Somatostatin analogues as a treatment option for cystoid maculopathy in retinitis pigmentosa.

AIMS: This study aimed to evaluate the effectiveness of somatostatin analogues (SA) for cystoid maculopathy (CM) in retinitis pigmentosa (RP) patients. MATERIALS AND METHODS: In this retrospective case series, clinical and imaging characteristics of 28 RP patients with CM, unresponsive to carbonic anhydrase inhibitors, were collected from medical charts. All patients received SA treatment as an alternative (octreotide long-acting release at 20 mg/month or 30 mg/month, or lanreotide at 90 mg/month or 120 mg/month). Outcome measures were mean reduction in foveal thickness (FT) and foveal volume (FV) and mean increase in best-corrected visual acuity at 3, 6 and 12 months of treatment initiation. Linear mixed models were used to calculate the effectiveness over time. RESULTS: 52 eyes of 28 RP patients were included; 39% were male. The median age at the start of treatment was 39 years (IQR 30-53). Median follow-up was 12 months (range 6-12). From baseline to 12 months, the mean FT decreased from 409±136 µm to 334±119 µm and the mean FV decreased from 0.31±0.10 mm3 to 0.25±0.04 mm3. Linear mixed model analyses showed a significant decrease in log FT and log FV at 3, 6 and 12 months after the start of treatment compared with baseline measurements (p<0.001, p<0.001, p<0.001). Mean best-corrected visual acuity did not increase significantly (0.46±0.35 logMAR to 0.45±0.38 logMAR after 12 months). DISCUSSION: SA may be an effective alternative treatment to reduce CM in RP patients.

Diagnostic analysis of the highly complex OPN1LW/OPN1MW gene cluster using long-read sequencing and MLPA.

Pathogenic variants in the OPN1LW/OPN1MW gene cluster are causal for a range of mild to severe visual impairments with color deficiencies. The widely utilized short-read next-generation sequencing (NGS) is inappropriate for the analysis of the OPN1LW/OPN1MW gene cluster and many patients with pathogenic variants stay underdiagnosed. A diagnostic genetic assay was developed for the OPN1LW/OPN1MW gene cluster, consisting of copy number analysis via multiplex ligation-dependent probe amplification and sequence analysis via long-read circular consensus sequencing. Performance was determined on 50 clinical samples referred for genetic confirmation of the clinical diagnosis (n = 43) or carrier status analysis (n = 7). A broad range of pathogenic haplotypes were detected, including deletions, hybrid genes, single variants and combinations of variants. The developed genetic assay for the OPN1LW/OPN1MW gene cluster is a diagnostic test that can detect both structural and nucleotide variants with a straightforward analysis, improving diagnostic care of patients with visual impairment.

Complement Activation Levels Are Related to Disease Stage in AMD.

Purpose: To study the levels of complement activation in different disease stages of AMD and the influence of genetic polymorphisms in complement genes. Methods: We included 797 patients with AMD and 945 controls from the European Genetic Database. Patients were grouped into five AMD stages: early AMD, intermediate AMD, central geographic atrophy, active choroidal neovascularization or inactive choroidal neovascularization. Differences in complement activation, as defined by the systemic C3d/C3 ratio, between AMD stages were evaluated using general linear modeling. In addition, we evaluated the influence of 18 genetic AMD polymorphisms in complement genes and their effect on complement activation. Differences in complement activation between stages were evaluated stratifying by complement associated haplotypes. Results: Complement activation levels differed significantly between AMD disease stages. As compared with controls, the C3d/C3 ratio was higher in patients with intermediate AMD (P < 0.001) and central geographic atrophy (P = 0.001). Two polymorphisms in CFH (rs10922109 and rs570618) and one in CFB (rs116503776) were significantly associated with complement activation. The association between AMD disease stage and complement activation was more pronounced in patients with haplotypes associated with the highest complement activation. Conclusions: In general, consecutive AMD disease stages showed increasing levels of complement activation, especially in individuals with a genetic burden in complement genes. These findings contribute to the discussion on the pathogenesis of AMD in relation to complement activation and might suggest refinement in patient selection and the optimum window of treatment with complement inhibitors. Prospective studies are needed to confirm these results.

GWAS study using DNA pooling strategy identifies association of variant rs4910623 in OR52B4 gene with anti-VEGF treatment response in age-related macular degeneration.

Pooled DNA based GWAS to determine genetic association of SNPs with visual acuity (VA) outcome in anti-vascular endothelial growth factor (anti-VEGF) treated neovascular age-related macular degeneration (nAMD) patients. We performed pooled DNA based GWAS on 285 anti-VEGF treated nAMD patients using high density Illumina 4.3 M array. Primary outcome was change in VA in Early Treatment Diabetic Retinopathy Study (ETDRS) letters after 6 months of anti-VEGF treatment (patients who lost ≥5 ETDRS letters classified as non-responders and all remaining classified as responders). GWAS analysis identified 44 SNPs of interest: 37 with strong evidence of association (p < 9 × 10-8), 2 in drug resistance genes (p < 5 × 10-6) and 5 nonsynonymous changes (p < 1 × 10-4). In the validation phase, individual genotyping of 44 variants showed three SNPs (rs4910623 p = 5.6 × 10-5, rs323085 p = 6.5 × 10-4 and rs10198937 p = 1.30 × 10-3) remained associated with VA response at 6 months. SNP rs4910623 also associated with treatment response at 3 months (p = 1.5 × 10-3). Replication of these three SNPs in 376 patients revealed association of rs4910623 with poor VA response after 3 and 6 months of treatment (p = 2.4 × 10-3 and p = 3.5 × 10-2, respectively). Meta-analysis of both cohorts (673 samples) confirmed association of rs4910623 with poor VA response after 3 months (p = 1.2 × 10-5) and 6 months (p = 9.3 × 10-6) of treatment in nAMD patients.

A genetic variant in NRP1 is associated with worse response to ranibizumab treatment in neovascular age-related macular degeneration.

OBJECTIVE: The aim of the study was to investigate the role of single-nucleotide polymorphisms (SNPs) located in the neuropilin-1 (NRP1) gene in treatment response to antivascular endothelial growth factor (VEGF) therapy for neovascular age-related macular degeneration (nvAMD). METHODS: Four SNPs in the NRP1 gene (rs2229935, rs2247383, rs2070296, and rs2804495) were genotyped in a study cohort of 377 nvAMD patients who received the loading dose of three monthly ranibizumab injections. Treatment response was assessed as the change in visual acuity after three monthly loading injections compared with baseline. RESULTS: SNP rs2070296 was associated with change in visual acuity after 3 months of treatment. Patients carrying the GA or AA genotypes performed significantly worse than individuals carrying the GG genotype (P=0.01). A cumulative effect of rs2070296 in the NRP1 gene and rs4576072 located in the VEGF receptor 2 (VEGFR2 or KDR) gene, previously associated with treatment response, was observed. Patients carrying two risk alleles performed significantly worse than patients carrying zero or one risk allele (P=0.03), and patients with more than two risk alleles responded even worse to the therapy (P=3×10). The combined effect of these two SNPs on the response was also seen after 6 and 12 months of treatment. CONCLUSION: This study suggests that genetic variation in NRP1, a key molecule in VEGFA-driven neovascularization, influences treatment response to ranibizumab in nvAMD patients. The results of this study may be used to generate prediction models for treatment response, which in the future may help tailor medical care to individual needs.

Association of Smoking and CFH and ARMS2 Risk Variants With Younger Age at Onset of Neovascular Age-Related Macular Degeneration.

IMPORTANCE: The age at which the first signs of age-related macular degeneration (AMD) manifest is variable. Better insight into factors that influence disease onset has direct implications for preventive measures and patient counseling. OBJECTIVE: To identify risk factors for an earlier age at onset of neovascular AMD. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study, including patient data from the European Genetic Database collected between April 2006 and July 2010. All patients had at least 1 documented visit to the outpatient AMD clinic of the Radboud University Medical Center, Nijmegen, the Netherlands, a tertiary referral center for retinal disorders. In total, 275 patients with a known age at onset of neovascular AMD and a genetic risk analysis were included. MAIN OUTCOMES AND MEASURES: Effects of several genetic, sociodemographic, behavioral, and ocular factors on the age at onset of neovascular AMD. The mean differences in the age at onset were determined using general linear models with the age at onset as the dependent variable. RESULTS: Past smokers and current smokers developed neovascular AMD on average 4.9 (95% CI, 3.0-6.8) and 7.7 (95% CI, 5.3-10.0) years earlier, respectively, than never smokers (P < .001 for both). Compared with the reference group, the age at onset was 5.2 (95% CI, 2.8-7.7) years earlier for homozygous carriers of the A69S risk allele in the age-related maculopathy susceptibility 2 (ARMS2) gene (P < .001). Homozygous carriers of the Y402H risk variant in the complement factor H (CFH) gene developed neovascular AMD 2.8 (95% CI, 0.5-5.0) years earlier (P = .02). Patients carrying 4 risk alleles in CFH and ARMS2 developed neovascular AMD 12.2 (95% CI, 6.2-18.3) years earlier than patients with zero risk alleles (P < .001). CONCLUSIONS AND RELEVANCE: Genetic and environmental risk factors influence the age at onset of neovascular AMD. Individuals at risk could be identified at an early age if and when preventive or therapeutic options become available. Insight into individual risk profiles might influence patients' consideration of interventions to increase their chance of avoiding vision loss from AMD.

Zinc supplementation inhibits complement activation in age-related macular degeneration.

UNLABELLED: Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. AMD is a multifactorial disorder but complement-mediated inflammation at the level of the retina plays a pivotal role. Oral zinc supplementation can reduce the progression of AMD but the precise mechanism of this protective effect is as yet unclear. We investigated whether zinc supplementation directly affects the degree of complement activation in AMD and whether there is a relation between serum complement catabolism during zinc administration and the complement factor H (CFH) gene or the Age-Related Maculopathy susceptibility 2 (ARMS2) genotype. In this open-label clinical study, 72 randomly selected AMD patients in various stages of AMD received a daily supplement of 50 mg zinc sulphate and 1 mg cupric sulphate for three months. Serum complement catabolism-defined as the C3d/C3 ratio-was measured at baseline, throughout the three months of supplementation and after discontinuation of zinc administration. Additionally, downstream inhibition of complement catabolism was evaluated by measurement of anaphylatoxin C5a. Furthermore, we investigated the effect of zinc on complement activation in vitro. AMD patients with high levels of complement catabolism at baseline exhibited a steeper decline in serum complement activation (p<0.001) during the three month zinc supplementation period compared to patients with low complement levels. There was no significant association of change in complement catabolism and CFH and ARMS2 genotype. In vitro zinc sulphate directly inhibits complement catabolism in hemolytic assays and membrane attack complex (MAC) deposition on RPE cells. This study provides evidence that daily administration of 50 mg zinc sulphate can inhibit complement catabolism in AMD patients with increased complement activation. This could explain part of the mechanism by which zinc slows AMD progression. TRIAL REGISTRATION: The Netherlands National Trial Register NTR2605.

Predicting non-response to ranibizumab in patients with neovascular age-related macular degeneration.

PURPOSE: To validate known and determine new predictors of non-response to ranibizumab in patients with neovascular age-related macular degeneration (AMD) and to incorporate these factors into a prediction rule. METHODS: This multicenter, observational cohort study included 391 patients treated with ranibizumab for neovascular AMD. We performed genetic analysis for single nucleotide polymorphisms in AMD-associated genes and collected questionnaires regarding environmental factors and disease history. The primary outcome was non-response to treatment, defined as a loss of visual acuity ≥30% of letters. RESULTS: Of the 391 patients, 47 were classified as non-responsive. Independent predictors for non-response were age, baseline visual acuity, diabetes mellitus and accumulation of risk alleles in the CFH, ARMS2 and VEGF-A genes. The area under the receiver operating characteristic curve was 0.77 (95% confidence interval 0.70-0.84). We derived a clinical prediction rule, with possible total risk scores ranging from 0-19 points. The absolute risk of non-response varied from 3-52% between risk score groups. CONCLUSION: This is an important step towards a clinical prediction rule that can aid clinicians in identifying AMD patients with increased likelihood of non-response, and consequently contribute to making shared treatment decisions.

Polymorphisms in vascular endothelial growth factor receptor 2 are associated with better response rates to ranibizumab treatment in age-related macular degeneration.

PURPOSE: Intravitreal anti-vascular endothelial growth factor (VEGF) injections are currently the standard treatment for neovascular age-related macular degeneration (AMD), but a broad range of response rates has been observed. We evaluated the association of single nucleotide polymorphisms (SNPs) in VEGF genes and their receptors (VEGFR) with the response rate to ranibizumab in 366 patients with neovascular AMD. DESIGN: Case series study. PARTICIPANTS: A total of 366 eyes of 366 patients with neovascular AMD. METHODS: Visual acuity (VA) was determined at baseline, after 3 monthly ranibizumab injections, and after 1 year of treatment. Genotyping of 126 SNPs in the genes encoding VEGF family members VEGFA, VEGFB, VEGFC, VEGFD (FIGF), and placental growth factor (PGF); VEGF receptors VEGFR1 (FLT1), VEGFR2 (KDR), and VEGFR3 (FLT4); and the gene encoding pigment epithelium-derived factor (PEDF) (SERPINF1) was performed. MAIN OUTCOME MEASURES: The changes in VA after 3 injections and after 1 year of treatment and their association with VEGF and VEGFR genotypes. RESULTS: Univariate analyses of variance (ANOVAs) revealed a significant effect of SNP rs4576072 in the VEGFR2 gene on VA change after 12 months (F[1,235] = 14.05; P = 0.02). A stepwise linear regression analysis returned a model (P = 0.01) with SNPs rs4576072 and rs6828477 in the VEGFR2 gene as independent predictors for VA change after 12 months, with a mean increase in VA of 0.26 on the logarithm of the minimum angle of resolution (logMAR) scale in patients with 3 contributing minor alleles compared with a loss of 0.03 logMAR in patients with no minor allele. CONCLUSIONS: Polymorphisms in the VEGFR2/KDR gene significantly influence visual outcome in patients receiving ranibizumab treatment for neovascular AMD. This study shows that genetic variation partially explains the wide range of response to ranibizumab treatment, which in the future might help clinicians tailoring medical interventions to individual needs.

A functional variant in the CFI gene confers a high risk of age-related macular degeneration.

Up to half of the heritability of age-related macular degeneration (AMD) is explained by common variants. Here, we report the identification of a rare, highly penetrant missense mutation in CFI encoding a p.Gly119Arg substitution that confers high risk of AMD (P = 3.79 × 10⁻6; odds ratio (OR) = 22.20, 95% confidence interval (CI) = 2.98-164.49). Plasma and sera from cases carrying the p.Gly119Arg substitution mediated the degradation of C3b, both in the fluid phase and on the cell surface, to a lesser extent than those from controls. Recombinant protein studies showed that the Gly119Arg mutant protein is both expressed and secreted at lower levels than wild-type protein. Consistent with these findings, human CFI mRNA encoding Arg119 had reduced activity compared to wild-type mRNA encoding Gly119 in regulating vessel thickness and branching in the zebrafish retina. Taken together, these findings demonstrate that rare, highly penetrant mutations contribute to the genetic burden of AMD.

Association analysis of genetic and environmental risk factors in the cuticular drusen subtype of age-related macular degeneration.

PURPOSE: To assess the association of gender, cigarette smoking, body-mass index, and nine genetic risk variants with cuticular drusen (CD), a well recognized subtype of age-related macular degeneration (AMD). METHODS: A total of 757 patients with AMD, including 217 patients with CD, and 553 control individuals were interviewed with a questionnaire and underwent an ophthalmic examination. Venous blood samples were obtained for genomic DNA extraction, and genotyping was performed of single nucleotide polymorphisms previously associated with AMD. Odds ratios were calculated for patients with CD, using unaffected control individuals as a reference. Furthermore, odds ratios in patients with CD were compared to those in patients with "non-CD" AMD. RESULTS: The CD subtype of AMD was significantly associated with current smoking as well as variants in the complement factor H (CFH), age-related maculopathy susceptibility 2 (ARMS2), complement factor B/complement component 2 (CFB/C2), complement component 3 (C3), and apolipoprotein E (APOE) genes. In patients with CD, the association with the CFH Y402H risk allele was significantly higher (p=0.022), whereas the association with current smoking was significantly lower (p<0.001) than in the heterogeneous group of patients with "non-CD" AMD. CONCLUSIONS: The AMD subtype of CD was associated with previously identified genetic AMD risk factors. However, the association with the CFH Y402H risk allele appeared to be stronger, whereas the association with smoking was less pronounced when compared to AMD as a whole. This study suggests a more important role for genetic factors than environmental factors in the development of this well defined subtype of AMD. These findings stress the importance of detailed phenotyping in AMD to identify homogeneous AMD subtypes, which may be associated with different risk factors and disease mechanisms. Such studies will improve the accuracy of predictive models and the effectiveness of preventive and therapeutic options in AMD.

Cumulative effect of risk alleles in CFH, ARMS2, and VEGFA on the response to ranibizumab treatment in age-related macular degeneration.

PURPOSE: Intravitreal ranibizumab injections currently are the standard treatment for neovascular age-related macular degeneration (AMD). However, a broad range of response rates have been observed, the reasons for which are poorly understood. This pharmacogenetic study evaluated the impact of high-risk alleles in CFH, ARMS2, VEGFA, vascular endothelial growth factor (VEGF) receptor KDR, and genes involved in angiogenesis (LRP5, FZD4) on the response to ranibizumab treatment and on the age of treatment onset. In contrast to previous studies, the data were stratified according to the number of high-risk alleles to enable the study of the combined effects of these genotypes on the treatment response. DESIGN: Case series study. PARTICIPANTS: A cohort of 420 eyes of 397 neovascular AMD patients. METHODS: The change in visual acuity (VA) between baseline and after 3 ranibizumab injections was calculated. Genotyping of single nucleotide polymorphisms in the CFH, ARMS2, VEGFA, KDR, LPR5, and FZD4 genes was performed. Associations were assessed using linear mixed models. MAIN OUTCOME MEASURES: The VA change after 3 ranibizumab injections and the age of neovascular disease onset. RESULTS: After ranibizumab treatment, AMD patients without risk alleles in the CFH and ARMS2 genes (4.8%) demonstrated a mean VA improvement of 10 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, whereas no VA improvement was observed in AMD patients with 4 CFH and ARMS2 risk alleles (6.9%; P = 0.014). Patients with 4 high-risk alleles in CFH and ARMS2 were 5.2 years younger than patients with 1 or 2 risk alleles, respectively (63.5%; P<0.0001). The mean age at which the first ranibizumab treatment was carried out among AMD patients with all 6 risk alleles in CFH, ARMS2, and VEGFA was 65.9 years (2%) versus 75.3 years in patients with 0 or 1 high-risk allele (8.8%; P = 0.001). After ranibizumab treatment, patients with 6 high-risk alleles demonstrated a mean VA loss of 10 ETDRS letters (P<0.0001). CONCLUSIONS: This study evaluated the largest pharmacogenetic AMD cohort reported to date. A cumulative effect of high-risk alleles in CFH, ARMS2, and VEGFA seems to be associated with a younger age of onset in combination with poor response rates to ranibizumab treatment.

Genetic, behavioral, and sociodemographic risk factors for second eye progression in age-related macular degeneration.

PURPOSE: This study was conducted to investigate the correlation of genetic, sociodemographic, and behavioral risk factors with second eye progression to end-stage AMD. METHODS: One hundred and eight patients with end-stage AMD in one or both eyes were included in a retrospective time-to-event analysis of the onset of end-stage AMD in the second eye. Multivariate Cox regression survival analysis was performed for sex, age, smoking, body mass index (BMI), education, and 16 single nucleotide polymorphisms (SNPs) associated with AMD. RESULTS: Except for education, all sociodemographic and behavioral risk factors analyzed were significantly associated with a more rapid progression toward second eye involvement. Hazard ratios (HRs) were 2.6 (95% confidence interval [CI], 1.4-5.0) for female sex; 5.0 (95% CI, 2.0-12.5) for age >80; 2.2 (95% CI, 1.1-4.1) for BMI >30; and 4.4 (95% CI, 1.4-14.3) for >40 pack years, compared with the referent groups. Carriers of the lipoprotein lipase (LPL; rs12678919) risk alleles were at risk for more rapid progression to end-stage AMD in the second eye compared with the referent wild-type genotype (HR 2.0; 95% CI, 1.0-3.6). For complement factor I (CFI; rs10033900), homozygous carriers of the risk allele progressed faster than wild-type individuals (HR 2.2; 95% CI, 1.1-4.3). CONCLUSIONS: Sociodemographic, behavioral, and genetic risk factors are associated with the rate of second eye progression toward end-stage AMD. The findings of this study underline the importance of lifestyle factors and the complement pathway in AMD progression and suggest a role of the high-density-lipoprotein metabolism in second eye progression.

Short-term changes of Basal laminar drusen on spectral-domain optical coherence tomography.

PURPOSE: To determine if small hard drusen in patients with basal laminar drusen show short-term changes. DESIGN: Prospective observational case series. METHODS: Ten subjects with basal laminar drusen were longitudinally followed during a period of 4 months by spectral-domain optical coherence tomography. Drusen that showed a spontaneous change in volume were further analyzed according to 5 morphologic parameters: shape, reflectivity, homogeneity, and concurring photoreceptor layer/retinal pigment epithelium damage. Odds ratios (OR) and risk for regression and progression of drusen volumes were calculated. RESULTS: One hundred and five small hard drusen in 19 eyes showed a spontaneous change in volume over the period of follow-up. Drusen with a "pointed" shape were significantly associated (P = .031; OR 4.89; 95% confidence interval [CI] 1.16-20.67) with spontaneous progression in drusen volume, with a chance of 0.80 (95% CI 0.55-0.93) to progress. Drusen that showed a decreased reflectivity of overlying photoreceptor layer (P = .041; OR 7.67; 95% CI 1.09-54.24) or retinal pigment epithelium (P = .022; OR 12.38; 95% CI 1.44-106.57), showed a significant association with spontaneous regression in drusen volume, with chances of regression of 0.86 (95% CI 0.41-0.98) and 0.89 (95% CI 0.49-0.99), respectively. CONCLUSION: Small hard drusen in patients with the basal laminar drusen phenotype are subject to a process of short-term remodeling. The dynamic nature of this disease points to high biochemical activity that may be sensitive to future pharmacologic treatment strategies. In addition, these short-term changes of drusen may be a source of misclassification in disease staging.

Clinical evaluation of 3 families with basal laminar drusen caused by novel mutations in the complement factor H gene.

OBJECTIVES: To identify novel complement factor H (CFH) gene mutations and to specify the clinical characteristics in patients with basal laminar drusen (BLD), a clinical subtype of age-related macular degeneration. METHODS: Twenty-one probands with BLD were included in this study. The ophthalmic examination included nonstereoscopic 30° color fundus photography, fluorescein angiography, and high-resolution spectral-domain optical coherence tomography. Renal function was tested by measurement of serum creatinine and urea nitrogen levels. Venous blood samples were drawn for genomic DNA, and all coding exons and splice junctions of the CFH gene were analyzed by direct sequencing. RESULTS: In 3 families, we identified novel heterozygous mutations in theCFHgene: p.Ile184fsX, p.Lys204fsX, and c.1697-17_-8del. Ten of 13 mutation carriers displayed the BLD phenotype with a wide variety in clinical presentation, ranging from limited macular drusen to extensive drusen in the posterior pole as well as the peripheral retina. Two patients with BLD developed endstage kidney disease as a result of membranoproliferative glomerulonephritis type II. CONCLUSIONS: The early-onset BLD phenotype can be caused by heterozygous mutations in the CFH gene. Because some patients with BLD are at risk to develop membranoproliferative glomerulonephritis type II, we recommend that patients with extensive BLD undergo screening for renal dysfunction. CLINICAL RELEVANCE: Elucidation of the clinical BLD phenotype will facilitate identification of individuals predisposed to developing disease-related comorbidity, such as membranoproliferative glomerulonephritis type II. Moreover, with upcoming treatment modalities targeting specific components of the complement system, early identification of patients with BLD and detection of the genetic defect become increasingly important.

Risk alleles in CFH and ARMS2 are independently associated with systemic complement activation in age-related macular degeneration.

PURPOSE: Systemic complement activation is associated with age-related macular degeneration (AMD) and has mainly been attributed to a risk allele in the complement factor H (CFH) gene. Whether other important AMD genes also influence complement activation is unclear. In the present case-control study, complement activity and concentrations of complement components and their activation products are measured in AMD patients and in unaffected controls and correlated with genetic variants in the CFH, ARMS2, C3, CFI, and CFB genes. DESIGN: Case-control study. PARTICIPANTS: A cohort of 197 confirmed AMD patients and 150 unaffected age-matched controls were recruited prospectively for the study. METHODS: Hemolytic complement assays (AP50, CP50, and LP50), complement components (C3, CFB, CFI, and CFH), and the activation products (C3d, C5a, and SC5b-9) were analyzed in serum or plasma. The DNA samples were genotyped for 5 single nucleotide polymorphisms (SNPs) previously associated with AMD in the CFH, ARMS2, C3, CFB, and CFI genes. MAIN OUTCOME MEASURES: Complement concentrations and their associations with SNPs in the CFH, ARMS2, C3, CFB, and CFI genes. RESULTS: The AMD patients had increased activation of the alternative complement pathway (P = 0.003) and elevated levels of complement activation components C3d (P<0.0001) and C5a (P<0.0001), CFB (P<0.0001), and an increased C3d/C3 ratio (P<0.0001) calculated as a measure of C3 activation. While the CFH risk genotype was significantly associated with the elevated C3d/C3 ratios obtained, in the absence of CFH risk alleles the ARMS2 risk genotype also showed significantly increased levels of complement activation (P = 0.013). Furthermore, the carriers of the CFB protective allele had lower CFB concentrations. CONCLUSIONS: The current study found evidence showing that in AMD risk alleles in CFH and ARMS2 are independently associated with complement activation. Especially the C3d/C3 ratio seems to be a strong marker for AMD. The findings suggest that CFH and ARMS2 share a common pathway in the pathogenesis of AMD.

Central areolar choroidal dystrophy (CACD) and age-related macular degeneration (AMD): differentiating characteristics in multimodal imaging.

PURPOSE: Late-onset central areolar choroidal dystrophy (CACD) may easily be confused with geographic atrophy (GA) in AMD. To detect discerning features, the morphologic changes in CACD patients and in AMD patients were assessed with confocal scanning laser ophthalmoscopy (cSLO), fundus autofluorescence (FAF), and spectral-domain optical coherence tomography (SD-OCT). METHODS: A total of 30 CACD patients with identified PRPH2 gene mutations were analyzed and compared to 19 patients with early AMD and 13 patients with AMD-associated GA. The presence of drusen and pigment clumping was determined with color fundus photography. High-resolution in vivo imaging was performed with cSLO and SD-OCT. FAF images and SD-OCT volume scans were analyzed in each study eye. RESULTS: On FAF, a speckled FAF pattern occurred significantly more often in CACD (85%) than in early AMD (5.6%; P < 0.0001). There was a significantly higher frequency of sub-RPE deposits in eyes with AMD than in eyes with CACD (36.8% versus 2.1% of scans, P = 0.0019). Reticular drusen could be visualized by SD-OCT and FAF imaging in 52.6% of the eyes with early AMD and in 100% of the eyes with GA, whereas this drusen phenotype did not manifest in eyes with CACD. CONCLUSIONS: Although outer retinal atrophy is the clinically common feature in advanced CACD as well as GA, there are microstructural alterations on high-resolution SD-OCT and FAF imaging that allow for the differentiation between CACD and AMD. The findings may help to identify patients in whom a diagnostic PRPH2 screening is warranted. (ClinicalTrials.gov number, NCT00393692.).

Evaluation of serum lipid concentrations and genetic variants at high-density lipoprotein metabolism loci and TIMP3 in age-related macular degeneration.

PURPOSE: To analyze the association between polymorphisms in the TIMP3 gene and genes of the high-density lipoprotein (HDL) metabolism and age-related macular degeneration (AMD), and evaluate serum lipid and lipoprotein levels in AMD patients compared with control individuals. METHODS: Single nucleotide polymorphisms in or near the TIMP3, ABCA1, FADS1-3, CETP, LIPC, and LPL genes were genotyped. Serum levels of apolipoprotein B (ApoB), apolipoprotein A1, lipoprotein a, cholesterol, triglycerides, and HDL-cholesterol were determined. RESULTS: Significant associations were found between AMD and variants in ABCA1 and FADS1-3, and a nearly significant association in TIMP3. No significant associations were observed for variants in LPL, LIPC, and CETP. We also observed a significant elevation of ApoB levels in serum of AMD patients. Other lipids and lipoproteins were not significantly altered. CONCLUSIONS: These results confirm associations of AMD with variants near the TIMP3 gene and at loci involved in HDL metabolism. They further highlight a role of the extracellular matrix and the HDL metabolism in the pathogenesis of AMD. This study identified increased ApoB levels as a possible new serum biomarker for AMD.