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.

Ranibizumab therapy for choroidal neovascularization secondary to non-age-related macular degeneration causes.

BACKGROUND: To investigate the efficacy of ranibizumab therapy for choroidal neovascular (CNV) membranes secondary to conditions other than macular degeneration. DESIGN: Prospective case series conducted at the Royal Victorian Eye and Ear Hospital. PARTICIPANTS: Twelve-month follow-up data for 41 patients with CNV recruited from the outpatient clinic from May 2008 to April 2010 is presented. Fifteen patients had myopia, seven had multifocal choroiditis, and eight had other primary causes. METHODS: All patients had visual acuity, fluorescein angiogram and optical coherence tomography performed at the initial visit (baseline). Ranibizumab was injected with a standard sterile technique. Patients were reviewed after 1 month, and further injections were given at the treating doctors' discretion. MAIN OUTCOME MEASURES: Change in visual acuity and central macular thickness at 12 months was compared with baseline for each of the groups. Local and systemic adverse outcomes were recorded. RESULTS: Analysis was stratified by primary pathology. On average, 40%, 43% and 25% of patients with myopia, multifocal choroiditis and 'other' pathologies, respectively, experienced a three or more line improvement in vision. The average number of injections in 12 months was 4.2 for the entire group. Central macular thickness significantly decreased in the 12-month period for the combined group (P = 0.03). No patient had an adverse systemic side-effect; however, there was one case of endophthalmitis. CONCLUSIONS: Ranibizumab is an effective treatment for CNV secondary to non-age-related macular degeneration causes, with most patients gaining an improvement in the first 2 months following injection.

Identification of urinary biomarkers for age-related macular degeneration.

PURPOSE: Age-related macular degeneration (AMD) can be considered as a chronic low-grade systemic inflammatory disease. This study was undertaken to test the associations of AMD with the urinary proinflammatory cytokines transforming growth factor (TGF)-ß1, macrophage chemoattractant protein (MCP)-1 and C3a-desArg, as potential noninvasive biomarkers for monitoring AMD. METHODS: A cross-sectional study of 103 AMD cases, comprising early AMD (n = 51), geographic atrophy (GA; n = 19), or choroidal neovascularization (CNV; 33), and 54 unrelated controls, aged 73 ± 9 years, who attended the Royal Victorian Eye and Ear Hospital and private practice in Victoria, Australia. AMD status was determined from the bilateral retinal digital photographs and through angiography and optical coherence tomography images when confirmation of CNV was needed. Serum and urine cytokine levels were measured by immunoassay and the rs1061170 (Y402H) single-nucleotide polymorphism of the complement factor H (CFH) gene was determined. RESULTS: Multivariate logistic regression analyses demonstrated significant associations of urinary TGF-ß1 levels (odds ratio [95% confidence interval]: OR = 1.24 [1.02-1.50]; P < 0.031) and MCP-1 levels (OR = 1.07 [1.02-1.12]; P < 0.008), in early AMD, and also MCP-1 levels with GA (OR = 1.10 [1.03-1.17]; P < 0.003). There was no correlation between urinary and serum cytokine levels. Individuals with one or more copies of the C allele (Y402H) were 2.5 times more likely to have urinary MCP-1 above median levels (P < 0.040). CONCLUSIONS: This study demonstrates a novel finding of an association between elevated urinary cytokines TGF-ß1 and MCP-1 and AMD. Further development of a urinary biomarker profile could provide a practical tool for detection of early AMD, progression monitoring, and assessment of treatment efficacy.

A tag-single nucleotide polymorphisms approach to the vascular endothelial growth factor-A gene in age-related macular degeneration.

PURPOSE: Age-related macular degeneration (AMD) is the leading cause of poor vision in the developed world, and its pathogenesis remains unknown. The most devastating form of end stage disease is neovascular or wet AMD, where there is abnormal growth of new blood vessels under the retina. Vascular endothelial growth factor (VEGF) is thought to be a major player in the stimulus of this abnormal growth of blood vessels. We undertook a case-control association study to investigate the VEGF-A gene, a known angiogenic gene that has previously been associated with AMD. METHODS: We recruited 577 individuals with AMD (early, atrophic, and neovascular AMD) and 173 ethnically matched controls for our study. We employed a tag-single nucleotide polymorphisms (tSNP) approach to investigate this gene using a series of seven tSNPs that encompassed the coding region of the VEGF gene as well as its promoter. Alleles were determined by a MALDI-TOF based approach followed by statistical analysis. RESULTS: One SNP (rs3024997) showed evidence of departure from Hardy-Weinberg equilibrium in only the AMD cases. Therefore, it was retained for further analysis. All other SNPs in our study showed no departure from Hardy-Weinberg equilibrium. No association was found between any of the VEGF tSNPs analyzed in our study and AMD nor any of its sub-types. CONCLUSIONS: Using a tSNP approach, we found no evidence of an association of these SNPs within the VEGF-A gene being associated with either AMD or any of its subtypes in our population.

Analysis of the Y402H variant of the complement factor H gene in age-related macular degeneration.

PURPOSE: Recent studies in U.S. populations have indicated that the Y402H variant of the complement factor H (CFH) gene contains a major risk susceptibility allele for age-related macular degeneration (AMD). This study was conducted to ascertain whether this is also true in a non-U.S. population and also whether the at-risk allele is associated with the clinical phenotype of disease and the age at diagnosis. METHODS: Two hundred thirty-six unrelated individuals with AMD and 144 unrelated but ethnically matched control subjects were recruited and examined. All subjects completed a standard questionnaire, were given a fundus examination, and provided a blood sample for DNA extraction. Alleles of Y402H in the CFH gene were determined by use of a MALDI-TOF-based approach followed by statistical analysis. RESULTS: Individuals with AMD who had at least one copy of the C allele of Y402H had an increased risk of disease (odds ratio [OR] 2.98; 95% confidence interval [CI] 1.81-4.93) compared with cases with the T allele. On subgroup analysis, this risk was found to be most significant in individuals with neovascular disease (OR 4.34; 95% CI 1.94, 9.71). In addition, individuals with neovascular disease who were homozygous CC presented with a significant 7.0-year earlier age at diagnosis relative to those individuals who were homozygous TT. The population-attributable risk for the C allele ranged between 47% to 69%, depending on the AMD disease subtype. CONCLUSIONS: The C allele of Y402H represents a significant risk factor in individuals with AMD, and this effect is most pronounced in individuals with neovascular disease.

Photodynamic therapy in practice: a review of the results of the first 12 months experience with verteporfin at the Royal Victorian Eye and Ear Hospital.

PURPOSE: To review the 12-month results of the first 136 eyes treated with photodynamic therapy (PDT) with verteporfin at a single institution, and to determine if this treatment when used in the broader community could reproduce the results achieved in the Treatment of Age-related Macular Degeneration (AMD) with PDT (TAP) study. METHODS: A record of all patients who first received PDT with verteporfin at The Royal Victorian Eye and Ear Hospital between the time of its introduction in February 2000 and February 2001 was prospectively maintained. The medical charts of these cases were reviewed and fluorescein angiograms were graded. Eyes with AMD were classified into three groups: TAP comparable if they had predominantly classic subfoveal choroidal neovascularization (CNV) and visual acuity between 6/12 and 6/60; VIP comparable if they had occult but no classic subfoveal CNV and visual acuity better than 6/36; and PDT ineligible if they fell outside recommended eligibility guidelines of the TAP/VIP studies. The main outcome measure was visual acuity change, with total number of treatments a secondary outcome variable. RESULTS: A total of 136 eyes of 130 patients began PDT during this period. The baseline angiogram and clinical data were available for 123 eyes (90%), and these were reviewed. Fourteen eyes had non-AMD related CNV, while 109 eyes of 105 patients had AMD. Of the 109 AMD related lesions, 72 (66%) were TAP comparable, six (5.5%) were VIP comparable and 31 (28%) were PDT ineligible. At the 12-month visit the proportion of TAP comparable eyes with same or better vision was 36/72 (50%), compared to 13/31 (42%) of the PDT ineligible eyes (P = 0.45). Only 30/72 (42%) of the TAP comparable eyes were still undergoing regular angiographic and clinical assessment (similar to the TAP protocol) at the time of the 12 month visit. The number of these who had same or better vision at 12 months was 17/30 (57%) compared to 19/42 (44%) TAP comparable eyes without regular angiographic follow up to 12 months (P = 0.37). CONCLUSDIONS; When used according to the guidelines established by the TAP study, the visual acuity results with PDT approached those achieved in the TAP study. When eyes were either enrolled outside the TAP study eligibility guidelines, or were not actively followed up over the 12-month period as per TAP study guidelines, the visual outcome was similar to natural history of CNV secondary to AMD.

Analysis of the Arg345Trp disease-associated allele of the EFEMP1 gene in individuals with early onset drusen or familial age-related macular degeneration.

BACKGROUND: A single base change within the EFEMP1 gene has been associated with malattia leventinese and Doyne honeycomb retinal dystrophy, two dominantly inherited macular diseases with early onset drusen. The aim of this study was to determine whether the same disease allele was also associated with other forms of early onset drusen or familial cases of age-related macular degeneration. METHODS: Thirteen index cases of early onset drusen together with 15 other family members were examined. In addition, 54 familial cases of age-related macular degeneration were examined. Blood was taken for DNA analysis and screened for the Arg345Trp disease-associated allele of the EFEMP1 gene. Twenty-four cases of malattia leventinese or Doyne honeycomb retinal dystrophy were also screened as positive controls. Another 150 ethnicity- and age-matched individuals acted as controls. RESULTS: The Arg345Trp disease-associated allele in the EFEMP1 gene was confirmed in individuals with malattia leventinese and Doyne honeycomb retinal dystrophy. However, involvement of this allele was not evident in either early onset drusen or familial age-related macular degeneration. CONCLUSIONS: The Arg345Trp disease-associated allele of the EFEMP1 gene does not appear to be associated with cases of early onset drusen that fall outside the diagnosis of malattia leventinese or Doyne honeycomb retinal dystrophy, nor does it appear to play a role in familial age-related macular degeneration. These findings do not exclude the involvement of other alleles of the EFEMP1 gene in either phenotype. The genetic mechanisms involved in the heterogeneous group of early onset drusen remain to be elucidated but should lead to insights into the genetic causes of macular diseases.