Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration

Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a degenerative condition of the back of the eye that occurs in people over the age of 50 years. Antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption. Higher dietary levels of antioxidant vitamins and minerals may reduce the risk of progression of AMD. This is the third update of the review.

OBJECTIVES

To assess the effects of antioxidant vitamin and mineral supplements on the progression of AMD in people with AMD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, one other database, and three trials registers, most recently on 29 November 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared antioxidant vitamin or mineral supplementation to placebo or no intervention, in people with AMD.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane.

MAIN RESULTS

We included 26 studies conducted in the USA, Europe, China, and Australia. These studies enroled 11,952 people aged 65 to 75 years and included slightly more women (on average 56% women). We judged the studies that contributed data to the review to be at low or unclear risk of bias. Thirteen studies compared multivitamins with control in people with early and intermediate AMD. Most evidence came from the Age-Related Eye Disease Study (AREDS) in the USA. People taking antioxidant vitamins were less likely to progress to late AMD (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.58 to 0.90; 3 studies, 2445 participants; moderate-certainty evidence). In people with early AMD, who are at low risk of progression, this means there would be approximately four fewer cases of progression to late AMD for every 1000 people taking vitamins (one fewer to six fewer cases). In people with intermediate AMD at higher risk of progression, this corresponds to approximately 78 fewer cases of progression for every 1000 people taking vitamins (26 fewer to 126 fewer). AREDS also provided evidence of a lower risk of progression for both neovascular AMD (OR 0.62, 95% CI 0.47 to 0.82; moderate-certainty evidence) and geographic atrophy (OR 0.75, 95% CI 0.51 to 1.10; moderate-certainty evidence), and a lower risk of losing 3 or more lines of visual acuity (OR 0.77, 95% CI 0.62 to 0.96; moderate-certainty evidence). Low-certainty evidence from one study of 110 people suggested higher quality of life scores (measured with the Visual Function Questionnaire) in treated compared with non-treated people after 24 months (mean difference (MD) 12.30, 95% CI 4.24 to 20.36). In exploratory subgroup analyses in the follow-on study to AREDS (AREDS2), replacing beta-carotene with lutein/zeaxanthin gave hazard ratios (HR) of 0.82 (95% CI 0.69 to 0.96), 0.78 (95% CI 0.64 to 0.94), 0.94 (95% CI 0.70 to 1.26), and 0.88 (95% CI 0.75 to 1.03) for progression to late AMD, neovascular AMD, geographic atrophy, and vision loss, respectively. Six studies compared lutein (with or without zeaxanthin) with placebo and one study compared a multivitamin including lutein/zeaxanthin with multivitamin alone. The duration of supplementation and follow-up ranged from six months to five years. Most evidence came from the AREDS2 study in the USA; almost all participants in AREDS2 also took the original AREDS supplementation formula. People taking lutein/zeaxanthin may have similar or slightly reduced risk of progression to late AMD (RR 0.94, 95% CI 0.87 to 1.01), neovascular AMD (RR 0.92, 95% CI 0.84 to 1.02), and geographic atrophy (RR 0.92, 95% CI 0.80 to 1.05) compared with control (1 study, 4176 participants, 6891 eyes; low-certainty evidence). A similar risk of progression to visual loss of 15 or more letters was seen in the lutein/zeaxanthin and control groups (RR 0.98, 95% CI 0.91 to 1.05; 6656 eyes; low-certainty evidence). Quality of life (Visual Function Questionnaire) was similar between groups (MD 1.21, 95% CI -2.59 to 5.01; 2 studies, 308 participants; moderate-certainty evidence). One study in Australia randomised 1204 people to vitamin E or placebo with four years of follow-up; 19% of participants had AMD. The number of late AMD events was low (N = 7) and the estimate of effect was uncertain (RR 1.36, 95% CI 0.31 to 6.05; very low-certainty evidence). There was no evidence of any effect of treatment on visual loss (RR 1.04, 95% CI 0.74 to 1.47; low-certainty evidence). There were no data on neovascular AMD, geographic atrophy, or quality of life. Five studies compared zinc with placebo. Evidence largely drawn from the largest study (AREDS) found a lower progression to late AMD over six years (OR 0.83, 95% CI 0.70 to 0.98; 3 studies, 3790 participants; moderate-certainty evidence), neovascular AMD (OR 0.76, 95% CI 0.62 to 0.93; moderate-certainty evidence), geographic atrophy (OR 0.84, 95% CI 0.64 to 1.10; moderate-certainty evidence), or visual loss (OR 0.87, 95% CI 0.75 to 1.00; 2 studies, 3791 participants; moderate-certainty evidence). There were no data on quality of life. Gastrointestinal symptoms were the main reported adverse effect. In AREDS, zinc was associated with a higher risk of genitourinary problems in men, but no difference was seen between high- and low-dose zinc groups in AREDS2. Most studies were too small to detect rare adverse effects. Data from larger studies (AREDS/AREDS2) suggested there may be little or no effect on mortality with multivitamin (HR 0.87, 95% CI 0.60 to 1.25; low-certainty evidence) or lutein/zeaxanthin supplementation (HR 1.06, 95% CI 0.87 to 1.31; very low-certainty evidence), but confirmed the increased risk of lung cancer with beta-carotene, mostly in former smokers.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence suggests that antioxidant vitamin and mineral supplementation (AREDS: vitamin C, E, beta-carotene, and zinc) probably slows down progression to late AMD. People with intermediate AMD have a higher chance of benefiting from antioxidant supplements because their risk of progression is higher than people with early AMD. Although low-certainty evidence suggested little effect with lutein/zeaxanthin alone compared with placebo, exploratory subgroup analyses from one large American study support the view that lutein/zeaxanthin may be a suitable replacement for the beta-carotene used in the original AREDS formula.

Cordyceps militaris Carotenoids Protect Human Retinal Endothelial Cells against the Oxidative Injury and Apoptosis Resulting from H2O2

Vision loss is primarily caused by age-related macular degeneration (AMD) due to oxidative retinal pigment epithelial (RPE) cell injury. Carotenoid utilization is deemed a possible strategy for treating AMD. Cordyceps militaris has advantages like immunomodulatory, anti-inflammatory, and antioxidative characteristics. This paper assessed the possible protective influence of carotenoids obtained by isolating and purifying the Cordyceps militaris (CMCT) into human RPE cells (ARPE-19) damaged by hydrogen peroxide (H₂O₂). The findings demonstrated that CMCT safeguarded the ARPE-19 cells against the damage and apoptosis caused by H₂O₂ and oxidative stress via Bcl-2 protein upregulation, as well as the expression of Bax and cleaved caspase-3 protein. In addition, CMCT treatment increased cell survival and restricted the generation of H₂O₂-induced reactive oxygen species (ROS) and the protein expression of NADPH oxidase-1 (NOX1). Additionally, the CMCT treatment of H₂O₂-induced ARPE-19 cells ameliorated high malondialdehyde (MDA) levels in oxidative stress-induced cells. The catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) returned to standard levels, which were governed by the higher expression of nuclear Nrf2 protein in the ARPE-19 cells. Moreover, this study showed that CMCT safeguarded the ARPE-19 cells against the damage caused by oxidative stress via its antioxidant activity and antiapoptotic functionality, suggesting the potential therapeutic role of CMCT in AMD prevention and mitigation.

Zinc and Autophagy in Age-Related Macular Degeneration

Zinc supplementation is reported to slow down the progression of age-related macular degeneration (AMD), but there is no general consensus on the beneficiary effect on zinc in AMD. As zinc can stimulate autophagy that is declined in AMD, it is rational to assume that it can slow down its progression. As melanosomes are the main reservoir of zinc in the retina, zinc may decrease the number of lipofuscin granules that are substrates for autophagy. The triad zinc–autophagy–AMD could explain some controversies associated with population studies on zinc supplementation in AMD as the effect of zinc on AMD may be modulated by genetic background. This aspect was not determined in many studies regarding zinc in AMD. Zinc deficiency induces several events associated with AMD pathogenesis, including increased oxidative stress, lipid peroxidation and the resulting lipofuscinogenesis. The latter requires autophagy, which is impaired. This is a vicious cycle-like reaction that may contribute to AMD progression. Promising results with zinc deficiency and supplementation in AMD patients and animal models, as well as emerging evidence of the importance of autophagy in AMD, are the rationale for future research on the role of autophagy in the role of zinc supplementation in AMD.

Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration

BACKGROUND

It has been proposed that antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption. Higher dietary levels of antioxidant vitamins and minerals may reduce the risk of progression of age-related macular degeneration (AMD).

OBJECTIVES

The objective of this review was to assess the effects of antioxidant vitamin or mineral supplementation on the progression of AMD in people with AMD.

SEARCH METHODS

We searched CENTRAL (2017, Issue 2), MEDLINE Ovid (1946 to March 2017), Embase Ovid (1947 to March 2017), AMED (1985 to March 2017), OpenGrey (System for Information on Grey Literature in Europe, the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 29 March 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared antioxidant vitamin or mineral supplementation (alone or in combination) to placebo or no intervention, in people with AMD.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed risk of bias in the included studies and extracted data. One author entered data into RevMan 5; the other author checked the data entry. We graded the certainty of the evidence using GRADE.

MAIN RESULTS

We included 19 studies conducted in USA, Europe, China, and Australia. We judged the trials that contributed data to the review to be at low or unclear risk of bias.Nine studies compared multivitamins with placebo (7 studies) or no treatment (2 studies) in people with early and moderate AMD. The duration of supplementation and follow-up ranged from nine months to six years; one trial followed up beyond two years. Most evidence came from the Age-Related Eye Disease Study (AREDS) in the USA. People taking antioxidant vitamins were less likely to progress to late AMD (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.58 to 0.90; 2445 participants; 3 RCTs; moderate-certainty evidence). In people with very early signs of AMD, who are at low risk of progression, this would mean that there would be approximately 4 fewer cases of progression to late AMD for every 1000 people taking vitamins (1 fewer to 6 fewer cases). In people at high risk of progression (i.e. people with moderate AMD) this would correspond to approximately 8 fewer cases of progression for every 100 people taking vitamins (3 fewer to 13 fewer). In one study of 1206 people, there was a lower risk of progression for both neovascular AMD (OR 0.62, 95% CI 0.47 to 0.82; moderate-certainty evidence) and geographic atrophy (OR 0.75, 95% CI 0.51 to 1.10; moderate-certainty evidence) and a lower risk of losing 3 or more lines of visual acuity (OR 0.77, 95% CI 0.62 to 0.96; 1791 participants; moderate-certainty evidence). Low-certainty evidence from one study of 110 people suggested higher quality of life scores (National Eye Institute Visual Function Questionnaire) in treated compared with the non-treated people after 24 months (mean difference (MD) 12.30, 95% CI 4.24 to 20.36). Six studies compared lutein (with or without zeaxanthin) with placebo. The duration of supplementation and follow-up ranged from six months to five years. Most evidence came from the AREDS2 study in the USA. People taking lutein or zeaxanthin may have similar or slightly reduced risk of progression to late AMD (RR 0.94, 95% CI 0.87 to 1.01; 6891 eyes; low-certainty evidence), neovascular AMD (RR 0.92, 95% CI 0.84 to 1.02; 6891 eyes; low-certainty evidence), and geographic atrophy (RR 0.92, 95% CI 0.80 to 1.05; 6891 eyes; low-certainty evidence). A similar risk of progression to visual loss of 15 or more letters was seen in the lutein and control groups (RR 0.98, 95% CI 0.91 to 1.05; 6656 eyes; low-certainty evidence). Quality of life (measured with Visual Function Questionnaire) was similar between groups in one study of 108 participants (MD 1.48, 95% -5.53 to 8.49, moderate-certainty evidence). One study, conducted in Australia, compared vitamin E with placebo. This study randomised 1204 people to vitamin E or placebo, and followed up for four years. Participants were enrolled from the general population; 19% had AMD. The number of late AMD events was low (N = 7) and the estimate of effect was uncertain (RR 1.36, 95% CI 0.31 to 6.05, very low-certainty evidence). There were no data on neovascular AMD or geographic atrophy.There was no evidence of any effect of treatment on visual loss (RR 1.04, 95% CI 0.74 to 1.47, low-certainty evidence). There were no data on quality of life. Five studies compared zinc with placebo. The duration of supplementation and follow-up ranged from six months to seven years. People taking zinc supplements may be less likely to progress to late AMD (OR 0.83, 95% CI 0.70 to 0.98; 3790 participants; 3 RCTs; low-certainty evidence), neovascular AMD (OR 0.76, 95% CI 0.62 to 0.93; 2442 participants; 1 RCT; moderate-certainty evidence), geographic atrophy (OR 0.84, 95% CI 0.64 to 1.10; 2442 participants; 1 RCT; moderate-certainty evidence), or visual loss (OR 0.87, 95% CI 0.75 to 1.00; 3791 participants; 2 RCTs; moderate-certainty evidence). There were no data reported on quality of life.Very low-certainty evidence was available on adverse effects because the included studies were underpowered and adverse effects inconsistently reported.

AUTHORS' CONCLUSIONS

People with AMD may experience some delay in progression of the disease with multivitamin antioxidant vitamin and mineral supplementation. This finding was largely drawn from one large trial, conducted in a relatively well-nourished American population. We do not know the generalisability of these findings to other populations. Although generally regarded as safe, vitamin supplements may have harmful effects. A systematic review of the evidence on harms of vitamin supplements is needed. Supplements containing lutein and zeaxanthin are heavily marketed for people with age-related macular degeneration but our review shows they may have little or no effect on the progression of AMD.

Surgery for cataracts in people with age-related macular degeneration

BACKGROUND

Cataract and age-related macular degeneration (AMD) are common causes of decreased vision that often occur simultaneously in people over age 50. Although cataract surgery is an effective treatment for cataract-induced visual loss, some clinicians suspect that such an intervention may increase the risk of worsening of underlying AMD and thus have deleterious effects on vision.

OBJECTIVES

The objective of this review was to evaluate the effectiveness and safety of cataract surgery compared with no surgery in eyes with AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 11), Ovid MEDLINE, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE Daily (January 1946 to December 2016), Embase (January 1980 to December 2016), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to December 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 2 December 2016.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-randomized trials that enrolled participants whose eyes were affected by both cataract and AMD in which cataract surgery was compared with no surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated the search results against the inclusion and exclusion criteria. Two review authors independently extracted data, assessed risk of bias for included studies, and graded the certainty of evidence. We followed methods as recommended by Cochrane.

MAIN RESULTS

We included two RCTs with a total of 114 participants (114 study eyes) with visually significant cataract and AMD. We identified no ongoing trials. Participants in each RCT were randomized to immediate cataract surgery (within two weeks of enrollment) or delayed cataract surgery (six months after enrollment). The risk of bias was unclear for most domains in each study; one study was registered prospectively.In one study conducted in Australia outcomes were reported only at six months (before participants in the delayed-surgery group had cataract surgery). At six months, the immediate-surgery group showed mean improvement in best-corrected visual acuity (BCVA) compared with the delayed-surgery group (mean difference (MD) -0.15 LogMAR, 95% confidence interval (CI) -0.28 to -0.02; 56 participants; moderate-certainty evidence). In the other study, conducted in Austria, outcomes were reported only at 12 months (12 months after participants in the immediate-surgery group and six months after participants in the delayed-surgery group had cataract surgery). There was uncertainty as to which treatment group had better improvement in distance visual acuity at 12 months (unit of measure not reported; very low-certainty evidence).At 12 months, the mean change from baseline between groups in cumulated drusen or geographic atrophy area size was small and there was uncertainty which, if either, of the groups was favored (MD 0.76, 95% CI -8.49 to 10.00; 49 participants; low-certainty evidence). No participant in one study had exudative AMD develop in the study eye during 12 months of follow-up; in the other study, choroidal neovascularization developed in the study eye of 1 of 27 participants in the immediate-surgery group versus 0 of 29 participants in the delayed-surgery group at six months (risk ratio 3.21, 95% CI 0.14 to 75.68; 56 participants; very low-certainty evidence). Quality of life was measured using two different questionnaires. Scores on the Impact of Vision Impairment (IVI) questionnaire suggested that the immediate-surgery group fared better regarding vision-related quality of life than the delayed-surgery group at six months (MD in IVI logit scores 1.60, 95% CI 0.61 to 2.59; low-certainty evidence). However, we could not analyze scores from the Visual Function-14 (VF-14) questionnaire from the other study due to insufficient data. No postoperative complication was reported from either study.

AUTHORS' CONCLUSIONS

At this time, it is not possible to draw reliable conclusions from the available data as to whether cataract surgery is beneficial or harmful in people with AMD after 12 months. Although cataract surgery provides short-term (six months) improvement in BCVA in eyes with AMD compared with no surgery, it is unclear whether the timing of surgery has an effect on long-term outcomes. Physicians must make recommendations to their AMD patients regarding cataract surgery based on experience and clinical judgment until large controlled trials are conducted and their findings published.There is a need for prospective RCTs in which cataract surgery is compared with no surgery in people with AMD to better evaluate whether cataract surgery is beneficial or harmful in all or a subset of AMD patients. However, ethical considerations preclude withholding surgery, or delaying it for several years, if it may be a potentially beneficial treatment. Designers of future trials are encouraged to utilize existing standardized systems for grading cataract and AMD and for measuring key outcomes: visual acuity, change in visual acuity, worsening of AMD, quality of life measures, and adverse events.

Cochrane systematic reviews and co-publication: dissemination of evidence on interventions for ophthalmic conditions

BACKGROUND

Systematic reviews of interventions provide a summary of the evidence available on intervention effectiveness and harm. Cochrane systematic reviews (CSRs) have been published electronically in the Cochrane Database of Systematic Reviews (CDSR) since 1994, and co-publication (publication of a Cochrane review in another journal) has been allowed since that time, as long as the co-publishing journal has agreed to the arrangement. Although standards for co-publication were established in 2008, the frequency of co-publication and adherence to the standards have remained largely unexamined. Our objective was to examine the frequency of co-publication of Cochrane Eyes and Vision Group (CEVG) reviews, adherence to the co-publication policy, the relative numbers of citations of the two modes of publishing, and differences in times cited in CSRs with and without a co-publication.

METHODS

We identified all CEVG reviews published by May 30, 2014 in The Cochrane Library. Using keywords from the title, author names, and "Cochrane Eyes and Vision Group", we searched Google Scholar, Web of Science, Scopus, and PubMed databases to identify possible co-publications. We also emailed contact authors of all identified CEVG reviews to ask them whether they had published their CSR elsewhere. We compared each co-publication to the corresponding CEVG review for adherence to the Cochrane Policy Manual (dated June 10, 2014). We recorded the number of times each CEVG review and each co-publication had been cited by others according to Google Scholar, Web of Science, and Scopus, as of June 11, 2014.

RESULTS

We identified 117 CEVG reviews;19 had been co-published in 22 articles. Adherence to Cochrane policy on co-publication was moderate, with all authors complying with at least one of four requirements we addressed. Co-publications were cited more often than the corresponding CEVG reviews; CEVG reviews with at least one co-publication were cited approximately twice as often as CEVG reviews without a co-publication. The number of citations varied considerably depending on whether the CEVG review had a co-publication or not.

CONCLUSIONS

The findings support encouraging co-publication while maintaining the primacy of the Cochrane systematic review. Support for co-publication may be tempered by other factors such as the possibility that CEVG reviews with a co-publication covered more clinically important and timely topics than those without a co-publication. Assuming that citations are a valid measure of dissemination effectiveness, the 15-year CEVG experience with co-publication of systematic reviews suggests that Cochrane authors should be encouraged to co-publish in traditional medical journals.

The role of the complement system in age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a common retinal disease in older people. In Europe, about 1.6% of persons over age 65 and more than 13% of persons over age 85 have late-stage AMD, which can severely impair vision. The development of AMD is influenced both by environmental factors and by a strong hereditary component.

METHOD

We selectively searched the PubMed database for articles published between April 2001 and November 2013 with the key words "age-related macular degeneration," "risk factor," "complement," and "therapy." The website www.clinicaltrials.gov was also used to search for relevant clinical trials.

RESULTS

Old age and smoking are confirmed risk factors for AMD. Moreover, genetic association studies have pointed to signaling pathways in which the complement system, a part of the individual's innate immune system, takes on a central role in the pathogenesis of the disease. Several clinical trials designed to interfere specifically with these pathomechanisms have yielded rather disappointing results, although a phase II study of the monoclonal antibody lampalizumab showed that blocking complement factor D lessened the progression of geographic atrophy. A risk model based on 13 genetic markers was found to have positive predictive values in predisposed individuals that ranged from 5.1% (in persons aged 65 to 69) to 91.7% (in persons aged 85 or older). It should be borne in mind that 50% of patients with AMD are not carriers of risk-associated markers.

CONCLUSION

There is no rationale at present for genetic testing to estimate the individual risk of developing AMD. Several recent clinical trials have incorporated current pathophysiological knowledge, but nearly all of these trials have yielded negative findings, with only one exception.

The effect of intensive education on concordance with the Age-Related Eye Disease Study (AREDS) recommendations in a tertiary referral practice

BACKGROUND/AIMS

The Age-Related Eye Disease Study (AREDS) showed that supplementation with their formula led to a significant decrease in progression of age-related macular degeneration (AMD). This study aims to assess the effect of different education protocols on concordance with the trial recommendations in two retinal clinics.

METHODS

A prospective controlled survey of concordance with the AREDS recommendations in two retinal clinics was administered to 330 patients with AREDS category 3 or 4 AMD. The results were evaluated to assess the effect of differing levels of patient education. In clinic 1, there was a formal policy of giving the patient both verbal and written instructions and verbal repetition of these instructions from each staff member on each patient visit; in clinic 2, there was no specific education policy.

RESULTS

Clinic 1 had a concordance rate of 81.6% and clinic 2 of 44.1%. There were no significant differences in the patient demographics between the two clinics.

CONCLUSION

A high concordance rate can be achieved in clinical practice with rigorous patient education that includes a policy of having continual repetition of instructions.

Posterior segment eye disease in sub-Saharan Africa: review of recent population-based studies

Objective

To assess the burden of posterior segment eye diseases (PSEDs) in sub-Saharan Africa (SSA).

Methods

We reviewed published population-based data from SSA and other relevant populations on the leading PSED, specifically glaucoma, diabetic retinopathy and age-related macular degeneration, as causes of blindness and visual impairment in adults. Data were extracted from population-based studies conducted in SSA and elsewhere where relevant.

Results

PSEDs, when grouped or as individual diseases, are a major contributor to blindness and visual impairment in SSA. PSED, grouped together, was usually the second leading cause of blindness after cataract, ranging as a proportion of blindness from 13 to 37%.

Conclusions

PSEDs are likely to grow in importance as causes of visual impairment and blindness in SSA in the coming years as populations grow, age and become more urban in lifestyle. African-based cohort studies are required to help estimate present and future needs and plan services to prevent avoidable blindness.

Surgical implantation of steroids with antiangiogenic characteristics for treating neovascular age-related macular degeneration

BACKGROUND

Neovascular age-related macular degeneration (AMD) is associated with rapid vision loss due to choroidal neovascularization (CNV), leakage, and scarring. Steroids have gained attention in their role for the treatment of neovascular AMD for their antiangiogenic and anti-inflammatory properties.

OBJECTIVES

This review aims to examine effects of steroids with antiangiogenic properties in the treatment of neovascular AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 11), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2012), EMBASE (January 1980 to November 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 21 November 2012.

SELECTION CRITERIA

We included randomized controlled clinical trials of intra- and peri-ocular antiangiogenic steroids in people diagnosed with neovascular AMD.

DATA COLLECTION AND ANALYSIS

Two authors independently screened abstracts and full-text articles, assessed risk of bias in the included trials, and extracted data. We did not conduct a meta-analysis.

MAIN RESULTS

We included three trials after screening a total of 1503 abstracts and 21 full-text articles. The three trials included a total of 809 participants. One trial compared different doses of acetonide anecortave acetate with placebo, a second trial compared triamcinolone acetonide versus placebo, and the third trial compared anecortave acetate against photodynamic therapy (PDT). We did not conduct a meta-analysis owing to heterogeneity of interventions and comparisons. The risk ratio for loss of 3 or more lines of vision at 12 months follow-up was 0.8 (95% confidence interval (CI) 0.45 to 1.45) with 3 mg anecortave acetate, 0.45 (95% CI = 0.21 to 0.97) with 15 mg anecortave acetate, 0.91 (0.52 to 1.58) with 30 mg anecortave acetate, 0.97 (95% CI 0.74 to 1.26) with triamcinolone acetonide, all compared to placebo and 1.08 (95% CI 0.91 to 1.29) with anecortave acetate compared with PDT.

AUTHORS' CONCLUSIONS

Based on the included trials, we found no evidence that antiangiogenic steroids prevent visual loss in patients with neovascular AMD. With the emergence of anti-vascular endothelial growth factor modalities, based on evidence summarized in this review, it is unclear what role steroids have in treating patients with neovascular AMD.

Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration

BACKGROUND

It has been proposed that antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption. Higher dietary levels of antioxidant vitamins and minerals may reduce the risk of progression of age-related macular degeneration (AMD).

OBJECTIVES

The objective of this review was to assess the effects of antioxidant vitamin or mineral supplementation on the progression of AMD in people with AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 8), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2012), EMBASE (January 1980 to August 2012), Allied and Complementary Medicine Database (AMED) (January 1985 to August 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 20 August 2012. We searched the reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies. We also searched for systematic reviews of harms of vitamin supplements.

SELECTION CRITERIA

We included randomised trials comparing antioxidant vitamin or mineral supplementation (alone or in combination) to placebo or no intervention in people with AMD.

DATA COLLECTION AND ANALYSIS

Two authors assessed risk of bias and extracted data from the included trials. Where appropriate, we pooled data using a random-effects model unless three or fewer trials were available in which case we used a fixed-effect model.

MAIN RESULTS

Thirteen trials (6150 participants) were included in this review. Over half the participants (3640) were randomised in one trial (AREDS in the USA), which found a beneficial effect of antioxidant (beta-carotene, vitamin C and vitamin E) and zinc supplementation on progression to advanced AMD (adjusted odds ratio (OR) 0.68, 95% confidence interval (CI) 0.53 to 0.87) over an average of 6.3 years. People taking supplements were less likely to lose 15 or more letters of visual acuity (adjusted OR 0.77, 95% CI 0.62 to 0.96). The other trials, in general, had shorter follow-up (less than two years). No evidence for an effect of supplementation was seen in these smaller trials of shorter duration. Overall we considered the strength of the evidence to be moderate. We did not consider included trials, in general, to be at risk of bias, although we found it difficult to assess reporting biases. The main reason for downgrading the strength of the evidence was because, for several analyses, only one trial was included and therefore consistency of the findings could not be assessed. The included trials reported the following adverse effects: hospitalisation for genito-urinary problems was more common in people taking zinc and yellowing of skin was more common in people taking antioxidants. Systematic searching of the literature identified other potential harms of vitamin supplementation, in particular an increased risk of lung cancer in smokers associated with beta-carotene supplements, but we were unable to identify a good systematic review of the evidence for harms of nutritional supplementation.

AUTHORS' CONCLUSIONS

People with AMD may experience delay in progression of the disease with antioxidant vitamin and mineral supplementation. This finding is drawn from one large trial conducted in a relatively well-nourished American population. The generalisability of these findings to other populations is not known. Although generally regarded as safe, vitamin supplements may have harmful effects. A systematic review of the evidence on harms of vitamin supplements is needed.

Critical review: vegetables and fruit in the prevention of chronic diseases

BACKGROUND

Vegetables and fruit provide a significant part of human nutrition, as they are important sources of nutrients, dietary fibre, and phytochemicals. However, it is uncertain whether the risk of certain chronic diseases can be reduced by increased consumption of vegetables or fruit by the general public, and what strength of evidence has to be allocated to such an association.

METHODS

Therefore, a comprehensive analysis of the studies available in the literature and the respective study results has been performed and evaluated regarding obesity, type 2 diabetes mellitus, hypertension, coronary heart disease (CHD), stroke, cancer, chronic inflammatory bowel disease (IBD), rheumatoid arthritis (RA), chronic obstructive pulmonary disease (COPD), asthma, osteoporosis, eye diseases, and dementia. For judgement, the strength of evidence for a risk association, the level of evidence, and the number of studies were considered, the quality of the studies and their estimated relevance based on study design and size.

RESULTS

For hypertension, CHD, and stroke, there is convincing evidence that increasing the consumption of vegetables and fruit reduces the risk of disease. There is probable evidence that the risk of cancer in general is inversely associated with the consumption of vegetables and fruit. In addition, there is possible evidence that an increased consumption of vegetables and fruit may prevent body weight gain. As overweight is the most important risk factor for type 2 diabetes mellitus, an increased consumption of vegetables and fruit therefore might indirectly reduces the incidence of type 2 diabetes mellitus. Independent of overweight, there is probable evidence that there is no influence of increased consumption on the risk of type 2 diabetes mellitus. There is possible evidence that increasing the consumption of vegetables and fruit lowers the risk of certain eye diseases, dementia and the risk of osteoporosis. Likewise, current data on asthma, COPD, and RA indicate that an increase in vegetable and fruit consumption may contribute to the prevention of these diseases. For IBD, glaucoma, and diabetic retinopathy, there was insufficient evidence regarding an association with the consumption of vegetables and fruit.

CONCLUSIONS

This critical review on the associations between the intake of vegetables and fruit and the risk of several chronic diseases shows that a high daily intake of these foods promotes health. Therefore, from a scientific point of view, national campaigns to increase vegetable and fruit consumption are justified. The promotion of vegetable and fruit consumption by nutrition and health policies is a preferable strategy to decrease the burden of several chronic diseases in Western societies.

Glutathione redox control of asthma: from molecular mechanisms to therapeutic opportunities

Asthma is a chronic inflammatory disorder of the airways associated with airway hyper-responsiveness and airflow limitation in response to specific triggers. Whereas inflammation is important for tissue regeneration and wound healing, the profound and sustained inflammatory response associated with asthma may result in airway remodeling that involves smooth muscle hypertrophy, epithelial goblet-cell hyperplasia, and permanent deposition of airway extracellular matrix proteins. Although the specific mechanisms responsible for asthma are still being unraveled, free radicals such as reactive oxygen species and reactive nitrogen species are important mediators of airway tissue damage that are increased in subjects with asthma. There is also a growing body of literature implicating disturbances in oxidation/reduction (redox) reactions and impaired antioxidant defenses as a risk factor for asthma development and asthma severity. Ultimately, these redox-related perturbations result in a vicious cycle of airway inflammation and injury that is not always amenable to current asthma therapy, particularly in cases of severe asthma. This review will discuss disruptions of redox signaling and control in asthma with a focus on the thiol, glutathione, and reduced (thiol) form (GSH). First, GSH synthesis, GSH distribution, and GSH function and homeostasis are discussed. We then review the literature related to GSH redox balance in health and asthma, with an emphasis on human studies. Finally, therapeutic opportunities to restore the GSH redox balance in subjects with asthma are discussed.

Surgery for cataracts in people with age-related macular degeneration

BACKGROUND

Cataract and age-related macular degeneration (AMD) are common causes of decreased vision that often occur simultaneously in people over age 50. Although cataract surgery is an effective treatment for cataract-induced visual loss, some clinicians suspect that such an intervention may increase the risk of worsening of underlying AMD and thus have deleterious effects on vision.

OBJECTIVES

The objective of this review was to evaluate the effectiveness and safety of cataract surgery in eyes with AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 4), MEDLINE (January 1950 to April 2012), EMBASE (January 1980 to April 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to April 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 16 April 2012.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-randomized trials of eyes affected by both cataract and AMD in which cataract surgery would be compared to no surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated the search results against the inclusion and exclusion criteria. Two authors independently extracted data and assessed risk of bias for included studies. We resolved discrepancies by discussion.

MAIN RESULTS

One RCT with 60 participants with visually significant cataract and AMD was included in this review. Participants were randomized to immediate cataract surgery (within two weeks of enrollment) (n = 29) or delayed cataract surgery (six months after enrollment) (n = 31). At six months, four participants were lost to follow-up; two participants from each group. The immediate surgery group showed mean improvement in best-corrected visual acuity (BCVA) compared with the delayed surgery group at six months (mean difference (MD) 0.15 LogMAR, 95% confidence interval (CI) 0.28 to 0.02). There was no significant difference in the development of choroidal neovascularization between groups (1/27 eyes in the immediate surgery group versus 0/29 eyes in the delayed surgery group). Results from Impact of Vision Impairment (IVI) questionnaires suggested that the immediate surgery group faired better with quality of life outcomes than the delayed surgery group (MD in IVI logit scores 1.60, 95% CI 0.61 to 2.59). No postoperative complication was reported. We identified a second potentially relevant study of immediate versus delayed cataract surgery in 54 people with AMD. Results for the study are not yet available, but may be eligible for future updates of this review.

AUTHORS' CONCLUSIONS

At this time, it is not possible to draw reliable conclusions from the available data to determine whether cataract surgery is beneficial or harmful in people with AMD. Physicians will have to make practice decisions based on best clinical judgment until controlled trials are conducted and their findings published.It would be valuable for future research to investigate prospective RCTs comparing cataract surgery to no surgery in patients with AMD to better evaluate whether cataract surgery is beneficial or harmful in this group. However ethical considerations need to be addressed when delaying a potentially beneficial treatment and it may not be feasible to conduct a long-term study where surgery is withheld from the control group. Utilization of pre-existing, standardized systems for grading cataract and AMD and measuring outcomes (visual acuity, change in visual acuity, worsening of AMD and quality of life measures) should be encouraged.

Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration

BACKGROUND

There is inconclusive evidence from observational studies to suggest that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD).

OBJECTIVES

To examine the evidence as to whether or not taking antioxidant vitamin or mineral supplements prevents the development of AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 12), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 26 January 2012.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed risk of bias in the included studies and extracted data. One author entered data into RevMan 5 and the other author checked the data entry. We pooled data using a fixed-effect model.

MAIN RESULTS

We included four RCTs in this review; 62,520 people were included in the analyses. The trials were conducted in Australia, Finland and the USA and investigated vitamin E and beta-carotene supplements. Overall the quality of the evidence was high. People who took these supplements were not at decreased (or increased) risk of developing AMD. The pooled risk ratio for any antioxidant supplement in the prevention of any AMD was 0.98 (95% confidence interval 0.89 to 1.08) and for advanced AMD was 1.05 (95% CI 0.80 to 1.39). Similar results were seen when the analyses were restricted to beta-carotene and alpha-tocopherol alone.

AUTHORS' CONCLUSIONS

There is accumulating evidence that taking vitamin E or beta-carotene supplements will not prevent or delay the onset of AMD. There is no evidence with respect to other antioxidant supplements, such as vitamin C, lutein and zeaxanthin, or any of the commonly marketed multivitamin combinations. Although generally regarded as safe, vitamin supplements may have harmful effects and clear evidence of benefit is needed before they can be recommended. People with AMD should see the related Cochrane review 'Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration' written by the same review team.

Interventions for age-related visual problems in patients with stroke

BACKGROUND

The prevalence of eye problems increases with age and, consequently, so does the level of visual impairment. As the incidence of stroke also increases with age, a significant proportion of stroke patients will have age-related visual problems. It is possible that the effect of interventions for age-related visual problems may differ in the population of stroke patients compared to the wider population of older people. The interaction between the problems arising directly from stroke and those arising directly from age-related visual problems will be complex. Interventions for age-related visual problems may also be affected by the presence of other stroke-related co-morbidities. Consequently, the nature and outcome of interventions for age-related visual problems may be different in patients with stroke.

OBJECTIVES

The aim of this review is to determine if interventions for age-related visual problems improve functional ability following stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (March 2011), the Cochrane Eyes and Vision Group Trials Register (December 2009) and nine electronic bibliographic databases including: the Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), MEDLINE (1950 to February 2011), EMBASE (1980 to February 2011), CINAHL (1982 to February 2011), AMED (1985 to February 2011) and PsycINFO (1967 to February 2011). We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts.

SELECTION CRITERIA

Randomised trials in adults after stroke, where the intervention is specifically targeted at assessing, treating or correcting age-related visual problems, or improving the ability of the patient to cope with visual impairment. Primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, visual acuity, visual field, visual function, balance, falls, depression and anxiety, discharge destination/residence after stroke, quality of life and social isolation, adverse events and death.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts and planned to extract data and appraise trials. We planned that assessment of methodological quality would be undertaken for allocation concealment, blinding of outcome assessor, method of dealing with missing data and other potential sources of bias.

MAIN RESULTS

We considered 7357 titles, 460 abstracts and 85 full papers. We identified no studies for inclusion in this review.

AUTHORS' CONCLUSIONS

There are no implications for practice arising from this review. Evidence relating to the management of patients (from the general population) with age-related visual problems is available from other Cochrane reviews and is likely to be the best evidence available for making treatment decisions about individual patients. Subgroup analyses within these reviews to explore the effect of interventions for age-related visual problems in patients with stroke are recommended. We recommend that the objectives and selection criteria for this Cochrane review are amended and clarified prior to any future updates.

Statins for age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a progressive late onset disorder of the macula affecting central vision. Age-related macular degeneration is the leading cause of blindness in people over 65 years in industrialized countries (Congdon 2003). Recent epidemiologic, genetic and pathological evidence has shown AMD shares a number of risk factors with atherosclerosis, leading to the hypothesis that statins may exert protective effects in AMD.

OBJECTIVES

To examine the effectiveness of statins compared with other treatments, no treatment, or placebo in delaying the onset and/or progression of AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 9), MEDLINE (January 1950 to September 2011), EMBASE (January 1980 to September 2011), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to September 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 16 September 2011.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared statins with other treatments, no treatment, or placebo in participants who were either susceptible to or diagnosed as having early stages of AMD.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated the search results against the selection criteria. Two Italian speaking colleagues extracted data. One author entered data. We did not perform a meta-analysis because only one completed RCT was identified.

MAIN RESULTS

Two studies met the selection criteria. One trial reported insufficient details to assess the risk of bias; the other trial is ongoing.Of the completed trial, the analyses of 30 participants did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity at three months of treatment (decimal visual acuity 0.21± 0.56 in simvastatin and 0.19± 0.40 in placebo arm) or 45 days after the completion of treatment (decimal visual acuity 0.20± 0.50 in simvastatin and 0.19± 0.48 in placebo arm). The lens and retina status were unchanged during and after the treatment period for both groups.Of the ongoing trial, the preliminary analyses of 42 participants who completed 12 months follow-up did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity, drusen score or visual function (effect estimates and confidence intervals were not available). We contacted the investigators and will update the review as data become available.

AUTHORS' CONCLUSIONS

Evidence from currently available RCTs was insufficient to conclude that statins have any role in preventing or delaying the onset or progression of AMD.

Prevention of age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the developed world. Although effective treatment modalities such as anti-VEGF treatment have been developed for neovascular AMD, there is still no effective treatment for geographical atrophy, and therefore the most cost-effective management of AMD is to start with prevention. This review looks at current evidence on preventive measures targeted at AMD. Modalities reviewed include (1) nutritional supplements such as the Age-Related Eye Disease Study (AREDS) formula, lutein and zeaxanthin, omega-3 fatty acid, and berry extracts, (2) lifestyle modifications, including smoking and body-mass-index, and (3) filtering sunlight, i.e. sunglasses and blue-blocking intraocular lenses. In summary, the only proven effective preventive measures are stopping smoking and the AREDS formula.

Nutritional supplements for age-related macular degeneration

PURPOSE OF REVIEW

Age-related macular degeneration (AMD), a leading cause of visual loss in older adults, has limited therapeutic options. This review describes the current literature on the role of nutritional supplementation in primary and secondary prevention of AMD.

RECENT FINDINGS

Many observational studies have explored the association between diet, nutrient intake, and AMD. In particular, high dietary intakes of omega-3 fatty acids, and macular xanthophylls lutein and zeaxanthin have been associated with a lower risk of prevalent and incident AMD. However, the Age-Related Eye Disease study (AREDS) is the only large-scale randomized controlled clinical trial to show a 25% beneficial effect of nutritional supplementation in reducing the risk progression to advanced AMD in patients with intermediate AMD or with advanced AMD in one eye at 5 years of follow-up. On the basis of the results of AREDS, these patients are recommended to take AREDS formulation of vitamins C, E, beta-carotene, and zinc with copper.

SUMMARY

At the present time, there is insufficient evidence in the literature to recommend routine nutritional supplementation in healthy adults for primary prevention of AMD. However, patients with intermediate risk of AMD or advanced AMD in one eye should consider taking AREDS-type supplements. Observational studies have also suggested benefit from increased dietary intake of macular xanthophylls and omega-3 fatty acids. These are currently being evaluated prospectively in a randomized controlled clinical trial, the AREDS2.

Statins for age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a progressive late onset disorder of the macula affecting central vision. Age-related macular degeneration is the leading cause of blindness in people over 65 years in industrialized countries (Congdon 2003). Recent epidemiologic, genetic and pathological evidence has shown AMD shares a number of risk factors with atherosclerosis, leading to the hypothesis that statins may exert protective effects in AMD.

OBJECTIVES

To examine the effectiveness of statins compared with other treatments, no treatment, or placebo in delaying the onset and/or progression of AMD.

SEARCH STRATEGY

We searched CENTRAL in The Cochrane Library, MEDLINE, EMBASE and LILACS on 30 April 2009 and the WHO International Clinical Trials Registry Platform on 11 May 2009. We searched reference lists and the Science Citation Index. There were no language or date restrictions in the search for trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared statins with other treatments, no treatment, or placebo in participants who were either susceptible to or diagnosed as having early stages of AMD.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated the search results against the selection criteria. Two Italian speaking colleagues extracted data. One author entered data. We did not perform a meta-analysis because only one completed RCT was identified.

MAIN RESULTS

Two studies met the selection criteria. One trial reported insufficient details to assess the risk of bias; the other trial is ongoing.Of the completed trial, the analyses of 30 participants did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity at three months of treatment (decimal visual acuity 0.21+/- 0.56 in simvastatin and 0.19+/- 0.40 in placebo arm) or 45 days after the completion of treatment (decimal visual acuity 0.20+/- 0.50 in simvastatin and 0.19+/- 0.48 in placebo arm). The lens and retina status were unchanged during and after the treatment period for both groups.Of the ongoing trial, the preliminary analyses of 42 participants who completed 12 months follow-up did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity, drusen score or visual function (effect estimates and confidence intervals were not available). We contacted the investigators and will update the review as data become available.

AUTHORS' CONCLUSIONS

Evidence from currently available RCTs was insufficient to conclude that statins have any role in preventing or delaying the onset or progression of AMD.

Laser treatment of drusen to prevent progression to advanced age-related macular degeneration

BACKGROUND

Drusen are amorphous yellowish deposits beneath the sensory retina. People with drusen, particularly large drusen, are at higher risk of developing age-related macular degeneration (AMD). The most common complication in AMD is choroidal neovascularisation (CNV), the growth of new blood vessels in the centre of the macula. The risk of CNV is higher among patients who are already affected by CNV in one eye.It has been observed clinically that laser photocoagulation of drusen leads to their disappearance and may prevent the occurrence of advanced disease (CNV or geographic atrophy) associated with visual loss.

OBJECTIVES

To examine the effectiveness and adverse effects of laser photocoagulation of drusen in AMD.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE and EMBASE on 14 November 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of laser treatment of drusen in AMD in which laser treatment had been compared with no intervention or sham treatment. Two types of trials were included. Some trials studied one eye of each patient (unilateral studies); other studies recruited patients with bilateral drusen and randomised one eye to photocoagulation or control and the fellow eye to the other group.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We pooled data from unilateral and bilateral studies using a random-effects model. For the bilateral studies, we estimated the within-patient correlation coefficient from one study and assumed it was valid for the others.

MAIN RESULTS

We found nine studies which randomised 2216 people: four unilateral trials, three bilateral trials and two trials that included both a unilateral and a bilateral study arm.Overall, the studies were of moderate quality. Only half of the trials reported adequate allocation sequence generation, allocation concealment and masking of visual acuity outcome assessors.Although two (of the nine) studies reported significant drusen disappearance at two years, photocoagulation did not appear to affect the development of CNV at two years follow up (nine studies, 1767 people followed up, odds ratio (OR) 1.04, 95% CI 0.71 to 1.51) or the loss of three or more lines of visual acuity (six studies, 1628 people followed up, OR 1.17, 95% CI 0.75 to 1.82).

AUTHORS' CONCLUSIONS

The trials included in this review confirm the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, there is no evidence that this subsequently results in a reduction in the risk of developing CNV, geographic atrophy or visual acuity loss.

Submacular surgery for choroidal neovascularisation secondary to age-related macular degeneration

BACKGROUND

Vitreoretinal surgeons proposed submacular surgery to remove the fibrovascular tissue causing damage to the centre of the retina, in the attempt to limit central visual loss in people affected by neovascular age-related macular degeneration (AMD).

OBJECTIVES

This review aims at assessing the effectiveness of submacular surgery for preserving or improving vision in patients with AMD.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE and LILACS. There were no language or date restrictions in the search for trials. The electronic databases were last searched on 11 February 2009.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials comparing submacular surgery with any other treatment or observation.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. The risk ratio (RR) of visual loss and visual gain was estimated at one year.

MAIN RESULTS

Two multicentre studies with a similar design were conducted between 1997 and 2003 and compared submacular surgery with observation in people affected by subfoveal neovascular AMD with (n=336) or without (n=454) extensive blood in the macula. At one year there was high quality evidence of no benefit for preventing visual loss (RR: 0.96; 95% confidence interval (CI): 0.84 to 1.09). No difference could be demonstrated regarding the chance of visual gain (RR: 1.06; 95% CI: 0.75 to 1.51), although this evidence was of low quality because of imprecision. The risk difference was -2% (95% CI: -10% to 5%) and 1% (95% CI: -4% to 6%) for visual loss and visual gain, respectively, thus excluding a large benefit with surgery in terms of absolute risk in this sample. There was high quality evidence that cataract needing surgery (RR: 8.69; 95% CI: 4.06 to 18.61) and retinal detachment (RR: 6.13; 95% CI: 2.81 to 13.38) were more common among operated patients, and detachment occurred in 5% of patients with no extensive blood and in 18% of those with extensive blood beneath the macula.A pilot study compared submacular surgery with laser photocoagulation in 70 patients. No difference between the two treatments could be demonstrated for any outcome measure, but estimates were very imprecise because of small sample size.

AUTHORS' CONCLUSIONS

There is no benefit with submacular surgery in most people with subfoveal choroidal neovascularisation due to AMD in terms of prevention of visual loss. Furthermore, the risk of developing cataract and retinal detachment increases after surgery.

Surgery for cataracts in people with age-related macular degeneration

BACKGROUND

Cataract and age-related macular degeneration (AMD) are significant causes of decreased vision in the elderly that often occur simultaneously. Although cataract surgery is an effective treatment for cataract-induced visual loss, some clinicians suspect that such an intervention may increase the risk of progression of underlying AMD and thus have deleterious effects on vision.

OBJECTIVES

The objective of this review was to evaluate the effectiveness and safety of cataract surgery in eyes with AMD.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 4, 2008), MEDLINE (January 1966 to November 2008), EMBASE (January 1980 to November 2008) and Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2008). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 4 November 2008.

SELECTION CRITERIA

We planned to include randomized controlled trials (RCTs) and quasi-randomized trials of eyes affected by both cataract and AMD in which cataract surgery would be compared to no surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated the search results against the inclusion and exclusion criteria. Discrepancies were resolved by discussion.

MAIN RESULTS

We found no RCTs, thus no analysis was conducted. Evidence was limited to non-randomized clinical trials and prospective cohort and case-control studies.

AUTHORS' CONCLUSIONS

At this time, it is not possible to draw reliable conclusions from the available data to determine whether cataract surgery is beneficial or harmful in people with AMD. Physicians will have to make practice decisions based on best clinical judgement until controlled trials are conducted and their findings published.

Macular translocation for neovascular age-related macular degeneration

BACKGROUND

Macular translocation has been proposed by vitreoretinal surgeons to displace the neuroretinal tissue onto healthy retinal pigment epithelium and choroid when the macula has been invaded by subretinal neovascularisation.

OBJECTIVES

This review aims at assessing the effectiveness of macular translocation for preserving or improving vision in patients with neovascular age-related macular degeneration (AMD).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and Caribbean Literature on Health Sciences (LILACS). There were no language or date restrictions in the search for trials.The electronic databases were last searched on 21 July 2008.

SELECTION CRITERIA

We included randomised or quasi randomised controlled trials comparing macular translocation with any other treatment or observation.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. The risk ratio (RR) of visual loss and visual gain was estimated at one year after treatment.

MAIN RESULTS

Only one small unblinded study on 50 people compared full macular translocation with photodynamic therapy (PDT) in AMD patients with predominantly classic subfoveal choroidal neovascularisation (CNV). At the last examination, performed in most of the cases after one year, there was no difference in the rate of visual loss of 3 or more lines (translocation versus PDT: RR 0.56, 95% confidence interval (CI) 0.22 to 1.43), as well as in the mean change of contrast sensitivity (1 letter favouring translocation; 95% CI -3.51 to 5.51) and the rate of recurrence of CNV (translocation versus PDT: RR 1.56, 95% CI 0.83 to 2.91). Other outcomes significantly favoured translocation, such as the gain of 3 or more ETDRS lines (RR 21, 95% CI 1.30 to 340.02), the mean change of visual acuity (mean difference (MD) 14.60, 95% CI 5.39 to 23.81) and the mean change of near visual acuity score (MD 17.80, 95% CI 3.98 to 31.62) which is obtained with an algorithm. Serious complications reported after macular translocation were retinal detachment in 6/25 patients and diplopia requiring prismatic correction in 5/25 patients.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised controlled trials on the effectiveness of macular translocation, which is also not free of important risks. Furthermore, this technique is difficult to perform and a long surgical training is required. Future studies might include patients with small neovascular lesions that failed to respond to current pharmacological therapies and are willing to accept the risks associated with surgery to try to improve visual acuity.

[Vitamins for the eyes? Risks and opportunities for physician and patient]

This article discusses the effects of dietetic measures and specialized food supplements on age-related macular degeneration (AMD) and diabetic retinopathy. The sale of products in doctors' offices is already prohibited by laws governing the medical profession. The results of the Age-Related Eye Disease Study (AREDS) concerning high doses of vitamins and zinc cannot simply be transferred to other doses and substances. Furthermore, there are health risks that have to be examined. Opportunities could arise for both doctor and patient if the AREDS formulation were granted authorization to be marketed as a medicinal product; however, a certain protective effect can be expected only for specific forms of AMD after a careful risk-benefit analysis and assessment within the statutory marketing authorization procedure for medicinal products.

[Lutein and antioxidants in the prevention of age-related macular degeneration]

Demographic developments in Europe and North America are causing an increase of age-related diseases. Age-related macular degeneration (AMD) is one of the leading causes of severe central visual acuity loss in elderly people and seems to be an economic problem, too. There is evidence that oxidative damage is an important factor for exacerbation of AMD. Macular pigment with its antioxidative effect may serve as"natural sunglasses" filtering the blue light acting as a possible source of photooxidative damage to the neurosensory retina. The macular pigment consists mostly of lutein and zeaxanthin. These micronutrients from the group of carotenoids, as is the case for vitamins (vitamins C, E, and beta-carotene), cannot be synthesized in mammals and that is the reason why the role of micronutrition or its supplementation and its correlation to AMD progression has been discussed for years. The results of currently published studies are often contradictory. At present there are no results from randomized controlled studies confirming that supplementation of lutein and zeaxanthin can reduce the risk for AMD. Several epidemiological studies investigating the impact of antioxidants and omega-3 fatty acids on the incidence of AMD provided conflicting results.Up to now, AREDS is the largest randomized controlled study investigating the effect of supplementation of antioxidants, zinc, and copper on the progression of AMD. AREDS showed a significant effect of this supplementation in some particular groups of patients with AMD. The supplementation of lutein and omega-3 fatty acids is not toxic but a positive effect has not been proven by randomized studies.

Dietary Antioxidants and the Long-term Incidence of Age-Related Macular Degeneration

PURPOSE

To assess the relationship between baseline dietary and supplement intakes of antioxidants and the long-term risk of incident age-related macular degeneration (AMD).

DESIGN

Australian population-based cohort study.

PARTICIPANTS

Of 3654 baseline (1992-1994) participants initially 49 years of older, 2454 were reexamined after 5 years, 10 years, or both.

METHODS

Stereoscopic retinal photographs were graded using the Wisconsin Grading System. Data on potential risk factors were collected. Energy-adjusted intakes of alpha-carotene; beta-carotene; beta-cryptoxanthin; lutein and zeaxanthin; lycopene; vitamins A, C, and E; and iron and zinc were the study factors. Discrete logistic models assessed AMD risk. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated after adjusting for age, gender, smoking, and other risk factors.

MAIN OUTCOME MEASURES

Incident early, late, and any AMD.

RESULTS

For dietary lutein and zeaxanthin, participants in the top tertile of intake had a reduced risk of incident neovascular AMD (RR, 0.35; 95% CI, 0.13-0.92), and those with above median intakes had a reduced risk of indistinct soft or reticular drusen (RR, 0.66; 95% CI, 0.48-0.92). For total zinc intake the RR comparing the top decile intake with the remaining population was 0.56 (95% CI, 0.32-0.97) for any AMD and 0.54 (95% CI, 0.30-0.97) for early AMD. The highest compared with the lowest tertile of total beta-carotene intake predicted incident neovascular AMD (RR, 2.68; 95% CI, 1.03-6.96; P = 0.029, for trend). Similarly, beta-carotene intake from diet alone predicted neovascular AMD (RR comparing tertile 3 with tertile 1, 2.40; 95% CI, 0.98-5.91; P = 0.027, for trend). This association was evident in both ever and never smokers. Higher intakes of total vitamin E predicted late AMD (RR compared with the lowest tertile, 2.83; 95% CI, 1.28-6.23; and RR, 2.55; 95% CI, 1.14-5.70 for the middle and highest tertiles, respectively; P = 0.22, for trend).

CONCLUSIONS

In this population-based cohort study, higher dietary lutein and zeaxanthin intake reduced the risk of long-term incident AMD. This study confirmed the Age-Related Eye Disease Study finding of protective influences from zinc against AMD. Higher beta-carotene intake was associated with an increased risk of AMD.

Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration

BACKGROUND

Some observational studies have suggested that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD).

OBJECTIVES

The aim of this review was to examine the evidence as to whether or not taking vitamin or mineral supplements prevents the development of AMD.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) in The Cochrane Library (2007, Issue 3), MEDLINE (1966 to August 2007), SIGLE (1980 to 2005/03), EMBASE (1980 to August 2007), National Research Register (2007, Issue 3), AMED (1985 to January 2006) and PubMed (on 24 January 2006 covering last 60 days), reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies.

SELECTION CRITERIA

We included all randomised trials comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control. We included only studies where supplementation had been given for at least one year.

DATA COLLECTION AND ANALYSIS

Both review authors independently extracted data and assessed trial quality. Data were pooled using a fixed-effect model.

MAIN RESULTS

Three randomised controlled trials were included in this review (23,099 people randomised). These trials investigated alpha-tocopherol and beta-carotene supplements. There was no evidence that antioxidant vitamin supplementation prevented or delayed the onset of AMD. The pooled risk ratio for any age-related maculopathy (ARM) was 1.04 (95% CI 0.92 to 1.18), for AMD (late ARM) was 1.03 (95% CI 0.74 to 1.43). Similar results were seen when the analyses were restricted to beta-carotene and alpha-tocopherol.

AUTHORS' CONCLUSIONS

There is no evidence to date that the general population should take antioxidant vitamin and mineral supplements to prevent or delay the onset of AMD. There are several large ongoing trials. People with AMD should see the related Cochrane review "Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration" written by the same author.

Antioxidant effects of vitamins C and E, multivitamin-mineral complex and flavonoids in a model of retinal oxidative stress: the ApoE-deficient mouse

The aim of the current study was to investigate the biochemical changes in the plasma and retina of apolipoprotein E deficient (apoE-/-) mice supplemented with various antioxidants. Ten wild type (WT-Con, C57BL/6) and 10 apoE-/- (AE-Con) mice received drinking water. Another 40 apoE-/- animals were divided into four groups of 10 mice each and received either chromocarbe diethylamine (AE-CD, 50mg/kg), cyaninosides chloride (AE-CC, 50mg/kg), multivitamin complex (AE-MC, 50mg/kg), or vitamins C and E (AE-CE, 100mg/kg and 200IU/kg). Cholesterol, triglycerides, and lipid peroxidation (thiobarbituric acid reactive substances [TBARS]) were measured in plasma, and TBARS and nitric oxide metabolites (NOx) concentration were determined in retinal homogenates. Transmission electron microscopy was performed to examine the retinal ultrastructure. AE-Con mice had significantly (P<0.05) increased oxidative stress in the plasma and retina with augmented production of retinal NOx compared with WT-Con mice. Retinal TBARS decreased in the AE-MC and AE-CE animals compared with the AE-Con group (P<0.05 and P<0.01, respectively). Only AE-CE treatment significantly (P<0.01) lowered retinal NOx. Morphologic retinal changes in the AE-Con group decreased in the AE-CE and AE-MC groups. There were no significant changes in the biochemical and structural parameters in the AE-CD and AE-CC groups. AE-Con mice had increased systemic and retinal oxidative stress compared with WT-Con animals. Vitamins C and E and the multivitamin-mineral complex reduced oxidative stress and ultrastructural retinal changes in this murine model of hypercholesterolemia.

Lifestyle exposures and eye diseases in adults

PURPOSE

To provide a perspective of observed associations between lifestyle exposures and eye diseases in adults.

DESIGN

Summary of recent epidemiologic studies.

METHODS

Nonsystematic review of the literature.

RESULTS

Data suggest that some lifestyle exposures (e.g., smoking) are significantly associated with risk of several different diseases, suggesting that altering behaviors may decrease risk. Where risk is inherent to an occupational or recreational activity, eye protection is likely to decrease risk.

CONCLUSIONS

Although data are imperfect, it seems that some lifestyle alterations may decrease the risk of eye diseases at little or no risk to the individual.

Surgical implantation of steroids with antiangiogenic characteristics for treating neovascular age-related macular degeneration

BACKGROUND

Neovascular age-related macular degeneration (AMD) is associated with rapid vision loss due to choroidal neovascularization (CNV), leakage, and scarring. Steroids have gained attention in their role for the treatment of neovascular AMD for their antiangiogenic and anti-inflammatory properties.

OBJECTIVES

This review aims to examine effects of steroids with antiangiogenic properties in the treatment of neovascular AMD.

SEARCH STRATEGY

We searched for trials in CENTRAL, MEDLINE, EMBASE, and LILACS on 2 October 2006.

SELECTION CRITERIA

We included randomised controlled clinical trials of intra- and peri-ocular steroids in people diagnosed with neovascular AMD.

DATA COLLECTION AND ANALYSIS

Review authors extracted the data and assessed trial quality independently. We did not pool data since the included studies evaluated difference comparisons.

MAIN RESULTS

We report the risk of losing three or more lines vision at 12 months - "vision loss". One trial (139 people randomized) reported that a single dose of intravitreal triamcinolone (n = 75) (4 mg) had no significant effect on the risk of vision loss compared to placebo (n = 76). (Risk ratio vision loss 0.97, 95% confidence interval (CI) 0.74 to 1.26). Eyes treated with triamcinolone were more likely to develop cataracts and experience increased intraocular pressure (IOP) compared to untreated eyes. One trial (128 people randomized) reported the effects of anecortave acetate (3 mg (n = 32), 15 mg (n = 33) or 30 mg (n = 33) single dose with retreatment every six months if indicated) compared to placebo (n = 30). Risk ratio vision loss 0.80 (95% CI 0.45 to 1.45) in the 3 mg group, 0.45 (95% CI 0.21 to 0.97) in the 15 mg group and 0.91 (95% CI 0.52 to 1.58) in the 30 mg group. Side effects were similar in all treatment groups with the anecortave group having a slightly higher incidence of foreign body sensation compared to placebo. There was a high loss to follow-up. The final analysis may have been subject to selection bias as participants who were not selected for retreatment, possibly with worsening disease, were excluded. There was also a possibility of type I error due to multiple statistical comparisons. The sample size was estimated on the basis of a single 2-way comparison but three 2-way comparisons were analysed and presented. One trial reported that anecortave acetate (n = 263) (15 mg administered at beginning of study and six months) gave similar results to photodynamic therapy (n = 267) (risk ratio vision loss 1.08, 95% CI 0.91 to 1.29).

AUTHORS' CONCLUSIONS

Overall there is weak evidence as to the benefits and harms of steroids with antiangiogenic properties for treating neovascular AMD with only three published trials of variable quality. Intravitreal triamcinolone injection for neovascular AMD does not appear to prevent severe vision loss and is associated with increased IOP and higher risk of cataract formation. Anecortave acetate 15 mg may have a mild benefit in stabilizing vision, but further better quality evidence is needed. The role of steroids in combination with other treatment modalities is yet to be determined.

Dietary antioxidants and primary prevention of age related macular degeneration: systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of dietary antioxidants in the primary prevention of age related macular degeneration (AMD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Search of seven databases without limits on year or language of publication, and retrieval of references in pertinent reviews and articles.

METHODS

Two reviewers independently searched the databases and selected the studies, using standardised criteria. Randomised clinical trials and prospective cohort studies were included. Of the 4192 abstracts initially identified, 12 studies (nine prospective cohort studies and three randomised clinical trials) met the selection criteria and were included. Data extraction and study quality evaluation were independently reviewed, using standardised criteria. Results were pooled quantitatively using meta-analytic methods.

RESULTS

The nine prospective cohort studies included 149 203 people, with 1878 incident cases of early AMD. The antioxidants investigated differed across studies, and not all studies contributed to the meta-analysis of each antioxidant. Pooled results from prospective cohort studies indicated that vitamin A, vitamin C, vitamin E, zinc, lutein, zeaxanthin, alpha carotene, beta carotene, beta cryptoxanthin, and lycopene have little or no effect in the primary prevention of early AMD. The three randomised clinical trials did not show that antioxidant supplements prevented early AMD.

CONCLUSIONS

There is insufficient evidence to support the role of dietary antioxidants, including the use of dietary antioxidant supplements, for the primary prevention of early AMD.

Tackling malnutrition among older people in the community

Undernutrition - of both macronutrients and micronutrients - is still a surprisingly common problem among older people in the UK. There is a variety of nutritional supplements that community nurses need to be aware of in managing their patients' nutritional requirements. Different supplements are taken for different disease states. This article looks at the various nutrient and energy requirements that relate directly to clients on the district nurse's caseload. Some of the negative consequences of malnutrition of the older adult are discussed, as are the NICE guidelines for nutrition. Factors affecting dietary intake in older people are considered.