Characterisation of a C1qtnf5 Ser163Arg Knock-In Mouse Model of Late-Onset Retinal Macular Degeneration

A single founder mutation resulting in a Ser163Arg substitution in the C1QTNF5 gene product causes autosomal dominant late-onset retinal macular degeneration (L-ORMD) in humans, which has clinical and pathological features resembling age-related macular degeneration. We generated and characterised a mouse

GENOTYPE-PHENOTYPE ASSOCIATIONS IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

PURPOSE:To examine associations between recognized genetic susceptibility loci and angiographic subphenotypes of the neovascular variant of age-related macular degeneration (nvAMD).METHODS:Participants (247 nvAMD, 52 early age-related macular degeneration [AMD], and 103 controls) were genotyped (complement factor H and ARMS2/HTRA1). nvAMD participants were assigned to one of two subcategories: mainly classic or mainly occult (based on the proportions of classic and occult choroidal neovascularization). nvAMD and early AMD were reassigned to two groups based on the extent and severity of drusen (retinal pigment epithelium dysfunction or not). Univariate and multivariate analysis were used to examine for associations between participant characteristics and genetic loci after adjusting for age, smoking status, and history of cardiovascular disease.RESULTS:Univariate analysis confirmed the known significant associations between AMD stage and age, hypertension, and a history of cardiovascular disease. Those with retinal pigment epithelium dysfunction (F = 5.46; P = 0.02) or a positive smoking history (F = 3.89; P = 0.05) were more likely to have been classified as having mainly an occult rather than a mainly classic lesion. Multivariate analysis showed that significant associations were noted with the number of ARMS2/HTRA1 risk alleles (P

Ranibizumab versus Bevacizumab to Treat Neovascular Age-related Macular Degeneration: One-Year Findings from the IVAN Randomized Trial.

Purpose
To compare the efficacy and safety of ranibizumab and bevacizumab intravitreal injections to treat neovascular age-related macular degeneration (nAMD).

Design
Multicenter, noninferiority factorial trial with equal allocation to groups. The noninferiority limit was 3.5 letters. This trial is registered (ISRCTN92166560).

Participants
People >50 years of age with untreated nAMD in the study eye who read =25 letters on the Early Treatment Diabetic Retinopathy Study chart.

Methods
We randomized participants to 4 groups: ranibizumab or bevacizumab, given either every month (continuous) or as needed (discontinuous), with monthly review.

Main Outcome Measures
The primary outcome is at 2 years; this paper reports a prespecified interim analysis at 1 year. The primary efficacy and safety outcome measures are distance visual acuity and arteriothrombotic events or heart failure. Other outcome measures are health-related quality of life, contrast sensitivity, near visual acuity, reading index, lesion morphology, serum vascular endothelial growth factor (VEGF) levels, and costs.

Results
Between March 27, 2008 and October 15, 2010, we randomized and treated 610 participants. One year after randomization, the comparison between bevacizumab and ranibizumab was inconclusive (bevacizumab minus ranibizumab -1.99 letters, 95% confidence interval [CI], -4.04 to 0.06). Discontinuous treatment was equivalent to continuous treatment (discontinuous minus continuous -0.35 letters; 95% CI, -2.40 to 1.70). Foveal total thickness did not differ by drug, but was 9% less with continuous treatment (geometric mean ratio [GMR], 0.91; 95% CI, 0.86 to 0.97; P = 0.005). Fewer participants receiving bevacizumab had an arteriothrombotic event or heart failure (odds ratio [OR], 0.23; 95% CI, 0.05 to 1.07; P = 0.03). There was no difference between drugs in the proportion experiencing a serious systemic adverse event (OR, 1.35; 95% CI, 0.80 to 2.27; P = 0.25). Serum VEGF was lower with bevacizumab (GMR, 0.47; 95% CI, 0.41 to 0.54; P<0.0001) and higher with discontinuous treatment (GMR, 1.23; 95% CI, 1.07 to 1.42; P = 0.004). Continuous and discontinuous treatment costs were £9656 and £6398 per patient per year for ranibizumab and £1654 and £1509 for bevacizumab; bevacizumab was less costly for both treatment regimens (P<0.0001).

Conclusions
The comparison of visual acuity at 1 year between bevacizumab and ranibizumab was inconclusive. Visual acuities with continuous and discontinuous treatment were equivalent. Other outcomes are consistent with the drugs and treatment regimens having similar efficacy and safety.

Financial Disclosure(s)
Proprietary or commercial disclosures may be found after the references.

Common variants near FRK/COL10A1 and VEGFA are associated with advanced age-related macular degeneration

Despite significant progress in the identification of genetic loci for age-related macular degeneration (AMD), not all of the heritability has been explained. To identify variants which contribute to the remaining genetic susceptibility, we performed the largest meta-analysis of genome-wide association studies to date for advanced AMD. We imputed 6 036 699 single-nucleotide polymorphisms with the 1000 Genomes Project reference genotypes on 2594 cases and 4134 controls with follow-up replication of top signals in 5640 cases and 52 174 controls. We identified two new common susceptibility alleles, rs1999930 on 6q21-q22.3 near FRK/COL10A1 [odds ratio (OR) 0.87; P = 1.1 × 10(-8)] and rs4711751 on 6p12 near VEGFA (OR 1.15; P = 8.7 × 10(-9)). In addition to the two novel loci, 10 previously reported loci in ARMS2/HTRA1 (rs10490924), CFH (rs1061170, and rs1410996), CFB (rs641153), C3 (rs2230199), C2 (rs9332739), CFI (rs10033900), LIPC (rs10468017), TIMP3 (rs9621532) and CETP (rs3764261) were confirmed with genome-wide significant signals in this large study. Loci in the recently reported genes ABCA1 and COL8A1 were also detected with suggestive evidence of association with advanced AMD. The novel variants identified in this study suggest that angiogenesis (VEGFA) and extracellular collagen matrix (FRK/COL10A1) pathways contribute to the development of advanced AMD.

Identification of lesion components that influence visual function in age related macular degeneration

To explore the relation between lesion composition as assessed by fundus photography and fluorescein angiography with clinical measures of vision in eyes of patients with age related macular degeneration (AMD).

Heritability and Genome-Wide Association Study to Assess Genetic Differences between Advanced Age-Related Macular Degeneration Subtypes

PURPOSE: To investigate whether the 2 subtypes of advanced age-related macular degeneration (AMD), choroidal neovascularization (CNV), and geographic atrophy (GA) segregate separately in families and to identify which genetic variants are associated with these 2 subtypes. DESIGN: Sibling correlation study and genome-wide association study (GWAS). PARTICIPANTS: For the sibling correlation study, 209 sibling pairs with advanced AMD were included. For the GWAS, 2594 participants with advanced AMD subtypes and 4134 controls were included. Replication cohorts included 5383 advanced AMD participants and 15 240 controls. METHODS: Participants had the AMD grade assigned based on fundus photography, examination, or both. To determine heritability of advanced AMD subtypes, a sibling correlation study was performed. For the GWAS, genome-wide genotyping was conducted and 6 036 699 single nucleotide polymorphisms (SNPs) were imputed. Then, the SNPs were analyzed with a generalized linear model controlling for genotyping platform and genetic ancestry. The most significant associations were evaluated in independent cohorts. MAIN OUTCOME MEASURES: Concordance of advanced AMD subtypes in sibling pairs and associations between SNPs with GA and CNV advanced AMD subtypes. RESULTS: The difference between the observed and expected proportion of siblings concordant for the same subtype of advanced AMD was different to a statistically significant degree (P = 4.2×10(-5)), meaning that in siblings of probands with CNV or GA, the same advanced subtype is more likely to develop. In the analysis comparing participants with CNV to those with GA, a statistically significant association was observed at the ARMS2/HTRA1 locus (rs10490924; odds ratio [OR], 1.47; P = 4.3×10(-9)), which was confirmed in the replication samples (OR, 1.38; P = 7.4×10(-14) for combined discovery and replication analysis). CONCLUSIONS: Whether CNV versus GA develops in a patient with AMD is determined in part by genetic variation. In this large GWAS meta-analysis and replication analysis, the ARMS2/HTRA1 locus confers increased risk for both advanced AMD subtypes, but imparts greater risk for CNV than for GA. This locus explains a small proportion of the excess sibling correlation for advanced AMD subtype. Other loci were detected with suggestive associations that differ for advanced AMD subtypes and deserve follow-up in additional studies. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Alzheimer's disease and age-related macular degeneration have different genetic models for complement gene variation

Alzheimer's disease (AD) and age-related macular degeneration (AMD) are both neurodegenerative disorders which share common pathological and biochemical features of the complement pathway. The aim of this study was to investigate whether there is an association between well replicated AMD genetic risk factors and AD. A large cohort of AD (n = 3898) patients and controls were genotyped for single nucleotide polymorphisms (SNPs) in the complement factor H (CFH), the Age-related maculopathy susceptibility protein 2 (ARMS2) the complement component 2 (C2), the complement factor B (CFB), and the complement component 3 (C3) genes. While significant but modest associations were identified between the complement factor H, the age-related maculopathy susceptibility protein 2, and the complement component 3 single nucleotide polymorphisms and AD, these were different in direction or genetic model to that observed in AMD. In addition the multilocus genetic model that predicts around a half of the sibling risk for AMD does not predict risk for AD. Our study provides further support to the hypothesis that while activation of the alternative complement pathway is central to AMD pathogenesis, it is less involved in AD.

ARMS2 Increases the Risk of Early and Late Age-Related Macular Degeneration in the European Eye Study

OBJECTIVE:
To study associations between severity stages of early and late age-related macular degeneration (AMD) and genetic variations in age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) and to investigate potential interactions between smoking and ARMS2.
DESIGN:
Population-based, cross-sectional European Eye Study in 7 countries in Europe.
PARTICIPANTS:
Four thousand seven hundred fifty participants, 65 years of age and older, recruited through random sampling.
METHODS:
Participants were classified on the basis of the more severely affected eye into 5 mutually exclusive AMD severity stages ranging from no AMD, 3 categories of early AMD, and late AMD. History of cigarette smoking was available and allowed classification into never, former, and current smokers, with the latter 2 groups combined into a single category of ever smokers for analysis. Genotyping was performed for single nucleotide polymorphisms rs10490924 and rs4146894 in ARMS2 and rs1061170 in CFH. Associations were analyzed by logistic regression.
MAIN OUTCOME MEASURES:
Odds ratios (ORs) for stage of AMD associated with genetic variations in ARMS2 and CFH and interactions between ARMS2 and smoking status.
RESULTS:
Early AMD was present in 36.4% and late AMD was present in 3.3% of participants. Data on both genotype and AMD were available for 4276 people. The ORs for associations between AMD stage and ARMS2 increased monotonically with more severe stages of early AMD and were altered little by adjustment for potential confounders. Compared with persons with no AMD, carriers of the TT genotype for rs10490924 in ARMS2 had a 10-fold increase in risk of late AMD (P<3 × 10(-20)). The ORs for associations with CFH were similar for stage 3 early AMD and late AMD. Interactions between rs10490924 in ARMS2 and smoking status were significant in both unadjusted and adjusted models (P = 0.001). The highest risk was observed in those doubly homozygous for rs10490924 and rs1061170 in CFH (OR, 62.3; 95% confidence interval, 16-242), with P values for trend ranging from 0.03 (early AMD, stage 1) to 1 × 10(-26) (late AMD).
CONCLUSIONS:
A strong association was demonstrated between all stages of AMD and genetic variation in ARMS2, and a significant gene-environment interaction with cigarette smoking was confirmed.

Secondary Outcomes in a Clinical Trial of Carotenoids with Coantioxidants versus Placebo in Early Age-Related Macular Degeneration

Purpose: To report the secondary outcomes in the Carotenoids with Coantioxidants in Age-Related Maculopathy trial.

Design: Randomized double-masked placebo-controlled clinical trial (registered as ISRCTN 94557601).

Participants: Participants included 433 adults 55 years of age or older with early age-related macular degeneration (AMD) in 1 eye and late-stage disease in the fellow eye (group 1) or early AMD in both eyes (group 2).

Intervention: An oral preparation containing lutein (L), zeaxanthin (Z), vitamin C, vitamin E, copper, and zinc or placebo. Best-corrected visual acuity (BCVA), contrast sensitivity (CS), Raman spectroscopy, stereoscopic colour fundus photography, and serum sampling were performed every 6 months with a minimum follow-up time of 12 months.

Main Outcome Measures: Secondary outcomes included differences in BCVA (at 24 and 36 months), CS, Raman counts, serum antioxidant levels, and progression along the AMD severity scale (at 12, 24, and 36 months).

Results: The differential between active and placebo groups increased steadily, with average BCVA in the former being approximately 4.8 letters better than the latter for those who had 36 months of follow-up, and this difference was statistically significant (P = 0.04). In the longitudinal analysis, for a 1-log-unit increase in serum L, visual acuity was better by 1.4 letters (95% confidence interval, 0.3-2.5; P = 0.01), and a slower progression along a morphologic severity scale (P = 0.014) was observed.

Conclusions: Functional and morphologic benefits were observed in key secondary outcomes after supplementation with L, Z, and coantioxidants in persons with early AMD.

Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2012 American Academy of Ophthalmology.

Seven new loci associated with age-related macular degeneration

Age-related macular degeneration (AMD) is a common cause of blindness in older individuals. To accelerate the understanding of AMD biology and help design new therapies, we executed a collaborative genome-wide association study, including >17,100 advanced AMD cases and >60,000 controls of European and Asian ancestry. We identified 19 loci associated at P <5 × 10(-8). These loci show enrichment for genes involved in the regulation of complement activity, lipid metabolism, extracellular matrix remodeling and angiogenesis. Our results include seven loci with associations reaching P <5 × 10(-8) for the first time, near the genes COL8A1-FILIP1L, IER3-DDR1, SLC16A8, TGFBR1, RAD51B, ADAMTS9 and B3GALTL. A genetic risk score combining SNP genotypes from all loci showed similar ability to distinguish cases and controls in all samples examined. Our findings provide new directions for biological, genetic and therapeutic studies of AMD.

Fundus autofluorescence in exudative age-related macular degeneration

Aim: To evaluate the distribution of fundus autofluorescence in patients with age-related macular degeneration and choroidal neovascularisation (CNV). Methods: Colour fundus photographs, fundus fluorescein angiograms (FFA) and fundus autofluorescence images were obtained from a group of 40 patients (43 eyes) with age-related macular degeneration and purely classic or occult CNV. Only patients with newly diagnosed CNV and in whom autofluorescence images were obtained within 2 weeks from FFA were included. The distribution of autofluorescence was qualitatively evaluated, and the findings compared with those from colour fundus photographs and FFA. Results: 29 (67%) eyes had classic CNV and 14 (33%) had occult CNV. In 26 (90%) eyes with classic CNV, a low autofluorescence signal was detected at the site of the CNV; in 7 (50%) eyes with occult CNV, multiple foci of low autofluorescence signal were detected. Outside the area affected by the lesion, homogeneous autofluorescence was observed in most of the cases (n = 33, 77%). Similarly, homogeneous autofluorescence was commonly observed in fellow eyes (62%). A pattern of focal increased autofluorescence was rarely seen in eyes with CNV (n = 4, 9%) or in fellow eyes (n = 4, 15%). In 11 of 43 (25%) eyes, areas of increased autofluorescence, other than a pattern of focal increased autofluorescence, were detected. In four patients, autofluorescence images had been obtained before the development of CNV; in none was any increased autofluorescence detected before the formation of CNV. Conclusions: Distinct patterns of autofluorescence were observed in eyes with pure classic and occult CNV. Increased autofluorescence was rarely seen in eyes with CNV and in fellow eyes, suggesting that increased autofluorescence, and thus, retinal pigment epithelium lipofuscin, may not play an essential part in the formation of CNV.

Retinal pigment epithelial atrophy in patients with exudative age-related macular degeneration undergoing anti-vascular endothelial growth factor therapy

PURPOSE:: To evaluate the occurrence of retinal pigment epithelial atrophy in patients with age-related macular degeneration undergoing anti-vascular endothelial growth factor therapy. METHODS:: The study is a retrospective review. Eligible were patients with age-related macular degeneration and choroidal neovascular membranes treated with anti-vascular endothelial growth factor between October 2007 and February 2011; they were followed for >3 months, with fundus photographs and fluorescein angiography at baseline and with autofluorescence and near-infrared autofluorescence images at baseline and follow-up. Demographics, visual acuity, the type of choroidal neovascular membranes, the number of treatments performed, and the length of follow-up were recorded. Autofluorescence and near-infrared autofluorescence images were evaluated for the presence or absence of areas of reduced signal. A multilevel logistic regression model was used to investigate the factors that may be associated with progression of atrophy at follow-up, which was the primary outcome of this study. RESULTS:: Sixty-three patients (72 eyes) were followed for a median of 16 months (range, 3-36 months). Atrophy at baseline was observed in 47% (34/72) of eyes; progression of atrophy occurred in 62% (45/72) of eyes at the last visit. The number of anti-vascular endothelial growth factor injections received was statistically significantly associated with the progression of atrophy at follow-up (odds ratio, 1.35; 95% confidence interval, 1.05-1.73; P = 0.02). CONCLUSION:: Atrophy was frequently observed in patients with age-related macular degeneration and choroidal neovascular membranes undergoing anti-vascular endothelial growth factor therapy.