Prospective study of incident age-related macular degeneration in relation to vigorous physical activity during a 7-year follow-up

Genetically determined physical activity levels, sedentary behaviours, and their association with the risk of age-related macular degeneration

OBJECTIVE

To investigate the causal effects of physical activity and sedentary traits on risk of Age-related macular degeneration (AMD).

METHODS

A two-sample Mendelian randomization (MR) analysis was used to investigate the causal relationship between physical activity and risk of AMD. We used genome-wide association studies (GWAS) summary statistics from two publicly available biobank-scale cohorts: UK Biobank and FinnGen. Physical activity data were self-reported by 703,901 UK Biobank participants and sedentary behaviour data were gathered from 159,606 FinnGen participants. Our analysis primarily used the inverse variance weighted (IVW) method.

RESULT

Engaging in moderate-to-vigorous physical activity significantly reduced the risk of AMD with an odds ratio of 0.77 (95% CI: 0.66-0.89). However, leisure screen time showed a slight but non-statistically significant upward trend. Sedentary behaviour at work, sedentary commuting showed no causal effects on AMD risk.

CONCLUSIONS

This study used MR analysis to examine the causal relationship between physical activity, sedentary behaviour, and AMD. It offers genetic evidence suggesting that physical activity may protect against AMD, emphasizing the significance of lifestyle factors in maintaining ocular health.

Macular Pigment Assessment in Indian Population Using Degree of Polarization Threshold: Impact of Diet on Macular Pigment Density

Purpose

To determine macular pigment (MP) density scores in healthy Indians and examine correlations with demographic and lifestyle variables.

Methods

We observed 484 Indians without an ocular pathology. Body mass index (BMI) and self-reported lifestyle factors (sunglasses usage, physical activity, and smoking) were noted. MP density was assessed as the threshold of perception of the shadow of their macular pigments on their retina using a new MP assessment tool (MP-eye). Lutein and zeaxanthin intake was assessed using a prevalidated questionnaire regionally designed for the Indian diet. Clusters of participants were created for statistical analysis based on MP-eye scores secondarily to detect any relevant effects in very low, low, medium, and high ranges of MPs.

Results

Data analyzed included 235 males and 249 females with mean age of 36.1 ± 12.9 years (range, 14-72). The median MP-eye score was 6 (range, 0-10, with 10 being high). Most were non-smokers (413, 85.3%) and did not use sunglasses (438, 90.5%), and 314 (64.9%) had low physical activity. Diabetes was present in 62 participants (12.8%) and hypertension in 53 (10.9%). Advancing age (r = -0.209; P < 0.000) and BMI (r = -0.094; P = 0.038) had weak negative correlation with MP-eye scores. Hypertension was less prevalent (7/88) in the cluster with the highest median MP-eye score (P = 0.033). Dietary intake of MPs and other lifestyle factors did not correlate significantly with MP-eye score overall or when analyzed in clusters.

Conclusions

MP-eye scores of an Indian population were normally distributed. Higher age, high BMI, and presence of hypertension were weakly associated with lower MP-eye scores. The impact of diet on MPs requires further evaluation.

Translational Relevance

This normative regional database enables risk stratification of macular degeneration.

Complementary Approaches to Retinal Health Focusing on Diabetic Retinopathy

Diabetes mellitus affects carbohydrate homeostasis but also influences fat and protein metabolism. Due to ophthalmic complications, it is a leading cause of blindness worldwide. The molecular pathology reveals that nuclear factor kappa B (NFκB) has a central role in the progression of diabetic retinopathy, sharing this signaling pathway with another major retinal disorder, glaucoma. Therefore, new therapeutic approaches can be elaborated to decelerate the ever-emerging "epidemics" of diabetic retinopathy and glaucoma targeting this critical node. In our review, we emphasize the role of an improvement of lifestyle in its prevention as well as the use of phytomedicals associated with evidence-based protocols. A balanced personalized therapy requires an integrative approach to be more successful for prevention and early treatment.

The effect of moderate-intensity aerobic exercise on non-proliferative diabetic retinopathy in type II diabetes mellitus patients: A clinical trial

INTRODUCTION

Diabetic retinopathy (DR) is one of the most threatening complications of diabetes and a leading cause of visual loss in working-age population. Although exercise is beneficial in diabetes, previous studies have showed contradictory and inconclusive results on how it effects DR. In this study, we aimed to investigate the effect of moderate-intensity aerobic exercise on non-proliferative diabetic retinopathy.

MATERIALS & METHODS

In this before-after clinical trial, 40 patients with diabetic retinopathy were enrolled by convenient sampling method in Shahid Labbafinejad Hospital in Tehran during 2021-2022. Before the intervention, central macular thickness (CMT, microns) measured by optical coherence tomography (OCT) and fasting blood sugar (FBS, mg/dl) were obtained. Then, patients took part in a 12-week moderate-intensity aerobic exercise (3 sessions per week, each session 45 min). Data were analyzed using SPSS version 26.0.

RESULTS

Out of 40 examined patients, 21 (52.5 %) were male and 19 (47.5 %) were female. The mean age of the patients was 50.8 years. The mean rank of FBS (mg/dl) significantly decreased from 21.12 before the exercise to 8.75 after the exercise (p < 0.001). Also, the mean rank of CMT (microns) showed a significant decrease from 21.11 before the intervention to 16.20 after the exercise (p < 0.001). There was a significant positive correlation between patients' age and FBS (mg/dl) before (rho = 0.457, p = 0.003) and after (rho = 0.365, p = 0.021) the intervention. Also, a significant positive correlation was found between patients' age and CMT (microns) before (rho = 0.525, p = 0.001) and after (rho = 0.461, p = 0.003) moderate exercise.

CONCLUSION

Moderate-intensity aerobic exercise leads to lower FBS (mg/dl) and CMT (microns) in patients with diabetic retinopathy, so it may be beneficial for diabetic patients to avoid sedentary lifestyle.

Voluntary exercise modulates pathways associated with amelioration of retinal degenerative diseases

Background: Exercise has been shown to promote a healthier and longer life and linked to a reduced risk of developing neurodegenerative diseases including retinal degenerations. However, the molecular pathways underpinning exercise-induced cellular protection are not well understood. In this work we aim to profile the molecular changes underlying exercise-induced retinal protection and investigate how exercise-induced inflammatory pathway modulation may slow the progression of retinal degenerations. Methods: Female C57Bl/6J mice at 6 weeks old were given free access to open voluntary running wheels for a period of 28 days and then subjected to 5 days of photo-oxidative damage (PD)-induced retinal degeneration. Following, retinal function (electroretinography; ERG), morphology (optical coherence tomography; OCT) and measures of cell death (TUNEL) and inflammation (IBA1) were analysed and compared to sedentary controls. To decipher global gene expression changes as a result of voluntary exercise, RNA sequencing and pathway and modular gene co-expression analyses were performed on retinal lysates of exercised and sedentary mice that were subjected to PD, as well as healthy dim-reared controls. Results: Following 5 days of PD, exercised mice had significantly preserved retinal function, integrity and reduced levels of retinal cell death and inflammation, compared to sedentary controls. In response to voluntary exercise, inflammatory and extracellular matrix integrity pathways were significantly modulated, with the gene expression profile of exercised mice more closely trending towards that of a healthy dim-reared retina. Conclusion: We suggest that voluntary exercise may mediate retinal protection by influencing key pathways involved in regulating retinal health and shifting the transcriptomic profile to a healthy phenotype.

The Assessment of Acute Chorioretinal Changes Due to Intensive Physical Exercise in Senior Elite Athletes

Regular physical exercise is known to lower the incidence of age-related eye diseases. We aimed to assess the acute chorioretinal alterations in older adults following intense physical strain. Seventeen senior elite athletes were recruited who underwent an aerobic exercise on a cycle ergometer and macular scanning by optical coherence tomography. A significant thinning of the entire retina was observed 1 min after exercise, followed by a thickening at 5 min, after which the thickness returned to baseline. This trend was similar in almost every single retinal layer, although a significant change was observed only in the inner retina. Choroidal thickness changes were neither significant nor did they correlate with the thickness changes of intraretinal layers. The mechanism of how these immediate retinal changes chronically impact age-related sight-threatening pathologies that, in turn, result in a substantially reduced quality of life warrants further investigation on nontrained older adults as well.

Correlation between genetic and environmental risk factors for age-related macular degeneration in Brazilian patients

PURPOSE

To analyze the correlations between age-related macular degeneration (AMD) and genetic and environmental risk factors for in a Brazilian population.

DESIGN

Cross-sectional study with a control group.

METHODS

We collected data on 236 participants 50 years of age or older (141 with AMD and 95 controls without the disease). Data was obtained using a questionnaire and included information on demographics, ocular and medical history, family history of AMD, lifestyle, and smoking and drinking habits. Genetic evaluations included direct sequencing for the LOC387715 (rs10490924) variant, as well as PCR and enzymatic digestion for the CFH Y402H (rs1061170) and HTRA1 (rs11200638) variants. We performed a risk assessment of environmental risk factors and genetic variants associated with AMD and determined correlations between AMD and the data collected using multiple linear regression analysis.

RESULTS

Of the 141 AMD cases, 99 (70%) had advanced AMD in at least one eye (57% neovascular AMD and 13% geographic atrophy), and 42 (30%) had not-advanced AMD. Family history of AMD (OR: 6.58; 95% CI: 1.94-22.31), presence of cardiovascular disease (CVD) (OR: 2.39; 95% CI: 1.08-5.28), low physical activity level (OR: 1.39; 95% CI: 0.82-2.37), and high serum cholesterol (OR: 1.49; 95% CI: 0.84-2.65) were associated with an increased risk for AMD. There was a significant association between CVD and incidence of advanced AMD (OR: 2.29; 95% CI 0.81-6.44). The OR for the risk allele of the LOC387715 gene, the CFH gene and the HTRA1 gene were 2.21 (95% CI: 1.47-3.35), 2.27 (95% CI: 1.52-3.37), and 2.76 (95% CI: 1.89-4.03), respectively. In the stepwise multiple linear regression analyses, the HTRA1 and CFH risk alleles, family history of AMD, the LOC387715 risk allele, and CVD were associated with an increased risk of AMD for a total of 25.6% contribution to the AMD phenotype.

CONCLUSIONS

The analysis correlating environmental and genetic risk factors such as family history of AMD, and CVD and the variants of HTRA1, CFH, and LOC387715 genes showed an expressive contribution for the development of AMD among this admixed population.

Running to save sight: The effects of exercise on retinal health and function

The benefits of exercise to human health have long been recognised. However, only in the past decade have researchers started to discover the molecular benefits that exercise confers, especially to the central nervous system (CNS). These discoveries include the magnitude of molecular messages that are communicated from skeletal muscle to the CNS. Despite these advances in understanding, very limited studies have been conducted to decipher the molecular benefits of exercise in retinal health and disease. Here, we review the latest work on the effects of exercise on the retina and discuss its effects on the wider CNS, with a focus on demonstrating the potential applicability and comparative molecular mechanisms that may be occurring in the retina. This review covers the key molecular pathways where exercise exerts its effects: oxidative stress and mitochondrial health; inflammation; protein aggregation; neuronal health; and tissue crosstalk via extracellular vesicles. Further research on the benefits of exercise to the retina and its molecular messages within extracellular vesicles is highly topical in this field.

Evaluation of the effect of high-intensity interval training on macular microcirculation via swept-source optical coherence tomography angiography in young football players

Purpose:

This study was conducted to evaluate the effect of high intensity interval training (HIIT) on macular microcirculation, measured by swept source optical coherence tomography angiography (ss OCTA) in young football players.

Methods:

Football players between 18–20 years old were included. After a detailed ophthalmological examination, physiological parameters, including height, body weight, body fat, systemic blood pressure, hematocrit values, oxygen saturation, and heart rate, were recorded. Intraocular pressure and ss OCTA parameters were measured one day before and the day after the high intensity interval training program using DRI OCT Triton (Topcon, Tokyo, Japan) between 11:00 am and 1:00 pm.

Results:

Fifteen participants completed the study. All were males with a mean age of 18.1 ± 0.4 years. Systolic and diastolic blood pressure and oxygen saturation did not change significantly (P > 0.05), while hematocrit levels increased remarkably (P = 0.049) after the HIIT program. Heart rates and intraocular pressure decreased (P = 0.003, P = 0.017, respectively). There was a significant increase in the central vessel density in deep capillary plexus (before: 18.7 ± 3.8%, after: 21.1 ± 4.5%) and central vessel density in choriocapillaris (before: 54.5 ± 2.8%, after 56.9 ± 2.2%) (P = 0.02, P = 0.02, respectively), although no changes were observed in other ss OCTA or in the central macular thickness and subfoveal choroidal thickness.

Conclusion:

A 6 week, high intensity interval training program with three exercise sessions per week seems not to alter mean superficial vascular densities, deep foveal avascular zone, and superficial foveal avascular zones, central macular thickness, or subfoveal choroidal thickness, while the central deep vascular density and central choriocapillaris vascular density increased remarkably among ss OCTA parameters.

Prevention of the Onset of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) represents the leading cause of irreversible blindness in elderly people, mostly after the age of 65. The progressive deterioration of visual function in patients affected by AMD has a significant impact on quality of life and has also high social costs. The current therapeutic options are only partially able to slow down the natural course of the disease, without being capable of stopping its progression. Therefore, better understanding of the possibilities to prevent the onset of the disease is needed. In this regard, a central role is played by the identification of risk factors, which might participate to the development of the disease. Among these, the most researched are dietary risk factors, lifestyle, and light exposure. Many studies showed that a higher dietary intake of nutrients, such as lutein, zeaxanthin, beta carotene, omega-3 fatty acids and zinc, reduced the risk of early AMD. Regarding lifestyle habits, the association between smoking and AMD is currently accepted. Finally, retinal damage caused by ultraviolet rays and blue light is also worthy of attention. The scope of this review is to summarize the present knowledge focusing on the measures to adopt in order to prevent the onset of AMD.

The impact of vascular risk factors on the thickness and volume of the choroid in AMD patients

Disturbances in choroidal microcirculation may lead to the onset and progression of age-related macular degeneration (AMD). We aimed to assess changes in the choroidal volume and thickness in the macular region in AMD eyes and to investigate whether coexisting vascular risk factors alter choroidal status. We enrolled 354 AMD patients (175 dry, 179 wet AMD) and 121 healthy controls. All participants underwent a complete ophthalmologic examination and assessment of choroidal thickness and volume. A multivariate analysis adjusted for age, sex, and smoking status revealed that wet AMD was an independent factor associated with higher average thickness of the central ring area (ATC) and average volume of the central ring area (AVC) and lower choroidal vascularity index (CVI) compared to controls (β =  + 0.18, p = 0.0007, β =  + 0.18, p = 0.0008, respectively) and to dry AMD (β =  + 0.17, p = 0.00003 for both ATC and AVC and β =  - 0.30 p < 0.0001 for CVI). ATC, AVC and average volume (AV) were lower in AMD patients with hypertension and ischaemic heart disease (IHD). The duration of hypertension was inversely correlated with ATC, AVC and AV (Rs =  - 0.13, p < 0.05; Rs =  - 0.12; p < 0.05, Rs =  - 0.12; p < 0.05, respectively) while IHD duration negatively correlated with AV (Rs =  - 0.15, p < 0.05). No such associations were observed in the control group. Our findings show that the choroidal vascular system in eyes with AMD is much more susceptible to damage in the presence than in the absence of systemic vascular disease.

Oxidative stress as a therapeutic target for the prevention and treatment of early age-related macular degeneration

Age-related macular degeneration, the leading cause of irreversible visual loss among older adults in developed countries, is a chronic, multifactorial, and progressive disease with the development of painless, central vision loss. Retinal pigment epithelial cell dysfunction is a core change in age-related macular degeneration that results from aging and the accumulated effects of genetic and environmental factors that, in part, is both caused by and leads to oxidative stress. In this review, we describe the role of oxidative stress, the cytoprotective oxidative stress pathways, and the impact of oxidative stress on critical cellular processes involved in age-related macular degeneration pathobiology. We also offer targeted therapy that may define how antioxidant therapy can either prevent or improve specific stages of age-related macular degeneration.

Aerobic exercise delays retinal ganglion cell death after optic nerve injury

Aerobic exercise has been shown to play a crucial role in preventing neurological diseases and improving cognitive function. In the present study, we investigated the effect of treadmill training on retinal ganglion cells (RGCs) following optic nerve transection in adult rats. We exercised the rats on a treadmill for 5 d/week (30 min/d at a rate of 9 m/min) or placed control rats on static treadmills. After 3 weeks of exercise, the left optic nerve of each rat was transected. After the surgery, the rat was exercised for another week. The percentages of surviving RGCs in the axotomized eyes of inactive rats were 67% and 39% at 5 and 7 days postaxotomy, respectively. However, exercised rats had significant more RGCs at 5 (74% survival) and 7 days (48% survival) after axotomy. Moreover, retinal brain-derived neurotrophic factor (BDNF) protein levels were significantly upregulated in response to exercise compared with those in the axotomized eyes of inactive rats. Blocking BNDF signaling during exercise by intraperitoneal injections of ANA-12, a BDNF tropomyosin receptor kinase (TrkB) receptor antagonist, reduced the number of RGCs in exercised rats to the level of RGCs in the inactive rats, effectively abolishing the protection of RGCs afforded by exercise. The results suggest that treadmill training effectively rescues RGCs from neurodegeneration following optic nerve transection by upregulating the expression of BDNF.

Findings from Optometrists' Practices in Advising about Lifestyle Study

SIGNIFICANCE

Lifestyle influences eye health and other chronic diseases. All health care providers, not just primary care physicians, should have the necessary information and training to advise and refer patients on lifestyle to take advantage of opportunities to provide such advice.

PURPOSE

The extent to which optometrists offer lifestyle advice to their patients is largely unknown. The Optometrists' Practices in Advising about Lifestyle (OPAL) study aimed to examine lifestyle advice that optometrists offer, to whom such advice is offered, and reasons for not offering this advice.

METHODS

We developed and administered a mail-in survey to 140 optometrists in Western New York.

RESULTS

Five surveys were returned because of death, retirement, and relocation. Of the 135 remaining eligible participants, 46 of the optometrists contacted responded to our survey; however, only 42 (31%) provided signed consent forms. Of these, more than 93% report offering advice on smoking, dietary supplements, and diet, and >59% reported offering on physical activity and alcohol use. Eighty-three percent offer advice to only those with unhealthy behaviors or certain conditions. Most advice consisted of mentioning the lifestyle factor's influence on eye or overall health. Reasons for not offering advice included lack of knowledge or training or the belief that advice would not change behaviors.

CONCLUSIONS

Optometrists reported offering advice primarily to those with unhealthy lifestyle behaviors or pre-existing health conditions. Future studies should address low response rates, include nonphysician health care providers in addition to optometrists, and also examine patients' perceptions and understanding of the advice offered to better understand whether this advice is received as the provider envisioned.

Voluntary Exercise Suppresses Choroidal Neovascularization in Mice

Purpose

To determine the effect of voluntary exercise on choroidal neovascularization (CNV) in mice.

Methods

Age-matched wild-type C57BL/6J mice were housed in cages equipped with or without running wheels. After four weeks of voluntary running or sedentariness, mice were subjected to laser injury to induce CNV. After surgical recovery, mice were placed back in cages with or without exercise wheels for seven days. CNV lesion volumes were measured by confocal microscopy. The effect of wheel running only in the seven days after injury was also evaluated. Macrophage abundance and cytokine expression were quantified.

Results

In the first study, exercise-trained mice exhibited a 45% reduction in CNV volume compared to sedentary mice. In the replication study, a 32% reduction in CNV volume in exercise-trained mice was observed (P = 0.029). Combining these two studies, voluntary exercise was found to reduce CNV by 41% (P = 0.0005). Exercise-trained male and female mice had similar CNV volumes (P = 0.99). The daily running distance did not correlate with CNV lesion size. Exercise only after the laser injury without a preconditioning period did not reduce CNV size (P = 0.41). CNV lesions of exercise-trained mice also exhibited significantly lower F4/80+ macrophage staining and Vegfa and Ccl2 mRNA expression.

Conclusions

These findings provide the first experimental evidence that voluntary exercise improves CNV outcomes. These studies indicate that exercise before laser treatment is required to improve CNV outcomes.

Impact of visual impairment on physical activity in early and late age-related macular degeneration

BACKGROUND

Modifiable risk factors for age-related macular degeneration (AMD) include smoking, nutrition and likely physical activity (PA). Levels of PA, however, are impacted by any visual impairment which makes the assessment of any association with AMD difficult.

PURPOSE

To assess the impact of visual impairment under both high and low luminance conditions on levels of PA in early and late AMD.

METHODS

Ninety participants with early to late AMD underwent a clinical assessment including conventional best-corrected visual acuity, low luminance visual acuity, contrast sensitivity and the Moorfields acuity test. PA was recorded using a wrist-worn accelerometer (GENEActiv, Activeinsights) on seven consecutive days. Patient characteristics were compared with the Wilcoxon rank-sum test and determinants of moderate-to-vigorous-PA (MVPA) were assessed using linear regression models.

RESULTS

Mean age was 73.9 ± 8.5 years (range 50-89) and 47 subjects (52.2%) were women. Average MVPA time was longer in the early (355.1 ± 252.0 minutes/week) compared to the late AMD group (162.2 ± 134.6 minutes/week; p<0.001). Using linear regression, age [β = -0.25; 95% confidence interval (CI): -12.9; -0.8, p = 0.028] and AMD stage (β = -0.28; 95% CI: -230.9, -25.0; p = 0.015) but not visual impairment on any of the employed tests were associated with MVPA (minutes/week).

CONCLUSIONS

We found late AMD to be associated with reduced PA. As performance on any of the visual tests was not associated with PA, this association cannot entirely be explained by functional impairment. More research is needed to further explore the association of PA and AMD as PA may be a potentially modifiable risk factor.

Optometry Australia's chairside reference for the diagnosis and management of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in people over the age of 50 years in Australia. Optometry Australia has developed this AMD chairside reference in consultation with a member-based working group comprised of experienced practitioners. It provides an evidence-based approach to current best practice in the diagnosis and management of AMD. Optometrists should be competent in assessing patients with or at risk of developing AMD, so that they are able to provide evidence-based management including appropriate communication, diagnosis and referral when indicated. This AMD chairside reference covers risk factors for the development of AMD or progression to late-stage AMD; the current clinical classification of AMD; common signs and symptoms; optometric assessment including ocular imaging and biomarkers; differential diagnoses; and management of early, intermediate and late AMD. Optometry Australia's chairside reference is intended as a general guide for optometrists, and is not a formal management protocol.

Awareness of Age-Related Macular Degeneration in Community-Dwelling Elderly Persons in Germany

Background: Due to current demographic trends age-related macular degeneration (AMD) is becoming more prevalent. When disease progresses to late-stage neovascular AMD, rapid initiation of treatment is required to achieve optimal outcomes. However, many affected individuals may be unaware of their disease impeding and delaying care seeking. Therefore, in an exploratory study we assessed whether elderly persons living independently in the community were aware of their AMD. Methods: Participants were recruited in eleven seniors' community centers. Participants underwent a standardized interview followed by non-mydriatic fundus photography of the macula and the optic disc in both eyes (Canon CR-2AF, Canon, New York, USA). The images were graded by an ophthalmologist and the data were analyzed descriptively. Results: A total of 281 participants (73.9 ± 8.1 years; 71.9% women) underwent bilateral fundus photography. The fundus photographs of 208 participants (74%; 73.6 ± 7.0 years; 73.1% women) could be graded. In a third (32.2%, n = 67) no pathological changes were detected. AMD was present in 24.5% of the examined subjects (n = 51). Half of the cases had early (47.1%), followed by intermediate (41.2%) and late (11.7%) AMD. Only one third (n = 16, 31.4%) were aware of their disease. Conclusions: A quarter of community dwelling elderly had AMD but only a third of these were aware of being affected with AMD. This confirms previous studies demonstrating low awareness for age-related eye diseases in the community. Considering the increase in population aging, awareness campaigns for AMD are needed.

Adherence to a Mediterranean diet, lifestyle and age-related macular degeneration: the Coimbra Eye Study - report 3

PURPOSE

To characterize the lifestyle and nutritional risk profile associated with the Mediterranean diet in a Portuguese population with and without age-related macular degeneration (AMD).

METHODS

Nested case-control study (n = 883) within the Coimbra Eye Study, including 434 subjects with AMD and 449 age- and sex-matched subjects without AMD. All enrolled subjects underwent a full risk assessment, including lifestyle-related risk factors and a thorough food frequency questionnaire. This allowed us to build an adherence score to the Mediterranean diet (mediSCORE, range 0-9) constructed from individual food intakes. Food intake was also further analysed by conversion to micronutrient consumption.

RESULTS

Our results suggest that physical activity has a protective role in AMD [p = 0.018 after multivariate adjustment, OR: 0.69 (0.51-0.93)]. High (mediSCORE ≥6) was also found to be protective [p = 0.041, OR: 0.62 (95% CI: 0.38-0.97)]. Food group analysis unveiled a specific protective role for increased fruits consumption (p = 0.029). Finally, micronutrient analysis revealed a protective role associated with increased consumption of caffeine, fibres, beta-carotene, vitamin C and vitamin E (p < 0.05).

CONCLUSION

High mediSCORE appears to confer protection against the development of AMD in a Mediterranean population. This effect is driven by increased consumption of fruits and some antioxidant micronutrients, which emerged as statistically significant protective factors. Further studies are required to establish dietary recommendations with clinical application.

[Physical activity in older persons with eye diseases : Applicability of wrist-worn accelerometer]

BACKGROUND AND OBJECTIVES

Physical activity (PA) impacts age-related diseases but its measurement is difficult. The acceptance of wrist-worn accelerometers (ACC) in older patients with eye diseases was evaluated and the results were compared with a validated activity questionnaire.

MATERIALS AND METHODS

In this study 50 patients underwent a clinical examination and were interviewed with the International Physical Activity Questionnaire (IPAQ). They then wore an ACC for 7 days and then for 30 days. After descriptive analysis of the data, influencing factors on the PA were assessed using multiple, linear models.

RESULTS

A total of 94% of participants wore the ACC for 7 days and 74% for 30 days. For 36 patients complete data were available. In comparison, IPAQ (e. g. moderate PA: 1183.4 ± 864.3 min/week) vs. ACC across 7 and 30 days (248.5 ± 266.0 min/week and 248.8 ± 190.6 min/week, respectively) showed substantially higher results (p < 0.05 for both intervals). The ACC data across 7 and 30 days were comparable (e. g. high PA: 25.4 ± 33.7 min/week and 22.5 ± 29.0 min/week). In multiple, linear models body mass index (BMI) was associated with 7 days moderate activity (β = -0.22 [95% confidence intervals CI: -21.7; -1.9]; p = 0.021) and vigorous activity (β = -0.35 [95% CI: -4.3; -0.5]; p = 0.033) as well as 30 days vigorous activity (β = -0.45 [95% CI: -5.9; -0.1]; p = 0.044). Other factors such as better visual acuity, age and gender were not associated.

CONCLUSION

The use of ACCs are acceptable to the majority of older patients with eye diseases. The results of ACC are more precise with lower variation, and much lower PA than those of a comparable activity questionnaire. Measurement over 7 days is sufficient for capturing the average PA in older patients and can be easily applied in clinical trials.

Adherence to a Mediterranean diet and its association with age-related macular degeneration. The Coimbra Eye Study-Report 4

OBJECTIVES

This study aimed to characterize the association of lifestyle and nutritional risk profiles with age-related macular degeneration (AMD) in two subpopulations with differing AMD prevalence.

METHODS

This case-control study (n = 1992) included 768 patients with AMD and 1224 age- and sex-matched participants without AMD with a single visit at a primary health care unit. Enrolled participants completed a validated lifestyle and food frequency questionnaire. A score to measure adherence to the Mediterranean diet (mediSCORE; Range, 0-9) was constructed from individual food intakes, which were further analyzed by conversion to nutrient consumption.

RESULTS

Higher adherence to the Mediterranean diet (mediSCORE ≥6) was significantly associated with no AMD (odds ratio [OR] = 0.73; P = 0.009). The subpopulation with lower AMD prevalence presented significantly higher adherence to the Mediterranean diet in relation to all individual food groups that comprised the mediSCORE (P < 0.014) with the exception of cereals. Food group analysis showed significant associations between the increased consumption of vegetables (OR = 0.63; P < 0.001) and fruit and nuts (OR = 0.78; P = 0.010) with no AMD. Nutrient analysis revealed that an increased ingestion of water, fibers, total fat, monounsaturated and polyunsaturated fatty acids, linoleic acid, vitamins A and C, carotene, alpha-tocopherol, folate, magnesium, iron, and zinc were significantly associated with no AMD (P < 0.0013). Finally, regular physical activity was associated with no AMD (P = 0.003).

CONCLUSIONS

High adherence to a Mediterranean diet and regular physical activity seem to be protective factors for AMD in a Portuguese population. The effect of the diet is likely driven by the increased consumption of vegetables, fruits, and nuts.

Physical Activity and Age-related Macular Degeneration: A Systematic Literature Review and Meta-analysis

PURPOSE

To better understand the association, in a white population, of physical activity and age-related macular degeneration (AMD)-the main cause of irreversible severe vision loss in developed countries-given the suggestion that a healthy lifestyle may assist in delaying the onset and progression of AMD.

DESIGN

Systematic review and meta-analysis.

METHODS

Medline, EMBASE, and Google Scholar were systematically searched for studies up to May 2015. Reference lists of published articles were hand searched and study authors were contacted to provide additional data. Those in the lowest category of activity in each study were compared with all other participants to assess the association between physical activity and both early and late AMD using random-effects meta-analysis.

RESULTS

Nine studies (subject age range 30-97 years) were included in the meta-analysis. Physical activity was found to have a protective association with both early AMD (8 studies, n = 38 112, odds ratio (OR) 0.92, 95% confidence interval [CI] 0.86-0.98) and late AMD (7 studies, n = 28 854, OR 0.59, 95% CI 0.49-0.72).

CONCLUSIONS

Physical activity is associated with lower odds of early and late AMD in white populations. These findings have important implications, reinforcing the public health message of staying active throughout life. However, further longitudinal studies are required to confirm and further characterize a protective effect of physical activity on the onset and/or progression of AMD.

Physical Activity and Quality of Life in Retinitis Pigmentosa

PURPOSE

Aerobic exercise has been found to be neuroprotective in animal models of retinal degeneration. This study aims to report physical activity levels in patients with RP and investigate the relationship between physical activity and vision-related quality-of-life (QOL).

MATERIALS AND METHODS

A retrospective study of adult patients with RP examined in 2005-2014. Physical activity levels were assessed using the Godin Exercise Questionnaire. The NEI-Visual Function Questionaire-25 (VFQ-25), SF-36 General Health survey, and Pepper Assessment Tool for Disability (PAT-D) were administered.

RESULTS

143 patients participated. 81 (56.6%) patients were classified as "active" and 62 (43.4%) as "insufficiently active" by Godin score. VFQ-25 revealed statistically significant differences between the active and insufficiently active patients, including overall visual function (53.3 versus 45.1, p = 0.010), color vision (73.8 versus 52.9, p < 0.001), and peripheral vision (34.3 versus 23.8, p = 0.021). The physical component of the SF-36 and the PAT-D survey also demonstrated statistically significant differences (47.2 versus 52.9, p = 0.002; 24.3 versus 30.0, p = 0.010). Active patients had a higher initial Goldmann visual field (GVF) score (74.8 versus 60.1 degrees, p = 0.255) and final GVF score (78.7 versus 47.1 degrees, p = 0.069) but did not reach statistical significance.

CONCLUSIONS

In RP, increased physical activity is associated with greater self-reported visual function and QOL.

Precursors of age-related macular degeneration: associations with vitamin A and interaction with CFHY402H in the Inter99 Eye Study

PURPOSE

To investigate associations of very early age-related macular degeneration (AMD) with daily intake of vitamin A, beta-carotene, vitamin E, vitamin C, zinc and copper and interactions with AMD-associated polymorphisms in complement factor H (CFHY402H) and ARMS2/LOC387715.

METHODS

Cross-sectional study of 848 subjects aged 30-60 years from the Inter99 Eye Study. Daily intake of vitamins and minerals was estimated from a 198-item food frequency questionnaire. Digital fundus photographs were recorded in red-free illumination and graded for macular drusen >63 μm and numerous (>20) small hard macular drusen as a mean of both eyes.

RESULTS

Higher intake of vitamin A increased the risk of having macular drusen >63 μm with odds ratio = 1.82 (CI₉₅ 1.02-3.24, p = 0.042) comparing participants in the highest quartile of vitamin A intake with participants in the lowest quartile, adjusted for recruitment group, age and sex. There was a significant interaction with CFHY402H (p = 0.038). Among 504 participants with CFHY402H, the relative risk of having macular drusen >63 μm was increased in participants in the highest quartile of vitamin A intake (odds ratio = 2.58; CI₉₅ 1.16-5.73, p = 0.020) and in the second highest quartile (odds ratio = 3.27; CI₉₅ 1.50-7.13, p = 0.0029) compared with the lowest quartile. Further adjusting for total fat intake, energy intake, plasma cholesterol, body mass index (BMI), smoking, alcohol intake, education and physical activity strengthened the association.

CONCLUSIONS

In this cross-sectional study, a higher intake of vitamin A increased the risk of macular drusen >63 μm in subjects with CFHY402H. The study supports that vitamin A may be a risk factor for early AMD.

Age-Related Macular Degeneration Is Associated with Less Physical Activity among US Adults: Cross-Sectional Study

BACKGROUND

We have a limited understanding of the effects of age-related macular degeneration (AMD) on physical activity (PA), and we have no prevalence estimates of the daily movement patterns among Americans with AMD. Therefore, we examined the association between AMD and PA and provided estimates of the daily movement patterns of Americans with AMD.

METHODS

Data from the 2005-2006 National Health and Nutrition Examination Survey were used, including 1,656 adults (40-85 yrs). Retinal imaging was performed to classify individuals as no AMD, early AMD, or late AMD. Participants wore an ActiGraph 7164 accelerometer for 7 days to measure PA behavior.

RESULTS

93.2% of participants with late AMD were in the least desirable group (not sufficiently active and having a negative light intensity-sedentary behavior balance). After adjustments (including age), participants with late AMD, as compared to those with no AMD, engaged in 50% less moderate-to-vigorous physical activity (MVPA) (RR = 0.50; 95% CI: 0.28-0.90). When visual acuity was entered into the model along with the other covariates, the association between late AMD and MVPA was no longer significant (RR = 0.54; 95% CI: 0.29-1.01), suggesting that visual acuity may partially mediate this relationship.

CONCLUSIONS

Individuals with late AMD engage in very little moderate-to-vigorous physical activity. Visually acuity, in part, explains the relationship between late AMD and PA.

Vitamin D deficiency in neovascular versus nonneovascular age-related macular degeneration

PURPOSE

To compare 25-hydroxyvitamin D (25OHD) levels in patients with neovascular age-related macular degeneration (NVAMD) with patients with nonneovascular age-related macular degeneration and control patients.

METHODS

Medical records of all patients diagnosed with age-related macular degeneration and tested for serum 25OHD level at a single medical center were reviewed. Control patients were selected from patients diagnosed with pseudophakia but without age-related macular degeneration. The lowest 25OHD level available for each patient was recorded.

RESULTS

Two hundred sixteen patients with nonneovascular age-related macular degeneration, 146 with NVAMD, and 100 non-age-related macular degeneration control patients were included. The levels of 25OHD (mean ± SD) were significantly lower in NVAMD patients (26.1 ± 14.4 ng/mL) versus nonneovascular age-related macular degeneration (31.5 ± 18.2 ng/mL, P = 0.003) and control (29.4 ± 10.1 ng/mL, P = 0.049) patients. The prevalence of vitamin D insufficiency (<30 ng/mL 25OHD), deficiency (<20 ng/mL), and severe deficiency (<10 ng/mL) were highest in the NVAMD group. The highest quintile of 25OHD was associated with a 0.35 (95% confidence interval, 0.18-0.68) odds ratio for NVAMD.

CONCLUSION

This is the largest study to compare 25OHD levels in patients with the different clinical forms of age-related macular degeneration. Mean 25OHD levels were lower and vitamin D deficiency was more prevalent in NVAMD patients. These associations suggest that further research is necessary regarding vitamin D deficiency as a potentially modifiable risk factor for the development of NVAMD.

Aerobic exercise protects retinal function and structure from light-induced retinal degeneration

Aerobic exercise is a common intervention for rehabilitation of motor, and more recently, cognitive function (Intlekofer and Cotman, 2013; Wood et al., 2012). While the underlying mechanisms are complex, BDNF may mediate much of the beneficial effects of exercise to these neurons (Ploughman et al., 2007; Griffin et al., 2011; Real et al., 2013). We studied the effects of aerobic exercise on retinal neurons undergoing degeneration. We exercised wild-type BALB/c mice on a treadmill (10 m/min for 1 h) for 5 d/week or placed control mice on static treadmills. After 2 weeks of exercise, mice were exposed to either toxic bright light (10,000 lux) for 4 h to induce photoreceptor degeneration or maintenance dim light (25 lux). Bright light caused 75% loss of both retinal function and photoreceptor numbers. However, exercised mice exposed to bright light had 2 times greater retinal function and photoreceptor nuclei than inactive mice exposed to bright light. In addition, exercise increased retinal BDNF protein levels by 20% compared with inactive mice. Systemic injections of a BDNF tropomyosin-receptor-kinase (TrkB) receptor antagonist reduced retinal function and photoreceptor nuclei counts in exercised mice to inactive levels, effectively blocking the protective effects seen with aerobic exercise. The data suggest that aerobic exercise is neuroprotective for retinal degeneration and that this effect is mediated by BDNF signaling.

Relation of smoking, drinking, and physical activity to changes in vision over a 20-year period: the Beaver Dam Eye Study

OBJECTIVE

To describe the relationships of lifestyle characteristics to changes in vision and incidence of visual impairment (VI) over a 20-year period in the Beaver Dam Eye Study (BDES).

DESIGN

Longitudinal, population-based cohort study.

PARTICIPANTS

A cohort of 4926 persons aged 43 to 86 years participated in the baseline examinations in 1988-1990, and 3721, 2962, 2375, and 1913 persons participated in follow-up examinations in 1993-1995, 1998-2000, 2003-2005, and 2008-2010, respectively.

METHODS

Best-corrected visual acuity (BCVA) measured by a modified Early Treatment Diabetic Retinopathy Study protocol.

MAIN OUTCOME MEASURES

Change in number of letters read correctly and incidence of VI based on BCVA in the better eye assessed at each examination over a 20-year period.

RESULTS

The 20-year cumulative incidence of VI was 5.4%. There was a mean loss of 1.6 letters between examinations, with a 20-year loss of 6.6 letters. While adjusting for age, income, and age-related macular degeneration (AMD) severity, being a current or past smoker was related to a greater change in the numbers of letters lost. Persons who had not consumed alcoholic beverages over the past year and sedentary persons had higher odds of incident VI than persons who drank occasionally or who were physically active. For example, in women with early AMD and annual household income less than $10,000, the estimated 20-year cumulative incidence of VI in those who drank occasionally and were physically active was 5.9% compared with 25.8% in women who had not consumed alcoholic beverages over the past year and were sedentary.

CONCLUSIONS

Three modifiable behaviors-smoking, drinking alcohol, and physical activity-were associated with changes in vision. Further evidence that changes in these behaviors will result in less loss of vision is needed because of the expected increase in the burden of VI due to the aging of the population.

Distance walked and run as improved metrics over time-based energy estimation in epidemiological studies and prevention; evidence from medication use

PURPOSE

The guideline physical activity levels are prescribed in terms of time, frequency, and intensity (e.g., 30 minutes brisk walking, five days a week or its energy equivalence) and assume that different activities may be combined to meet targeted goals (exchangeability premise). Habitual runners and walkers may quantify exercise in terms of distance (km/day), and for them, the relationship between activity dose and health benefits may be better assessed in terms of distance rather than time. Analyses were therefore performed to test: 1) whether time-based or distance-based estimates of energy expenditure provide the best metric for relating running and walking to hypertensive, high cholesterol, and diabetes medication use (conditions known to be diminished by exercise), and 2) the exchangeability premise.

METHODS

Logistic regression analyses of medication use (dependent variable) vs. metabolic equivalent hours per day (METhr/d) of running, walking and other exercise (independent variables) using cross-sectional data from the National Runners' (17,201 male, 16,173 female) and Walkers' Health Studies (3,434 male, 12,384 female).

RESULTS

Estimated METhr/d of running and walking activity were 38% and 31% greater, respectively, when calculated from self-reported time than distance in men, and 43% and 37% greater in women, respectively. Percent reductions in the odds for hypertension and high cholesterol medication use per METhr/d run or per METhr/d walked were ≥ 2-fold greater when estimated from reported distance (km/wk) than from time (hr/wk). The per METhr/d odds reduction was significantly greater for the distance- than the time-based estimate for hypertension (runners: P<10(-5) for males and P=0.003 for females; walkers: P=0.03 for males and P<10(-4) for females), high cholesterol medication use in runners (P<10(-4) for males and P=0.02 for females) and male walkers (P=0.01 for males and P=0.08 for females) and for diabetes medication use in male runners (P<10(-3)).

CONCLUSIONS

Although causality between greater exercise and lower prevalence of hypertension, high cholesterol and diabetes cannot be inferred from these cross-sectional data, the results do suggest that distance-based estimates of METhr/d run or walked provide superior metrics for epidemiological analyses to their traditional time-based estimates.

Complement in age-related macular degeneration: a focus on function

Age-related macular degeneration (AMD) is an inflammatory disease, which causes visual impairment and blindness in older people. The proteins of the complement system are central to the development of this disease. Local and systemic inflammation in AMD are mediated by the deregulated action of the alternative pathway of the complement system. Variants in complement system genes alter an individual's risk of developing AMD. Recent studies have shown how some risk-associated genetic variants alter the function of the complement system. In this review, we describe the evolution of the complement system and bring together recent research to form a picture of how changes in complement system genes and proteins affect the function of the complement cascade, and how this affects the development of AMD. We discuss the application of this knowledge to prevention and possible future treatments of AMD.

Lifestyle strategies for the prevention of vision loss

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

Healthy lifestyles related to subsequent prevalence of age-related macular degeneration

OBJECTIVE

To investigate the relationships between lifestyle behaviors of diet, smoking, and physical activity and the subsequent prevalence of age-related macular degeneration (AMD).

METHODS

The population included 1313 participants (aged 55-74 years) in the Carotenoids in Age-Related Eye Disease Study, an ancillary study of the Women's Health Initiative Observational Study. Scores on a modified 2005 Healthy Eating Index were assigned using responses to a food frequency questionnaire administered at baseline of the Women's Health Initiative Observational Study (1994-1998). Physical activity and lifetime smoking history were queried. An average of 6 years later, stereoscopic fundus photographs were taken to assess the presence and severity of AMD; it was present in 202 women, 94% of whom had early AMD, the primary outcome.

RESULTS

In multivariate models, women whose diets scored in the highest quintile compared with the lowest quintile on the modified 2005 Healthy Eating Index had 46% lower odds for early AMD. Women in the highest quintile compared with those in the lowest quintile for physical activity (in metabolic energy task hours per week) had 54% lower odds for early AMD. Although smoking was not independently associated with AMD on its own, having a combination of 3 healthy behaviors (healthy diet, physical activity, and not smoking) was associated with 71% lower odds for AMD compared with having high-risk scores (P < .001).

CONCLUSION

Modifying lifestyles might reduce risk for early AMD as much as 3-fold, lowering the risk for advanced AMD in a person's lifetime and the social and economic costs of AMD to society.

Relationship of incident glaucoma versus physical activity and fitness in male runners

PURPOSE

To assess the dose-response relationship of vigorous physical activity (running distance, km x d(-1)) or cardiorespiratory fitness (meters-per-second pace during a 10-km footrace) to the risk for incident glaucoma.

DESIGN

Prospective epidemiologic cohort study.

METHODS

Participant-reported, physician-diagnosed incident glaucoma was compared with distance run per week and 10-km footrace performance in a cohort of 29,854 male runners without diabetes followed prospectively for 7.7 yr. The survival analyses were adjusted for age, hypertension, current and past cigarette use, and intakes of meat, fish, fruit, and alcohol.

RESULTS

Two hundred incident glaucoma cases were reported during follow-up. The risk for reported glaucoma decreased 37% per meter per second increment in a 10-km race performance (P = 0.005). Relative to the least fit men (i.e., slowest, < or = 3.5 m x s(-1)), the risk for incident-reported glaucoma declined 29% in those who ran 3.6-4.0 m x s(-1) (P = 0.06), 54% for those who ran 4.1-4.5 m x s(-1) (P = 0.001), 51% for those who ran 4.6-5.0 m x s(-1) (P = 0.04), and glaucoma was nonexistent among the 781 men who exceeded 5.0 m x s(-1) (P = 0.03). The risk for incident, reported glaucoma decreased 5% per kilometer per day run at baseline (P = 0.04), which remained significant when adjusted for the 10-km race performance (5% reduction per kilometer per day, P = 0.04), and both body mass index and race performance (P = 0.04). Baseline hypertension was unrelated to the incident glaucoma.

CONCLUSIONS

These data provide preliminary evidence that vigorous physical activity may reduce glaucoma risk, which, in the absence of medical record validation, could represent ocular hypertension in addition to frank glaucoma. Additional follow-up with validation is needed to identify the type of glaucoma affected.

Incident diverticular disease is inversely related to vigorous physical activity

PURPOSE

In 1995, the Health Professionals Follow-up Study published an isolated report of lower diverticular disease risk in physically active men, particularly among those who ran. The purpose of this article was to assess whether this finding can be verified among older men and women of the National Runners' Health Study.

METHODS

Survival analyses were applied to incident disease occurring during 7.7 yr of follow-up in 9072 men and 1664 women, representing 84% follow-up of the original >or=50-yr-old cohort. In addition to the usual running distance (km x d(-1)), 80% of the baseline respondents included 10-km footrace performance times (a measure of cardiorespiratory fitness). Results were adjusted for age, sex, and reported intakes of meat, fish, fruit, and alcohol.

RESULTS

A total of 127 men and 21 women reported clinically diagnosed diverticular disease since baseline. The risk for incident diverticular disease decreased 6.2% per km x d(-1) run (P = 0.04). Relative to men and women who ran <or=2 km x d(-1), those who ran an average of >8 km x d(-1) had 48% lower risk (P = 0.05). Each meter-per-second increment in the 10-km performance was associated with a 68% risk reduction (P = 0.04). Men and women who ran >4 m x s(-1) had 70% lower risk for diverticular disease than those who ran <or=2.8 m x s(-1) (P = 0.01), which persisted when adjusted for baseline body mass index (69% risk reduction, P = 0.02) or usual running distance (36% risk reduction, P = 0.03).

CONCLUSION

These results demonstrate an inverse association between vigorous physical activity and incident diverticular disease among older men and women but are limited by their reliance on self-reported physician diagnosis.