Association of Genetic Variants with Polypoidal Choroidal Vasculopathy: A Systematic Review and Updated Meta-analysis

Genetic Associations of Primary Angle-Closure Disease: A Systematic Review and Meta-Analysis

Importance

Effects of genetic variants on primary angle-closure disease remained uncertain.

Objective

To systematically review the associations of common single-nucleotide variants (SNVs) and rare coding variants with primary angle-closure disease, its subtypes (including primary angle-closure glaucoma, primary angle-closure suspect, and primary angle-closure) and progression.

Data Sources

Eligible studies from PubMed, Embase, and Web of Science were retrieved up to April 3, 2023. SNV information was extracted from eligible reports and 2 genome-wide association studies summary statistics, UK BioBank and FinnGen.

Study Selection

Studies providing analyzable genotype or allele data in a case-control design for primary angle-closure disease association and longitudinal case-only design for primary angle-closure disease progression.

Data Extraction and Synthesis

PRISMA guidelines were used for literature screening and the Newcastle Ottawa Scale for data quality assessment. Pooled effect size with 95% CIs of SNV associations were calculated using fixed- or random-effect models according to I2 statistics.

Main Outcomes and Measures

SNVs reported in 2 or more studies were meta-analyzed to generate pooled odds ratios and P values. Common and rare coding variants from single reports were summarized.

Results

Sixty-nine citations were eligible for meta-analysis on overall primary angle-closure disease, involving 206 SNVs in 64 genes or loci. Seventeen SNVs in 15 genes or loci showed associations with primary angle-closure disease, and 15 SNVs in 13 genes or loci showed associations with primary angle-closure glaucoma. Two SNVs, ABCA1 rs2422493 and ZNRF3 rs3178915, were associated only with primary angle-closure disease. Two SNVs, PCMTD1-ST18 rs1015213 and COL11A1 rs3753841, were associated with primary angle-closure suspect, and 1 SNV, MMP9 rs3918249, was associated with primary angle-closure. This systematic review and meta-analysis newly confirmed 7 genes or loci associated with primary angle-closure glaucoma: ATOH7, CALCRL, FBN1, IL6, LOXL1, MMP19, and VAV3. Common and rare coding variants in 16 genes or loci that have been associated with primary angle-closure disease were cataloged. Stratification analysis revealed different primary angle-closure disease-associated genes in different ethnic populations. Only 1 study regarding the genetic association of primary angle-closure glaucoma progression was identified.

Conclusions and Relevance

This study revealed the genetic complexity of primary angle-closure disease, involving common SNVs and rare coding variants in more than 30 genes or loci, with ethnic and phenotypic diversities. Further replication, genotype-phenotype correlation, and pathway analyses are warranted.

Macular neovascularization and polypoidal choroidal vasculopathy: phenotypic variations, pathogenic mechanisms and implications in management

Advances in imaging have led to improved ability to characterize variations in clinical sub-phenotypes of macular neovascularization (MNV) in Age-related macular degeneration (AMD). Polypoidal choroidal vasculopathy (PCV) was initially described based on characteristic features observed in indocyanine green angiography (ICGA) and was thought to be a distinct entity from AMD. However, subsequent careful observations based on confocal scanning laser ophthalmoscopy-based ICGA, optical coherence tomography (OCT) and OCT angiography have led researchers to appreciate similarities between PCV lesion and type 1 MNV in typical neovascular AMD. Concurrently, clinical trials have shown that anti-VEGF monotherapy can achieve favourable visual outcome in the majority of eyes with PCV. These learnings have led to a shift in the way PCV is managed over the past decade. Recent studies have supported the use of non-ICGA based imaging modality to screen for PCV and the adoption of anti-VEGF monotherapy as initial therapy for PCV. A focus of recent research has been in the understanding of the role of choroidal alterations in the pathogenesis of PCV. The concept of pachychoroid in leading to outer retinal ischemia has garnered increasing support. Future research in this area should evaluate the potential of choroidal morphology in guiding personalized therapy in PCV.

Clinical variations of polypoidal choroidal vasculopathy: A cohort study from Japan and the USA

We describe the clinical characteristics of treatment-naïve polypoidal choroidal vasculopathy (PCV) in three tertiary clinic settings in 2 cities (Chicago in the USA and Nishinomiya in Japan). This cohort study was a retrospective, multicenter, consecutive case series. A total of 126 patients with treatment-naïve PCV-46 in Chicago and 80 in Nishinomiya-were identified. The proportion of PCV in patients with neovascular age-related macular degeneration was lower in Chicago (10.8% vs. 36.9%). Patients in Chicago had a significantly higher prevalence of soft drusen (50.0% vs 25.0%, p = 0.006) and intra-retinal cyst (37.0% vs 15.0%, p = 0.008), and a significantly lower prevalence of pachyvessels (41.3% vs 62.5%, p = 0.03). At baseline, presenting vision for patients in Chicago was worse than in Nishinomiya (mean log MAR: 0.609 vs. 0.312, p < 0.001). Ninety-five eyes were followed for more than one year. The Nishinomiya group received a higher rate of combination therapy (61.0%) compared to the Chicago group (5.3%). Vision and central foveal thickness at month 12 were significantly improved from baseline in both Chicago (p = 0.009 and p = 0.01) and Nishinomiya groups (both p < 0.001). Our study highlights interesting differences in the proportion of PCV, clinical findings and treatment responses of PCV, that need to be further evaluated in larger, epidemiologic cohorts.

Genome-Wide Associations and Confirmatory Meta-Analyses in Diabetic Retinopathy

The present study aimed to summarize and validate the genomic association signals for diabetic retinopathy (DR), proliferative DR, and diabetic macular edema/diabetic maculopathy. A systematic search of the genome-wide association study (GWAS) catalog and PubMed/MELINE databases was conducted to curate a comprehensive list of significant GWAS discoveries. The top signals were then subjected to meta-analysis using established protocols. The results indicate the need for improved consensus among DR GWASs, highlighting the importance of validation efforts. A subsequent meta-analysis confirmed the association of two SNPs, rs4462262 (ZWINT-MRPS35P3) (odds ratio = 1.38, p = 0.001) and rs7903146 (TCF7L2) (odd ratio = 1.30, p < 0.001), with DR in independent populations, strengthening the evidence of their true association. We also compiled a list of candidate SNPs for further validation. This study highlights the importance of consistent validation and replication efforts in the field of DR genetics. The two identified gene loci warrant further functional investigation to understand their role in DR pathogenesis.

Polypoidal Choroidal Vasculopathy: Updates on Risk Factors, Diagnosis, and Treatments

There have been recent advances in basic research and clinical studies in polypoidal choroidal vasculopathy (PCV). A recent, large-scale, population-based study found systemic factors, such as male gender and smoking, were associated with PCV, and a recent systematic review reported plasma C-reactive protein, a systemic biomarker, was associated with PCV. Growing evidence points to an association between pachydrusen, recently proposed extracellular deposits associated with the thick choroid, and the risk of development of PCV. Many recent studies on diagnosis of PCV have focused on applying criteria from noninvasive multimodal retinal imaging without requirement of indocyanine green angiography. There have been attempts to develop deep learning models, a recent subset of artificial intelligence, for detecting PCV from different types of retinal imaging modality. Some of these deep learning models were found to have high performance when they were trained and tested on color retinal images with corresponding images from optical coherence tomography. The treatment of PCV is either a combination therapy using verteporfin photodynamic therapy and anti-vascular endothelial growth factor (VEGF), or anti-VEGF monotherapy, often used with a treat-and-extend regimen. New anti-VEGF agents may provide more durable treatment with similar efficacy, compared with existing anti-VEGF agents. It is not known if they can induce greater closure of polypoidal lesions, in which case, combination therapy may still be a mainstay. Recent evidence supports long-term follow-up of patients with PCV after treatment for early detection of recurrence, particularly in patients with incomplete closure of polypoidal lesions.

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.

Class II Human Leukocyte Antigen (HLA) and Susceptibility to Polypoidal Choroidal Vasculopathy in Afro-Caribbean Descent

Purpose

To evaluate how the HLA genotype is associated to the polypoidal choroidal vasculopathy (PCV) in a population of patients of Afro-Caribbean descent.

Methods

Forty-seven patients were diagnosed with PCV. The number of control patients was 457. All affected patients and control patients were of Afro-Caribbean descent and natives to Martinique. HLA typing was based on blood sample, using the polymerase chain reaction technique. Comparison of HLA alleles between the 2 groups was done using chi-2 test, odds ratio (OR) and confidence interval using Woolf’s method. The Bonferroni correction was considered significant when p-value ≤0.05. Alleles frequency was analyzed for DRB1 and DQB1 locus.

Results

HLA-DRB1*13 allele was significantly associated to PCV (OR = 2.02, CI = [1.3; 3.13], p = 0.003). In group DRB1, the Bonferroni correction significance threshold was <0.004. HLA-DQB1*04 allele was significantly associated to PCV (OR = 3.5, CI = [1.48; 8.3], p = 0.006). In group DQB1, the Bonferroni correction significance threshold was <0.006.

Conclusion

Two HLA alleles are positively associated to PCV. The possible association between PCV and certain alleles suggest HLA implication in PCV pathogeny, most likely by modeling the immune system response.

Multimodal Imaging Comparison of Polypoidal Choroidal Vasculopathy Between Asian and Caucasian Populations

PURPOSE

Differences in multimodal imaging features between Asian and Caucasian eyes may contribute to our understanding of the etiology of the polypoidal choroidal vasculopathy (PCV). The purpose of this study was to compare the multimodal imaging features of Asian and Caucasian eyes with PCV.

DESIGN

Cross-sectional, retrospective, multicenter, observational case series.

METHODS

Consecutive treatment-naïve patients diagnosed with PCV based on indocyanine green angiography in accordance with published guidelines. Demographic and multimodal imaging findings based on color fundus photography, spectral domain optical coherence tomography, fluorescein angiography, and indocyanine green angiography were graded.

RESULTS

A total of 250 participants with PCV (128 Asian vs 122 Caucasian participants) were included. Asian participants presented with lower best-corrected visual acuity (mean ± SD: 0.7 ± 0.6 logMAR vs 0.4 ± 0.3 logMAR; P < .001) compared with Caucasian participants. More Asian eyes had subretinal hemorrhage (mean ± SD: 53.9% vs 24.6%; P < .001) and larger areas of hemorrhage (mean ± SD: 7.5 ± 15.2 mm² vs 1.3 ± 3.3 mm²; P < .001). More Asian eyes had pachyvessels (84.4% vs 28.7%; P < .001), choroidal vascular hyperpermeability (70.3% vs 17.2%; P < .001), and widespread polypoidal lesions (19.5% vs 8.2%; P = .005), and Caucasian eyes had more drusen (79.5% vs 49.2%; P = .02).

CONCLUSIONS

Multimodal imaging analysis revealed ethnic differences in disease characteristics of PCV, suggesting pathophysiologic mechanism of the disease vary based on ethnicity.

Recurrence and visual prognostic factors of polypoidal choroidal vasculopathy: 5-year results

This retrospective study aimed to evaluate the factors affecting recurrence and visual prognosis in patients with treatment-naïve subfoveal polypoidal choroidal vasculopathy (PCV). Patients who had received three consecutive intravitreal injections of ranibizumab or aflibercept and had reached remission were enrolled. They were divided into a group without recurrence (group 1, 26 eyes) and a group with recurrence (group 2, 121 eyes) and followed up for at least 5 years. Patients in group 2 received additional treatment for worsening. Logistic regression analysis revealed that a young age of onset (P = 0.001), high choroidal vascularity index (CVI; P = 0.019), and presence of choroidal vascular hyperpermeability (CVH; P = 0.037) were associated with a low risk of recurrence. Multiple regression analysis revealed that recurrence (P = 0.001), greatest linear dimension (P = 0.003), and polyp configuration (single or cluster; P = 0.043) were associated with final visual acuity. Patients without recurrence had a lower age of onset and higher CVI than those with recurrence, and they tended to have CVH. In addition, patients with recurrence, large lesion, and cluster polyps had worse final visual acuity than those without these factors. CVI and CVH may be used to predict recurrence of PCV.

Genetic associations of central serous chorioretinopathy: a systematic review and meta-analysis

AIMS

To identify single-nucleotide polymorphisms (SNPs) associated with central serous chorioretinopathy (CSCR) by a systematic review and meta-analysis, and to compare the association profiles between CSCR, neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV).

METHODS

We searched the EMBASE, PubMed and Web of Science for genetic studies of CSCR from the starting dates of the databases to 12 September 2020. We then performed meta-analyses on all SNPs reported by more than two studies and calculated the pooled OR and 95% CIs. We also conducted sensitivity analysis and adopted the funnel plot to assess potential publication bias.

RESULTS

Totally 415 publications were reviewed, among them 10 were eligible for meta-analysis. We found 10 SNPs that have been reported at least twice. Meta-analysis and sensitivity analysis confirmed significant associations between CSCR and six SNPs in three genes, namely age-related maculopathy susceptibility 2 (ARMS2) (rs10490924, OR=1.37; p=0.00064), complement factor H (CFH) (rs800292, OR=1.44; p=7.80×10^-5; rs1061170, OR=1.34; p=0.0028; rs1329428, OR=1.40; p=0.012; and rs2284664, OR=1.36; p=0.0089) and tumour necrosis factor receptor superfamily, member 10a (TNFRSF10A) (rs13278062, OR=1.34; p=1.44×10^-15). Among them, only TNFRSF10A rs13278062 showed the same trend of effect on CSCR, nAMD and PCV, while the SNPs in ARMS2 and CFH showed opposite trends in the SNP associations.

CONCLUSIONS

This study confirmed the associations of ARMS2, CFH and TNFRSF10A with CSCR, and revealed that ARMS2, CFH and TNFRSF10A may affect different phenotypic expressions of CSCR, nAMD and PCV.

The Polymorphism rs2968 of LSS Gene Confers Susceptibility to Age-Related Cataract

Research showed that lanosterol can decrease protein aggregation in lens and reduce cataract formation. Lanosterol synthase (LSS) and 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) are the limiting enzymes in the process of synthesis of lanosterol. We demonstrate to investigate the association between functional single-nucleotide polymorphisms (SNPs) of LSS and HMGCR genes and age-related cataract (ARC) risks in Han Chinese population from Jiangsu Eye Study. This is a case-control study. We collected participants' venous blood for DNA genotyping and lens capsule samples for RNA. The SNPs of the genes were assayed with TaqMan RT-PCR genotyping. The quantitative RT-PCR was used to detect the LSS mRNA levels of lens epithelial cells (LECs) in individuals. The chi-square test was used to compare differences between ARC groups and controls of each SNP and to calculate the odds ratio (OR). We found that LSS-rs2968 of ARCs was different from controls (p = 0.018), but the significance was lost after Bonferroni correction (p = 0.072). We then further performed stratification analysis and found that LSS-rs2968 A allele was associated with nuclear type of ARC risk in Chinese population (p = 0.012, OR = 0.68). Consequently, we found that the mRNA expression of LSS was lower in LECs of all subtypes of ARC group than that of control group (p < 0.05). LSS-rs2968 A allele might play a role in the formation and development of nuclear type of ARC risk in Chinese population.

The spectrum of polypoidal choroidal vasculopathy in Caucasians: clinical characteristics and proposal of a classification

Purpose

To describe the clinical characteristics and outcome of polypoidal choroidal vasculopathy (PCV), also known as aneurysmal type 1 (sub-retinal pigment epithelium (RPE)) neovascularization, in Caucasian patients.

Methods

Single-centre study in 66 Caucasian patients with a diagnosis of PCV based on optical coherence tomography scan and indocyanine green angiography. Clinical characteristics and multimodal imaging were collected and assessed by an experienced retina specialist.

Results

This study involved 74 eyes of 66 patients with PCV, with a mean age at onset of 73 years and a female preponderance of 66%. The mean number of polypoidal lesions per eye was 1 (range: 1–5 lesions), out of which 75% was located in the macula and 19% in the peripapillary region. Of the 74 eyes, 37 eyes (50%) had PCV associated with a drusenoidal neovascular age-related macular degeneration (AMD) phenotype (PCV-AMD) and 18 eyes (24%) had PCV associated with non-polypoidal type 1 choroidal neovascularization/branching vascular network (PCV-BVN) without signs of drusenoidal AMD, while 19 eyes (26%) had idiopathic, isolated PCV (iPCV). The mean subfoveal choroidal thickness measured in 22 patients was 245 μm (range: 71–420 μm). In 51% of patients, the initially performed therapy showed good anatomical recovery (resolution of intra- and subretinal fluid).

Conclusions

A spectrum of PCV (aneurysmal type 1/sub-RPE neovascularization) can be seen in Caucasian patients. PCV associated with a drusenoidal neovascular AMD phenotype in Caucasians is phenotypically and presumably pathophysiologically more associated with neovascular AMD (PCV-AMD: type A PCV). However, this may not be the case for patients with PCV with non-polypoidal type 1 choroidal neovascularization or BVN and no signs of drusenoidal AMD (PCV-BVN: type B PCV), and for patients with idiopathic PCV without associated drusen or BVN (iPCV; type C PCV). Most patients have a thin choroid, even when drusen are absent. For the entire patient group, a moderate anatomical recovery was observed after treatment.

Electronic supplementary material

The online version of this article (10.1007/s00417-020-04844-z) contains supplementary material, which is available to authorized users.

Development of an automated system for the detection of genotype in polypoidal choroidal vasculopathy using retinal image phenotype

BACKGROUND AND OBJECTIVES

Polypoidal choroidal vasculopathy (PCV) is a retinal disorder characterized by the presence of aneurismal polypoidal lesions in the choroidal vasculature. A single nucleotide polymorphism (SNP) is a common genetic variant which may be associated with the disease. This study is to investigate the association of HERPUD1 (rs2217332) gene with PCV in the Indian population and develop an automated system for genotype and phenotype correlation using fundus images and machine learning methods.

METHODS

A cohort of 54 PCV patients and 120 control subjects were recruited for the study. Genotyping of SNP (HERPUD1, rs2217332) was performed by following polymerase chain reaction and direct sequencing method. Statistical association of SNP to PCV was determined using chi-square analysis. The acquired GG and AG images were preprocessed using an adaptive histogram. 19 and 18 texture features were extracted from the images in the PCV naïve cases and PCV patients on treatment, respectively. Student's independent t-test was then employed for the selection of significant features, which were input to the ensemble tree for automated classification. Leave-one-out validation was used to evaluate the system.

RESULTS

HERPUD1 rs2217332 SNP is significantly associated in PCV patients compared to control (P = 0.0296, odds ratio [OD] = 2.297, 95% confidence interval [CI] = 1.087-4.856) in the Indian population. High F1 and precision values of 85.71%, 86.84% and 85.71%, 93.75% were achieved in the pre and post- treatment phases, respectively.

CONCLUSION

Our results suggest that the HERPUD1 polymorphism is associated in PCV patients. Based on our analysis, it may be possible to predict the genotype and disease status of PCV patients using fundus images in assistance with a machine learning algorithm.

The association of polypoidal choroidal vasculopathy clinical phenotypes with previously reported genetic markers

PURPOSE

Genetic studies have identified the association of some single-nucleotide polymorphisms (SNPs) with polypoidal choroidal vasculopathy (PCV), but little is known about whether these SNPs are related to PCV clinical features as well. We performed this study to examine the association of 12 SNPs with PCV clinical phenotypes.

METHODS

Sixty-nine PCV eyes of 69 patients were included. Genomic DNA was extracted from peripheral blood. Agilent SureSelect Human ALL Exon V6 was used to sequence the 12 SNPs previously reported to associate with PCV. Baseline best-corrected visual acuity (BCVA), sub-foveal choroidal thickness (SFCT), choroid maximum vascular diameter (MVD), choroidal vascular hyperpermeability (CVH), and greatest linear dimension (GLD) of entire lesion were measured and compared between patients of different genotypes. Fisher's exact test and Mann-Whitney U test were mainly used to compare categorical variables and continuous variables respectively.

RESULTS

HTRA1 rs2293870 was a protective factor of PCV or AMD in the fellow eye (P = 0.040) and was related with greater SFCT in PCV eye after multiple linear regression (P = 0.043). C3 rs17030 was associated with smaller GLD (P = 0.033). CFH rs2274700 was related to lower MVD (P = 0.043) and was a protective factor for CVH (P = 0.034).

CONCLUSION

Multiple PCV-associated SNPs are associated with PCV clinical phenotypes. The involvement of several synonymous SNPs calls for further research on the role of transcriptional alterations and trans-regulation of distant signaling pathways in PCV pathogenesis.

Identification of TIE2 as a susceptibility gene for neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

PURPOSE

The endothelial and cell-specific angiopoietin-Tie pathway plays an important regulatory role in angiogenesis. In this study, we investigated the associations of the TIE2 (tyrosine kinase, endothelial, TEK) gene with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV), using haplotype-tagging single-nucleotide polymorphisms (SNPs) analysis.

METHODS

This study involved totally 2343 subjects, including a Hong Kong Chinese cohort (214 nAMD patients, 236 PCV patients and 433 control subjects), a Shantou Chinese cohort (189 nAMD patients, 187 PCV patients and 531 control subjects) and an Osaka Japanese cohort (192 nAMD patients, 204 PCV patients and 157 control subjects). Thirty haplotype-tagging SNPs in TIE2 were genotyped in the Hong Kong cohort using TaqMan technology. Two SNPs (rs625767 and rs2273717) showing association in the Hong Kong cohort were genotyped in the Shantou and Osaka cohorts. The SNP-disease association of individual and pooled cohorts were analysed.

RESULTS

Two SNPs (rs625767 and rs2273717) showed suggestive association with both nAMD and PCV in the Hong Kong cohort. In the meta-analysis involving all the three cohorts, rs625767 showed significant associations with nAMD (p=0.01; OR=0.82, 95% CI 0.70 to 0.96; I²=0%), PCV (p=0.02; OR=0.83, 95% CI 0.71 to 0.97; I²=27%) and pooled nAMD and PCV (p=0.002; OR=0.82, 95% CI 0.72 to 0.93; I²=0%), with low inter-cohort heterogeneities.

CONCLUSION

This study revealed TIE2 as a novel susceptibility gene for nAMD and PCV in Japanese and Chinese. Further studies in other populations are warranted to confirm its role.

Genetic Association of Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) are leading causes of irreversible blindness among the elderly population in developed countries. Although being considered as different subtypes of a same disease, neovascular AMD and PCV have differences in clinical, epidemiological, therapeutic, and genetic profiles. Both AMD and PCV are complex diseases involving multiple genetic and environmental risk factors. Different genetic strategies have been adopted to discover associated genes and variants for neovascular AMD and PCV, including genome-wide association study (GWAS), next-generation sequencing (NGS) based sequence analysis, and candidate gene analyses. So far, a number of susceptible genes have been identified for AMD and/or PCV, such as CFH, ARMS2-HTRA1, C2-CFB-SKIV2L, C3, CETP, and FGD6. Although many of these genes are shared by AMD and PCV, some showed difference between them, such as ARMS2-HTRA1 and FGD6. Also, some of the genes showed ethnic diversities, such as the CFH p.Tyr402His variant. Further larger-scale genomic studies should be warranted to identify more susceptibility genes for AMD and, in particular, PCV among different populations, and differentiate the genetic architectures between neovascular AMD and PCV.

Evaluation of the association of C5 with neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

Background

Neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) are sight-threatening maculopathies with both environmental and genetic risk factors. We have previously shown relative risks posed by genes of the complement pathways to neovascular AMD and PCV.

Methods

In this study, we investigated the haplotype-tagging single nucleotide polymorphisms (SNPs) in the complement component 5 (C5) gene in 708 unrelated Chinese individuals: 200 neovascular AMD patients, 233 PCV patients and 275 controls. Six tagging SNPs in C5 were genotyped. Univariate single SNP association analysis, haplotype-based association analysis and gene-gene interaction analysis between C5 and other AMD-associated genes were performed.

Results

The results revealed none of the six tagging SNPs of the C5 gene had a significant association with neovascular AMD or PCV (P > 0.05). We also found insignificant haplotype-based association, and no significant SNP-SNP interaction between C5 and other genes (including C2-CFB-RDBP-SKIV2L, SERPING1, CETP, ABCG1, PGF, ANGPT2, CFH and HTRA1) for neovascular AMD and PCV.

Conclusions

This study showed no statistical significance in the genetic association of C5 with neovascular AMD or PCV in a Hong Kong Chinese population. Further studies in large samples from different populations are warranted to elucidate the role of C5 in the genetic susceptibility of AMD and PCV.

PREVALENCE OF POLYPOIDAL CHOROIDAL VASCULOPATHY IN WHITE PATIENTS WITH EXUDATIVE AGE-RELATED MACULAR DEGENERATION: Systematic Review and Meta-Analysis

PURPOSE

Polypoidal choroidal vasculopathy (PCV) is a disease with significant inter-ethnical differences. In this study, we systematically review the literature on the prevalence of PCV in whites referred with a diagnosis of exudative age-related macular degeneration (AMD).

METHODS

We searched PubMed, Embase, the Cochrane Library, and the Web of Science on 24 March, 2017 for studies evaluating the prevalence of PCV in white patients with exudative AMD. Data extraction and risk of bias assessments were performed in duplicate. Studies were included for a qualitative review and a meta-analysis, including subgroup analysis for differences in age and sex.

RESULTS

We included data from 11 studies (>2,200 participants). For diagnosis, indocyanine green angiography was used together with a set of supporting criteria on fundus examination and optical coherence tomography. Extramacular location was more prevalent in eyes with PCV. Drusen was present in the fellow eye in 17% to 27%. Pooled prevalence of PCV in white patients with exudative AMD was 8.7% (confidence interval 95%: 7.2%-10.3%). Patients with PCV were 3.7 years (confidence interval 95%: 2.1 years-5.3 years) younger than those with other exudative AMD. Sex did not differ significantly.

CONCLUSION

Polypoidal choroidal vasculopathy is not a rare subtype of exudative AMD in whites-it is present in approximately one in 11 patients.

Choroidal binarization analysis: clinical application

INTRODUCTION

Image processing of optical coherence tomography scans through binarization techniques represent a non-invasive way to separately asses and measure choroidal components, in vivo. In this review, we systematically search the scientific literature regarding binarization studies published so far.

METHODS

A systematic research was conducted at PubMed database, including English literature articles for all of the following terms in various combinations: binarization, choroid/al, enhanced depth spectral domain/swept source optic coherence tomography, and latest publications up to November 2018 were reviewed.

RESULTS

Thirty-seven articles were included and analyzed regarding studied disease, binarization method, studied variables, and outcomes. Most of the studies have focused on the more common retinal pathologies, such as age-related macular degeneration, central serous chorioretinopathy and diabetic retinopathy but binarization techniques have also been applied to the study of choroidal characteristics in ocular inflammatory diseases, corneal dystrophies and in postsurgical follow-up. Advantages and disadvantages of binarization techniques are also discussed.

CONCLUSION

Binarization of choroidal images seems to represent a promising approach to study choroid subcomponents in an increasingly detailed manner.

Age-Related Scattered Hypofluorescent Spots on Late-Phase Indocyanine Green Angiography as Precursor Lesions of Polypoidal Choroidal Vasculopathy

Purpose

Age-related scattered hypofluorescent spots on late-phase indocyanine green angiography (ASHS-LIA) might represent lipid accumulation in Bruch's membrane in the form of basal linear deposits (BlinD). The present study was conducted to describe the clinical characteristics of polypoidal choroidal vasculopathy (PCV) associated with ASHS-LIA.

Methods

Consecutive patients with treatment-naïve PCV who underwent color fundus photography (FP), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and spectral-domain optical coherence tomography (SD-OCT) at the Zhongshan Ophthalmic Center from June 2016 through May 2018, were reviewed. ASHS-LIA and choroidal vascular hyperpermeability (CVH) were evaluated by ICGA. Subfoveal choroidal thickness (SFCT) was assessed by SD-OCT.

Results

A total of 187 patients were eligible for inclusion in this study (mean, 63.2 ± 7.6 years; range, 41-85 years). Of these patients, 117 (62.6%) showed ASHS-LIA, 57 (30.5%) had bilateral lesions and 70 (37.4%) showed CVH. Moreover, compared with patients without ASHS-LIA, PCV patients with ASHS-LIA were older (P = 0.001), more frequently had bilateral lesions (P = 0.001), and less frequently showed CVH (P = 0.006). SFCT in eyes with ASHS-LIA was significantly greater than that in eyes without ASHS-LIA after adjusting for age, sex, and CVH (P = 0.026). Nevertheless, there was no significant difference in best-corrected visual acuity or lesion characteristics between the two groups.

Conclusions

ASHS-LIA, which is very common in PCV patients, might be involved in the pathogenesis of PCV. PCV with ASHS-LIA was more frequently associated with bilateral involvement, less CVH, and a thicker choroid than PCV without ASHS-LIA.

Age-related differences in the prevalence of subtypes of Neovascular age-related macular degeneration in the first diagnosed eye

PURPOSE

To evaluate age-related differences in the prevalence of subtypes of neovascular age-related macular degeneration (AMD) in the first diagnosed eye.

METHODS

This retrospective, observational study included 1099 eyes of 1099 patients diagnosed with neovascular AMD. The neovascular AMD cases were classified into three subtypes: typical neovascular AMD, polypoidal choroidal vasculopathy (PCV), and type 3 neovascularization. The patients were divided into four groups, according to age: > 50 and < 60 years, ≥ 60 and < 70 years, ≥ 70 and < 80 years, and ≥ 80 years. Difference in the prevalence of three AMD subtypes was evaluated among the four age groups.

RESULTS

In the age group > 50 and < 60 years, 34 (25.0%) and 102 patients (75.0%) were diagnosed with typical neovascular AMD and PCV, respectively. In the age group ≥ 60 and < 70 years, 90 (28.1%), 206 (64.4%), and 24 patients (7.5%) were diagnosed with typical neovascular AMD, PCV, and type 3 neovascularization, respectively. In the age group ≥ 70 and < 80 years, the corresponding numbers were 200 (41.9%), 197 (41.3%), and 80 (16.8%), respectively; in the age group ≥80 years, the corresponding values were 83 (50.0%), 39 (23.5%), and 44 (26.5%), respectively. A significant difference was observed in the prevalence of the subtypes of neovascular AMD among the four age groups (chi-square test, P < 0.001).

CONCLUSION

Subtype prevalence in newly diagnosed neovascular AMD differs significantly according to age. This result suggests that different pathophysiology may be involved in the development of different subtypes of neovascular AMD.

Polypoidal choroidal vasculopathy: An update on current management and review of literature

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular age-related macular degeneration (nAMD), commonly seen in the Asian population. It is dissimilar in epidemiology, genetic heterogeneity, pathogenesis, natural history, and response to treatment in comparison to nAMD. Confocal scanning laser ophthalmoscopy-based simultaneous fluorescein angiography and indocyanine green angiography, spectral-domain optical coherence tomography (OCT) with enhanced depth imaging, swept-source OCT, and OCT angiography have improved the ability to detect PCV, understand its pathology, and monitor treatment response. A plethora of literature has discussed the efficacy of photodynamic therapy, anti-vascular endothelial growth factor (VEGF) monotherapy, and combination of both, but only a few studies with higher level of evidence and limited follow-up duration are available. This review discusses the understanding of PCV with respect to epidemiology, pathogenesis, clinical features, natural history, imaging techniques, and various treatment options. Recent clinical trials (EVEREST-II and PLANET study) have emphasized that either anti-VEGF monotherapy or combination treatment is equally capable to strike a balance between polyp regression and stabilization of visual acuity. The recurrent nature of the disease, the development of macular atrophy, and the long-term poor visual prognosis despite treatment are concerns that open avenues for further research.

Efficacy and safety of ranibizumab monotherapy versus ranibizumab in combination with verteporfin photodynamic therapy in patients with polypoidal choroidal vasculopathy: 12-month outcomes in the Japanese cohort of EVEREST II study

Purpose

To compare the efficacy and safety of ranibizumab 0.5 mg with or without verteporfin photodynamic therapy in Japanese patients with polypoidal choroidal vasculopathy over 12 months.

Study design

EVEREST II was a 24-month, Phase IV, multicenter, randomized, double-masked study in Asian patients with symptomatic macular polypoidal choroidal vasculopathy.

Methods

Of the 322 enrolled patients, 84 patients, including 46 patients who received ranibizumab + verteporfin photodynamic therapy (combination therapy arm) and 38 patients who received ranibizumab/sham PDT (monotherapy arm), were Japanese who were evaluated in this subanalysis. Mean change in best-corrected visual acuity (BCVA) and complete polyp regression at Month 12, ranibizumab treatment exposure, and safety over 12 months were assessed.

Results

Baseline demographics were well balanced between the arms. At Month 12, mean change in BCVA letter score was +8.5 with combination therapy versus +6.4 with monotherapy. Complete polyp regression was higher with combination therapy than with monotherapy at Month 12 (70.5% vs 27.3%). Over 12 months, patients in the combination arm received a median of 4.0 ranibizumab injections vs 7.0 in the monotherapy arm. Serious adverse events were generally low in both arms, and retinal hemorrhage, an adverse event, was reported in one patient (2.2%).

Conclusion

The results from the Japanese cohort were in agreement with the EVEREST II study. Combination therapy was effective in improving BCVA and achieving a higher rate of complete polyp regression with a lower number of ranibizumab injections than monotherapy. No new safety signals were reported, and safety events were comparable between both arms over 12 months.

Clinical outcomes in Caucasian patients with polypoidal choroidal vasculopathy

PURPOSE

To describe treatment outcomes in a cohort of Caucasian patients with polypoidal choroidal vasculopathy (PCV).

METHODS

Clinical charts from 48 eyes of 45 Caucasian patients with PCV were retrospectively reviewed. All cases were diagnosed with indocyanine green angiography. Best corrected visual acuity (BCVA) and optical coherence tomography (OCT) imaging were analyzed at baseline and final follow-up.

RESULTS

Eyes were treated with a combination of verteporfin photodynamic therapy (PDT) and anti-vascular endothelial growth factor (VEGF) (n = 24), or PDT monotherapy (n = 9), or anti-VEGF monotherapy (n = 8), or no treatment (n = 7). Aflibercept was the anti-VEGF agent in 30 out of 32 eyes. Sixteen out of 24 eyes in the combination treatment group received initial PDT at diagnosis. All treatments led to stabilization of BCVA at final visit with a trend for better visual acuity in the anti-VEGF monotherapy group. There was a substantial reduction in central retinal thickness associated with resolution of subfoveal fluid and improvement in retinal pigment epithelial detachment in all treatment groups. BCVA and OCT findings remained stable in eyes which received no treatment. The use of PDT was associated with 0.5 fewer intravitreal injections per annum, which was not statistically significant.

CONCLUSIONS

In the largest series of Caucasian patients with PCV presented to date, anti-VEGF monotherapy, PDT, or their combination preserved visual acuity and improved subfoveal exudative changes. Combination treatment was not superior to anti-VEGF monotherapy.

Understanding aneurysmal type 1 neovascularization (polypoidal choroidal vasculopathy): a lesson in the taxonomy of 'expanded spectra' - a review

The term aneurysmal type 1 neovascularization is derived from terminology, which is established in the literature but has fallen out of use. We believe that aneurysmal type 1 neovascularization accurately describes the lesions which define the entity known as polypoidal choroidal vasculopathy (PCV). Over the last three decades, the clinical spectrum of PCV has expanded to recognize the occurrence of the aneurysmal (polypoidal) lesions in different contexts, resulting in a complex and unwieldy taxonomy based sometimes on circumstantial findings rather than mechanistic considerations. Advances in multimodal imaging provides increasingly convincing evidence that the lesions which define various forms of PCV are indeed vascular and arise from type 1 neovascular networks. The understanding of PCV as type 1 neovascularization with aneurysms renews focus on the question as to why some patients with type 1 neovascularization develop aneurysms while others do not. Conceptual themes and potential for further study are discussed.

Type 2 choroidal neovascularisation in polypoidal choroidal vasculopathy: a retrospective case series

BACKGROUND AND OBJECTIVE

To demonstrate the coexistence of polypoidal choroidal vasculopathy (PCV) with type 2 neovascularisation (NV), we used multimodal imaging, including spectral-domain optical coherence tomography angiography (SD-OCTA), to identify both types of lesions in the same eye.

STUDY DESIGN

This retrospective case series reviewed patients with PCV diagnosed with indocyanine green angiography (ICGA), fluorescein angiography (FA), SD-OCT and SD-OCTA.

RESULTS

15 eyes of 14 patients were imaged and diagnosed with PCV by ICGA. ICGA identified polyps in all these eyes, while SD-OCTA imaging identified polypoidal lesions in only 11 (73%) of these eyes with PCV. Branching vascular networks (BVNs) were detected in 12 eyes (80%) by ICGA and SD-OCTA. Type 2 NV was detected in four eyes (27%) by FA and SD-OCTA. In these eyes, a combination of polyps, BVNs and type 2 NV were detected using FA, ICGA and SD-OCTA.

CONCLUSION

BVN and type 2 NV can coexist in the same PCV eye and communicate with each other. This suggests that polyps may represent a structural variant of neovascular tissue rather than a distinct pathogenic process in NV.

Genes and genetics in eye diseases: a genomic medicine approach for investigating hereditary and inflammatory ocular disorders

Past 25y have witnessed an exponential increase in knowledge and understanding of ocular diseases and their respective genetic underpinnings. As a result, scientists have mapped many genes and their variants that can influence vision and health of our eyes. Based on these findings, it is becoming clear that an early diagnosis employing genetic testing can help evaluate patients' conditions for instituting treatment plan(s) and follow-up care to avoid vision complications later. For example, knowing family history becomes crucial for inherited eye diseases as it can benefit members in family who may have similar eye diseases or predispositions. Therefore, gathering information from an elaborate examination along with complete assessment of past medical illness by ophthalmologists followed by consultation with geneticists can help create a roadmap for making diagnosis and treatment precise and beneficial. In this review, we present an update on ocular genomic medicine that we believe has tremendous potential towards unraveling genetic implications in ocular diseases and patients' susceptibilities. We also discuss translational aspects of genetic ophthalmology and genome engineering that may help advance molecular diagnostics and therapeutics.

Association of ARMS2 genotype with response to anti-vascular endothelial growth factor treatment in polypoidal choroidal vasculopathy

BACKGROUND

To investigate whether genetic risk variants for age-related macular degeneration (AMD) are associated with response to intravitreal anti-vascular endothelial growth factor (VEGF) in polypoidal choroidal vasculopathy (PCV) patients.

METHODS

This prospective cohort study included 95 treatment-naïve patients that underwent anti-VEGF treatment for PCV for 12 months. Patients were genotyped for 10 single nucleotide polymorphisms in eight AMD-relevant genes. Genotypic association with visual and anatomic outcome measures at 12 months after initial treatment, including mean change in best-corrected visual acuity (BCVA) and total foveal thickness, visual gain of ≥ 15 letters, dry status on optical coherence tomography (OCT), pigment epithelial detachment (PED) regression on OCT, polyp regression on indocyanine green angiography, and injection numbers, were investigated using regression models with adjustment for non-genetic covariates under additive genetic model.

RESULTS

In 81 patients who completed 12-month anti-VEGF monotherapy without photodynamic therapy, significant pharmacogenetic association was found between ARMS2 rs10490924 and PED regression on OCT. Proportions of PED regression were 26.4% for TT, 45.7% for TG, and 63.6% for GG genotype, showing additive effect of G allele for higher chance of PED regression (OR, 2.96; 95% CI, 1.38-6.36; corrected P = 0.043). For entire 95 patients, no significant association was found between candidate polymorphisms and receiving photodynamic therapy within 12 months.

CONCLUSIONS

In PCV patients, ARMS2 rs10490924 showed association with anatomic therapeutic response to anti-VEGF, suggesting pharmacogenetic relationship.

T-cell differentiation and CD56+ levels in polypoidal choroidal vasculopathy and neovascular age-related macular degeneration

Polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (AMD) are prevalent age-related diseases characterized by exudative changes in the macula. Although they share anatomical and clinical similarities, they are also distinctly characterized by their own features, e.g. vascular abnormalities in PCV and drusen-mediated progression in neovascular AMD. PCV remains etiologically uncharacterized, and ongoing discussion is whether PCV and neovascular AMD share the same etiology or constitute two substantially different diseases. In this study, we investigated T-cell differentiation and aging profile in human patients with PCV, patients with neovascular AMD, and age-matched healthy control individuals. Fresh venous blood was prepared for flow cytometry to investigate CD4⁺ and CD8⁺ T-cell differentiation (naïve, central memory, effector memory, effector memory CD45ra⁺), loss of differentiation markers CD27 and CD28, and expression of aging marker CD56. Patients with PCV were similar to the healthy controls in all aspects. In patients with neovascular AMD we found significantly accelerated T-cell differentiation (more CD28^-CD27^- cells) and aging (more CD56⁺ cells) in the CD8⁺ T-cell compartment. These findings suggest that PCV and neovascular AMD are etiologically different in terms of T cell immunity, and that neovascular AMD is associated with T-cell immunosenescence.

Genome-wide association study of neovascular age-related macular degeneration in the Thai population

We performed a genome-wide association study on 377 cases of neovascular age-related macular degeneration (AMD) and 1074 controls to determine the association of previously reported genetic variants associated with neovascular AMD in the Thai population. All patients were of Thai ancestry. We confirmed the association of age-related maculopathy susceptibility 2 (ARMS2) rs10490924 (P=7.38 × 10-17), HTRA1 rs11200638 (P=5.47 × 10-17) and complement factor H gene (CFH) rs800292 (P=2.53 × 10-8) with neovascular AMD, all loci passing the genome-wide significance level (P<5.22 × 10-8). We also found association of the previously reported CFH rs10737680 (P=1.76 × 10-6) locus in the discovery sample. Two loci not previously reported to be associated with neovascular AMD were selected for replication in 222 cases and 623 controls. The loci included LINCO1317 rs6733379 and rs2384550 on chromosome 12. LINCO1317 rs6733379 (P=3.85 × 10-2) remained significantly associated with neovascular AMD after replication. In conclusion, we confirm that ARMS2, HTRA1 and CFH variants are associated with neovascular AMD in the Thai population. Findings from this study also suggest that variants contributing to the susceptibility of neovascular AMD in the Thai population are mostly similar to other Asians with additional local genetic risks that may specifically be identified in Thai population.

Protocol for a randomised, double-masked, sham-controlled phase 4 study on the efficacy, safety and tolerability of intravitreal aflibercept monotherapy compared with aflibercept with adjunctive photodynamic therapy in polypoidal choroidal vasculopathy: the ATLANTIC study

PURPOSE

The purpose of this study is to compare the efficacy and safety of intravitreal aflibercept (IVA) with sham photodynamic therapy (sPDT) versus IVA with verteporfin PDT (vPDT) in a Caucasian population with treatment-naive polypoidal choroidal vasculopathy (PCV), enrolling into a treat and extend (T&E) regimen.

METHODS AND ANALYSIS

Randomised, double-masked, sham-controlled, multicentre phase 4 investigator-driven clinical trial. The primary outcomes are (1) change in best-corrected visual acuity (BCVA) from baseline and (2) polyp regression at week 52, assessed by indocyanine green angiography (ICGA). Fifty patients with treatment-naive PCV will be recruited from Portuguese and Spanish clinical sites. Eligible patients will receive monthly IVA for 3 months (week 0, week 4 and week 8). At week 16, all patients will repeat ICGA and undergo central randomisation (1:1 ratio) into one of the following groups: Group 1-IVA T&E + vPDT; Group 2-IVA T&E + sPDT. PDT will be performed at week 16, week 28 and week 40 in the presence of active polyps. After week 16, the presence of macular fluid on optical coherence tomography will determine the schedule of observations. When present, the interval between visits/injections will decrease 2 weeks (minimum 6 weeks). When not, the interval between visits/injections will increase 2 weeks (maximum 12 weeks). Efficacy will be evaluated based on BCVA, central retinal thickness and polyp regression. Safety parameters will include assessment of intraocular pressure, adverse events and serious adverse events.

ETHICS AND DISSEMINATION

This study was designed and shall be implemented and reported in accordance with the International Conference on Harmonisation (ICH) Harmonised Tripartite Guidelines for Good Clinical Practice, with applicable local regulations and with the ethical principles laid down in the Declaration of Helsinki. The study received approval from Comissão de Ética para a Investigação Clínica and Comité Ético de investigación Clínica del Hospital Universitari de Bellvitge.

TRIAL REGISTRATION NUMBER

This study is registered under the EudraCT number: 2015-001368-20 and the ClinicalTrials.gov Identifier: NCT02495181.

Shared genetic variants for polypoidal choroidal vasculopathy and typical neovascular age-related macular degeneration in East Asians

Polypoidal choroidal vasculopathy (PCV), a subtype of age-related macular degeneration (AMD) more frequently seen in East Asians, has both common and distinct clinical manifestations with typical neovascular AMD (tAMD). We aim to examine the extent to which common genetic variants are shared between these two subtypes. We performed the meta-analysis of association in a total of 1062 PCV patients, 1157 tAMD patients and 5275 controls of East Asian descent from the Genetics of AMD in Asians Consortium at the 34 known AMD loci. A total of eight loci were significantly associated with PCV, including age-related maculopathy susceptibility 2 (ARMS2)-HtrA serine peptidase 1 (HTRA1), complement factor H (CFH), C2-CFB-SKIV2L, CETP, VEGFA, ADAMTS9-AS2 and TGFBR1 (P<5 × 10^-4) from the single-nucleotide polymorphism-based test and COL4A3 from the gene-based tests (P_gene=2.02 × 10^-4). PCV and tAMD are genetically highly correlated (r_g=0.69, P=4.68 × 10^-3), with AMD known loci accounting for up to 36% variation. Weaker association for PCV was observed at ARMS2-HTRA1 (P_dif=4.39 × 10^-4) and KMT2E-SRPK2(P_dif=4.43 × 10^-3), compared with tAMD. Variants at CFH, CETP and VEGFA exhibited different association signals in East Asians, in contrast to those in European individuals. Our data suggest a substantially shared genetic susceptibility for PCV and tAMD, while also highlight the unique associations for PCV, which is useful in understanding the pathogenesis of PCV.

Association of WDR36 polymorphisms with primary open angle glaucoma: A systematic review and meta-analysis

BACKGROUND

The association of the WDR36 gene with glaucoma has been controversial in the literature. We therefore conducted a systematic review and meta-analysis to assess the association of all reported common polymorphisms in WDR36 with primary open angle glaucoma (POAG) and its subtypes: high tension glaucoma (HTG) and normal tension glaucoma (NTG).

METHODS

Publications in PUBMED and EMBASE databases up to March 9, 2016 were searched for case-control association studies of WDR36 with POAG, HTG, and/or NTG. Reported studies giving adequate genotype and/or allele information were included. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) of individual polymorphisms were estimated using the allelic model.

RESULTS

Our literature search yielded 122 records, among which 5 studies were eligible for meta-analysis, involving a total of 1352 POAG patients and 894 controls. Five WDR36 polymorphisms were meta-analyzed, rs11241095, rs10038177, rs17553936, rs13186912, and rs13153937. However, none of them was significantly associated with POAG, HTG, or NTG. The most-investigated polymorphisms, rs11241095 and rs10038177, had a pooled-OR of 1.09 (95% CI: 0.94-1.28, P = .25, I = 0) and 0.99 (95% CI: 0.71-1.39, P = .97, I = 77%), respectively, for POAG.

CONCLUSION

The existing data in the literature do not support a significant role of WDR36 in the genetic susceptibility of POAG or its subtypes. Further replication studies in specific populations are warranted.

Polypoidal Choroidal Vasculopathy

PURPOSE OF REVIEW

The goal of this paper is to review the recent literature of polypoidal choroidal vasculopathy (PCV) and provide an update on the epidemiology, pathophysiology, clinical findings, and management.

RECENT FINDINGS

Although indocyanine-green angiography (ICGA) is still the gold standard for diagnosis of PCV, the use of en face optical coherence tomography (OCT) and OCT angiography are useful tools in the diagnosis of PCV. Studies demonstrate superior treatment outcomes with combination photodynamic therapy (PDT) and anti-vascular endothelial growth factor (VEGF) therapy.

SUMMARY

PCV is a disease most commonly in Asians and African-Americans and presents with an orange-red nodule in the macula or the peripapillary region. While ICGA remains the most accurate method to diagnose PCV, newer non-invasive imaging modalities (eg. OCT-A and en face OCT) can be used to identify PCV lesions. The combination of PDT and anti-VEGF therapy is superior to either monotherapy. Future studies of OCT modalities and other anti-VEGF agents will be important in guiding PCV diagnosis and management, respectively.

Choroidal structures in polypoidal choroidal vasculopathy, neovascular age-related maculopathy, and healthy eyes determined by binarization of swept source optical coherence tomographic images

PURPOSE

To evaluate quantitatively the choroidal vascularity in polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (AMD) patients compared to healthy controls.

METHODS

All eyes underwent swept source optical coherence tomography (OCT), and choroidal images were binarized into blood vessels lumen and stroma. The choroidal vascular index (CVI) was defined as the ratio of luminal area (LA) over total choroidal area of the subfoveal region with a width of 1500 μm.

RESULTS

The study included 73 patients with neovascular AMD or PCV with mean ± standard deviation (SD) age of 71.8 ± 9.3 years, which was older than the mean age of 65.1 ± 10.8 years of 72 healthy eyes from control group (p < 0.01). The 44 PCV eyes had significantly higher mean SFCT of 214.23 ± 95.21 μm than neovascular AMD eyes (172.74 ± 96.48 μm, p = 0.03) and greater luminal area (0.23 ± 0.09 mm² vs. 0.19 ± 0.08 mm², p = 0.05). After adjusting for age, axial length, and gender in multivariate regression analysis, the SFCT of PCV and neovascular AMD eyes were not significantly different from healthy eyes (195.55 ± 93.11 μm), but the CVI of both PCV (64.94 ± 5.43%, p = 0.01) and neovascular AMD (62.54 ± 5.57%, p = <0.01) were significantly lower than control (68.53 ± 5.91%).

CONCLUSION

Despite physiological changes of choroidal vasculature due to aging, the choroidal morphology is different in PCV, neovascular AMD and healthy eyes, which has implication on disease pathogenesis.

Age-related macular degeneration and polypoidal choroidal vasculopathy in Asians

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in elderly people globally. It is estimated that there will be more Asians with AMD than the rest of the world combined by 2050. In Asian populations, polypoidal choroidal vasculopathy (PCV) is a common subtype of exudative AMD, while choroidal neovascularization secondary to AMD (CNV-AMD) is the typical subtype in Western populations. The two subtypes share many common clinical features and risk factors, but also have different epidemiological and clinical characteristics, natural history and treatment outcomes that point to distinct pathophysiological processes. Recent research in the fields of genetics, proteomics and imaging has provided further clarification of differences between PCV and CNV-AMD. Importantly, these differences have manifested as disparity in response to intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) treatment between PCV and CNV-AMD, emphasizing the need for accurate diagnosis of PCV and in distinguishing PCV from CNV-AMD, particularly in Asian patients. Current clinical trials of intravitreal anti-VEGF therapy and photodynamic therapy will provide clearer perspectives of evidence-based management of PCV and may lead to paradigm shifts in therapeutic strategies away from those currently employed in the treatment of CNV-AMD. Further research is needed to clarify the relative contribution of specific pathways in inflammation, complement activation, extracellular matrix dysregulation, lipid metabolism and angiogenesis to the pathogenesis of PCV. Findings from this research, together with improved diagnostic technology and new therapeutics, will facilitate more optimal management of Asian AMD.

Genetic Associations of Primary Angle-Closure Disease: A Systematic Review and Meta-analysis

TOPIC

Systematic review and meta-analysis of the genetic associations of primary angle-closure disease (PACD).

CLINICAL RELEVANCE

To confirm the genetic biomarkers for PACD, including primary angle-closure glaucoma (PACG) and related phenotypes.

METHODS

We searched in the MEDLINE and EMBASE databases for genetic studies of PACG or other PACD published from the start dates of the databases to May 11, 2015. We estimated the summary odds ratios (ORs) and 95% confidence intervals (CIs) for each polymorphism in PACG, primary angle-closure suspect (PACS), and primary angle-closure (PAC) using fixed- or random-effect models. We also performed sensitivity analysis to test the robustness of the results.

RESULTS

Our literature search yielded 6463 reports. Among them, we identified 24 studies that fulfilled the eligibility criteria for meta-analysis, involving 28 polymorphisms in 11 genes/loci. We affirmed the association of PACG and combined PACS/PAC/PACG with 10 polymorphisms in 8 genes/loci, including COL11A1 (rs3753841-G, OR, 1.22; P = 0.00046), HGF (rs17427817-C, OR, 2.02; P = 6.9E-07; rs5745718-A, OR, 2.11; P = 9.9E-07), HSP70 (rs1043618, GG+GC, OR, 0.52; P = 0.0010), MFRP (rs2510143-C, OR, 0.66; P = 0.012; rs3814762-G, OR, 1.40; P = 0.0090), MMP9 (rs3918249-C, OR, 1.35; P = 0.034), NOS3 (rs7830-A, OR, 0.80; P = 0.036), PLEKHA7 (rs11024102-G, OR, 1.24; P = 8.3E-05), and PCMTD1-ST18 (rs1015213-A, OR, 1.59; P = 0.00013). Sensitivity analysis indicated that the results were robust.

CONCLUSIONS

In this study, we confirmed multiple polymorphisms in 8 genes/loci as genetic biomarkers for PACD, among which 3 were identified in a genome-wide association study (COL11A1, PLEKHA7, and PCMTD1-ST18), and 5 were identified in candidate gene studies (HGF, HSP70, MFRP, MMP9, and NOS3).

Association of toll-like receptor 3 polymorphism rs3775291 with age-related macular degeneration: a systematic review and meta-analysis

Association of a polymorphism rs3775291 in the toll-like receptor 3 (TLR3) gene with age-related macular degeneration (AMD) had been investigated intensively, with variable results across studies. Here we conducted a meta-analysis to verify the effect of rs3775291 on AMD. We searched for genetic association studies published in PubMed, EMBASE and Web of Science from start dates to March 10, 2015. Totally 235 reports were retrieved and 9 studies were included for meta-analysis, involving 7400 cases and 13579 controls. Summary odds ratios (ORs) with 95% confidence intervals (CIs) for alleles and genotypes were estimated. TLR3 rs3775291 was associated with both geographic atrophy (GA) and neovascular AMD (nAMD), with marginally significant pooled-P values. Stratification analysis by ethnicity indicated that rs3775291 was associated with all forms of AMD, GA and nAMD only in Caucasians (OR = 0.87, 0.78 and 0.77, respectively, for the TT genotype) but not in East Asians. However, the associations could not withstand Bonferroni correction. This meta-analysis has thus revealed suggestive evidence for TLR3 rs3775291 as an associated marker for AMD in Caucasians but not in Asians. This SNP may have only a small effect on AMD susceptibility. Further studies in larger samples are warranted to confirm its role.