The estimated prevalence and incidence of late stage age related macular degeneration in the UK

The Cost-Effectiveness of Ranibizumab Treat and Extend Regimen Versus Aflibercept in the UK

INTRODUCTION

Wet age-related macular degeneration (AMD) is a chronic eye condition that causes severe deterioration of vision and even blindness. Current wet AMD treatment in the UK involves the vascular endothelial growth factor inhibitors ranibizumab and aflibercept. Patients with wet AMD require frequent and long-term monitoring for treatment to be effective, contributing to a substantial resource burden at wet AMD centers. The European license for ranibizumab was recently updated with an individualized 'treat and extend' (T&E) regimen, comprising a structured monitoring and treatment protocol. This study evaluated the cost-effectiveness of ranibizumab T&E versus aflibercept within a UK setting.

METHODS

An individual patient-level simulation model was developed utilizing treatment effects from a network meta-analysis of randomized controlled trials. The model was conducted from a UK National Health Service (NHS) perspective over a lifetime horizon and the base case utilized probabilistic sensitivity analysis to assess uncertainty in the model. Additional scenario analyses were conducted to assess the impact of changes to the model inputs.

RESULTS

Ranibizumab T&E was found to be more effective and less costly than aflibercept, providing, on average, an additional 1.058 quality-adjusted life years (QALYs) and a cost-saving of £19,604 over a lifetime horizon. At list price, ranibizumab T&E was found to be cost-effective versus aflibercept in 100% of simulations at a willingness-to-pay threshold of £20,000 per QALY. The robustness of the results was tested in several scenario analyses; ranibizumab T&E was found to be more effective, and less costly, than aflibercept in the vast majority of cases.

CONCLUSION

This evaluation suggests that treating patients with ranibizumab according to the T&E regimen could be a better use of NHS resources than aflibercept, and could, therefore, be considered as a first-line regimen for patients with wet AMD in the UK.

FUNDING

Novartis Pharmaceuticals UK Limited.

Macular pigment optical density: repeatability, intereye correlation, and effect of ocular dominance

Purpose

To evaluate short-term repeatability, intereye correlation, and effect of ocular dominance on macular pigment optical density (MPOD) measurements obtained using the QuantifEye Heterochromatic Flicker Photometer.

Patients and methods

A total of 72 study participants were enrolled in this prospective, cross-sectional study. Participants underwent a comprehensive ocular evaluation, including visual acuity, evaluation of ocular dominance, slit lamp examination, intraocular pressure measurement, and optic nerve head and macula analysis using optical coherence tomography and fundus photography. All study participants after initial training underwent MPOD measurement twice in both eyes in a randomized sequence. The repeatability was tested using Altman and Bland plots for first measurements with the second measurements for right eye and left eye and additionally by grouping eyes as a function of ocular dominance. The Pearson correlation coefficient was performed to assess the intereye correlation of MPOD values.

Results

The mean age of study participants was 35.5 years (range 22–68 years). The mean MPOD measurements for OD (right eye) and OS (left eye) were 0.47 and 0.48, respectively, which followed a normal distribution (Shapiro–Wilk test, P=0.6 and 0.2). The 95% limits of agreement of Altman and Bland plots for the first and second measurements were −0.12 to +0.11 and −0.13 to +0.12 for OD and OS, respectively. The correlation coefficient of mean MPOD measurements of OD and OS was r statistic =0.94 (Pearson correlation coefficient P<0.0001; r² 0.89). The 95% limits of agreement of Altman and Bland plots when evaluated by laterality of eye or by ocular dominance were narrow, with limits of agreement ranging from −0.13 to +0.12.

Conclusion

The MPOD measurements obtained using the QuantifEye show good short-term repeatability. There is excellent intereye correlation, indicating that the MPOD values of one eye data can predict the fellow eye value with 89% accuracy. The ocular dominance had no bearing on the outcome of this psychophysical test in ocular healthy eyes.

Automated analysis of retinal imaging using machine learning techniques for computer vision

There are almost two million people in the United Kingdom living with sight loss, including around 360,000 people who are registered as blind or partially sighted. Sight threatening diseases, such as diabetic retinopathy and age related macular degeneration have contributed to the 40% increase in outpatient attendances in the last decade but are amenable to early detection and monitoring. With early and appropriate intervention, blindness may be prevented in many cases.

Ophthalmic imaging provides a way to diagnose and objectively assess the progression of a number of pathologies including neovascular (“wet”) age-related macular degeneration (wet AMD) and diabetic retinopathy. Two methods of imaging are commonly used: digital photographs of the fundus (the ‘back’ of the eye) and Optical Coherence Tomography (OCT, a modality that uses light waves in a similar way to how ultrasound uses sound waves). Changes in population demographics and expectations and the changing pattern of chronic diseases creates a rising demand for such imaging. Meanwhile, interrogation of such images is time consuming, costly, and prone to human error. The application of novel analysis methods may provide a solution to these challenges.

This research will focus on applying novel machine learning algorithms to automatic analysis of both digital fundus photographs and OCT in Moorfields Eye Hospital NHS Foundation Trust patients.

Through analysis of the images used in ophthalmology, along with relevant clinical and demographic information, DeepMind Health will investigate the feasibility of automated grading of digital fundus photographs and OCT and provide novel quantitative measures for specific disease features and for monitoring the therapeutic success.

Automated analysis of retinal imaging using machine learning techniques for computer vision

There are almost two million people in the United Kingdom living with sight loss, including around 360,000 people who are registered as blind or partially sighted. Sight threatening diseases, such as diabetic retinopathy and age related macular degeneration have contributed to the 40% increase in outpatient attendances in the last decade but are amenable to early detection and monitoring. With early and appropriate intervention, blindness may be prevented in many cases. Ophthalmic imaging provides a way to diagnose and objectively assess the progression of a number of pathologies including neovascular ("wet") age-related macular degeneration (wet AMD) and diabetic retinopathy. Two methods of imaging are commonly used: digital photographs of the fundus (the 'back' of the eye) and Optical Coherence Tomography (OCT, a modality that uses light waves in a similar way to how ultrasound uses sound waves). Changes in population demographics and expectations and the changing pattern of chronic diseases creates a rising demand for such imaging. Meanwhile, interrogation of such images is time consuming, costly, and prone to human error. The application of novel analysis methods may provide a solution to these challenges. This research will focus on applying novel machine learning algorithms to automatic analysis of both digital fundus photographs and OCT in Moorfields Eye Hospital NHS Foundation Trust patients. Through analysis of the images used in ophthalmology, along with relevant clinical and demographic information, DeepMind Health will investigate the feasibility of automated grading of digital fundus photographs and OCT and provide novel quantitative measures for specific disease features and for monitoring the therapeutic success.

The Prevalence of Visual Impairment in People with Dementia (the PrOVIDe study): a cross-sectional study of people aged 60–89 years with dementia and qualitative exploration of individual, carer and professional perspectives

Background

The prevalence of visual impairment (VI) and dementia increases with age and these conditions may coexist, but few UK data exist on VI among people with dementia.

Objectives

To measure the prevalence of eye conditions causing VI in people with dementia and to identify/describe reasons for underdetection or inappropriate management.

Design

Stage 1 – cross-sectional prevalence study. Stage 2 – qualitative research exploring participant, carer and professional perspectives of eye care.

Setting

Stage 1 – 20 NHS sites in six English regions. Stage 2 – six English regions.

Participants

Stage 1 – 708 participants with dementia (aged 60–89 years): 389 lived in the community (group 1) and 319 lived in care homes (group 2). Stage 2 – 119 participants.

Interventions

Stage 1 gathered eye examination data following domiciliary sight tests complying with General Ophthalmic Services requirements and professional guidelines. Cognitive impairment was assessed using the Standardised Mini-Mental State Examination (sMMSE) test, and functional ability and behaviour were assessed using the Bristol Activities of Daily Living Scale and Cambridge Behavioural Inventory – Revised. Stage 2 involved individual interviews (36 people with dementia and 11 care workers); and separate focus groups (34 optometrists; 38 family and professional carers).

Main outcome measures.

VI defined by visual acuity (VA) worse than 6/12 or worse than 6/18 measured before and after refraction.

Results

Stage 1 – when participants wore their current spectacles, VI prevalence was 32.5% [95% confidence interval (CI) 28.7% to 36.5%] and 16.3% (95% CI 13.5% to 19.6%) for commonly used criteria for VI of VA worse than 6/12 and 6/18, respectively. Of those with VI, 44% (VA < 6/12) and 47% (VA < 6/18) were correctable with new spectacles. Almost 50% of remaining uncorrectable VI (VA < 6/12) was associated with cataract, and was, therefore, potentially remediable, and one-third was associated with macular degeneration. Uncorrected/undercorrected VI prevalence (VA < 6/12) was significantly higher in participants in care homes (odds ratio 2.19, 95% CI 1.30 to 3.73;p < 0.01) when adjusted for age, sex and sMMSE score. VA could not be measured in 2.6% of group 1 and 34.2% of group 2 participants (p < 0.01). The main eye examination elements (excluding visual fields) could be performed in > 80% of participants. There was no evidence that the management of VI in people with dementia differed from that in older people in general. Exploratory analysis suggested significant deficits in some vision-related aspects of function and behaviour in participants with VI. Stage 2 key messages – carers and care workers underestimated how much can be achieved in an eye examination. People with dementia and carers were unaware of domiciliary sight test availability. Improved communication is needed between optometrists and carers; optometrists should be informed of the person’s dementia. Tailoring eye examinations to individual needs includes allowing extra time. Optometrists wanted training and guidance about dementia. Correcting VI may improve the quality of life of people with dementia but should be weighed against the risks and burdens of undergoing examinations and cataract surgery on an individual basis.

Limitations

Sampling bias is possible owing to quota-sampling and response bias.

Conclusions

The prevalence of VI is disproportionately higher in people with dementia living in care homes. Almost 50% of presenting VI is correctable with spectacles, and more with cataract surgery. Areas for future research are the development of an eye-care pathway for people with dementia; assessment of the benefits of early cataract surgery; and research into the feasibility of specialist optometrists for older people.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Etiologic Framework for the Study of Neurodegenerative Disorders as Well as Vascular and Metabolic Comorbidities on the Grounds of Shared Epidemiologic and Biologic Features

Background: During the last two decades, protein aggregation at all organismal levels, from viruses to humans, has emerged from a neglected area of protein science to become a central issue in biology and biomedicine. This article constitutes a risk-based review aimed at supporting an etiologic scenario of selected, sporadic, protein-associated, i.e., conformational, neurodegenerative disorders (NDDs), and their vascular- and metabolic-associated ailments.

Methods: A rationale is adopted, to incorporate selected clinical data and results from animal-model research, complementing epidemiologic evidences reported in two prior articles.

Findings: Theory is formulated assuming an underlying conformational transmission mechanism, mediated either by horizontal transfer of mammalian genes coding for specific aggregation-prone proteins, or by xeno-templating between bacterial and host proteins. We build a few population-based and experimentally-testable hypotheses focusing on: (1) non-disposable surgical instruments for sporadic Creutzfeldt-Jakob disease (sCJD) and other rapid progressive neurodegenerative dementia (sRPNDd), multiple system atrophy (MSA), and motor neuron disease (MND); and (2) specific bacterial infections such as B. pertussis and E. coli for all forms, but particularly for late-life sporadic conformational, NDDs, type 2 diabetes mellitus (T2DM), and atherosclerosis where natural protein fibrils present in such organisms as a result of adaptation to the human host induce prion-like mechanisms.

Conclusion: Implications for cohort alignment and experimental animal research are discussed and research lines proposed.

Exogenous NAD(+) decreases oxidative stress and protects H2O2-treated RPE cells against necrotic death through the up-regulation of autophagy

Increased oxidative stress, which can lead to the retinal pigment epithelium (RPE) cell death by inducing ATP depletion and DNA repair, is believed to be a prominent pathology in age-related macular degeneration (AMD). In the present study, we showed that and 0.1 mM nicotinamide adenine dinucleotide (NAD⁺) administration significantly blocked RPE cell death induced by 300 μM H₂O₂. Further investigation showed that H₂O₂ resulted in increased intracellular ROS level, activation of PARP-1 and subsequently necrotic death of RPE cells. Exogenous NAD⁺ administration significantly decreased intracellular and intranuclear ROS levels in H₂O₂-treated RPE cells. In addition, NAD⁺ administration to H₂O₂-treated RPE cells inhibited the activation of PARP-1 and protected the RPE cells against necrotic death. Moreover, exogenous NAD⁺ administration up-regulated autophagy in the H₂O₂-treated RPE cells. Inhibition of autophagy by LY294002 blocked the decrease of intracellular and intranuclear ROS level. Besides, inhibition of autophagy by LY294002 abolished the protection of exogenous NAD⁺ against H₂O₂-induced cell necrotic death. Taken together, our findings indicate that that exogenous NAD⁺ administration suppresses H₂O₂-induced oxidative stress and protects RPE cells against PARP-1 mediated necrotic death through the up-regulation of autophagy. The results suggest that exogenous NAD⁺ administration might be potential value for the treatment of AMD.

Amyloid beta deposition and phosphorylated tau accumulation are key features in aged choroidal vessels in the complement factor H knock out model of retinal degeneration

Extra-cellular deposition including amyloid beta (Aβ) is a feature of retinal ageing. It has been documented for Bruch's membrane (BM) where Aβ is elevated in complement factor H knockout mice (Cfh(-/-)) proposed as a model for age related macular degeneration. However, arterial deposition in choroidal vessels prior to perfusion across BM has not been examined. Aβ is associated with tau phosphorylation and these are linked in blood vessels in Alzheimers Disease where they can drive perivascular pathology. Here we ask if Aβ, tau and phosphorylated tau are features of ageing in choroidal vessels in 12 month C57 BL/6 and Cfh(-/-) mice, using immune staining and Western blot analysis. Greater levels of Aβ and phosphorylated tau are found in choroidal vessels in Cfh(-/-) mice. Western blot revealed a 40% increase in Aβ in Cfh(-/-) over C57 BL/6 mice. Aβ deposits coat around 55% of the luminal wall in Cfh(-/-) compared to only about 40% in C57 BL/6. Total tau was similar in both groups, but phosphorylated tau increased by >100% in Cfh(-/-) compared to C57 BL/6 and covered >75% of the luminal wall compared to 50% in C57 BL/6. Hence, phosphorylated tau is a marked choroidal feature in this mouse model. Aβ deposition was clumped in Cfh(-/-) mice and likely to influence blood flow dynamics. Disturbed flow is associated with atherogenesis and may be related to the accumulation of membrane attack complex recently identified between choroidal vessels in those at high risk of macular degeneration due to complement factor H polymorphisms.

Risk factors and biomarkers of age-related macular degeneration

A biomarker can be a substance or structure measured in body parts, fluids or products that can affect or predict disease incidence. As age-related macular degeneration (AMD) is the leading cause of blindness in the developed world, much research and effort has been invested in the identification of different biomarkers to predict disease incidence, identify at risk individuals, elucidate causative pathophysiological etiologies, guide screening, monitoring and treatment parameters, and predict disease outcomes. To date, a host of genetic, environmental, proteomic, and cellular targets have been identified as both risk factors and potential biomarkers for AMD. Despite this, their use has been confined to research settings and has not yet crossed into the clinical arena. A greater understanding of these factors and their use as potential biomarkers for AMD can guide future research and clinical practice. This article will discuss known risk factors and novel, potential biomarkers of AMD in addition to their application in both academic and clinical settings.

Protective Effect of Proanthocyanidins from Sea Buckthorn (Hippophae Rhamnoides L.) Seed against Visible Light-Induced Retinal Degeneration in Vivo

Dietary proanthocyanidins (PACs) as health-protective agents have become an important area of human nutrition research because of their potent bioactivities. We investigated the retinoprotective effects of PACs from sea buckthorn (Hippophae rhamnoides L.) seed against visible light-induced retinal degeneration in vivo. Pigmented rabbits were orally administered sea buckthorn seed PACs (50 and 100 mg/kg/day) for 14 consecutive days of pre-illumination and seven consecutive days of post-illumination. Retinal function was quantified via electroretinography 7 days after light exposure. Retinal damage was evaluated by measuring the thickness of the full-thickness retina and outer nuclear layer 7 days after light exposure. Sea buckthorn seed PACs significantly attenuated the destruction of electroretinograms and maintained the retinal structure. Increased retinal photooxidative damage was expressed by the depletion of glutathione peroxidase and catalase activities, the decrease of total antioxidant capacity level and the increase of malondialdehyde level. Light exposure induced a significant increase of inflammatory cytokines (IL-1β, TNF-α and IL-6) and angiogenesis (VEGF) levels in retina. Light exposure upregulated the expression of pro-apoptotic proteins Bax and caspase-3 and downregulated the expression of anti-apoptotic protein Bcl-2. However, sea buckthorn seed PACs ameliorated these changes induced by light exposure. Sea buckthorn seed PACs mediated the protective effect against light-induced retinal degeneration via antioxidant, anti-inflammatory and antiapoptotic mechanisms.

Oxidative stress-induced premature senescence dysregulates VEGF and CFH expression in retinal pigment epithelial cells: Implications for Age-related Macular Degeneration

Oxidative stress has a critical role in the pathogenesis of Age-related Macular Degeneration (AMD), a multifactorial disease that includes age, gene variants of complement regulatory proteins and smoking as the main risk factors. Stress-induced premature cellular senescence (SIPS) is postulated to contribute to this condition. In this study, we hypothesized that oxidative damage, promoted by endogenous or exogenous sources, could elicit a senescence response in RPE cells, which would in turn dysregulate the expression of major players in AMD pathogenic mechanisms. We showed that exposure of a human RPE cell line (ARPE-19) to a cigarette smoke concentrate (CSC), not only enhanced Reactive Oxygen Species (ROS) levels, but also induced 8-Hydroxydeoxyguanosine-immunoreactive (8-OHdG) DNA lesions and phosphorylated-Histone 2AX-immunoreactive (p-H2AX) nuclear foci. CSC-nuclear damage was followed by premature senescence as shown by positive senescence associated-β-galactosidase (SA-β-Gal) staining, and p16(INK4a) and p21(Waf-Cip1) protein upregulation. N-acetylcysteine (NAC) treatment, a ROS scavenger, decreased senescence markers, thus supporting the role of oxidative damage in CSC-induced senescence activation. ARPE-19 senescent cultures were also established by exposure to hydrogen peroxide (H2O2), which is an endogenous stress source produced in the retina under photo-oxidation conditions. Senescent cells upregulated the proinflammatory cytokines IL-6 and IL-8, the main markers of the senescence-associated secretory phenotype (SASP). Most important, we show for the first time that senescent ARPE-19 cells upregulated vascular endothelial growth factor (VEGF) and simultaneously downregulated complement factor H (CFH) expression. Since both phenomena are involved in AMD pathogenesis, our results support the hypothesis that SIPS could be a principal player in the induction and progression of AMD. Moreover, they would also explain the striking association of this disease with cigarette smoking.

Aflibercept in wet AMD beyond the first year of treatment: recommendations by an expert roundtable panel

This paper provides expert recommendations on administration of aflibercept in wet age-related macular degeneration (AMD) after Year 1 (Y1), based on a roundtable discussion held in London, UK in November 2014. The goals of treatment after Y1 are to maintain visual and anatomical gains whilst minimising treatment burden and using resources effectively. The treatment decision should be made at the seventh injection visit (assuming the label has been followed) in Y1, and three approaches are proposed: (a) eyes with active disease on imaging/examination but with stable visual acuity (VA) at the end of Y1 should continue with fixed 8-weekly dosing; (b) eyes with inactive disease on imaging/examination and stable VA should be managed using a 'treat and extend' (T&E) regimen. T&E involves treating and then extending the interval until the next treatment, by 2-week intervals, to a maximum of 12 weeks, provided the disease remains inactive. If there is new evidence of disease activity, treatment is administered and the interval to the next treatment shortened; and (c) if there has been no disease activity for ≥3 consecutive visits, a trial of monitoring without treatment may be appropriate, initiated at the end of Y1 or at any time during Y2. Where possible, VA testing, OCT imaging and injection should be performed at the same visit. The second eye should be monitored to detect fellow eye involvement. In bilateral disease, the re-treatment interval should be driven by the better-seeing eye or, if the VA is similar, the eye with the more active disease.

Determining patient preferences in the management of neovascular age-related macular degeneration: a conjoint analysis

PurposeTo determine the opinions from a patient perspective on relevant variables in the delivery of treatment for neovascular age-related macular degeneration (nAMD).MethodsPilot interviews with patients and doctors were conducted to identify what variables in the provision of a nAMD service were important. This led to the generation of two sets of scenario options. Subsequently 100 patients undergoing active treatment for nAMD in the National Health Service University Hospital, United Kingdom underwent interview assessment. They were asked to rank their preferences for provision of their care with reference to these two sets of scenario options. Using conjoint analysis, percentage preferences, and utility scores for each variable in each scenario design were calculated.ResultsNinety-five patients completed the preference ranking for both scenarios. Eight patients ranked worse vision as preferable to better vision and were excluded on the basis that they had not understood the task. The results of the remaining 87 patients are presented. The most important factor to patients was having good vision, followed by a one-stop service and less frequent follow up. The least important factors were label status of the drug, cost to the health service, and grade of the injector.ConclusionPatients regard good vision and minimal visits to the hospital above the status of injector, label status of drug, or cost to the NHS.

Modelling the Age Dynamics of Chronic Health Conditions: Life-Table-Consistent Transition Probabilities and their Application

Surveys of chronic health conditions provide information about prevalence but not incidence and the process of change within the population. Our study shows how "age dynamics" of chronic conditions – the probabilities of contracting conditions at different ages, of moving from one chronic condition state to another, and of dying – can be inferred from prevalence data for those conditions that can be viewed as irreversible. Transition probability matrices are constructed for successive age groups, with the sequence representing the age dynamics of the health conditions for a stationary population. We simulate the life path of a cohort under the initial probabilities, and again under altered probabilities, to explore the effects of reducing the incidence or mortality rate associated with a particular condition. We show that such surveys of chronic conditions can be made even more valuable by allowing the calculation of the transition probabilities that define the chronic conditions aging process.

Macular disease research in the United Kingdom 2011-2014: a bibliometric analysis of outputs, performance and coverage

Background

Bibliometric indicators, based on measuring patterns of publications and citations, are widely used by universities and research funders to assess research performance. Our aims were to: (1) perform a bibliometric analysis of UK macular disease research publications from 2011 to 2014 and compare this with the other countries producing major output in the area, and (2) compare the pattern of UK macular disease publication with the priorities for age-related macular degeneration (AMD) developed by the Sight Loss and Vision Priority Setting Partnership (SLV-PSP).

Methods

We used the Scopus database to retrieve macular disease articles published from 2011 to 2014. Citations to articles from 2011 to 2013 and journal impact factors (JIFs) for 2014 articles were obtained. Articles with UK authors were allocated to the 10 SLV-PSP priorities for age-related macular degeneration (AMD), where possible.

Results

The UK, USA, and Germany and China were the top four producers of macular disease research from 2011 to 2013. All except China had a higher proportion of citations than articles. There were 421 articles with UK authors published from 2011 to 2014, of which 49 % had international collaborators. The UK produced 9.7 % of the world’s output of macular disease articles from 2011 to 2013, but received 14.2 % of the world’s share of citations. UK authors’ share of the world’s top 10 % of cited publications from 2011 to 2013 was 16.2 %. In 2014, 13.2 % of UK articles were in journals in the top 10 % when ranked by Journal Impact Factors (JIFs), while the overall UK article share for that year was 9.9 %. UK articles did not show a strong correlation between citations and JIFs. The SLV-PSP published a set of 10 priorities for research into age-related macular degeneration in October 2103. Only 8 % of the UK’s 2011–2014 publications matched the SLV-PSP top priority (treatment to stop dry AMD progressing) and 34 % did not match any of the SLV-PSP priorities, mainly because the priorities did not include invasive treatment of wet AMD.

Conclusions

The UK is performing well in macular research, based on bibliometric indicators. The distribution of past research topics does not match the priorities set by the SLV-PSP.

Geographic atrophy in patients with advanced dry age-related macular degeneration: current challenges and future prospects

Geographic atrophy (GA) of the retinal pigment epithelium (RPE) is a devastating complication of age-related macular degeneration (AMD). GA may be classified as drusen-related (drusen-associated GA) or neovascularization-related (neovascular-associated GA). Drusen-related GA remains a large public health concern due to the burden of blindness it produces, but pathophysiology of the condition is obscure and there are no proven treatment options. Genotyping, cell biology, and clinical imaging point to upregulation of parainflammatory pathways, oxidative stress, and choroidal sclerosis as contributors, among other factors. Onset and monitoring of progression is accomplished through clinical imaging instrumentation such as optical coherence tomography, photography, and autofluorescence, which are the tools most helpful in determining end points for clinical trials at present. A number of treatment approaches with diverse targets are in development at this time, some of which are in human clinical trials. Neovascular-associated GA is a consequence of RPE loss after development of neovascular AMD. The neovascular process leads to a plethora of cellular stresses such as ischemia, inflammation, and dramatic changes in cell environment that further taxes RPE cells already dysfunctional from drusen-associated changes. GA may therefore develop secondary to the neovascular process de novo or preexisting drusen-associated GA may continue to worsen with the development of neovascular AMD. Neovascular-associated GA is a prominent cause of continued vision loss in patients with otherwise successfully treated neovascular AMD. Clearly, treatment with vascular endothelial growth factor (VEGF) inhibitors early in the course of the neovascular disease is of great clinical benefit. However, there is a rationale and some suggestive evidence that anti-VEGF agents themselves could be toxic to RPE and enhance neovascular-associated GA. The increasing prevalence of legal blindness from this condition due to the aging of the general population lends urgency to the search for a therapy to ameliorate GA.

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 people 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 METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2015), EMBASE (January 1980 to August 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to August 2015), 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 3 August 2015.

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 participant (unilateral studies); other studies recruited participants 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-person correlation coefficient from one study and assumed it was valid for the others.

MAIN RESULTS

The update of this review found two additional studies, totaling 11 studies that randomised 2159 participants (3580 eyes) and followed them up to two years, of which six studies (1454 participants) included people with one eye randomised to treatment and one to control. Studies were conducted in Australia, Europe and North America.Overall, the risk of bias in the included studies was low, particularly for the larger studies and for the primary outcome development of CNV. Photocoagulation did not reduce the development of CNV at two years' follow-up (odds ratio (OR) 1.07, 95% confidence interval (CI) 0.79 to 1.46, 11 studies, 2159 participants (3580 eyes), high quality evidence). This estimate means that, given an overall occurrence of CNV of 8.3% in the control group, we estimated an absolute risk reduction by no more than 1.4% in the laser group, according to the lower CI limit. Only two studies investigated the effect on the development of geographic atrophy and could not show a difference, but estimates were imprecise (OR 1.30, 95% CI 0.38 to 4.51, two studies, 148 participants (148 eyes), low quality evidence).Among secondary outcomes, photocoagulation led to drusen reduction (OR 9.16, 95% CI 6.28 to 13.4, three studies, 570 participants (944 eyes), high quality evidence) but was not shown to limit loss of 3 or more lines of visual acuity (OR 0.99, 95% CI 0.81 to 1.22, nine studies, 2002 participants (2386 eyes), moderate quality evidence).In a subgroup analysis, no difference could be shown for conventional visible (eight studies) versus subthreshold invisible (four studies) photocoagulation for the primary outcomes (P value = 0.29). The effect in the subthreshold group did not suggest a relevant benefit (OR 1.27, 95% CI 0.82 to 1.98). No study used micropulse subthreshold photocoagulation.No other adverse effects (apart from development of CNV, geographic atrophy or visual loss) were reported.

AUTHORS' CONCLUSIONS

The trials included in this review confirm the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, treatment does not result in a reduction in the risk of developing CNV, and was not shown to limit the occurrence of geographic atrophy or visual acuity loss.Ongoing studies are being conducted to assess whether the use of extremely short laser pulses (i.e. nanosecond laser treatment) cannot only lead to drusen regression but also prevent neovascular AMD.

Generic and disease-specific estimates of quality of life in macular degeneration: mapping the MacDQoL onto the EQ-5D-3L

PURPOSE

The macular degeneration quality of life (MacDQoL) instrument is a validated condition-specific measure of quality of life in patients with macular degeneration. This paper presents the first mapping algorithm to predict EQ-5D from responses to the MacDQoL instrument.

METHODS

Responses to the MacDQoL and EQ-5D-3L instruments from 482 patients were collected from the IVAN multicentre trial of two alternative drug treatments for neovascular age-related macular degeneration. Regression specifications were estimated using OLS, censored least absolute deviation, Tobit and two-part models. Their predictive performance was assessed using mean squared error. An internal validation sample based on a random selection of 25 % of patients was used to assess the performance of the model estimated on the remaining 75 % of patients.

RESULTS

A two-part model had the best predictive performance on the full sample. The covariates of this model include responses and weighted impact scores for all 23 condition-specific domains of the MacDQoL, and responses to a general MacDQoL quality of life question. The selected models were successful at predicting means and standard deviations of target populations, but prediction is weaker at the upper and lower extremes of the EQ-5D-3L distribution.

CONCLUSION

The mapping algorithms provide a means of predicting EQ-5D-3L index scores from MacDQoL scores, and could facilitate cost-effectiveness analyses when the latter but not the former are available to researchers. Further validation of the performance of the algorithms using external data would provide a means of establishing the robustness of the algorithms.

Differences in the Genetic Susceptibility to Age-Related Macular Degeneration Clinical Subtypes

PURPOSE

We compared across age-related macular degeneration (AMD) subtypes the effect of AMD risk variants, their predictive power, and heritability.

METHODS

The prevalence of AMD was estimated among active non-Hispanic white Kaiser Permanente Northern California members who were at least 65 years of age as of June 2013. The genetic analysis included 5,170 overall AMD cases ascertained from electronic health records (EHR), including 1,239 choroidal neovascularization (CNV) cases and 1,060 nonexudative AMD cases without CNV, and 23,130 controls of non-Hispanic white ancestry from the Kaiser Permanente Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort. Imputation was based on the 1000 Genomes Project reference panel.

RESULTS

The narrow-sense heritability due to common autosomal single nucleotide polymorphisms (SNPs) was 0.37 for overall AMD, 0.19 for AMD unspecified, 0.20 for nonexudative AMD, and 0.60 for CNV. For the 19 previously reported AMD risk loci, the area under the receiver operating characteristic (ROC) curve was 0.675 for overall AMD, 0.640 for AMD unspecified, 0.678 for nonexudative AMD, and 0.766 for CNV. The individual effects on the risk of AMD for 18 of the 19 SNPs were in a consistent direction with those previously reported, including a protective effect of the APOE ε4 allele. Conversely, the risk of AMD was significantly increased in carriers of the ε2 allele.

CONCLUSIONS

These findings provide an independent confirmation of many of the previously identified AMD risk loci, and support a potentially greater role of genetic factors in the development of CNV. The replication of established associations validates the use of EHR in genetic studies of ophthalmologic traits.

Comparative Incidence of Conformational, Neurodegenerative Disorders

Background

The purpose of this study was to identify incidence and survival patterns in conformational neurodegenerative disorders (CNDDs).

Methods

We identified 2563 reports on the incidence of eight conditions representing sporadic, acquired and genetic, protein-associated, i.e., conformational, NDD groups and age-related macular degeneration (AMD). We selected 245 papers for full-text examination and application of quality criteria. Additionally, data-collection was completed with detailed information from British, Swedish, and Spanish registries on Creutzfeldt-Jakob disease (CJD) forms, amyotrophic lateral sclerosis (ALS), and sporadic rapidly progressing neurodegenerative dementia (sRPNDd). For each condition, age-specific incidence curves, age-adjusted figures, and reported or calculated median survival were plotted and examined.

Findings

Based on 51 valid reported and seven new incidence data sets, nine out of eleven conditions shared specific features. Age-adjusted incidence per million person-years increased from ≤1.5 for sRPNDd, different CJD forms and Huntington's disease (HD), to 1589 and 2589 for AMD and Alzheimer's disease (AD) respectively. Age-specific profiles varied from (a) symmetrical, inverted V-shaped curves for low incidences to (b) those increasing with age for late-life sporadic CNDDs and for sRPNDd, with (c) a suggested, intermediate, non-symmetrical inverted V-shape for fronto-temporal dementia and Parkinson's disease. Frequently, peak age-specific incidences from 20–24 to ≥90 years increased with age at onset and survival. Distinct patterns were seen: for HD, with a low incidence, levelling off at middle age, and long median survival, 20 years; and for sRPNDd which displayed the lowest incidence, increasing with age, and a short median disease duration.

Interpretation

These results call for a unified population view of NDDs, with an age-at-onset-related pattern for acquired and sporadic CNDDs. The pattern linking age at onset to incidence magnitude and survival might be explained by differential pathophysiological mechanisms associated with specific misfolded protein deposits.

Optical coherence tomography for the diagnosis, monitoring and guiding of treatment for neovascular age-related macular degeneration: a systematic review and economic evaluation

BACKGROUND

Age-related macular degeneration is the most common cause of sight impairment in the UK. In neovascular age-related macular degeneration (nAMD), vision worsens rapidly (over weeks) due to abnormal blood vessels developing that leak fluid and blood at the macula.

OBJECTIVES

To determine the optimal role of optical coherence tomography (OCT) in diagnosing people newly presenting with suspected nAMD and monitoring those previously diagnosed with the disease.

DATA SOURCES

Databases searched: MEDLINE (1946 to March 2013), MEDLINE In-Process & Other Non-Indexed Citations (March 2013), EMBASE (1988 to March 2013), Biosciences Information Service (1995 to March 2013), Science Citation Index (1995 to March 2013), The Cochrane Library (Issue 2 2013), Database of Abstracts of Reviews of Effects (inception to March 2013), Medion (inception to March 2013), Health Technology Assessment database (inception to March 2013).

REVIEW METHODS

Types of studies: direct/indirect studies reporting diagnostic outcomes.

INDEX TEST

time domain optical coherence tomography (TD-OCT) or spectral domain optical coherence tomography (SD-OCT).

COMPARATORS

clinical evaluation, visual acuity, Amsler grid, colour fundus photographs, infrared reflectance, red-free images/blue reflectance, fundus autofluorescence imaging, indocyanine green angiography, preferential hyperacuity perimetry, microperimetry. Reference standard: fundus fluorescein angiography (FFA). Risk of bias was assessed using quality assessment of diagnostic accuracy studies, version 2. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. A Markov model was developed (65-year-old cohort, nAMD prevalence 70%), with nine strategies for diagnosis and/or monitoring, and cost-utility analysis conducted. NHS and Personal Social Services perspective was adopted. Costs (2011/12 prices) and quality-adjusted life-years (QALYs) were discounted (3.5%). Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

In pooled estimates of diagnostic studies (all TD-OCT), sensitivity and specificity [95% confidence interval (CI)] was 88% (46% to 98%) and 78% (64% to 88%) respectively. For monitoring, the pooled sensitivity and specificity (95% CI) was 85% (72% to 93%) and 48% (30% to 67%) respectively. The FFA for diagnosis and nurse-technician-led monitoring strategy had the lowest cost (£ 39,769; QALYs 10.473) and dominated all others except FFA for diagnosis and ophthalmologist-led monitoring (£ 44,649; QALYs 10.575; incremental cost-effectiveness ratio £ 47,768). The least costly strategy had a 46.4% probability of being cost-effective at £ 30,000 willingness-to-pay threshold.

LIMITATIONS

Very few studies provided sufficient information for inclusion in meta-analyses. Only a few studies reported other tests; for some tests no studies were identified. The modelling was hampered by a lack of data on the diagnostic accuracy of strategies involving several tests.

CONCLUSIONS

Based on a small body of evidence of variable quality, OCT had high sensitivity and moderate specificity for diagnosis, and relatively high sensitivity but low specificity for monitoring. Strategies involving OCT alone for diagnosis and/or monitoring were unlikely to be cost-effective. Further research is required on (i) the performance of SD-OCT compared with FFA, especially for monitoring but also for diagnosis; (ii) the performance of strategies involving combinations/sequences of tests, for diagnosis and monitoring; (iii) the likelihood of active and inactive nAMD becoming inactive or active respectively; and (iv) assessment of treatment-associated utility weights (e.g. decrements), through a preference-based study.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012001930.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

One-year results from clinical practice of epimacular strontium-90 brachytherapy for the treatment of subfoveal choroidal neovascularization secondary to AMD

BACKGROUND AND OBJECTIVE

To evaluate clinical feasibility, safety, and efficacy of epiretinal strontium-90 brachytherapy in subfoveal choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) in eyes unresponsive to repeated anti-VEGF injections.

PATIENTS AND METHODS

A retrospective, single-center study on patients treated with strontium-90 brachytherapy for CNV secondary to neovascular AMD. Patients underwent pars plana vitrectomy with a single 24 Gy dose brachytherapy. They were re-treated with anti-VEGF injections on an as-needed basis if subretinal or intraretinal fluid was detected on optical coherence tomography imaging.

RESULTS

Twenty-two patients were treated, and 20 completed 12 months of follow-up. Ten patients maintained stable vision, eight gained vision, and two lost more than three Snellen lines. The mean best corrected visual acuity change from baseline was -8 ± 5.7 letters. A mean of 5.5 ± 4.4 anti-VEGF injections were administered throughout 12 months.

CONCLUSION

Epimacular brachytherapy is feasible in clinical practice. While some patients benefit from the treatment and need significantly fewer as-needed injections, others appear not to react to irradiation treatment after 1 year of follow-up. Larger numbers of patients are needed to evaluate therapeutic efficacy and to determine which patients can benefit from combined radiation and anti-VEGF therapy.

Cross Sectional and Longitudinal Associations between Cardiovascular Risk Factors and Age Related Macular Degeneration in the EPIC-Norfolk Eye Study

Purpose

To examine the cross sectional and longitudinal relationship between cardiovascular risk factors and age-related macular degeneration (AMD) in a large British cohort study.

Methods

The EPIC Norfolk Eye study is nested in a larger prospective cohort study. Data on cardiovascular risk factors were collected at baseline (1993-1997) and follow up (2006-2011) via clinical examination, validated lifestyle questionnaires and serum blood samples. AMD was ascertained using standardised grading of fundus photographs at the follow up. Logistic regression was used to examine associations between baseline and follow up risk factors with AMD.

Results

5,344 pairs (62.0% of total 8623) of fundus photographs were of sufficient quality for grading of AMD in participants with mean age of 67.4 years old (range 44-91) at diagnosis. There were 28 cases of late AMD (0.5%, 95% confidence interval (CI)=0.3-0.8%) and 645 cases of early AMD (12.1%, 95%CI=11.2-13.0.%). In multivariable analysis, older people with higher levels of baseline high density lipoprotein- cholesterol (HDL-C ) and C-reactive protein (CRP) were more likely to have any signs of AMD, after adjusting for sex, education, smoking, and systolic blood pressure. In cross sectional analysis, only older age and higher HDL were significantly associated with AMD.

Conclusions

We have found that older age and higher levels of CRP and HDL-C were associated with increased odds of AMD in this population in the longitudinal analysis, but older age and HDL-C, not CRP was significantly associated with AMD in the cross sectional analysis. The prevalence of AMD in this cohort was low compared to other cohorts in Europe, the US and Australia, and probably reflects the some selection biases in follow up participation as well as the low rate of smoking among our healthy participants.

Visual acuity at presentation in the second eye versus first eye in patients with exudative age-related macular degeneration

PURPOSE

To assess the difference in best-corrected visual acuity (BCVA) at presentation between the first and second eye in patients with bilateral neovascular age-related macular degeneration (AMD).

METHODS

We reviewed the charts of all patients who had a clinical examination for neovascular AMD at the University Eye Clinic of Creteil in January 2013. We retrospectively analyzed demographic and clinical data for 264 patients.

RESULTS

In the fellow eye, choroidal neovascularization (CNV) developed in 75/264 patients (28.4%) with a time interval between the 2 events of 30.3 months (range 6-145). Data were available on 65 patients: 14/65 (21.5%) were asymptomatic, 24/65 (36.9%) had BCVA >20/40, whereas at the time of CNV diagnosis in the first eye, no patient was asymptomatic (p<0.0001), and 11/65 (16.9%) eyes had BCVA >20/40 (p<0.0001). The mean BCVA of the first affected eye was 0.68 (± 0.41) logarithm of minimum angle of resolution (logMAR) and the mean BCVA for the second eye was 0.36 (± 0.29) logMAR (p<0.0001).

CONCLUSIONS

The BCVA at the time of diagnosis of CNV was higher in the second eye than in the first affected eye. This was possibly due to several factors including systematic bilateral examination in follow-up of unilateral exudative AMD that allowed detection of 20% of cases.

Stereotactic radiotherapy for wet age-related macular degeneration (INTREPID): influence of baseline characteristics on clinical response

PURPOSE

To determine which patients respond best to stereotactic radiotherapy (SRT) for neovascular age-related macular degeneration.

METHODS

Participants (n = 230) receiving intravitreal anti-vascular endothelial growth factor injections for neovascular age-related macular degeneration enrolled in a randomized, double-masked sham-controlled trial comparing 16 Gray, 24 Gray, or Sham SRT. In a post hoc analysis, participants were grouped according to their baseline characteristics, to determine if these influenced SRT efficacy.

RESULTS

At 52 weeks, SRT was most effective for lesions ≤4 mm in greatest linear dimension and with a macular volume greater than the median value of 7.4 mm. For 26% of the participants with both these characteristics, SRT resulted in 55% fewer ranibizumab injections (2.08 vs. 4.60; P = 0.0002), a mean visual acuity change that was 5.33 letters superior to sham (+2.18 vs. -3.15 letters; P = 0.0284), and a 71.1-μm greater reduction in mean central subfield thickness (-122.6 vs. -51.5 μm; P = 0.027). Other features associated with a positive response to SRT included pigment epithelial detachment and the absence of fibrosis.

CONCLUSION

Stereotactic radiotherapy is most effective for neovascular age-related macular degeneration lesions that are actively leaking at the time of treatment, and no larger than the 4-mm treatment zone.

Dexamethasone Intravitreal Implant as Adjunctive Therapy to Ranibizumab in Neovascular Age-Related Macular Degeneration: A Multicenter Randomized Controlled Trial

Purpose: To evaluate the efficacy and safety of dexamethasone intravitreal implant 0.7 mg (DEX) as adjunctive therapy to ranibizumab in neovascular age-related macular degeneration (nvAMD). Procedures: This was a 6-month, single-masked, multicenter study. Patients were randomized to DEX implant (n = 123) or sham procedure (n = 120) and received 2 protocol-mandated intravitreal ranibizumab injections. The main outcome measure was injection-free interval to first as-needed ranibizumab injection. Results: DEX increased the injection-free interval versus sham (50th percentile, 34 vs. 29 days; 75th percentile, 85 vs. 56 days; p = 0.016). 8.3% of DEX versus 2.5% of sham-treated patients did not require rescue ranibizumab (p = 0.048). Visual acuity and retinal thickness outcomes were similar in DEX and sham-treated patients. Only reports of conjunctival hemorrhage (18.2 vs. 8.5%) and intraocular pressure elevation (13.2 vs. 4.2%) were significantly different in the DEX versus the sham treatment groups. Conclusion: DEX reduced the need for adjunctive ranibizumab treatment and showed acceptable tolerability in nvAMD patients.

Age-related macular degeneration: genome-wide association studies to translation

In recent years, genome-wide association studies (GWAS), which are able to analyze the contribution to disease of genetic variations that are common within a population, have attracted considerable investment. Despite identifying genetic variants for many conditions, they have been criticized for yielding data with minimal clinical utility. However, in this regard, age-related macular degeneration (AMD), the most common form of blindness in the Western world, is a striking exception. Through GWAS, common genetic variants at a number of loci have been discovered. Two loci in particular, including genes of the complement cascade on chromosome 1 and the ARMS2/HTRA1 genes on chromosome 10, have been shown to convey significantly increased susceptibility to developing AMD. Today, although it is possible to screen individuals for a genetic predisposition to the disease, effective interventional strategies for those at risk of developing AMD are scarce. Ongoing research in this area is nonetheless promising. After providing brief overviews of AMD and common disease genetics, we outline the main recent advances in the understanding of AMD, particularly those made through GWAS. Finally, the true merit of these findings and their current and potential translational value is examined.Genet Med 18 4, 283-289.

Omega 3 fatty acids for preventing or slowing the progression of age-related macular degeneration

BACKGROUND

Evidence from animal models and observational studies in humans has suggested that there is an inverse relationship between dietary intake of omega 3 long-chain polyunsaturated fatty acids (LCPUFA) and risk of developing age-related macular degeneration (AMD) or progression to advanced AMD.

OBJECTIVES

To review the evidence that increasing the levels of omega 3 LCPUFA in the diet (either by eating more foods rich in omega 3 or by taking nutritional supplements) prevents AMD or slows the progression of AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to February 2015), EMBASE (January 1980 to February 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to February 2015), 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 February 2015.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) where increased dietary intake of omega 3 LCPUFA was compared to placebo or no intervention with the aim of preventing the development of AMD, or slowing its progression.

DATA COLLECTION AND ANALYSIS

Both authors independently selected studies, assessed them for risk of bias and extracted data. One author entered data into RevMan 5 and the other author checked the data entry. We conducted a meta-analysis for one primary outcome, progression of AMD, using a fixed-effect inverse variance model.

MAIN RESULTS

We included two RCTs in this review, in which 2343 participants with AMD were randomised to receive either omega 3 fatty acid supplements or a placebo. The trials, which had a low risk of bias, were conducted in the USA and France. Overall, there was no evidence that people who took omega 3 fatty acid supplements were at decreased (or increased risk) of progression to advanced AMD (pooled hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.84 to 1.10, high quality evidence). Similarly, people taking these supplements were no more (or less) likely to lose 15 or more letters of visual acuity (USA study HR 0.96, 95% CI 0.84 to 1.10; French study at 36 months risk ratio (RR) 1.25, 95% CI 0.69 to 2.26, participants = 230). The number of adverse events was similar in the intervention and placebo groups (USA study participants with one or more serious adverse event RR 1.00, 95% CI 0.91 to 1.09, participants = 2080; French study total adverse events RR 1.05, 95% CI 0.97 to 1.13, participants = 263).

AUTHORS' CONCLUSIONS

This review found that omega 3 LCPUFA supplementation in people with AMD for periods up to five years does not reduce the risk of progression to advanced AMD or the development of moderate to severe visual loss. No published randomised trials were identified on dietary omega 3 fatty acids for primary prevention of AMD. Currently available evidence does not support increasing dietary intake of omega 3 LCPUFA for the explicit purpose of preventing or slowing the progression of AMD.

Supplementation with three different macular carotenoid formulations in patients with early age-related macular degeneration

PURPOSE

To investigate the impact of three different macular carotenoid formulations on macular pigment optical density and visual performance in subjects with early age-related macular degeneration.

METHODS

Fifty-two subjects were supplemented and followed for 12 months, 17 of them were in intervention Group 1 (20 mg/day lutein and 2 mg/day zeaxanthin); 21 in Group 2 (10 mg/day meso-zeaxanthin, 10 mg/day lutein, and 2 mg/day zeaxanthin); and 14 in Group 3 (17 mg/day meso-zeaxanthin, 3 mg/day lutein, and 2 mg/day zeaxanthin). The macular pigment optical density was measured using customized heterochromatic flicker photometry, and visual function was assessed using corrected distance visual acuity and by letter contrast sensitivity.

RESULTS

A statistically significant increase in the macular pigment optical density was observed at all measured eccentricities in Group 2 (P ≤ 0.005) and in Group 3 (P < 0.05, for all), but only at 1.75° in Group 1 (P = 0.018). Statistically significant (P < 0.05) improvements in letter contrast sensitivity were seen at all spatial frequencies (except 1.2 cycles per degree) in Group 3, and at low spatial frequencies in Groups 1 and 2.

CONCLUSION

Augmentation of the macular pigment optical density across its spatial profile and enhancements in contrast sensitivity were best achieved after supplementation with a formulation containing high doses of meso-zeaxanthin in combination with lutein and zeaxanthin.

Area deprivation and age related macular degeneration in the EPIC-Norfolk Eye Study

Objectives

To investigate the relationship between area deprivation, individual socio-economic status (SES) and age related macular degeneration (AMD).

Study design

Cross sectional study nested within a longitudinal cohort study.

Methods

Data were collected in the EPIC-Norfolk Eye Study by trained nurses, using standardized protocols and lifestyle questionnaires. The English Index of multiple deprivation 2010 (IMD) was derived from participants' postcodes. AMD was identified from standardized grading of fundus photographs. Logistic regression was used to examine associations between IMD, SES and AMD.

Results

5344 pairs (62.0% of total 8623) of fundus photographs were of sufficient quality for grading of AMD. Of 5182 participants with complete data, AMD was identified in 653 participants (12.60%, 95%CI = 11.7–13.5%). Multivariable logistic regression showed that people living in the most affluent 5% of areas had nearly half the odds of AMD compared to those living in comparatively more deprived areas (OR = 0.56, 95% CI = 0.36–0.89, P = 0.02), after adjusting for age, sex, education, social class and smoking.

Conclusions

The authors found that living in the most affluent areas exerted a protective effect on AMD, independently of education and social class. Further investigation into underlying mechanisms will inform potential interventions to reduce health inequalities relating to AMD.

•

The relationship between area deprivation and AMD diagnosed from fundus photographs was examined.

•

Data from 5182 participants from the EPIC-Norfolk Eye study were analyzed.

•

Predominantly early AMD was identified in 653 participants (12.6%).

•

People living in more affluent areas had nearly half the risk of AMD.

•

Results require interpretation with caution due to the healthy population studied.

A Candidate Gene Association Study Identifies DAPL1 as a Female-Specific Susceptibility Locus for Age-Related Macular Degeneration (AMD)

Age-related macular degeneration (AMD) is the leading cause of blindness among white caucasians over the age of 50 years with a prevalence rate expected to increase markedly with an anticipated increase in the life span of the world population. To further expand our knowledge of the genetic architecture of the disease, we pursued a candidate gene approach assessing 25 genes and a total of 109 variants. Of these, synonymous single nucleotide polymorphism (SNP) rs17810398 located in death-associated protein-like 1 (DAPL1) was found to be associated with AMD in a joint analysis of 3,229 cases and 2,835 controls from five studies [combined P_ADJ = 1.15 × 10⁻⁶, OR 1.332 (1.187–1.496)]. This association was characterized by a highly significant sex difference (P_diff = 0.0032) in that it was clearly confined to females with genome-wide significance [P_ADJ = 2.62 × 10⁻⁸, OR 1.541 (1.324–1.796); males: P_ADJ = 0.382, OR 1.084 (0.905–1.298)]. By targeted resequencing of risk and non-risk associated haplotypes in the DAPL1 locus, we identified additional potentially functional risk variants, namely a common 897-bp deletion and a SNP predicted to affect a putative binding site of an exonic splicing enhancer. We show that the risk haplotype correlates with a reduced retinal transcript level of two, less frequent, non-canonical DAPL1 isoforms. DAPL1 plays a role in epithelial differentiation and may be involved in apoptotic processes thereby suggesting a possible novel pathway in AMD pathogenesis.

Cellular strategies for retinal repair by photoreceptor replacement

Loss of photoreceptors due to retinal degeneration is a major cause of blindness in the developed world. While no effective treatment is currently available, cell replacement therapy, using pluripotent stem cell-derived photoreceptor precursor cells, may be a feasible future treatment. Recent reports have demonstrated rescue of visual function following the transplantation of immature photoreceptors and we have seen major advances in our ability to generate transplantation-competent donor cells from stem cell sources. Moreover, we are beginning to realise the possibilities of using endogenous populations of cells from within the retina itself to mediate retinal repair. Here, we present a review of our current understanding of endogenous repair mechanisms together with recent progress in the use of both ocular and pluripotent stem cells for the treatment of photoreceptor loss. We consider how our understanding of retinal development has underpinned many of the recent major advances in translation and moved us closer to the goal of restoring vision by cellular means.

Redesigning services for the management of vitreomacular traction and macular hole

Vitreomacular traction (VMT) and VMT with macular hole (MH) are serious conditions, being associated with visual disturbance, for example, metamorphopsia, and diminished visual acuity (VA). Pars plana vitrectomy is the routine treatment for symptomatic VMT and VMT+MH. However, ocriplasmin has demonstrated favourable efficacy and safety in specific patient groups with VMT/MH and is now recommended as a treatment option for certain patients by the National Institute of Health and Care Excellence. This means that services for managing patients with VMT/MH may need to be revised, as patients can now potentially receive treatment earlier in the course of the disease. VMT triage clinics could provide a more efficient way of managing VMT/MH patients. Patient assessment should always include high-definition optical coherence tomography, as this is the most accurate means of assessing abnormalities in the vitreoretinal (VR) interface, and an accurate measurement of best-corrected VA. It has been proposed that patients with VMT+MH be managed as a routine 6-week referral, with the complete patient journey—from initial referral to treatment—taking no longer than 6 months. It is important that patients are entered onto VR surgical lists so that there is no delay if ocriplasmin treatment is unsuccessful. Patients will need appropriate counselling about the expected outcomes and possible side effects of ocriplasmin treatment. One-year follow-up data should be collected by treatment centres in order to evaluate the new VMT service.

Photo-damage, photo-protection and age-related macular degeneration

The course of Age-related Macular Degeneration (AMD) is described as the effect of light (400–580 nm) on various molecular targets in photoreceptors and the retinal pigment epithelium (RPE). Photo-damage is followed by inflammation, increasing oxidative stress and, probably, unveiling new photosensitive molecules.

The effect of normal aging and age-related macular degeneration on perceptual learning

We investigated whether perceptual learning could be used to improve peripheral word identification speed. The relationship between the magnitude of learning and age was established in normal participants to determine whether perceptual learning effects are age invariant. We then investigated whether training could lead to improvements in patients with age-related macular degeneration (AMD). Twenty-eight participants with normal vision and five participants with AMD trained on a word identification task. They were required to identify three-letter words, presented 10° from fixation. To standardize crowding across each of the letters that made up the word, words were flanked laterally by randomly chosen letters. Word identification performance was measured psychophysically using a staircase procedure. Significant improvements in peripheral word identification speed were demonstrated following training (71% ± 18%). Initial task performance was correlated with age, with older participants having poorer performance. However, older adults learned more rapidly such that, following training, they reached the same level of performance as their younger counterparts. As a function of number of trials completed, patients with AMD learned at an equivalent rate as age-matched participants with normal vision. Improvements in word identification speed were maintained at least 6 months after training. We have demonstrated that temporal aspects of word recognition can be improved in peripheral vision with training across a range of ages and these learned improvements are relatively enduring. However, training targeted at other bottlenecks to peripheral reading ability, such as visual crowding, may need to be incorporated to optimize this approach.

Population-based age group specific annual incidence rates of symptomatic age-related macular degeneration

Purpose

To study the population-based annual incidence rates of exudative, dry and all cases of symptomatic age-related macular degeneration (AMD) in different age and sex groups.

Methods.

This is a one year, prospective, population-based study on all consecutive new patients with AMD in the hospital district of Central Finland. The diagnosis was confirmed in all patients with slit lamp biomicroscopy, optical coherence tomography (OCT) using a Spectralis HRA + OCT device, and the Heidelberg Eye Explorer 1.6.2.0 program. Fluorescein angiograms were taken when needed.

Results.

The population-based annual incidence rates of all cases of symptomatic AMD increased from 0.03% (95% CI, 0.01-0.05%) in the age group 50-59 years to 0.82% (95% CI, 0.55-1.09%) in the age group 85-89 years and were 0.2% (95% CI, 0.17-0.24%) in exudative, 0.11% (95% CI, 0.09-0.14%) in dry, and 0.32% (95% CI, 0.28-0.36%) in all cases of AMD in the age group 60 years and older. During the next 20 years in Central Finland the population-based annual incidence rates can be estimated to increase to 0.27% (95% CI, 0.24-0.30%) in exudative, to 0.13% (95% CI, 0.11-0.15%) in dry, and to 0.41% (95% CI, 0.37-0.45%) in all cases of AMD in the age group 60 years and older. The population-based annual incidence of AMD did not show statistically significant differences between males and females (p>0.1).

Conclusion:

The population-based age-group specific annual incidence rates of symptomatic AMD of this study may help to plan health care provision for patients of AMD.

Systemic adverse events after intravitreal bevacizumab versus ranibizumab for age-related macular degeneration: a meta-analysis

Objective

To assess whether the incidence of systemic adverse events differs between those who used bevacizumab and those who used ranibizumab in the treatment of age-related macular degeneration (AMD).

Methods

A systematic literature search was conducted to identify randomised controlled trials (RCTs) comparing the use of intravitreal bevacizumab with the use of ranibizumab in AMD patients. Results were expressed as risk ratios (RRs) with accompanying 95% confidence intervals (CIs). The data were pooled using the fixed-effect or random-effect model according to the heterogeneity present.

Results

Four RCTs were included in the final meta-analysis. Overall, the quality of the evidence was high. There were 2,613 treated patients: 1,291 treated with bevacizumab and 1,322 treated with ranibicizumab. No significant differences between bevacizumab use and ranizumab use were found in terms of the incidence of death from all causes, arteriothrombotic events, stroke, nonfatal myocardial infarction, vascular death, venous thrombotic events, and hypertension, with the pooled RRs being 1.11 (0.77, 1.61), 1.03 (0.69,1.55), 0.84 (0.39,1.80), 0.97 (0.48, 1.96), 1.24 (0.63, 2.44), 2.38 (0.94, 6.04), and 1.02 (0.29, 3.62), respectively.

Conclusions

The meta-analysis shows that both treatments are comparably safe. However, the findings from our study must be confirmed in future research via well-designed cohort or intervention studies because of the limited number of studies.

Engineering efficient retinal pigment epithelium differentiation from human pluripotent stem cells

Human embryonic stem cells (hESCs) are a promising source of retinal pigment epithelium (RPE) cells: cells that can be used for the treatment of common and incurable forms of blindness, such as age-related macular degeneration. Although most hESC lines will produce a number of clusters of pigmented RPE cells within 30-50 days when allowed to spontaneously differentiate, the timing and efficiency of differentiation is highly variable. This could prove problematic in the design of robust processes for the large scale production of RPE cells for cell therapy. In this study we sought to identify, quantify, and reduce the sources of variability in hESC-RPE differentiation. By monitoring the emergence of pigmented cells over time, we show how the cell line, passaging method, passage number, and seeding density have a significant and reproducible effect on the RPE yield. To counter this variability, we describe the production of RPE cells from two cell lines in feeder-free, density controlled conditions using single cell dissociation and seeding that is more amenable to scaled up production. The efficacy of small molecules in directing differentiation toward the RPE lineage was tested in two hESC lines with divergent RPE differentiation capacities. Neural induction by treatment with a bone morphogenetic protein inhibitor, dorsomorphin, significantly enhanced the RPE yield in one cell line but significantly reduce it in another, generating instead a Chx10 positive neural progenitor phenotype. This result underlines the necessity to tailor differentiation protocols to suit the innate properties of different cell lines.

Systemic safety of bevacizumab versus ranibizumab for neovascular age-related macular degeneration

BACKGROUND

Neovascular age-related macular degeneration (AMD) is the leading cause of legal blindness in elderly populations of industrialised countries. Bevacizumab (Avastin®) and ranibizumab (Lucentis®) are targeted biological drugs (a monoclonal antibody) that inhibit vascular endothelial growth factor, an angiogenic cytokine that promotes vascular leakage and growth, thereby preventing its pathological angiogenesis. Ranibizumab is approved for intravitreal use to treat neovascular AMD, while bevacizumab is approved for intravenous use as a cancer therapy. However, due to the biological similarity of the two drugs, bevacizumab is widely used off-label to treat neovascular AMD.

OBJECTIVES

To assess the systemic safety of intravitreal bevacizumab (brand name Avastin®; Genentech/Roche) compared with intravitreal ranibizumab (brand name Lucentis®; Novartis/Genentech) in people with neovascular AMD. Primary outcomes were death and All serious systemic adverse events (All SSAEs), the latter as a composite outcome in accordance with the International Conference on Harmonisation Good Clinical Practice. Secondary outcomes examined specific SSAEs: fatal and non-fatal myocardial infarctions, strokes, arteriothrombotic events, serious infections, and events grouped in some Medical Dictionary for Regulatory Activities System Organ Classes (MedDRA SOC). We assessed the safety at the longest available follow-up to a maximum of two years.

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE and other online databases up to 27 March 2014. We also searched abstracts and clinical study presentations at meetings, trial registries, and contacted authors of included studies when we had questions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) directly comparing intravitreal bevacizumab (1.25 mg) and ranibizumab (0.5 mg) in people with neovascular AMD, regardless of publication status, drug dose, treatment regimen, or follow-up length, and whether the SSAEs of interest were reported in the trial report.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies and assessed the risk of bias for each study. Three authors independently extracted data.We conducted random-effects meta-analyses for the primary and secondary outcomes. We planned a pre-specified analysis to explore deaths and All SSAEs at the one-year follow-up.

MAIN RESULTS

We included data from nine studies (3665 participants), including six published (2745 participants) and three unpublished (920 participants) RCTs, none supported by industry. Three studies excluded participants at high cardiovascular risk, increasing clinical heterogeneity among studies. The studies were well designed, and we did not downgrade the quality of the evidence for any of the outcomes due to risk of bias. Although the estimated effects of bevacizumab and ranibizumab on our outcomes were similar, we downgraded the quality of the evidence due to imprecision.At the maximum follow-up (one or two years), the estimated risk ratio (RR) of death with bevacizumab compared with ranibizumab was 1.10 (95% confidence interval (CI) 0.78 to 1.57, P value = 0.59; eight studies, 3338 participants; moderate quality evidence). Based on the event rates in the studies, this gives a risk of death with ranibizumab of 3.4% and with bevacizumab of 3.7% (95% CI 2.7% to 5.3%).For All SSAEs, the estimated RR was 1.08 (95% CI 0.90 to 1.31, P value = 0.41; nine studies, 3665 participants; low quality evidence). Based on the event rates in the studies, this gives a risk of SSAEs of 22.2% with ranibizumab and with bevacizumab of 24% (95% CI 20% to 29.1%).For the secondary outcomes, we could not detect any difference between bevacizumab and ranibizumab, with the exception of gastrointestinal disorders MedDRA SOC where there was a higher risk with bevacizumab (RR 1.82; 95% CI 1.04 to 3.19, P value = 0.04; six studies, 3190 participants).Pre-specified analyses of deaths and All SSAEs at one-year follow-up did not substantially alter the findings of our review.Fixed-effect analysis for deaths did not substantially alter the findings of our review, but fixed-effect analysis of All SSAEs showed an increased risk for bevacizumab (RR 1.12; 95% CI 1.00 to 1.26, P value = 0.04; nine studies, 3665 participants): the meta-analysis was dominated by a single study (weight = 46.9%).The available evidence was sensitive to the exclusion of CATT or unpublished results. For All SSAEs, the exclusion of CATT moved the overall estimate towards no difference (RR 1.01; 95% CI 0.82 to 1.25, P value = 0.92), while the exclusion of LUCAS yielded a larger RR, with more SSAEs in the bevacizumab group, largely driven by CATT (RR 1.19; 95% CI 1.06 to 1.34, P value = 0.004). The exclusion of all unpublished studies produced a RR of 1.12 for death (95% CI 0.78 to 1.62, P value = 0.53) and a RR of 1.21 for SSAEs (95% CI 1.06 to 1.37, P value = 0.004), indicating a higher risk of SSAEs in those assigned to bevacizumab than ranibizumab.

AUTHORS' CONCLUSIONS

This systematic review of non-industry sponsored RCTs could not determine a difference between intravitreal bevacizumab and ranibizumab for deaths, All SSAEs, or specific subsets of SSAEs in the first two years of treatment, with the exception of gastrointestinal disorders. The current evidence is imprecise and might vary across levels of patient risks, but overall suggests that if a difference exists, it is likely to be small. Health policies for the utilisation of ranibizumab instead of bevacizumab as a routine intervention for neovascular AMD for reasons of systemic safety are not sustained by evidence. The main results and quality of evidence should be verified once all trials are fully published.

γδ T cells as a major source of IL-17 production during age-dependent RPE degeneration

PURPOSE

Chronic inflammation is a key factor contributing to the progression of age-related macular degeneration (AMD). The goals of the current study were to develop an improved mouse model with retinal pathologic features similar to those of AMD and to characterize the immunoreactive cells in the outer retina and choroid during degeneration of the retinal pigment epithelium (RPE).

METHODS

Mice deficient in nuclear erythroid 2-related factor 2 (Nrf2) at 12 months of age were fed a high-fat, cholesterol-rich diet for up to 16 weeks. Ocular phenotype was monitored by optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) in live animals, and was further validated by retinal histopathology. Immunofluorescence staining of either cryosections or RPE flat mounts was used to define immunoreactive cells. Flow cytometry analyses were further performed to define the subsets of intraocular T lymphocytes.

RESULTS

After 16 weeks on a high-fat (HF) diet, 58% of the eyes from Nrf2-/- mice had progression of retinal lesions. Major histocompatibility complex class II (MHC II)-positive microglia, FoxP3+ regulatory T cells (Tregs), and CD3+ IL-17-producing T cells were detected in either the retina or sub-RPE space. Flow cytometry analyses further revealed that most of the IL-17-producing cells were CD3+ CD4- TCRγδ+ cells.

CONCLUSIONS

The results suggest that the T cell-mediated immune responses played important roles in controlling the progression of AMD-like phenotype in Nrf2-deficient mice.

Charles Bonnet syndrome and cognitive impairment: a systematic review

BACKGROUND

Charles Bonnet syndrome (CBS) is defined as complex persistent visual hallucinations in the absence of mental disorder. It is common in conditions causing significant visual impairment. Many authors advise reassurance, considering the condition benign. However, others have suggested that CBS may in some patients represent the early stages of dementia. This review seeks to systematically examine the evidence for any link between CBS and cognitive impairment.

METHODS

Literature search using OVID Medline, PsychINFO, and Embase.

RESULTS

Three studies where cognitive functioning was the primary focus of the research were found. All were small, did not properly apply diagnostic criteria, and reported conflicting results. Eight other studies commented on cognitive functioning, but none used tests sufficiently sensitive to detect changes seen in early dementia. One hundred and thirty four case reports were scrutinized, and reports found of 16 patients with CBS where dementia emerged. High rates of partial insight at diagnosis of CBS were seen in these patients.

CONCLUSIONS

There have been no adequately powered studies, using accepted diagnostic criteria, where changes in cognitive functioning were the primary outcome. Existing studies are of limited methodological quality and allow no conclusion regarding a relationship between cognitive impairment and CBS to be reached. Numerous case reports of dementia developing in patients with CBS and partial insight raise the possibility of a link between these conditions. There is a clear need for properly constructed studies to investigate this.

A safety audit of the first 10 000 intravitreal ranibizumab injections performed by nurse practitioners

PURPOSE

To evaluate the safety of a nurse practitioner (NP)-delivered injection service for the treatment of wet age-related macular degeneration (wAMD) with ranibizumab.

METHODS

An evaluation of medical staffing resources for providing an injection service for wAMD highlighted difficulties covering lists. An alternative strategy of an NP-delivered injection service was evaluated. Two suitable NPs with previous extensive experience in minor surgical procedures were identified. The department's senior vitreo-retinal consultant supervised the NP's training programme. A prospective safety audit was conducted for the first 5.5 years of the service.

RESULTS

The NPs administered 10 006 injections in the first 5.5 years of the service (1 May 2008 to 8 October 2013). This represented 84.1% of the total injections performed during this period. Four patients developed presumed infectious endophthalmitis (1 was culture positive and 3 were culture negative). The incidence of post-injection endophthalmitis was 0.04%. There was no evidence of lens touch, retinal detachment, or systemic thrombo-embolic events.

CONCLUSIONS

Carefully selected and well-trained NPs are capable of delivering a safe and effective wAMD injection treatment service. This work demonstrates how such a service can be established and provides safety data that other units can use as a benchmark when evaluating their own practice.

Photoreceptor replacement therapy: Challenges presented by the diseased recipient retinal environment

Vision loss caused by the death of photoreceptors is the leading cause of irreversible blindness in the developed world. Rapid advances in stem cell biology and techniques in cell transplantation have made photoreceptor replacement by transplantation a very plausible therapeutic strategy. These advances include the demonstration of restoration of vision following photoreceptor transplantation and the generation of transplantable populations of donor cells from stem cells. In this review, we present a brief overview of the recent progress in photoreceptor transplantation. We then consider in more detail some of the challenges presented by the degenerating retinal environment that must play host to these transplanted cells, how these may influence transplanted photoreceptor cell integration and survival, and some of the progress in developing strategies to circumnavigate these issues.

Modelling cost effectiveness in neovascular age-related macular degeneration: the impact of using contrast sensitivity vs. visual acuity

BACKGROUND

The cost utility of treatments of age-related macular degeneration (AMD) is commonly assessed using health state transition models defined by levels of visual acuity. However, there is evidence that another measure of visual function, contrast sensitivity, may be better associated with utility than visual acuity. This paper investigates the difference in cost effectiveness resulting from models based on visual acuity and contrast sensitivity using the example of bevacizumab (Avastin) for neovascular AMD. The implications of the choice of outcome on structural uncertainty in the model are investigated.

METHOD

Health state transition Markov models based on levels of visual acuity and contrast sensitivity are used to represent the costs, health utilities and outcomes of the Avastin for choroidal neovascular age-related macular degeneration (ABC) trial. Health states are associated with costs and utilities based on literature values. Treatment outcomes from the ABC trial are used to predict transitions between states in both models. Total costs and quality-adjusted life-years (QALYs) are calculated for a cohort of patients treated over a defined number of model cycles.

RESULTS

Over a 5-year time horizon, a contrast sensitivity model predicts a statistically significant (p < 0.05) 25% greater QALY gain than the visual acuity model based on 10,000 Monte Carlo simulations. Bevacizumab is more effective and less costly than the comparator in the contrast sensitivity model and the visual acuity model.

CONCLUSION

There is considerable structural uncertainty associated with the choice of outcome for modelling the cost effectiveness of AMD treatments. Bevacizumab has a higher incremental QALY gain and more favourable incremental cost-effectiveness ratio when cost effectiveness is assessed using contrast sensitivity outcomes compared with using visual acuity outcomes. Previous cost-effectiveness analyses may have underestimated the cost effectiveness of anti-vascular endothelial growth factor (anti-VEGF) therapy.