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 determine whether or not taking antioxidant vitamin or mineral supplements, or both, prevent the development of AMD. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 2), MEDLINE Ovid (1946 to 29 March 2017), Embase Ovid (1947 to 29 March 2017), AMED (Allied and Complementary Medicine Database) (1985 to 29 March 2017), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/); searched 29 March 2017, the ISRCTN registry (www.isrctn.com/editAdvancedSearch); searched 29 March 2017, ClinicalTrials.gov (www.clinicaltrials.gov); searched 29 March 2017 and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 29 March 2017. We did not use any date or language restrictions in the electronic searches for trials. Selection criteria: We included all randomised controlled trials (RCTs) comparing an antioxidant vitamin 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; the other author checked the data entry. We pooled data using a fixed-effect model. We graded the certainty of the evidence using GRADE. Main results: We included a total of five RCTs in this review with data available for 76,756 people. The trials were conducted in Australia, Finland, and the USA, and investigated vitamin C, vitamin E, beta-carotene, and multivitamin supplements. All trials were judged to be at low risk of bias. Four studies reported the comparison of vitamin E with placebo. Average treatment and follow-up duration ranged from 4 to 10 years. Data were available for a total of 55,614 participants. There was evidence that vitamin E supplements do not prevent the development of any AMD (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.90 to 1.06; high-certainty evidence), and may slightly increase the risk of late AMD (RR 1.22, 95% CI 0.89 to 1.67; moderate-certainty evidence) compared with placebo. Only one study (941 participants) reported data separately for neovascular AMD and geographic atrophy. There were 10 cases of neovascular AMD (RR 3.62, 95% CI 0.77 to 16.95; very low-certainty evidence), and four cases of geographic atrophy (RR 2.71, 95% CI 0.28 to 26.0; very low-certainty evidence). Two trials reported similar numbers of adverse events in the vitamin E and placebo groups. Another trial reported excess of haemorrhagic strokes in the vitamin E group (39 versus 23 events, hazard ratio 1.74, 95% CI 1.04 to 2.91, low-certainty evidence). Two studies reported the comparison of beta-carotene with placebo. These studies took place in Finland and the USA. Both trials enrolled men only. Average treatment and follow-up duration was 6 years and 12 years. Data were available for a total of 22,083 participants. There was evidence that beta-carotene supplements did not prevent any AMD (RR 1.00, 95% CI 0.88 to 1.14; high-certainty evidence) nor have an important effect on late AMD (RR 0.90, 95% CI 0.65 to 1.24; moderate-certainty evidence). Only one study (941 participants) reported data separately for neovascular AMD and geographic atrophy. There were 10 cases of neovascular AMD (RR 0.61, 95% CI 0.17 to 2.15; very low-certainty evidence) and 4 cases of geographic atrophy (RR 0.31 95% CI 0.03 to 2.93; very low-certainty evidence). Beta-carotene was associated with increased risk of lung cancer in people who smoked. One study reported the comparison of vitamin C with placebo, and multivitamin (Centrum Silver) versus placebo. This was a study in men in the USA with average treatment duration and follow-up of 8 years for vitamin C and 11 years for multivitamin. Data were available for a total of 14,236 participants. AMD was assessed by self-report followed by medical record review. There was evidence that vitamin C supplementation did not prevent any AMD (RR 0.96, 95% CI 0.79 to 1.18; high-certainty evidence) or late AMD (RR 0.94, 0.61 to 1.46; moderate-certainty evidence). There was a slight increased risk of any AMD (RR 1.21, 95% CI 1.02 to 1.43; moderate-certainty evidence) and late AMD (RR 1.22, 95% CI 0.88 to 1.69; moderate-certainty evidence) in the multivitamin group. Neovascular AMD and geographic atrophy were not reported separately. Adverse effects were not reported but there was possible increased risk of skin rashes in the multivitamin group. Adverse effects were not consistently reported in these eye studies, but there is evidence from other large studies that beta-carotene increases the risk of lung cancer in people who smoke or who have been exposed to asbestos. None of the studies reported quality of life or resource use and costs. Authors' conclusions: Taking vitamin E or beta-carotene supplements will not prevent or delay the onset of AMD. The same probably applies to vitamin C and the multivitamin (Centrum Silver) investigated in the one trial reported to date. There is no evidence with respect to other antioxidant supplements, such as lutein and zeaxanthin. 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 on antioxidant vitamin and mineral supplements for slowing the progression of AMD, written by the same review team

Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess whether blue-light filtering spectacle lenses impart effects on visual function, provide protection to the macula, or both. We will also examine potential effects on the sleep-wake cycle

Role of advanced technology in the detection of sight-threatening eye disease in a UK community setting.

Background/aims: To determine the performance of combinations of structural and functional screening tests in detecting sight-threatening eye disease in a cohort of elderly subjects recruited from primary care. Methods: 505 subjects aged ≥60 years underwent frequency doubling technology (FDT) perimetry, iVue optical coherence tomography (iWellness and peripapillary retinal nerve fibre layer (RNFL) scans) and intraocular pressure with the Ocular Response Analyzer, all performed by an ophthalmic technician. The reference standard was a full ophthalmic examination by an experienced clinician who was masked to the index test results. Subjects were classified as presence or absence of sight-threatening eye disease (clinically significant cataract, primary open-angle glaucoma, intermediate or advanced age-related macular degeneration and significant diabetic retinopathy). Univariate and multivariate logistic regression analyses were used to determine the association between abnormal screening test results and the presence of sight-threatening eye disease. Results: 171 subjects (33.8%) had one or more sight-threatening eye diseases. The multivariate analysis found significant associations with any of the target conditions for visual acuity of <6/12, an abnormal FDT and peripapillary RNFL thickness outside the 99% normal limit. The sensitivity of this optimised screening panel was 61.3% (95% CI 53.5 to 68.7), with a specificity of 78.8% (95% CI 74.0 to 83.1), a positive predictive value of 59.5% (95% CI 53.7 to 65.2) and an overall diagnostic accuracy of 72.9% (95% CI 68.8 to 76.8). Conclusions: A subset of screening tests may provide an accurate and efficient means of population screening for significant eye disease in the elderly. This study provides useful preliminary data to inform the development of further larger, multicentre screening studies to validate this screening panel

A Critical Appraisal of National and International Clinical Practice Guidelines Reporting Nutritional Recommendations for Age-Related Macular Degeneration: Are Recommendations Evidence-Based?

Eye care professionals should have access to high quality clinical practice guidelines that ideally are underpinned by evidence from robust systematic reviews of relevant research. The aim of this study was to identify clinical guidelines with recommendations pertaining to dietary modification and/or nutritional supplementation for age-related macular degeneration (AMD), and to evaluate the overall quality of the guidelines using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument. We also mapped recommendations to existing systematic review evidence. A comprehensive search was undertaken using bibliographic databases and other electronic resources for eligible guidelines. Quality appraisal was undertaken to generate scores for each of the six AGREE II domains, and mapping of extracted nutritional recommendations was performed for systematic reviews published up to March 2017. We identified 13 national and international guidelines, developed or updated between 2004 and 2019. These varied substantially in quality. The lowest scoring AGREE II domains were for 'Rigour of Development', 'Applicability' (which measures implementation strategies to improve uptake of recommendations), and 'Editorial Independence'. Only four guidelines used evidence from systematic reviews to support their nutritional recommendations. In conclusion, there is significant scope for improving current Clinical Practice Guidelines for AMD, and guideline developers should use evidence from existing high quality systematic reviews to inform clinical recommendations

Normal left ventricular function does not protect against propafenone-induced incessant ventricular tachycardia

Propafenone is a class Ic anti-arrhythmic agent with mild B-blocking properties which has recently become available in South Africa. We have used the drug in 3 patients with sustained m.onomorphic ventricular tachycardia not due to ischaemic heart disease. All had norm.al left ventricular function; 1 had Wegener's granulom.atosis and 2 had arrhythmogenic right ventricular dysplasia. In the latter 2, propafenone provoked incessant monomorphic ventricular tachycardia which persisted for m.ore than 24 hours despite repeated efforts at term.ination. The morphology was similar to the patients' spontaneous ventricular tachycardia, but the rate was slower and the QRS complexes broader, consistent with propafenone's marked ability to slow intraventricular conduction. It is postulated that incessant tachycardia results from. perpetuation of re-entry due to marked conduction slowing produced by the drug. Previous reports have suggested that this is most likely to occur in patients with poor left ventricular function, but our experience indicates that those with normal left ventricular function are also at risk, particularly if the substrate for reentry is present. Propafenone, like all other powerful antiarrhythmic agents, may provoke life-threatening arrhythmias and should be used with great caution after due consideration of the indications, even in patients with norm.al left ventricular function

Multi-stakeholder perspectives of locally commissioned enhanced optometric services

OBJECTIVES: To explore views of all stakeholders (patients, optometrists, general practitioners (GPs), commissioners and ophthalmologists) regarding the operation of community-based enhanced optometric services. DESIGN: Qualitative study using mixed methods (patient satisfaction surveys, semi-structured telephone interviews and optometrist focus groups). SETTING: A minor eye conditions scheme (MECS) and glaucoma referral refinement scheme (GRRS) provided by accredited community optometrists. PARTICIPANTS: 189 patients, 25 community optometrists, 4 glaucoma specialist hospital optometrists (GRRS), 5 ophthalmologists, 6 GPs (MECS), 4 commissioners. RESULTS: Overall, 99% (GRRS) and 100% (MECS) patients were satisfied with their optometrists' examination. The vast majority rated the following as 'very good'; examination duration, optometrists' listening skills, explanations of tests and management, patient involvement in decision-making, treating the patient with care and concern. 99% of MECS patients would recommend the service. Manchester optometrists were enthusiastic about GRRS, feeling fortunate to practise in a 'pro-optometry' area. No major negatives were reported, although both schemes were limited to patients resident within certain postcode areas, and some inappropriate GP referrals occurred (MECS). Communication with hospitals was praised in GRRS but was variable, depending on hospital (MECS). Training for both schemes was valuable and appropriate but should be ongoing. MECS GPs were very supportive, reporting the scheme would reduce secondary care referral numbers, although some MECS patients were referred back to GPs for medication. Ophthalmologists (MECS and GRRS) expressed very positive views and widely acknowledged that these new care pathways would reduce unnecessary referrals and shorten patient waiting times. Commissioners felt both schemes met or exceeded expectations in terms of quality of care, allowing patients to be seen quicker and more efficiently. CONCLUSIONS: Locally commissioned schemes can be a positive experience for all involved. With appropriate training, clear referral pathways and good communication, community optometrists can offer high-quality services that are highly acceptable to patients, health professionals and commissioners

A qualitative study of stakeholder views regarding participation in locally commissioned enhanced optometric services

Objectives: To explore the views of optometrists, general practitioners (GPs) and ophthalmologists regarding the development and organisation of community-based enhanced optometric services. Design: Qualitative study using free-text questionnaires and telephone interviews. Setting: A minor eye conditions scheme (MECS) and a glaucoma referral refinement scheme (GRRS) are based on accredited community optometry practices. Participants: 41 optometrists, 6 ophthalmologists and 25 GPs. Results: The most common reason given by optometrists for participation in enhanced schemes was to further their professional development; however, as providers of ‘for-profit’ healthcare, it was clear that participants had also considered the impact of the schemes on their business. Lack of fit with the ‘retail’ business model of optometry was a frequently given reason for non-participation. The methods used for training and accreditation were generally thought to be appropriate, and participating optometrists welcomed the opportunities for ongoing training. The ophthalmologists involved in the MECS and GRRS expressed very positive views regarding the schemes and widely acknowledged that the new care pathways would reduce unnecessary referrals and shorten patient waiting times. GPs involved in the MECS were also very supportive. They felt that the scheme provided an ‘expert’ local opinion that could potentially reduce the number of secondary care referrals. Conclusions: The results of this study demonstrated strong stakeholder support for the development of community-based enhanced optometric services. Although optometrists welcomed the opportunity to develop their professional skills and knowledge, enhanced schemes must also provide a sufficient financial incentive so as not to compromise the profitability of their business