inhibited VEGF-A-induced phosphorylations ofextracellular signal-regulated kinase 1/2 (ERK 1/2) and serine/threonineprotein kinase family protein kinase B (Akt), but not that ofphospholipase C (PLC). In an in vivo assay, intravitreal administrationof VME inhibited the formation of neovascular tufts during oxygen-inducedretinopathy in mice. Thus, VME inhibited angiogenesis both invitro and in vivo, presumably by inhibiting the phosphorylationsof ERK 1/2 and Akt. These findings indicate that VME may beeffective against retinal diseases involving angiogenesis, providingit can reach the retina after its administration. Further investigationswill be needed to clarify the major angiogenesis-modulatingconstituent(s) of VME.
Angiogenesis is the process by which blood vessels are formedfrom pre-existing ones. In adults, physiological angiogenesisis observed only at restricted sites, such as the endometriumand ovarian follicle, and it is normally transient. However,abnormal angiogenesis causes many ocular diseases, such as diabeticretinopathy (1), age-related macular degeneration (2) and neovascular glaucoma (3). Previous studies have revealed that angiogenesisis explicitly increased by several growth factors, such as VEGF(4), basic fibroblast growth factor (5) and platelet-derivedgrowth factor (6).
Galardy et al. (7) reported that a carcinoma extract implantedin the rat cornea can be used to stimulate angiogenesis fromthe vessels of the limbus, and also that continuous administrationof GM6001, a broad-spectrum matrix metalloproteinase (MMP) inhibitor,reduced both the vessel number and vessel area. More recently,Koike et al. (8) found that GM6001 decreases tubulogenesis inmicrovascular endothelial cells from young humans. These findings suggest that MMP plays a pivotal role in angiogenesis, and that MMP inhibitors may be effective angiostatic agents.
Vaccinium myrtillus (Bilberry), a member of the Ericaceous family,can be found in the mountains and forests of Europe and NorthAmerica. Vaccinium myrtillus extracts (VME) containing 15 differentanthocyanins (9,10) have been shown to possess potent antioxidantproperties (9), stabilize collagen fibers and promote collagenbiosynthesis (11) and inhibit platelet aggregation (12). Animalstudies have demonstrated VME to be of benefit in improvingvascular tone, blood flow and vasoprotection (13,14). When administeredto healthy subjects or to patients with visual disorders, VME(either alone or in combination with β-carotene and vitaminE) induces a significant improvement in night vision, a quickeradaptation to darkness and a more rapid restoration of visualacuity following exposure to a flash of bright light (11). Hence,bilberries (or VME) have been utilized as a popular edible aidor supplement for asthenopia and improved visual function. Furthermore,an extract of V. myrtillus fruits (a low concentration of anthocyanosidesin a highly purified extract) has been reported to induce significantimprovements in ophthalmoscopic and angiographic images in diabeticor hypertensive patients (15), but it has remained unclear whetherit inhibits angiogenesis.
Roy et al. (16) noted that in the human keratinocytes cell-lineHaCaT, VEGF expression is decreased by a variety of berry seeds,such as bilberry, raspberry, strawberry, blueberry and optiberry(a blend of wild blueberry, strawberry, cranberry and raspberryseeds, and elderberry and wild bilberry samples). They alsoobserved that optiberry inhibits the tube formation among humanmicrovascular endothelial cells induced by basement proteinsfrom mouse tumors. These findings suggest that certain berryseeds have inhibitory actions against angiogenesis, although,the precise mechanism remains unclear. We therefore examinedthe in vitro effects of VME on the angiogenesis (tube formation,and cell proliferation and migration) and phosphorylation ofextracellular signal-regulated kinase 1/2 (ERK 1/2), phospholipaseC (PLC) and serine/threonine protein kinase family protein kinaseB (Akt) that are induced by vascular endothelial growth factor-A(VEGF-A). We also evaluated the in vivo effects of VME on oxygen-inducedretinopathy in mice.
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