Association of Complement Factor H and LOC387715 Genotypes with Response of Exudative Age-Related Macular Degeneration to Intravitreal Bevacizumab

Suitability of machine learning for atrophy and fibrosis development in neovascular age-related macular degeneration

PURPOSE

To assess the suitability of machine learning (ML) techniques in predicting the development of fibrosis and atrophy in patients with neovascular age-related macular degeneration (nAMD), receiving anti-VEGF treatment over a 36-month period.

METHODS

An extensive analysis was conducted on the use of ML to predict fibrosis and atrophy development on nAMD patients at 36 months from start of anti-VEGF treatment, using only data from the first 12 months. We use data collected according to real-world practice, which includes clinical and genetic factors.

RESULTS

The ML analysis consistently identified ETDRS as a relevant factor for predicting the development of atrophy and fibrosis, confirming previous statistical analyses. Also, it was shown that genetic variables did not demonstrate statistical relevance in the prediction. Despite the complexity of predicting macular degeneration, our model was able to obtain a balance accuracy of 63% and an AUC of 0.72 when predicting the development of atrophy or fibrosis at 36 months.

CONCLUSION

This study demonstrates the potential of ML techniques in predicting the development of fibrosis and atrophy in nAMD patients receiving long-term anti-VEGF treatment. The findings highlight the importance of clinical factors, particularly ETDRS (early treatment diabetic retinopathy study) visual acuity test, in predicting these outcomes. The lessons learned from this research can guide future ML-based prediction tasks in the field of ophthalmology and contribute to the design of data collection processes.

Association of the Complement Factor H Y402H Polymorphism and Response to Anti-Vascular Endothelial Growth Factor Treatment in Age-Related Macular Degeneration: An Updated Meta-Analysis

INTRODUCTION

Anti-vascular endothelial growth factor (anti-VEGF) agents have a variable effect on patients with age-related macular degeneration (AMD) that has been attributed to several causes, including genetic factors. We evaluated the effects of Complement Factor H (CFH) rs1061170/Y402H polymorphism on the response to anti-VEGF therapy among AMD patients.

METHODS

PubMed, Scopus, EMBASE, Web of Science, and Google Scholar were used for a literature search. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated to assess the effects of CFH Y402H polymorphism on the response to anti-VEGF therapy in AMD. I2 was used to present the amount of heterogeneity. We used STATA version 14.0 software.

RESULTS

Twenty-five papers reporting data for 4,681 patients were included in this study. Better response to anti-VEGF therapy was seen in T over C (OR = 1.25, 95% CI = 1.04-1.50), TT over CC (OR = 1.60, 95% CI = 1.06-2.4), and TT + TC over CC (OR = 1.68, 95% CI = 1.23-2.28) genotypes. There was no significant difference in the three other genetic models (TT vs. TC, TT vs. TC + CC, TC vs. TT + CC). In Asians, no significant difference was observed in all six genetic models. Ranibizumab and bevacizumab had similar efficacy; however, conbercept was more effective in homozygous genotypes. The literature indicated that TT and TC genotypes and T allele were associated with a better functional response, while the CC genotype and C alleles had a better anatomical response. The combination of risk alleles in ARMS2 A69S (rs10490924), VEGF-A (rs699947), and VEGF-A (rs833069) with Y420H is a predictor of non-respondents.

CONCLUSION

In patients with AMD, the CFH Y402H is a predictor of the response to anti-VEGF agents and should be considered in the treatment plan.

CFH (rs1061170, rs1410996), KDR (rs2071559, rs1870377) and KDR and CFH Serum Levels in AMD Development and Treatment Efficacy

BACKGROUND

Age-related macular degeneration (AMD) is a major global health problem as it is the leading cause of irreversible loss of central vision in the aging population. Av-vascular endothelial growth factor (anti-VEGF) therapies have been shown to be effective, but they do not respond optimally to all patients.

OBJECTIVE

This study investigates the genetic factors associated with susceptibility to AMD and response to treatment, focusing on key polymorphisms in the CFH (rs1061170, rs1410996) and KDR (rs2071559, rs1870377) genes and the association of CFH and KDR serum levels in patients with AMD.

RESULTS

A cohort of 255 patients with early AMD, 252 patients with exudative AMD, and 349 healthy controls underwent genotyping analysis, which revealed significant associations between CFH polymorphisms and the risk of exudative AMD. The CFH rs1061170 CC genotype was associated with an increased risk of early AMD (p = 0.046). For exudative AMD, the CFH rs1061170 TC + CC genotype increased odds (p < 0.001), while the rs1410996 GA + AA genotype decreased odds (p < 0.001). Haplotypes of CFH SNPs were associated with decreased odds of AMD. In terms of response to treatment, none of the SNPs were associated with the response to anti-VEGF treatment. We also found that both early and exudative AMD patients had lower CFH serum levels compared to the control group (p = 0.038 and p = 0.006, respectively). Exudative AMD patients with the CT genotype of CFH rs1061170 had lower CFH serum levels compared to the control group (p = 0.035). Exudative AMD patients with the GG genotype of CFH rs1410996 also had lower CFH serum levels compared to the control group (p = 0.021).

CONCLUSIONS

CFH polymorphisms influence susceptibility to AMD but do not correlate with a response to anti-VEGF therapy. Further research is imperative to fully evaluate the developmental significance, treatment efficacy, and predictive role in influencing susceptibility to anti-VEGF therapy for KDR and CFH.

Latest Development on Genetics of Common Retinal Diseases

Many complex forms of retinal diseases are common and pan-ethnic in occurrence. Among them, neovascular age-related macular degeneration, polypoidal choroidal vasculopathy, and central serous choroid retinopathy involve both choroidopathy and neovascularization with multifactorial etiology. They are sight-threatening and potentially blinding. Early treatment is crucial to prevent disease progression. To understand their genetic basis, candidate gene mutational and association analyses, linkage analysis, genome-wide association studies, transcriptome analysis, next-generation sequencing, which includes targeted deep sequencing, whole-exome sequencing, and whole genome sequencing have been conducted. Advanced genomic technologies have led to the identification of many associated genes. But their etiologies are attributed to complicated interactions of multiple genetic and environmental risk factors. Onset and progression of neovascular age-related macular degeneration and polypoidal choroidal vasculopathy are affected by aging, smoking, lifestyle, and variants in over 30 genes. Although some genetic associations have been confirmed and validated, individual genes or polygenic risk markers of clinical value have not been established. The genetic architectures of all these complex retinal diseases that involve sequence variant quantitative trait loci have not been fully delineated. Recently artificial intelligence is making an impact in the collection and advanced analysis of genetic, investigative, and lifestyle data for the establishment of predictive factors for the risk of disease onset, progression, and prognosis. This will contribute to individualized precision medicine for the management of complex retinal diseases.

Genetic Association Analysis of Anti-VEGF Treatment Response in Neovascular Age-Related Macular Degeneration

Anti-VEGF treatment for neovascular age-related macular degeneration (nAMD) has been FDA-approved in 2004, and since then has helped tens of thousands of patients worldwide to preserve vision. Still, treatment responses vary widely, emphasizing the need for genetic biomarkers to robustly separate responders from non-responders. Here, we report the findings of an observational study compromising 179 treatment-naïve nAMD patients and their reaction to treatment after three monthly doses of anti-VEGF antibodies. We show that established criteria of treatment response such as visual acuity and central retinal thickness successfully divides our cohort into 128 responders and 51 non-responders. Nevertheless, retinal thickness around the fovea revealed significant reaction to treatment even in the formally categorized non-responders. To elucidate genetic effects underlying our criteria, we conducted an undirected genome-wide association study followed by a directed replication study of 30 previously reported genetic variants. Remarkably, both approaches failed to result in significant findings, suggesting study-specific effects were confounding the present and previous discovery studies. Of note, all studies so far are greatly underpowered, hampering interpretation of genetic findings. In consequence, we highlight the need for an extensive phenotyping study with sample sizes exceeding at least 15,000 to reliably assess anti-VEGF treatment responses in nAMD.

Genetic Variants of Complement Factor H Y402H (rs1061170), C2 R102G (rs2230199), and C3 E318D (rs9332739) and Response to Intravitreal Anti-VEGF Treatment in Patients with Exudative Age-Related Macular Degeneration

Background and Objectives: To assess the association between the single nucleotide polymorphisms (SNPs) in the genes encoding complement factors CFH, C2, and C3 (Y402H rs1061170, R102G rs2230199, and E318D rs9332739, respectively) and response to intravitreal anti-vascular endothelial growth factor (VEGF) therapy in patients with exudative age-related macular degeneration (AMD). Materials and Methods: The study included 111 patients with exudative AMD treated with intravitreal bevacizumab or ranibizumab injections. Response to therapy was assessed on the basis of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) measured every 4 weeks for 12 months. The control group included 58 individuals without AMD. The SNPs were genotyped by a real-time polymerase chain reaction in genomic DNA isolated from peripheral blood samples. Results: The CC genotype in SNP rs1061170 of the CFH gene was more frequent in patients with AMD than in controls (p = 0.0058). It was also more common among the 28 patients (25.2%) with poor response to therapy compared with good responders (p = 0.0002). Poor responders, especially those without this genotype, benefited from switching to another anti-VEGF drug. At the last follow-up assessment, carriers of this genotype had significantly worse BCVA (p = 0.0350) and greater CRT (p = 0.0168) than noncarriers. TT genotype carriers showed improved BCVA (p = 0.0467) and reduced CRT compared with CC and CT genotype carriers (p = 0.0194). No associations with AMD or anti-VEGF therapy outcomes for SNP rs9332739 in the C2 gene and SNP rs2230199 in the C3 gene were found. Conclusions: The CC genotype for SNP rs1061170 in the CFH gene was associated with AMD in our population. Additionally, it promoted a poor response to anti-VEGF therapy. On the other hand, TT genotype carriers showed better functional and anatomical response to anti-VEGF therapy at 12 months than carriers of the other genotypes for this SNP.

Genetic associations of anti-vascular endothelial growth factor therapy response in age-related macular degeneration: a systematic review and meta-analysis

PURPOSE

To investigate the association of all reported common polymorphisms in anti-vascular endothelial growth factor (VEGF) therapy response and to identify potential clinically useful biomarkers for anti-VEGF therapy response in patients with age-related macular degeneration (AMD).

METHODS

We searched the Embase, PubMed, Web of Science databases in English and the China National Knowledge Infrastructure, WanFang and VIP databases in Chinese for pharmacogenetics studies on anti-VEGF therapy response in AMD. Odds ratios with 95% confidence intervals were calculated using the random effects model.

RESULTS

Among the 10 468 records yielded by the literature search, 33 articles that met the eligibility criteria were included in the meta-analysis. Nine single-nucleotide polymorphisms (SNP) in four genes were observed to be associated with the anti-VEGF therapy response in AMD patients. That is, rs1120063 in the HTRA1 gene; rs10490924 in the age-related maculopathy susceptibility (ARMS2) gene; rs1061170 in the complement factor H (CFH) gene; and rs323085 in the OR52B4 gene were associated with good anti-VEGF therapy responses, while rs800292, rs1410996 and rs1329428 in the CFH gene and rs4910623 and rs10158937 in the OR52B4 gene were associated with poor anti-VEGF therapy response in the AMD patients in our sample.

CONCLUSION

In this study, nine SNPs of four genes were indicated to be significantly associated with the anti-VEGF therapy response in the samples: rs11200638 in the HTRA1 gene; rs10490924 in the ARMS2 gene; rs1061170, rs800292, rs1410996 and rs1329428 in the CFH gene; and rs323085, rs4910623 and rs10158937 in the OR52B4 gene. Further studies based on various ethnicities and large sample sizes are warranted to strengthen the evidence found in the present study.

AMISH EYE STUDY: Baseline Spectral Domain Optical Coherence Tomography Characteristics of Age-Related Macular Degeneration

PURPOSE

To describe spectral domain optical coherence tomography (SD-OCT) findings in an Amish cohort to assess SD-OCT markers for early age-related macular degeneration (AMD).

METHODS

The authors performed a family-based prospective cohort study of 1,146 elderly Amish subjects (age range 50-99 years) (2,292 eyes) who had a family history of at least 1 individual with AMD. All subjects underwent complete ophthalmic examinations, SD-OCT using both Cirrus and Spectralis (20 × 20° scan area) instruments, fundus autofluorescence, infrared imaging, and color fundus photography. Spectral domain optical coherence tomography characteristics were analyzed in subjects with AMD (with and without subretinal drusenoid deposits [SDDs]) and normal healthy cohorts.

RESULTS

Participants' mean age was 65.2 years (SD ± 11). Color fundus photographic findings in 596 (53%) subjects (1,009 eyes) were consistent with AMD; the remaining 478 (43%) subjects showed no signs of AMD. The choroid was significantly thinner on OCT (242 ± 76 µm, P < 0.001) in those with AMD compared with those without (263 ± 63 µm). Subretinal drusenoid deposits were found in 143 eyes (7%); 11 of the 143 eyes (8%) had no other manifestations of AMD. Drusen volume (P < 0.001) and area of geographic atrophy (P < 0.001) were significantly greater, and choroid was significantly (P < 0.001) thinner in subjects with SDDs versus those without SDDs.

CONCLUSION

The authors describe spectral domain optical coherence tomography characteristics in an elderly Amish population with and without AMD, including the frequency of SDD. Although relatively uncommon in this population, the authors confirmed that SDDs can be found in the absence of other features of AMD and that eyes with SDDs have thinner choroids.

Ranibizumab plus fufang xueshuantong capsule versus ranibizumab alone for exudative age-related macular degeneration

Objective

To compare the efficacy of ranibizumab plus fufang xueshuantong capsule (cFXST) with the efficacy of ranibizumab alone in treatment of exudative age-related macular degeneration.

Methods

This prospective, randomized, controlled, pilot study included 38 eyes from 38 patients with exudative age-related macular degeneration (AMD) that were randomly allocated into two cohorts of 19 eyes each: ranibizumab (C_r) and ranibizumab plus cFXST (C_fr). All patients received three monthly injections of ranibizumab. Patients in C_fr also received daily oral supplementation of cFXST. Best corrected visual acuity (BCVA) and thickness of the choroidal neovascularization-pigment epithelial detachment (CNV-PED) complex (measured by optical coherence tomography) were recorded at baseline and at 1 and 3 months after the first intravitreal injection of ranibizumab.

Results

In the C_fr, the CNV-PED complex thickness was reduced by 31.7% and 36.1% at 1 and 3 months, respectively; these reductions were significantly greater than the 19.7% and 24.2% reductions in the C_r. BCVA improvement was significantly greater in the C_fr than in the C_r after 3 months; the proportion of patients with functional response was also greater in the C_fr than in the C_r (16/16 vs. 8/17).

Conclusion

Oral cFXST increases the efficacy of short-term ranibizumab treatment for exudative AMD.

Relationship between Aflibercept Efficacy and Genetic Variants of Genes Associated with Neovascular Age-Related Macular Degeneration: The BIOIMAGE Trial

PURPOSE

To identify the genetic variants of the vascular endothelial growth factor (VEGF) pathway genes and other genes associated with neovascular age-related macular degeneration (nAMD) as possible predictive biomarkers of a favorable treatment response to aflibercept.

DESIGN

A 52-week (with extension phase: 104-week), prospective, open-label, single-arm, multicenter, phase IV trial was conducted in Spain.

PARTICIPANTS

Patients with nAMD were enrolled.

METHODS

Aflibercept was administered every 8 weeks until week 48 (after 1-monthly loading doses over 3 months). After week 48, the interval between visits for aflibercept administration was extended by 2 weeks per visit to a maximum of 12 weeks if no evidence of disease activity was observed. A total of 338 SNPs in 90 genes associated with nAMD were analyzed.

MAIN OUTCOME MEASURES

Efficacy was evaluated mainly with best-corrected visual acuity (BCVA), and adverse events (AEs) were reported. Treatment efficacy was defined as an increase in BCVA ≥15 letters versus the baseline visit. Univariate and multivariate logistic regressions were used to associate single-nucleotide polymorphisms (SNPs) and treatment efficacy.

RESULTS

194 nonconsecutive patients were enrolled, 170 completed the 52-week follow-up, and of the 85 patients who started the extension phase, 77 completed this phase. Mean BCVA increased from baseline to weeks 52 and 104 by 9 and 10 letters (p = 0.0001 for both), respectively. The percentages of patients gaining ≥15 letters in weeks 52 and 104 were 33 and 31%, respectively. Multivariate logistic regression showed significant associations of 6 SNPs (in 6 genes) with treatment efficacy: rs12366035 (VEGFB; TT; odds ratio [OR] 217), rs25681 (C5; AA/AG; OR 19.7/8.3), rs17793056 (CX3CR1; CT/CC; OR 8.1/6.2), rs1800775 (CETP; CC; OR 6.6), rs2069845 (IL6; GG/AA; OR 5.6/3.3), and rs13900 (CCL2; CT; OR 4.0). One percent of the patients reported arteriothrombolic events related to aflibercept (cerebrovascular accident) according to the Antiplatelet Trialist Collaboration, and 2% reported serious ocular (retinal pigment epithelial tear, retinal tear, and endophthalmitis) and systemic (cardiac failure, hypersensitivity, and transient ischemic attack) AEs related to aflibercept.

CONCLUSIONS

Results suggest strong pharmacogenetic associations between one genetic variant of VEGFB (TT, rs12366035) and C5 (AA, rs12366035) genes and the BCVA response after 52-week aflibercept treatment in patients with nAMD. Likewise, the results support the efficacy of aflibercept observed in phase III studies and a good safety profile.

Meta-Analysis of the Pharmacogenetics of ARMS2 A69S Polymorphism and the Response to Advanced Age-Related Macular Degeneration

Age-related macular degeneration (AMD) causes irreversible vision loss, and targeted anti-vascular endothelial growth factor (VEGF) therapy is now the most common and effective treatment. The aim of this meta-analysis is to discuss whether genetic polymorphism of ARMS2 A69S could confer susceptibility to advanced AMD with the response to anti-VEGF treatment. We performed a meta-analysis of relevant published studies selected through electronic databases. A total of 21 preferred studies regarding the association between ARMS2 gene and anti-VEGF treatment response in advanced AMD were generally included in the meta-analysis. The pooled results demonstrated that the carriage of G allele for ARMS2 A69S presented a better clinical prognosis for advanced AMD treated with anti-VEGF drugs (OR = 1.38, 95% CI = 1.13-1.69, p = 0.002). In addition, in the subgroup analysis based on ethnicity, ARMS2 polymorphisms were more likely to be a positive responder for East Asian patients (OR = 1.67, 95% CI = 1.29-2.16, p < 0.001). This meta-analysis through a series of rigorous methodology data demonstrated a significant association between ARMS2 A69S polymorphism and the anti-VEGF treatment response in advanced AMD, especially among East Asian population. Numerous well-designed, randomized, multicenter clinical trials with large sample size are required to validate the association.

Association of a Variant in VWA3A with Response to Anti-Vascular Endothelial Growth Factor Treatment in Neovascular AMD

Purpose

Anti–vascular endothelial growth factor (VEGF) therapy for neovascular AMD (nvAMD) obtains a variable outcome. We performed a genome-wide association study for anti-VEGF treatment response in nvAMD to identify variants potentially underlying such a variable outcome.

Methods

Israeli patients with nvAMD who underwent anti-VEGF treatment (n = 187) were genotyped on a whole exome chip containing approximately 500,000 variants. Genotyping was correlated with delta visual acuity (deltaVA) between baseline and after three injections of anti-VEGF. Top principal components, age, and baseline VA were included in the analysis. Two lead associated variants were genotyped in an independent validation set of patients with nvAMD (n = 108).

Results

Linear regression analysis on 5,353,842 variants revealed five exonic variants with an association P value of less than 6 × 10⁻⁵. The top variant in the gene VWA3A (P = 1.77 × 10⁻⁶) was tested in the validation cohort. The minor allele of the VWA3A variant was associated with worse response to treatment (P = 0.02). The average deltaVA of discovery plus validation was –0.214 logMAR (≈ a gain of 10.7 Early Treatment Diabetic Retinopathy Study letters) for homozygote for the major allele, 0.172 logMAR for heterozygotes (≈ a loss of 8.6 Early Treatment Diabetic Retinopathy Study letters), and 0.21 logMAR for homozygote for the minor allele (≈ a loss of 10.5 Early Treatment Diabetic Retinopathy Study letters). Minor allele carriers had a higher frequency of macular hemorrhage at baseline.

Conclusions

An VWA3A gene variant was associated with worse response to anti-VEGF treatment in Israeli patients with nvAMD. The VWA3A protein is a precursor of the multimeric von Willebrand factor which is involved in blood coagulation, a system previously associated with nvAMD.

Investigation of genetic base in the treatment of age-related macular degeneration

PURPOSE

To determine whether gene polymorphisms which are associated with age-related macular degeneration (AMD) influence treatments' response and specifically the antioxidant supplementation in dry AMD patients, as well as the anti-vascular endothelial growth factor (anti-VEGF) therapy in neovascular AMD patients.

METHODS

A total of 170 patients with dry AMD and 52 neovascular AMD patients were genotyped for the following single nucleotide polymorphisms (SNPs): rs1061170/Y402H in CFH gene, rs10490924/A69S in ARMS2 gene, rs9332739/E318D and rs547154/IVS10 in C2 gene, and rs4151667/L9H and rs2072633/IVS17 in CFB gene. Treatment response was evaluated by comparing visual acuity and optical coherence tomography between baseline and at the end of the treatment.

RESULTS

Τhe CFH/Y402H variant was associated with the response to antioxidants in dry AMD patients. Carriers of one or two CFH risk alleles displayed a lower chance of responding compared to those with no risk allele. No association of antioxidants' response and ARMS2/A69S genotype was identified. The analysis of the C2 and CFB genetic variants (protective SNPs) revealed that antioxidant supplementation was much more effective in protective SNP carriers. In neovascular AMD patients, the analysis indicated that Y402H homozygous patients were less likely to respond to anti-VEGF therapy compared to heterozygous. Regarding the ARMS2/A69S genotype, carriers of the risk variant experienced significantly worse treatment outcome compared to wild-type patients.

CONCLUSION

In AMD patients, the efficacy of the antioxidant supplementation and the anti-VEGF therapy appears to differ by genotype. The detection of genetic variants, associated with treatment responsiveness, could lead to improved visual outcomes through genotype-directed therapy.

Effects of Antiangiogenic Drugs on Expression Patterns of Epigenetic Pathway Genes

BACKGROUND AND OBJECTIVE

To investigate the effects of antiangiogenic drugs on the transcription profile of acetylation genes in immortalized human retinal pigment epithelium cells (ARPE-19) in vitro.

MATERIALS AND METHODS

This in vitro study evaluated the effect of antiangiogenic drugs on the expression of histone acetylation genes on immortalized ARPE-19 cell cultures. ARPE-19 cells were cultured, plated, and treated for 24 hours with aflibercept (Eylea; Regeneron, Tarrytown, NY), ranibizumab (Lucentis; Genentech, South San Francisco, CA), or bevacizumab (Avastin; Genentech, South San Francisco, CA) at one (1×) or two times (2×) the concentrations of the clinical intravitreal dose. Untreated cells were used as controls. RNA was isolated, and real-time quantitative reverse transcription polymerase chain reaction analysis was performed on individual samples to quantify expression levels of genes associated with epigenetic acetylation pathways: histone acetyltransferase 1 (HAT1) and histone deacetylases 1, 6, and 11 (HDAC1, HDAC6, and HDAC11). Differences in cycle thresholds (ΔΔCts) were obtained, and folds were calculated using the formula 2^{^ΔΔCt}. Main outcome measures were expression levels of candidate genes in treated versus untreated samples.

RESULTS

Compared with untreated cells, 1× ranibizumab-treated cells expressed higher levels of HDAC6, and 2× ranibizumab-treated cells expressed higher HDAC11 levels. Bevacizumab-treated (1×) cells had significant change in HDAC1, HDAC6, and HDAC11. In cultures treated with 2× bevacizumab, only HDAC11 expression levels were significantly affected compared with controls. Aflibercept-treated (1×) cells had changes in expression of HDAC1, HDAC6, and HDAC11. At 2× concentration, only HDAC11 was significantly changed.

CONCLUSION

Our results show that antiangiogenic drugs can affect the transcription profile of genes regulating the histone acetylation status in ARPE-19 cells in vitro. This finding may have an implication in differential patient response to anti-vascular endothelial growth factor therapy by means of possible interactions between treatment and patient's epigenomic profile. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:S29-S33.].

Analysis of the association between CFH Y402H polymorphism and response to intravitreal ranibizumab in patients with neovascular age-related macular degeneration (nAMD)

Pharmacogenetic studies indicate that a variable response to anti-vascular endothelial growth factor (VEGF) therapy in patients with neovascular form of AMD (nAMD) may be due to polymorphisms in the complement factor H gene (CFH). This study is the first to investigate the association between CFH Y402H polymorphism and the response to ranibizumab therapy in Malaysian patients with nAMD. We included 134 patients with nAMD, examined between September 2014 and February 2016. The diagnosis of nAMD was confirmed by ophthalmologic examination, before ranibizumab therapy was started. Each patient received an intravitreal injection of 0.5 mg/0.05 ml ranibizumab following a treat-and-extend (TE) regimen. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were recorded after 3 and 6 months following the first injection and compared with the baseline values. Genotyping of Y402H (rs1061170) polymorphism was performed using PCR-RFLP and the amplified product was digested with MluCI restriction enzyme. Association between the Y402H genotypes and response to treatment was determined by a logistic regression analysis of responder (n = 49) and non-responder (n = 84) group. Significantly worse mean BCVA was observed for the CC genotype compared to the TT + CT genotype in the total sample after 6-month follow-up (p = 0.018). Comparing the baseline and 6-month point measurements, improved mean BCVA was observed in responder group, while worse mean BCVA was recorded for non-responder group. However, our regression analysis, adjusted for confounding factors, showed no significant association between the Y402H genotypes and response to treatment in nAMD patients under the recessive model (p > 0.05). Overall, our results suggest that factors other than Y402H polymorphism may be involved in the progression of nAMD after treatment with anti-VEGF agents, in Malaysian population.

Genome-wide association study suggests four variants influencing outcomes with ranibizumab therapy in exudative age-related macular degeneration

To identify factors associated with ranibizumab responses in patients with exudative age-related macular degeneration (AMD), we performed a genome-wide association study (GWAS) and a replication study using a total of 919 exudative AMD patients treated with intravitreal ranibizumab in a Japanese population. In the combined analysis of GWAS and the replication study, no loci reached genome-wide significant level; however, we found four variants showed suggestive level of associations with visual loss at month three (rs17822656, rs76150532, rs17296444, and rs75165563: P_combined < 1.0 × 10^-5). Of the candidate genes within these loci, three were relevant to VEGF-related pathway (KCNMA1, SOCS2, and OTX2). The proportions of patients who worsened visual acuity were 13.7%, 38.8%, 58.0%, and 80.0% in patients with 0, 1, 2, and 3 or more identified risk variants, respectively. Changes in visual acuity decreased linearly as the number of risk variants increased (P = 1.67 × 10^-12). The area under the curve using age, baseline visual acuity, and history of previous treatment was 0.607, and improved significantly to 0.713 in combination with identified variants (P < 0.0001). Although further study is needed to confirm their associations, our results offer candidate variants influencing response to ranibizumab therapy.

Exploring the Use of Molecular Biomarkers for Precision Medicine in Age-Related Macular Degeneration

Precision medicine aims to improve patient care by adjusting medication to each patient's individual needs. Age-related macular degeneration (AMD) is a heterogeneous eye disease in which several pathways are involved, and the risk factors driving the disease differ per patient. As a consequence, precision medicine holds promise for improved management of this disease, which is nowadays a main cause of vision loss in the elderly. In this review, we provide an overview of the studies that have evaluated the use of molecular biomarkers to predict response to treatment in AMD. We predominantly focus on genetic biomarkers, but also include studies that examined circulating or eye fluid biomarkers in treatment response. This involves studies on treatment response to dietary supplements, response to anti-vascular endothelial growth factor, and response to complement inhibitors. In addition, we highlight promising new therapies that have been or are currently being tested in clinical trials and discuss the molecular studies that can help identify the most suitable patients for these upcoming therapeutic approaches.

Changing vision: a review of pharmacogenetic studies for treatment response in age-related macular degeneration patients

Nonresponsiveness to age-related macular degeneration (AMD) treatments has become a growing concern in ophthalmology. Disparity among publications that have assessed pharmacogenetic (PGx) connections between AMD disease genes and treatments has delayed the implementation of PGx testing in AMD. We assessed all AMD PGx publications to identify the degree of agreement for publications within similar ethnic cohorts and worldwide, and the causes for differences in study outcomes. There are no accepted genotype–phenotype correlations, either within similar ethnic cohorts or worldwide. The diversity of measured outcomes, treatment protocols and statistical methods used may be causing this discrepancy. A universally accepted treatment protocol and the creation of agreed response group classification may bridge the gap between AMD PGx publications.

Association between CFH, CFB, ARMS2, SERPINF1, VEGFR1 and VEGF polymorphisms and anatomical and functional response to ranibizumab treatment in neovascular age-related macular degeneration

PURPOSE

We sought to determine if specific genetic single nucleotide polymorphisms (SNPs) influence vascular endothelial growth factor inhibition response to ranibizumab in neovascular age-related macular degeneration (AMD).

METHODS

A total of 403 Caucasian patients diagnosed with exudative AMD were included. After a three-injection loading phase, a pro re nata regimen was followed. Nine SNPs from six different genes (CFH, CFB, ARMS2, SERPINF1, VEGFR1, VEGF) were genotyped. Non-genetic risk factors (gender, smoking habit and hypertension) were also assessed. Patients were classified as good or poor responders (GR or PR) according to functional (visual acuity), anatomical (foveal thickness measured by OCT) and fluid criteria (fluid/no fluid measured by OCT).

RESULTS

Hypertension was the environmental factor with the strongest poor response association with ranibizumab in the anatomical measure after the loading phase (p = 0.0004; OR 3.7; 95% CI, 2.4-5.8) and after 12 months of treatment (p = 10^-5 ; OR 2.3; 95% CI, 1.5-3.4). The genetic variants rs12614 (CFB), rs699947 (VEGFA) and rs7993418 (VEGFR1) predisposed patients to a good response, while rs12603486 and rs1136287 (SERPINF1) were associated with a poor response. The protective genotype of rs800292 variant (CFH) was also associated with a poor anatomical response (p 0.0048).

CONCLUSION

All these data suggest that genetics play an important role in treatment response in AMD patients.

[Role of genetic markers in personalization of anti-angiogenic therapy in patients with exudative age-related macular degeneration]

The review presents data of clinical and pharmacogenetic research by Russian and foreign authors conducted within the last three years on the effectiveness of anti-angiogenic treatment against wet age-related macular degeneration (AMD). Scientific results on the association between angiogenesis-related gene polymorphisms responsible for predisposition to AMD on the one hand and a positive response to anti-VEGF therapy on the other are presented. Particular attention is paid to the main regulator of angiogenesis - the VEGF-A gene.

Geographic atrophy: Etiopathogenesis and current therapies

Geographic atrophy is characterized by severe visual deficit whose etiology and pathophysiology are yet to be elucidated. As a working hypothesis, oxidative damage could trigger a chronic inflammation in Bruch's membrane-RPE-choriocapillaris complex, mostly due to complement pathway overactivation. Some individuals with mutations in the complement system and other factors have diminished capacity in the modulation of the inflammatory response, which results in cell damage and waste accumulation. This accumulation of intracellular and extracellular waste products manifests as drusen and pigmentary changes that precede the atrophy of photoreceptors, RPE, choriocapillaris with an ischemic process with decreased choroid flow. All these processes can be detected as tomographic findings and autofluorescence signals that are useful in the evaluation of patients with atrophic AMD, which helps to establish an individualized prognosis. Anti-inflammatory, antioxidant and therapies that decrease the accumulation of toxins for the preservation of the RPE cells and photoreceptors are being investigated in order to slow down the progression of this disease.

Towards the application of precision medicine in Age-Related Macular Degeneration

The review essentially describes genetic and non-genetic variables contributing to the onset and progression of exudative Age-related Macular Degeneration (AMD) in Italian population. In particular, AMD susceptibility within Italian population is contributed to by genetic variants, accounting for 23% of disease and non-genetic variants, accounting for 10% of AMD. Our data highlighted prominent differences concerning genetic and non-genetic contributors to AMD in our cohort with respect to worldwide populations. Among genetic variables, SNPs of CFH, ARMS2, IL-8, TIMP3, SLC16A8, RAD51B, VEGFA and COL8A1 were significantly associated with the risk of AMD in the Italian cohort. Surprisingly, other susceptibility variants described in European, American and Asiatic populations, did not reach the significance threshold in our cohort. As expected, advanced age, smoking and dietary habits were associated with the disease. In addition, we also describe a number of gene-gene and gene-phenotype interactions. In fact, AMD-associated genes may be involved in the alteration of Bruch's membrane and induction of angiogenesis, contributing to exacerbate the damage caused by aging and environmental factors. Our review provides an overview of genetic and non-genetic factors characterizing AMD susceptibility in Italian population, outlining the differences with respect to the worldwide populations. Altogether, these data reflect historical, geographic, demographic and lifestyle peculiarities of Italian population. The role of epigenetics, pharmacogenetics, comorbities and genetic counseling in the management of AMD patients have been described, in the perspective of the application of a "population-specific precision medicine" approach addressed to prevent AMD onset and improve patients' quality of life.

A prospective multicenter study on genome wide associations to ranibizumab treatment outcome for age-related macular degeneration

We conducted a genome-wide association study (GWAS) on the outcome of anti-VEGF treatment for exudative age-related macular degeneration (AMD) in a prospective cohort. Four hundred and sixty-one treatment-naïve AMD patients were recruited at 13 clinical centers and all patients were treated with 3 monthly injections of ranibizumab followed by pro re nata regimen treatment for one year. Genomic DNA was collected from all patients for a 2-stage GWAS on achieving dry macula after the initial treatment, the requirement for an additional treatment, and visual acuity changes during the 12-month observation period. In addition, we evaluated 9 single-nucleotide polymorphisms (SNPs) in 8 previously reported AMD-related genes for their associations with treatment outcome. The discovery stage with 256 patients evaluated 8,480,849 SNPs, but no SNPs showed genome-wide level significance in association with treatment outcomes. Although SNPs with P-values of <5 × 10⁻⁶ were evaluated in replication samples of 205 patients, no SNP was significantly associated with treatment outcomes. Among AMD-susceptibility genes, rs10490924 in ARMS2/HTRA1 was significantly associated with additional treatment requirement in the discovery stage (P = 0.0023), and pooled analysis with the replication stage further confirmed this association (P = 0.0013). ARMS2/HTRA1 polymorphism might be able to predict the frequency of injection after initial ranibizumab treatment.

ARMS2 A69S polymorphism is associated with the number of ranibizumab injections needed for exudative age-related macular degeneration in a pro re nata regimen during 4 years of follow-up

PURPOSE

To investigate whether single-nucleotide polymorphisms (SNPs) known to be strongly associated with the development of age-related macular degeneration (AMD) have an influence on recurrence rate of choroidal neovascularization (CNV) activity during 4-year ranibizumab treatment for exudative AMD.

METHODS

This prospective study included 103 treatment-naïve patients (103 eyes) that received initially a loading dose of 3 monthly ranibizumab injections and thereafter, were treated according to an as-needed regimen for a 4-year follow-up period. Baseline values, visual outcome, and recurrence rate were examined. CFH Y402H and ARMS2 A69S polymorphisms were determined and their association with lesion recurrence and visual outcome was analyzed using a one-way analysis of variance (ANOVA) with post hoc comparison tested by Fisher's LSD method. Multivariate linear regression analysis was then used to identify factors associated with recurrence rate.

RESULTS

The cumulative total mean number of ranibizumab injections at the end of each year of the follow-up was 5.3 ± 1.8, 9.2 ± 2.9, 12.6 ± 4.6, and 15.7 ± 6.1. There was great inter-patient variability. Nineteen eyes (18.5%) did not experience recurrence during the first year, and five (4.8%) still displayed inactive CNV after 4 years of follow-up. No significant association was found between the number of injections and mean best corrected visual acuity (BCVA) change or final BCVA at the end of the study period. Genotypes had no influence on baseline characteristics or visual outcome but a significant association was found between the A69S polymorphism and the number of injections needed by the patients. Homozygous for the T risk allele required more retreatments over the 48-month follow-up.

CONCLUSIONS

The ARMS2 A69S polymorphism was associated with CNV recurrence rate in our patient cohort. Prediction of a greater risk of recurrence could help to design more appropriate follow-up treatment strategies for patients with neovascular AMD.

VEGF regulates local inhibitory complement proteins in the eye and kidney

Outer retinal and renal glomerular functions rely on specialized vasculature maintained by VEGF that is produced by neighboring epithelial cells, the retinal pigment epithelium (RPE) and podocytes, respectively. Dysregulation of RPE- and podocyte-derived VEGF is associated with neovascularization in wet age-related macular degeneration (ARMD), choriocapillaris degeneration, and glomerular thrombotic microangiopathy (TMA). Since complement activation and genetic variants in inhibitory complement factor H (CFH) are also features of both ARMD and TMA, we hypothesized that VEGF and CFH interact. Here, we demonstrated that VEGF inhibition decreases local CFH and other complement regulators in the eye and kidney through reduced VEGFR2/PKC-α/CREB signaling. Patient podocytes and RPE cells carrying disease-associated CFH genetic variants had more alternative complement pathway deposits than controls. These deposits were increased by VEGF antagonism, a common wet ARMD treatment, suggesting that VEGF inhibition could reduce cellular complement regulatory capacity. VEGF antagonism also increased markers of endothelial cell activation, which was partially reduced by genetic complement inhibition. Together, these results suggest that VEGF protects the retinal and glomerular microvasculature, not only through VEGFR2-mediated vasculotrophism, but also through modulation of local complement proteins that could protect against complement-mediated damage. Though further study is warranted, these findings could be relevant for patients receiving VEGF antagonists.

Autophagy and KRT8/keratin 8 protect degeneration of retinal pigment epithelium under oxidative stress

Contribution of autophagy and regulation of related proteins to the degeneration of retinal pigment epithelium (RPE) in age-related macular degeneration (AMD) remain unknown. We report that upregulation of KRT8 (keratin 8) as well as its phosphorylation are accompanied with autophagy and attenuated with the inhibition of autophagy in RPE cells under oxidative stress. KRT8 appears to have a dual role in RPE pathophysiology. While increased expression of KRT8 following autophagy provides a cytoprotective role in RPE, phosphorylation of KRT8 induces pathologic epithelial-mesenchymal transition (EMT) of RPE cells under oxidative stress, which is mediated by MAPK1/ERK2 (mitogen-activated protein kinase 1) and MAPK3/ERK1. Inhibition of autophagy further promotes EMT, which can be reversed by inhibition of MAPK. Thus, regulated enhancement of autophagy with concurrent increased expression of KRT8 and the inhibition of KRT8 phosphorylation serve to inhibit oxidative stress-induced EMT of RPE cells as well as to prevent cell death, suggesting that pharmacological manipulation of KRT8 upregulation through autophagy with combined inhibition of the MAPK1/3 pathway may be attractive therapeutic strategies for the treatment of AMD.

SYSTEMIC BETA-BLOCKERS IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

PURPOSE

To evaluate whether oral beta-blockers (BBs) are associated with a decreased number of intravitreal injections in patients with incident neovascular age-related macular degeneration.

METHODS

A retrospective cohort study of subjects with a new diagnosis of neovascular age-related macular degeneration was conducted using a medical claims database from a large national US insurer. Two cohorts were created for comparison consisting of patients with regular use of BBs or calcium channel blockers. The main outcome measured was the difference in the mean number of intravitreal injections administered between the two cohorts.

RESULTS

After inclusion and exclusion criteria, 239 BB and 155 calcium channel blocker subjects remained for analysis. Univariate analysis revealed that the mean number of injections in the BB cohort was 6.43 (95% confidence interval [CI] 5.90-6.95) versus 6.55 (95% CI 5.85-7.25) in the calcium channel blocker cohort (P = 0.78). After multivariate adjustment, the mean number of injections in the BB group was 6.32 (95% CI 5.77-6.87) versus 6.71 (95% CI 6.02-7.40) in the calcium channel blocker group. The overall difference between the 2 groups was -0.39 (95% CI difference -1.29 to 0.51; P = 0.40).

CONCLUSION

The use of oral BBs is not associated with a decreased number of intravitreal injections in incident neovascular age-related macular degeneration patients.

CFH Y402H polymorphism and response to intravitreal ranibizumab in Brazilian patients with neovascular age-related macular degeneration

OBJECTIVE

To investigate the association between CFH gene polymorphism and response to ranibizumab in Brazilian patients with neovascular age-related macular degeneration (AMD).

METHODS

95 patients were genotyped for the CFH rs1061170 (Y402H) single nucleotide polymorphism. Patients with neovascular AMD initially received intravitreal ranibizumab injections for three months and were retreated as needed. Visual acuity (VA) and central retinal thickness (CRT) were measured before treatment and at 1, 3, 6, and 12 months post-treatment.

RESULTS

For patients with the TT and TC genotypes, paired comparisons of VA showed a statistically significant improvement when the data obtained at all visits were compared with baseline. Patients homozygous for the risk genotype (CC) did not show a statistically significant improvement when VA obtained at visits 1, 3, 6 and 12 were compared with baseline. For all genotypes, paired comparisons of CRT showed a statistically significant improvement when the data obtained at visits 1, 3, 6 and 12 were compared with baseline.

CONCLUSION

Patients with the CC genotype showed poorer long-term functional response to intravitreal ranibizumab.

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.

Influence of CFH, HTRA1 and ARMS2 polymorphisms in the response to intravitreal ranibizumab treatment for wet age-related macular degeneration in a Spanish population

AIM

To determine whether gene polymorphisms of the major genetic risk loci for age-related macular degeneration (AMD): ARMS2 (rs10490923), the complement factor H (CFH) (rs1410996) and HTRA1 (rs11200638) influence the response to a treatment regimen with ranibizumab for exudative AMD.

METHODS

This study included 100 patients (100 eyes) with exudative AMD. Patients underwent a treatment with ranibizumab injections monthly during three months. Reinjections were made when the best corrected visual acuity (BCVA) decrease five letters (ETDRS) or central subfield retinal thickness gained 100 µm in optical coherence tomography image. Genotypes (rs10490923, rs1410996 and rs11200638) were analyzed using TaqMan probes or polymerase chain reaction-restricted fragment length polymorphisms analysis.

RESULTS

There were no statistically significant differences in allelic distribution of CFH (rs1410996), ARMS2 (rs10490923) and HTRA1 (rs11200638) polymorphisms regarding to response to ranibizumab treatment.

CONCLUSION

Ranibizumab treatment response is not related to CFH (rs1410996), ARMS2 (rs10490923) and HTRA1 (rs11200638) poymorphisms.

UNTREATED OBSTRUCTIVE SLEEP APNEA HINDERS RESPONSE TO BEVACIZUMAB IN AGE-RELATED MACULAR DEGENERATION

PURPOSE

To compare functional and anatomical responses to intravitreal bevacizumab in patients with exudative age-related macular degeneration (AMD) between two groups of patients with obstructive sleep apnea (OSA) with and without treatment with continuous positive airway pressure therapy.

METHODS

Patients with OSA were categorized into 2 groups: 18 untreated and 20 treated with continuous positive airway pressure therapy. All patients had exudative AMD and received treatment with intravitreal bevacizumab. Central retinal thickness was plotted against time to assess anatomical response. Logarithm of the minimum angle of resolution visual acuity changes determined functional effect. Total number of intravitreal injections administered was assessed.

RESULTS

Treated OSA group received 8 ± 7 total injections; untreated OSA group received 16 ± 4 injections (P < 0.05). Treated OSA group achieved statistically significant better visual acuity (logarithm of the minimum angle of resolution, 0.3 ± 0.24, 20/40), as opposed to the untreated group (logarithm of the minimum angle of resolution, 0.7 ± 0.41; P < 0.05). Central retinal thickness improved in the treated OSA group compared with the untreated group: 358 ± 95 μm to 254 ± 45 μm and 350 ± 75 μm to 322 ± 105 μm, respectively (P < 0.05, 20/100).

CONCLUSION

Untreated OSA hinders the response of exudative AMD to intravitreal bevacizumab. Treatment of OSA with continuous positive airway pressure therapy yields a subsequent anatomical response and functional improvement while requiring significantly less injections. Identifying and treating underlying OSA earlier in patients with exudative AMD may yield better functional outcomes.

Macular morphology and response to ranibizumab treatment in patients with wet age-related macular degeneration

PURPOSE

The purpose of this study was to assess whether specific characteristics of spectral domain optical coherence tomography (SD-OCT) affect structural and functional outcomes and number of injections needed in ranibizumab (0.05 mL of 10 mg/mL Lucentis solution)-treated wet age-related macular degeneration (AMD) patients.

PATIENTS AND METHODS

This retrospective case series included 62 newly diagnosed wet AMD patients treated with three monthly intravitreal ranibizumab injections followed by monthly follow-up and pro re nata retreatment. The presence of dome-shaped pigment epithelial detachment (PED), disruption of the retinal pigment epithelium (RPE), and subretinal and intraretinal fluid was associated with changes in Early Treatment of Diabetic Retinopathy Study visual acuity, central macular thickness (CMT), and number of injections needed during the 6-month follow-up.

RESULTS

The presence of PED was associated with lower values of CMT at presentation (399 μm [±132 μm] vs 310 μm [±51 μm], P=0.005). The presence of RPE disruption was associated with worse visual acuity in month 6 (0.36 [±0.22] vs 0.61 [0.45], P=0.027) and fewer injections (4.23 [±0.92] vs 3.55 [±0.60], P=0.007). The presence of intraretinal fluid at presentation was associated with worse visual acuity outcomes in month 4 (P=0.045) but not in month 6.

CONCLUSION

The dome-shaped PED was associated with lower CMT at presentation, but it did not affect response to treatment. RPE disruption was associated with worse functional outcomes with fewer injections. Intraretinal fluid at presentation may suggest delayed response to treatment. Individualized SD-OCT analysis could lead to individualized approach to wet AMD patients. SD-OCT can offer imaging biomarkers to assess the prognosis of anti-VEGF treatment in AMD patients.

Single-Nucleotide Polymorphisms Associated With Age-Related Macular Degeneration and Lesion Phenotypes in the Comparison of Age-Related Macular Degeneration Treatments Trials

IMPORTANCE

Single-nucleotide polymorphisms (SNPs) associated with the CFH, ARMS2, C3, LIPC, CFB, and C2 genes are associated with age-related macular degeneration (AMD); however, the association of these SNPs with angiographic features of neovascular AMD has been inconsistent in previous studies, and to date, no studies have addressed their association with features on optical coherence tomography.

OBJECTIVE

To evaluate the influence of genotype of SNPs previously associated with AMD on the phenotype of neovascular lesions.

DESIGN, SETTING, AND PARTICIPANTS

Participants for this cross-sectional study were recruited from the 1185 patients enrolled in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT), a randomized clinical trial. Eligibility criteria for CATT specified that eyes have choroidal neovascularization and visual acuity between 20/25 and 20/320. A subgroup of 835 patients provided blood samples from July 2010 through September 2011 and were genotyped for the SNPs rs1061170 (CFH), rs10490924 (ARMS2),rs2230199 (C3), rs10468017 (LIPC), rs4151667 (CFB), rs547154 (C2) using TaqMan SNP genotyping assays. Data analysis was initiated in November 2013 and completed in January 2016.

MAIN OUTCOMES AND MEASURES

Pretreatment ocular characteristics on fluorescein angiography (lesion type, area of neovascularization and total lesion, retinal angiomatous proliferation) and on time-domain optical coherence tomography (presence of intraretinal, subretinal, and subretinal pigment epithelium fluid; thickness at the foveal center of the retina, subretinal fluid, and subretinal tissue complex), visual acuity, and age.

RESULTS

A total of 835 (73%) of 1150 CATT patients were genotyped. Mean age decreased with the number of risk alleles for CFH (P < .001), ARMS2 (P < .001), and C3 (P = .005). The following results were found as the number of risk alleles increased from 0 to 1 to 2. For CFH, mean total thickness decreased from 476 to 476 to 434 µm (P = .01; adjusted for age, sex, and smoking status). For ARMS2, the mean area of the total lesion increased from 2.0 to 2.8 to 2.4 mm2 (P = .03), the proportion with retinal angiomatous proliferation lesions increased from 8% to 10% to 12% (P = .05), and the proportion with intraretinal fluid increased from 72% to 71% to 82% (P = .008). For C3, the proportion with intraretinal fluid decreased from 78% to 69% to 64% (P = .001), and the mean retinal thickness decreased from 225 to 207 to 197 µm (P = .02).

CONCLUSIONS AND RELEVANCE

CFH, ARMS2, and C3 were associated with specific features of neovascularization at the time patients were enrolled in CATT. Previously identified associations of ARMS2 and CFH with type of choroidal neovascularization on fluorescein angiography were not confirmed. New associations with OCT features identified in CATT need confirmation to establish whether a true association exists.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00593450.

Association of the polymorphism Y402H in the CFH gene with response to anti-VEGF treatment in age-related macular degeneration: a systematic review and meta-analysis

To explore whether the complement factor H (CFH) polymorphism rs1061170/Y402H is associated with responsiveness to antivascular endothelial growth factor (VEGF) agents in age-related macular degeneration (AMD). We reviewed the English literature to examine the association between the polymorphism rs1061170/Y402H of the CFH gene and responsiveness to treatment with anti-VEGF drugs in AMD patients. A meta-analysis of eligible studies was also performed. Pooled odds ratios (ORs) and 95% CIs were estimated using Stata V.12.0. Statistical heterogeneity was measured using Q-statistic testing. Fourteen relevant studies including a total of 2963 AMD patients were eligible. In AMD patients without a treatment history, individuals carrying the rs1061170/Y402H TT genotype were more likely to achieve a better outcome (OR = 1.932, 95% CI = 1.125-3.317, p = 0.017) than those carrying the CC genotype. The polymorphism rs1061170/Y402H might be a genetic predictor of treatment response to anti-VEGF therapy in AMD patients. Further prospective research including a larger number of patients is needed to validate this finding.

Complement factor H and LOC387715/ARMS2/HTRA1 variant's frequencies and phenotypic associations in neovascular age-related macular degeneration, a pilot study

Purpose

To evaluate the frequency of 12 single nucleotide polymorphisms (SNPs) of complement factor H (CFH) and LOC387715/ARMS2/HRTA1 and their association with some of the presenting clinical features of neovascular age-related macular degeneration (AMD).

Methods

In this prospective non-comparative case series forty four naïve patients with neovascular AMD were genotyped using sequencing or Sequenom iPLEX technology. Descriptive tests were used for displaying the magnitude of each allele, gender distribution, and age at diagnosis. Fisher exact test was used to evaluate the correlation between visual acuity (VA) and different alleles. Also Kruskal-Wallis test was used for comparison between age at the time of diagnosis and different alleles.

Results

The most frequent SNP among studied patients was rs1061147 with 100% frequency rate. The least common was rs2672598 with a frequency of 52.27%. Only the allele rs800292 of CFH locus on 1q32 was associated with VA better than 20/200 (p value = 0.034). The frequency of this allele was 77.27% (34 patients) in this study. There was no significant association between any of alleles, and VA worse than 20/200(p > 0.05). Fifteen patients had bilateral exudative AMD (34.09%). There was no significant difference between alleles in bilateral neovascular AMD and unilateral disease. Also bilateral and unilateral patients were not different in terms of age, gender or VA (p value: 0.330, 0.764 and 0.456 respectively). There was also no significant association between any of SNPs and bilaterality of disease.

Conclusion

We designated the frequencies of SNPs of CFH and LOC387715/ARMS2/HRTA1 in neovascular AMD in a sample of Iranian patients. Only the allele rs800292 of CFH locus on chromosome 1q32 was associated with better VA.

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.

The role of sub-retinal fluid in determining treatment outcomes in patients with neovascular age-related macular degeneration--a phase IV randomised clinical trial with ranibizumab: the FLUID study

Background

With increasing experience using anti-VEGF therapy for the treatment of neovascular age-related macular degeneration (nAMD), ophthalmologists have shifted away from a “one size fits all” to an “individualised” approach based on disease activity with the aim of achieving a fluid-free retina. The FLUID study investigates the non-inferiority of a Treat and Extend (T&E) protocol of 0.5 mg ranibizumab, which allows treatment extension in the presence of incomplete resolution of sub-retinal fluid (SRF) ≤200 μm at the foveal centre relative to a T&E protocol that requires complete resolution of all retinal fluid (i.e., both SRF and intra-retinal fluid [IRF]) in patients with nAMD.

Methods/Design

This 24 month, randomised, phase IV trial has completed recruitment of treatment-naïve patients randomised 1:1 to ranibizumab “intensive” treatment (complete resolution of IRF and SRF) or ranibizumab “relaxed” treatment (resolution of IRF or >200 μm SRF only at foveal centre). Patients in both arms follow a T&E regimen where extension decisions are based upon assessment of lesion activity: loss of ≥5 letters of visual acuity, new haemorrhage, presence of IRF and SRF on an optical coherence tomography (OCT) scan. The determination of SRF is conducted at a reading centre while the assessment of IRF is physician-determined. The primary endpoint is the mean change in best-corrected visual acuity (BCVA) from baseline to 24 months. Secondary endpoints include the mean change in central retinal thickness (CRT) from baseline to 12 and 24 months, the number of ranibizumab injections administered at 12 and 24 months, and the pharmacogenomic assessment of AMD Gene Consortium-identified single-nucleotide polymorphisms (SNPs) and their association with treatment response. Three hundred and forty seven (347) patients have been recruited by 16 Australian sites within approximately 16 months. A protocol to adjudicate on SRF has been established by the central reading centre and is demonstrating good concordance with investigator assessment.

Discussion

This study will provide important insights into retreatment criteria for managing nAMD using a T&E regimen. The current paper describes the clinical rationale for using a less intensive treatment approach using ranibizumab and details of the treatment protocol.

Trial registration

Trial registration number: NCT01972789. Date of registration: 24th October 2013.

Predictors of Response to Intravitreal Anti-Vascular Endothelial Growth Factor Treatment of Age-Related Macular Degeneration

PURPOSE

To identify factors that influence visual and anatomic response to treatment with intravitreal anti-vascular endothelial growth factor (VEGF) for neovascular age-related macular degeneration (AMD).

DESIGN

Observational cohort study.

METHODS

Seventy-two patients were included in this study. Best-corrected Snellen visual acuity (VA) and central foveal thickness measured on optical coherence tomography (OCT) at time of treatment and post-treatment follow-up visits were recorded. Associations between demographic, behavioral, and genetic risk factors and the 2 outcomes were analyzed using mixed-effects linear regression models. Two loci in complement factor H (CFH) were included in a risk score to determine the association between CFH risk and improvement in VA and central foveal thickness.

RESULTS

There was a small improvement in VA following anti-VEGF treatment (mean: 3.7 ± 3.0 letters), which was not statistically significant. Significant improvement in VA was observed for the nonrisk CFH Y402H genotype (P < .001) and for a low CFH risk score (P = .019). Regarding the outcome of change in central foveal thickness, improvement was noted in all genotype groups, but reduction after treatment was significantly higher in the low CFH risk score group (P = .033). A significant improvement in mean VA was seen among smokers (P < .001), but this relationship was not observed for central foveal thickness.

CONCLUSION

After anti-VEGF therapy, significant improvement in VA was observed for low-risk CFH genotypes and subjects with a low risk score. There was a statistically significant reduction in central foveal thickness overall, and subjects with a low CFH risk score improved more than the high-risk group.

MMP20 and ARMS2/HTRA1 Are Associated with Neovascular Lesion Size in Age-Related Macular Degeneration

PURPOSE

Age-related macular degeneration (AMD) is the leading cause of severe visual impairment. Despite treatment, a central scotoma often remains. The size of the scotoma depends on the lesion size of the choroidal neovascular membrane and significantly affects the patient's quality of life, and the lesion size of neovascularization also affects response to treatments. The aim of this study was to identify genes associated with the neovascular lesion size in neovascular AMD.

DESIGN

A genome-wide association study (GWAS).

PARTICIPANTS

We included 1146 Japanese patients with neovascular AMD.

METHODS

We performed a 2-stage GWAS for the lesion size of AMD as a quantitative trait among 1146 (first stage: 727, second stage: 419) Japanese patients with neovascular AMD. Lesion size was determined by the greatest linear dimension measured with fluorescein angiography examination before treatment. We examined the association between the genotypic distribution of each single nucleotide polymorphism (SNP) and the trait using an additive model adjusted for age and sex. To evaluate the associations between AMD development and SNPs associated with lesion size, we also performed a case-control study by using the genotype data from these 1146 Japanese patients as case subjects and the fixed dataset from the Nagahama Study as control subjects.

MAIN OUTCOME MEASURES

Genes associated with the lesion size in neovascular AMD.

RESULTS

In the discovery stage, rs10895322 in MMP20 showed a genome-wide significant P value of 6.95×10(-8), and rs2284665 in ARMS2/HTRA1 showed a P value of 1.55×10(-7). The associations of these 2 SNPs were successfully replicated in the replication stage, and a meta-analysis of both stages showed genome-wide significant P values (2.80×10(-9) and 4.41×10(-9), respectively). In a case-control study using 3248 Japanese subjects as controls, we could not find contribution of MMP20 rs10895322 for AMD development. Although MMP20 has been thought to be expressed only in dental tissues, we confirmed MMP20 expression in the human retina and retinal pigment epithelium/choroid with polymerase chain reaction.

CONCLUSIONS

The growth of choroidal neovascularization in AMD would be affected by 2 genes: MMP20, a newly confirmed gene expressed in the retina, and ARMS2/HTRA1, a well-known susceptibility gene for AMD.

Complement pathway biomarkers and age-related macular degeneration

In the age-related macular degeneration (AMD) 'inflammation model', local inflammation plus complement activation contributes to the pathogenesis and progression of the disease. Multiple genetic associations have now been established correlating the risk of development or progression of AMD. Stratifying patients by their AMD genetic profile may facilitate future AMD therapeutic trials resulting in meaningful clinical trial end points with smaller sample sizes and study duration.

Pharmacogenetics of Complement Factor H Y402H Polymorphism and Treatment of Neovascular AMD with Anti-VEGF Agents: A Meta-Analysis

The purpose of this study is to investigate whether the Y402H polymorphism (rs1061170, a T-to-C transition at amino acid position 402) in the complement factor H (CFH) gene have a pharmacogenetics effect on the anti-vascular endothelial growth factor (VEGF) treatment for neovascular age-related macular degeneration (AMD). We performed a meta-analysis using databases including PubMed and EMBASE to find relevant studies. 13 published association studies were selected for this meta-analysis, including 2704 patients. For the CFH Y402H polymorphism, anti-VEGF treatment was much less effective in AMD patients with the CFH CC genotype (CC versus TT: odds ratio (OR) = 55, 95% confidence interval (CI), 0.31 to 0.95, P = 0.03; CC versus CT: OR = 0.60, 95% CI, 0.40 to 0.91, P = 0.02; and CC versus CT + TT: OR = 0.59, 95% CI, 0.38 to 0.90, P = 0.02, respectively). In subgroup analysis, CFH Y402H polymorphism was more likely to be a predictor of response for Caucasians (CC versus CT+TT: OR = 0.63, 95% CI, 0.42 to 0.95, P = 0.03). In conclusion, pharmacogenetics of CFH Y402H polymorphism may play a role in response to anti-VEGF treatment for neovascular AMD, especially for Caucasians.

Combined effects of genetic and non-genetic risk factors affect response to ranibizumab in exudative age-related macular degeneration

PURPOSE

To investigate whether genetic and non-genetic risk factors influence 12-month response to ranibizumab treatment for exudative age-related macular degeneration (AMD).

METHODS

A cohort of 94 Caucasian patients with unilateral exudative AMD received intravitreal ranibizumab. After a three-injection loading phase, a PRN regimen was followed. Patients were genotyped for three single-nucleotide polymorphisms: CFH rs1061170, ARMS2 rs10490924 and C3 rs2230199. Non-genetic risk factors [choroidal neovascularization (CNV) phenotype, smoking habit, hypertension and body mass index] were considered. The selected end-point was the 12-month variation of number of ETDRS letters.

RESULTS

Complement factor H (CFH) risk alleles, smoking history and arterial hypertension each independently influenced treatment response, with worse 12-month BCVA outcomes (p = 0.036, 0.037, 0.043, respectively). A significant cumulative effect of these risk factors was also observed: patients homozygous for the CFH risk alleles and with a positive smoking history showed a mean loss of 8.0 ETDRS letters (p = 0.010). Patients with CFH risk alleles, smoking history and hypertension had a mean loss of 13.9 ETDRS letters (p = 0.013). CNV phenotypes did not influence visual outcomes, nor were they associated with other genetic/non-genetic risk factors.

CONCLUSIONS

Complement factor H risk alleles, smoking history and hypertension affect the mid-term response to ranibizumab in exudative AMD.

Complement Factor H Expressed by Retinal Pigment Epithelium Cells Can Suppress Neovascularization of Human Umbilical Vein Endothelial Cells: An in vitro Study

Complement factor H (CFH) is one of the most important soluble complement regulatory proteins and is closely associated with age-related macular degeneration (AMD), the leading cause of irreversible central vision loss in the elderly population in developed countries. Our study searches to investigate whether CFH expression is changed in oxidative damaged retinal pigment epithelium (RPE) cells and the role of CFH in the in vitro neovascularization. First, it was confirmed by immunofluorescence staining that CFH was expressed by ARPE-19 cells. CFH mRNA and protein in oxidative (H₂O₂) damaged ARPE-19 cells were both reduced, as determined by Real-time PCR and Western blotting analysis. Enzyme-linked immunosorbent assay (ELISA) also showed that ARPE-19 cells treated with H₂O₂ caused an increase in C3a content, which indicates complement activation. Then, wound assays were performed to show that CFH expression suppression promoted human umbilical vein endothelial cell (HUVECs) migration. Thereafter, ARPE-19 cells were transfected with CFH-specific siRNA and CFH knockdown was confirmed with the aid of Real-time PCR, immunofluorescence staining and Western blotting. The ELISA results showed that specific CFH knockdown in ARPE-19 cells activated the complement system. Finally, in vitro matrigel tube formation assay was performed to determine whether change of CFH expression in RPE would affect tube formation by HUVECs. More tubes were formed by HUVECs co-cultured with ARPE-19 cells transfected with CFH specific-siRNA when compared with controls. Our results suggested that RPE cells might be the local CFH source, and RPE cell injuries (such as oxidative stress) may cause CFH expression suppression, which in turn may lead to complement activation and promotion of tube formation by HUVECs. This finding is of importance in elucidating the role of complement in the pathogenesis of ocular neovascularization including choroidal neovascularization.

Polymorphisms in the APOE gene and the location of retinal fluid in eyes with neovascular age-related macular degeneration

BACKGROUND

Previous reports suggest that the outcome of age-related macular degeneration treatment is dependent on variants in the apolipoprotein E (APOE) gene. We wish to establish if variants in this gene are associated with anatomical location of fluid within the macula on optical coherence tomography imaging before and after three anti-vascular endothelial growth factor treatments.

METHODS

Patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration were prospectively enrolled and monitored over a 12-month period. Main outcome measures were logMAR best-corrected visual acuity and correlation of qualitative optical coherence tomography features (intraretinal fluid [IRF] and/or subretinal fluid) at baseline and after three anti-vascular endothelial growth factor injections with genetic variants of the APOE gene.

RESULTS

One hundred and eighty-six eyes of 186 patients aged 79.4 years (range, 58-103 years). Subjects with an ε2 allele were more likely to have IRF at baseline compared with the eyes without (odds ratio: 2.98, 95% confidence interval: 1.22-7.29, P = 0.02). After 3 injections, 184 eyes remained. Of these, 114 of eyes (62.0%) were classified as "dry" on optical coherence tomography, whereas 48 eyes (26.1%) still had a component of IRF, and 22 (12.0%) had subretinal fluid alone. There was no statistically significant association between APOE variants and presence of persistent IRF, although there were almost double the number of subjects with ε2 (40%) who had persistent fluid compared with those with ε3/ε4 (23%) (P = 0.06).

CONCLUSION

In patients with neovascular age-related macular degeneration, the presence of the ε2 allele of the APOE gene was associated with having IRF at baseline. Larger studies are required to determine if a greater proportion of those with the ε2 allele retain this fluid after three initial injections.

Bevacizumab treatment for neovascular age-related macular degeneration in the setting of a clinic: "real life" long-term outcome

BACKGROUND

To evaluate the long-term outcome of bevacizumab therapy for neovascular age related macular degeneration (NVAMD) in the setting of a clinic.

METHODS

Consecutive group of NVAMD patients who were treated in a single 3(rd) referral center with bevacizumab using a loading dosage of 3 monthly injections followed by variable dosing for at least 48 months were retrospectively evaluated. Genotyping was performed for CFH (rs1061170), HTRA1 (rs1200638), and C3 (rs2230199). Main outcome measures included functional and morphological treatment outcomes as well as their risk allele associations.

RESULTS

Out of 128 patients who started bevacizumab treatment over 4 years before the study endpoint [mean (± SD): 60 ± 10.9 months], 75 eyes of 67 (52.3%) patients, were still followed. Mean best corrected visual acuity (BCVA) (LogMAR ± SEM) improved from 0.66 ± 0.07 at baseline to 0.48 ± 0.05 (p = 0.012) at 1 year, but deteriorated from the 3(rd) year on and at the final exam reduced to 0.69 ± 0.07 (p = 0.6, compared with initial BCVA). Macular thickness mirrored visual acuity (VA) changes showing initial thinning followed by thickening from the 3(rd) year on. Individuals carrying the CFH risk -allele had a mean thickening (microns ± SEM) of 66.9 ± 70.4 versus a mean thinning of 76.8 ± 22 in non-carriers (p = 0.015).

CONCLUSIONS

Bevacizumab therapy for NVAMD using a flexible treatment algorithm in a "real life" clinical setting initially obtained VA gain and thinning of the macula that were maintained for two years, but were lost later on.

Pharmacogenomics of response to anti-VEGF therapy in exudative age-related macular degeneration

PURPOSE

To determine whether there is an association between response to intravitreal anti-vascular endothelial growth factor agents and genotype in patients with neovascular age-related macular degeneration.

METHODS

Analysis of the current literature evaluating pharmacogenetics of treatment response in patients with neovascular age-related macular degeneration.

RESULTS

Studies have demonstrated associations between various genotypes and response to intravitreal anti-vascular endothelial growth factor agents. Lower-risk genotypes of the CFH, ARMS2, HTRA1, and VEGF-A genes may be associated with improved visual outcomes. Additionally, frequency of injections may be associated with certain genotypes.

CONCLUSION

Genetic background may influence an individual's response to treatment of neovascular age-related macular degeneration. Further studies to investigate biologic pathways of neovascular age-related macular degeneration and gene products that are directly involved might lead to better understanding of contribution of various genes to treatment response.

Lutein and Factor D: two intriguing players in the field of age-related macular degeneration

Age-related macular degeneration (AMD) is a progressive eye disease that impairs central vision among elderly populations in Western, industrialized countries. In this review we will focus on the role of factor D (FD) and lutein in AMD. FD is a rate-limiting enzyme of the alternative complement activation pathway that may play an important role in the development of AMD. Several independent studies have shown a significant increase in the level of a number of complement factors of the alternative pathway, including factor D in the blood of AMD patients as compared to healthy individuals, which suggests a systemic involvement in the pathogenesis of AMD. FD, also called adipsin, is mainly produced by adipose tissue. Besides playing a role in the activation of the alternative pathway, FD is also known to regulate the immune system. Of interest is our preliminary finding that lutein supplementation of early AMD cases was shown to lower the level of systemic FD. If confirmed, these findings provide further support for the application of anti-factor D intervention as a new approach to control the development of this disease.

Genetic predictive biomarkers of anti-VEGF treatment response in patients with neovascular age-related macular degeneration

Anti-vascular endothelial growth factor (anti-VEGF) therapies for neovascular age-related macular degeneration (nAMD) have proven efficacy at a study-population level, although individual patient responses vary, with most of the patients responding well to anti-VEGF therapies, while a few respond poorly. The pathogenesis of AMD is known to have a genetic component, but it is unclear if any particular genotype can predict response to anti-VEGF therapy. With the advent of less expensive genotyping technology, there have been numerous studies within this area. Here we analyze potential biomarker candidates identified that could be used in a clinical setting to predict response to anti-VEGF treatment of nAMD. We analyze single nucleotide polymorphisms (SNPs) identified from 39 publications. The SNPs that appeared to be of most importance fell into two main groups: those previously associated with AMD pathogenesis and those within the signaling pathway targeted by anti-VEGF therapies. A number of small studies found evidence supporting an association between anti-VEGF treatment response and two SNPs, CFH rs1061170 and VEGFA rs699947, but results from randomized controlled trials found no such association. It is possible that, in the future, the cumulative effect of several high-risk SNPs may prove useful in a clinical setting and that other genetic biomarkers may emerge.