Three major loci involved in age-related macular degeneration are also associated with polypoidal choroidal vasculopathy

The hypothetical molecular mechanism of the ethnic variations in the manifestation of age-related macular degeneration; focuses on the functions of the most significant susceptibility genes

Age-related macular degeneration (AMD) is the leading sight-threatening disease in developed countries. On the other hand, recent studies indicated an ethnic variation in the phenotype of AMD. For example, several reports demonstrated that the incidence of drusen in AMD patients is less in Asians compared to Caucasians though the reason has not been clarified yet. In the last decades, several genome association studies have disclosed many susceptible genes of AMD and revealed that the association strength of some genes was different among races and AMD phenotypes. In this review article, the essential findings of the clinical studies and genome association studies for the most significant genes CFH and ARMS2/HTRA1 in AMD of different races are summarized, and theoretical hypotheses about the molecular mechanisms underlying the ethnic variation in the AMD manifestation mainly focused on those genes between Caucasians and Asians are discussed.

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 Variability of Complement Factor H Has Ethnicity-Specific Associations With Choroidal Thickness

Purpose

To identify genetic alleles associated with differences in choroidal thickness (CT) in a population-based multiethnic Asian cohort.

Methods

A population-based multiethnic Asian cohort without retinal pathology was subjected to spectral-domain OCT (SD-OCT) and genotyping of risk alleles in CFH, VIPR2, ARMS2, and CETP. Subfoveal choroidal thickness (SFCT) values were assessed from SD-OCT, and associations with the risk alleles were determined for each cohort.

Results

A total of 1045 healthy Asian individuals (550 Chinese, 147 Indians, 348 Malays) were prospectively enrolled in the study. Several CFH alleles (rs800292, rs1061170, and rs1329428) were associated with increased SFCT in Indians (+18.7 to +31.7 µm; P = 0.001-0.038) and marginally associated with decreased SFCT in Malays (-12.7 to -20.6 µm; P = 0.014-0.022). Haplotype analysis of CFH revealed variable associations with SFCT among races, with the H6 haplotype being associated with a 29.08-µm reduction in SFCT in the Chinese cohort (P = 0.02) but a 35.2-µm increase in SFCT in the Indian cohort (P < 0.001). Finally, subfield analysis of the Chinese cohort identified associations between the CFH risk allele rs1061170 and reduced CT in the nasal and superior sectors (-20.2 to -25.8 µm; P = 0.003-0.027).

Conclusions

CFH variants are variably associated with CT among Asian ethnic groups. This has broad implications for the pathogenesis of common diseases such as age-related macular degeneration and central serous choroidopathy, the pathogenesis of which is associated with CT.

HTRA1 Regulates Subclinical Inflammation and Activates Proangiogenic Response in the Retina and Choroid

High-temperature requirement A1 (HtrA1) has been identified as a disease-susceptibility gene for age-related macular degeneration (AMD) including polypoidal choroidal neovasculopathy (PCV). We characterized the underlying phenotypic changes of transgenic (Tg) mice expressing ubiquitous CAG promoter (CAG-HtrA1 Tg). In vivo imaging modalities and histopathology were performed to investigate the possible neovascularization, drusen formation, and infiltration of macrophages. Subretinal white material deposition and scattered white-yellowish retinal foci were detected on CFP [(Tg—33% (20/60) and wild-type (WT)—7% (1/15), p < 0.05]. In 40% (4/10) of the CAG-HtrA1 Tg retina, ICGA showed punctate hyperfluorescent spots. There was no leakage on FFA and OCTA failed to confirm vascular flow signals from the subretinal materials. Increased macrophages and RPE cell migrations were noted from histopathological sections. Monocyte subpopulations were increased in peripheral blood in the CAG-HtrA1 Tg mice (p < 0.05). Laser induced CNV in the CAG-HtrA1 Tg mice and showed increased leakage from CNV compared to WT mice (p < 0.05). Finally, choroidal explants of the old CAG-HtrA1 Tg mice demonstrated an increased area of sprouting (p < 0.05). Signs of subclinical inflammation was observed in CAG-HtrA1 Tg mice. Such subclinical inflammation may have resulted in increased RPE cell activation and angiogenic potential.

Pachychoroid spectrum disease

Recent improvements in ophthalmic imaging have led to the identification of a thickened choroid or pachychoroid to be associated with a number of retinal diseases. The number of conditions linked to this phenotype has continued to widen with specific endophenotypes found within the pachychoroid spectrum. The spectrum includes choroidal features such as focal or diffuse choroidal thickening and thinning of the overlying inner choroid, and choroidal hyperpermeability as demonstrated by indocyanine green angiography. In addition, these diseases are associated with overlying retinal pigmentary changes and retinal pigment epithelial dysfunction and may also be associated with choroidal neovascularization. This article provides a comprehensive review of the literature looking at diseases currently described within the pachychoroid spectrum including central serous chorioretinopathy, pachychoroid pigment epitheliopathy, pachychoroid neovasculopathy, polypoidal choroidal vasculopathy/aneurysmal type 1 neovascularization, peripapillary pachychoroid disease and focal choroidal excavation. We particularly focus on clinical imaging, genetics and pathological findings in these conditions with the aim of updating evidence suggesting a common aetiology between diseases within the pachychoroid spectrum.

One-year results of intravitreal conbercept in treatment-naïve subjects with polypoidal choroidal vasculopathy

PURPOSE

To evaluate the functional and structural outcomes of intravitreal conbercept monotherapy using a "3 + pro re nata (PRN)" regimen in treatment-naïve subjects with polypoidal choroidal vasculopathy (PCV) up to 12 months.

METHODS

Thirty subjects (30 eyes) with PCV participated in this interventional, retrospective study. All subjects received intravitreal injections of 0.5 mg (0.05 ml) conbercept using a "3 + PRN" regimen for 12 months. The changes in best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) parameters, polyp lesion area, and regression rate were evaluated at baseline, month 3, and month 12.

RESULTS

At the study end-point, BCVA improved significantly from 52.80 ± 17.17 ETDRS letters at baseline to 62.20 ± 18.96 letters (P < 0.001), with a mean gain of 9.40 ± 14.97 letters. The central retinal thickness (CRT) significantly reduced from 454.93 ± 147.31 μm at baseline to 308.73 ± 106.80 μm (P < 0.001) at end-point, and the total macular volume (TMV) decreased from 9.51 ± 1.04 mm³ at baseline to 8.32 ± 0.84 mm3 at end-point (P < 0.001). The mean volume of pigment epithelial detachment (PED) decreased from 0.73 ± 0.97 mm³ at baseline to 0.48 ± 0.71 mm³ (P < 0.05) at month 3. At month 12, the mean volume of PED was 0.57 ± 0.80 mm³ (P > 0.05 compared to baseline). After the 3-monthly loading injections, 6 eyes (20.0%) showed complete polyp regression, whereas a total of 19 eyes (63.5%) showed complete regression at month 12. The average injections given per subject were 7.70 ± 1.81.

CONCLUSION

Intravitreal conbercept using the "3 + PRN" regimen was effective in the treatment of PCV.

Revisiting the role of factor H in age-related macular degeneration: Insights from complement-mediated renal disease and rare genetic variants

Ophthalmologists are long familiar with the eye showing signs of systemic disease, but the association between age-related macular degeneration and abnormal complement activation, common to several renal disorders, has only recently been elucidated. Although complement activation products were identified in drusen almost three decades ago, it was not until the early 21st century that a single-nucleotide polymorphism in the complement factor H gene was identified as a major heritable determinant of age-related macular degeneration, galvanizing global efforts to unravel the pathogenesis of this common disease. Advances in proteomic analyses and familial aggregation studies have revealed distinctive clinical phenotypes segregated by the functional effects of common and rare genetic variants on the mature protein and its splice variant, factor H-like protein 1. The predominance of loss-of-function, N-terminal mutations implicate age-related macular degeneration as a disease of general complement dysregulation, offering several therapeutic avenues for its modulation. Here, we explore the molecular impact of these mutations/polymorphisms on the ability of variant factor H/factor H-like protein 1 to localize to polyanions, pentraxins, proinflammatory triggers, and cell surfaces across ocular and renal tissues and exert its multimodal regulatory functions and their clinical implications. Finally, we critically evaluate key therapeutic and diagnostic efforts in this rapidly evolving field.

Deep phenotype unsupervised machine learning revealed the significance of pachychoroid features in etiology and visual prognosis of age-related macular degeneration

Unsupervised machine learning has received increased attention in clinical research because it allows researchers to identify novel and objective viewpoints for diseases with complex clinical characteristics. In this study, we applied a deep phenotyping method to classify Japanese patients with age-related macular degeneration (AMD), the leading cause of blindness in developed countries, showing high phenotypic heterogeneity. By applying unsupervised deep phenotype clustering, patients with AMD were classified into two groups. One of the groups had typical AMD features, whereas the other one showed the pachychoroid-related features that were recently identified as a potentially important factor in AMD pathogenesis. Based on these results, a scoring system for classification was established; a higher score was significantly associated with a rapid improvement in visual acuity after specific treatment. This needs to be validated in other datasets in the future. In conclusion, the current study demonstrates the usefulness of unsupervised classification and provides important knowledge for future AMD studies.

Association between axial length and choroidal thickness in early age-related macular degeneration

The clinical course of age-related macular degeneration (AMD) is related to choroidal conditions, and can be determined by the evaluation of the central choroidal thickness (CCT). The aim of this study was to determine the association between the axial length (AL) and choroidal thickness in AMD by measuring these parameters in patients with and without AMD. Seventy eyes of 70 patients (34 men and 36 women; age, 64-88 years; mean age, 77.0 ± 6.5 years) who underwent cataract surgery from February 2015 to March 2020 at the Department of Ophthalmology, Keio University School of Medicine were retrospectively analyzed. The AMD group (29 patients, 29 eyes) included eyes with early AMD, whereas the control group (41 patients, 41 eyes) included those without ocular diseases other than cataract. Optical coherence tomography images were used to measure the CCT and the choroidal vessel diameter (CVD). The IOL Master was used to measure the AL. The results revealed that mean CCT was greater in the AMD group (238.3 ± 108.3 μm) compared with the age-matched control group (187.2 ± 66.8 μm) (p = 0.03). The CCT was negatively correlated with AL in the overall sample (r = -0.42, p = 0.001), the AMD group (r = -0.42, p = 0.02), and the control group (r = -0.42, p = 0.006). Note that all eyes with CCT > 350 μm were included in the AMD group. CCT and CVD were positively correlated in the overall sample (r = 0.76, p < 0.001) as well as in the individual groups (AMD: r = 0.82, p < 0.001; control: r = 0.76, p = 0.004). Given that CCT is an important parameter for predicting the prognosis of subfoveal diseases, routine evaluation of AL may be valuable for a better understanding of the pathogenesis of AMD.

Phenotypic and genetic variations between Asian and Caucasian polypoidal choroidal vasculopathy

PURPOSE

To compare phenotypic and genetic variations in polypoidal choroidal vasculopathy (PCV) between Caucasian and Asian patients.

METHODS

We analysed phenotypic and genotypic data from two sites, Association for Innovation and Biomedical Research on Light and Image, Portugal and Singapore National Eye Centre, Singapore. Baseline fundus photography, spectral domain-optical coherence tomography, indocyanine green and fluorescein angiography scans were analysed by respective reading centres using a standardised grading protocol. Single nucleotide polymorphisms across 8 PCV loci were compared between cases and controls selected from each population.

RESULTS

One hundred and forty treatment-naïve PCV participants (35 Portuguese and 105 Singaporean) were included. The Portuguese cohort were older (72.33±8.44 vs 68.71±9.40 years, p=0.043) and were comprised of a lower proportion of males (43% vs 71%, p=0.005) compared with the Singaporean cohort. Differences in imaging features include higher prevalence of soft drusen (66% vs 30%, p=0.004), lower prevalence of subretinal haemorrhage (14% vs 67%, p<0.001), smaller polypoidal lesion (PL) area (0.09±0.09 vs 0.76±0.93 mm², p<0.001), lower ratio of PL to branching vascular network area (3% vs 38%, p<0.001) and lower central retinal thickness (346.48±93.74 vs 493.16±212.92 µm, p<0.001) in the Portuguese cohort. CETP rs3764261 (OR 2.467; 95% CI 1.282 to 4.745, p=0.006) in the Portuguese population was significantly associated with PCV and CFH rs800292 (OR 1.719; 95% CI 1.139 to 2.596, p=0.010) in the Singaporean population, respectively.

CONCLUSION

Among Asian and Caucasian patients with PCV, there are significant differences in the expression of phenotype. We also identified different polymorphisms associated with PCV in the two populations.

Characteristics of Pachychoroid Diseases and Age-Related Macular Degeneration: Multimodal Imaging and Genetic Backgrounds

The emergence of pachychoroid disease is changing the concept of age-related macular degeneration (AMD). The concept of pachychoroid diseases was developed through clinical observation of multimodal images of eyes with AMD and central serous chorioretinopathy; however, recent genetic studies have provided a proof of concept for pachychoroid spectrum disease, which should be differentiated from drusen-driven AMD. The genetic confirmation of pachychoroid concept further provides novel viewpoints to decode previously reported findings, which facilitates an understanding of the true nature of pachychoroid diseases and AMD. The purpose of this review was to elucidate the relationship between pachychoroid diseases and AMD by interpreting previous findings on pachychoroid diseases and AMD from the novel viewpoints of genetic associations. We confirmed that previous genetic studies supported the concept of pachychoroid diseases. From a genetic viewpoint, the presence of thick choroid and the presence of choroidal vascular hyperpermeability were important characteristics of pachychoroid spectrum diseases. Previous studies have also suggested the classification of polypoidal choroidal vasculopathy (PCV) into two subtypes, pachychoroid neovasculopathy and drusen-driven PCV. Genetic viewpoints will be beneficial to rearrange subtypes of drusen-driven AMD and pachychoroid spectrum diseases. Further genetic studies are needed to investigate pachyvessels, pachydrusen and the significance of polypoidal lesions in pachychoroid neovasculopathy and drusen-driven AMD/PCV.

The effect of complement factor B gene variation on age-related macular degeneration in Iranian patients

Purpose

To determine the possible association of rs4151667 (L9H) complement factor B (CFB) gene with age-related macular degeneration (AMD). The L9H is one of the functional variations of the CFB. CFB gene encodes the most important protein of the complement system.

Methods

Two hundred sixty-six patients with AMD and 194 unrelated age/sex-matched controls were genotyped for CFB gene (rs4151667) using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. All research subjects were selected from three regions of Iran (Tehran, Tabriz, and Gonabad).

Results

The results showed a significant difference between the frequency of non-TT genotype in total patients and controls [odds ratio (OR) = 0.424, P = 0.038]. The analysis for each studied region showed that in patients originating from the Gonabad population, the frequency of TT and non-TT genotypes between patients and the control group were significantly different (OR = 2.894, P = 0.046 for TT genotype and OR = 0.346, P = 0.026 for non-TT genotype). In patients originating from Tabriz population, TT and non-TT genotypes and A allele revealed considerably different frequencies between the patient and control groups (OR = 3.043, P = 0.017; OR = 0.329, P = 0.013 and OR = 0.347, P = 0.048, respectively). Analysis of patients from Tehran also showed that there was a significant difference in the frequency of TT genotype between patients and controls (OR = 2.168, P = 0.04).

Conclusions

The results of the current study indicated a possible protective role for non-TT genotype in L9H variation CFB gene against AMD in a sample of the Iranian population. The region segregation results showed that TT genotype might be a risk factor for susceptibility to AMD.

Association of rs10490924 in ARMS2/HTRA1 with age-related macular degeneration in the Pakistani population

Age-related macular degeneration (AMD) is a disease of the elderly in which central vision is lost because of degenerative changes of the macula. The current study investigated the association of single-nucleotide polymorphisms (SNPs) with AMD in the Pakistani population. Four SNPs were analyzed in this study: rs1061170 in the CFH, rs429608 near CFB, rs2230199 in the C3, and rs10490924 in ARMS2/HTRA1. This case-control association study was conducted on 300 AMD patients (125 wet AMD and 175 dry AMD) and 200 unaffected age- and gender-matched control individuals. The association of the SNP genotypes and allele frequency distributions were compared between patients and healthy controls, keeping age, gender, and smoking status as covariates. A significant genotype and variant allele association was found of rs10490924 in ARMS2/HTRA1 with wet AMD, while the SNPs in CFH, CFB, and C3 were not associated with AMD in the current Pakistani cohort. The lack of association of CFH, CFB, and C3 may be attributed to limited sample size. This study demonstrates that genetic causative factors of AMD differ among populations and supports the need for genetic association studies among cohorts from various populations to increase our global understanding of the disease pathogenesis.

IMPROVING THE AGE-RELATED MACULAR DEGENERATION CONSTRUCT: A New Classification System

Previous models of disease in age-related macular degeneration (AMD) were incomplete in that they did not encompass subretinal drusenoid deposits (pseudodrusen), subtypes of neovascularization, and polypoidal choroidal vasculopathy. In addition, Type 3 neovascularization starts in the retina and may not necessarily involve the choroid. As such, the term choroidal neovascularization is not appropriate for these eyes. The new aspects in the AMD construct are to include specific lipoprotein extracellular accumulations, namely drusen and subretinal drusenoid deposits, as early AMD. The deposition of specific types of deposit seems to be highly correlated with choroidal thickness and topographical location in the macula. Late AMD includes macular neovascularization or atrophy. The particular type of extracellular deposit is predictive of the future course of the patient. For example, eyes with subretinal drusenoid deposits have a propensity to develop outer retinal atrophy, complete outer retinal and retinal pigment epithelial atrophy, or Type 3 neovascularization as specific forms of late AMD. Given Type 3 neovascularization may never involve the choroid, the term macular neovascularization is suggested for the entire spectrum of neovascular disease in AMD. In contrast to older classification systems, the proposed system encompasses the relevant presentations of disease and more precisely predicts the future course of the patient. In doing so, the concept was developed that there may be genetic risk alleles, which are not necessarily the same alleles that influence disease expression.

Proteolytic Degradation and Inflammation Play Critical Roles in Polypoidal Choroidal Vasculopathy

Polypoidal choroidal vasculopathy (PCV) is a common subtype of wet age-related macular degeneration in Asian populations, whereas choroidal neovascularization is the typical subtype in Western populations. The cause of PCV is unknown. By comparing the phenotype of a PCV mouse model expressing protease high temperature requirement factor A1 (HTRA1) in retinal pigment epithelium with transgenic mice expressing the inactive HTRA1S328A, we showed that HTRA1-mediated degradation of elastin in choroidal vessels is critical for the development of PCV, which exhibited destructive extracellular matrix remodeling and vascular smooth muscle cell loss. Compared with weak PCV, severe PCV exhibited prominent immune complex deposition, complement activation, and infiltration of inflammatory cells, suggesting inflammation plays a key role in PCV progression. More important, we validated these findings in human PCV specimens. Intravitreal delivery of an HTRA1 inhibitor (DPMFKLboroV) was effective (36% lesion reduction; P = 0.009) in preventing PCV initiation but ineffective in treating existing lesions. Anti-inflammatory glucocorticoid was effective in preventing PCV progression but ineffective in preventing PCV initiation. These results suggest that PCV pathogenesis occurs through two stages. The initiation stage is mediated by proteolytic degradation of extracellular matrix proteins attributable to increased HTRA1 activity, whereas the progression stage is driven by inflammatory cascades. This study provides a basis for understanding the differences between PCV and choroidal neovascularization, and helps guide the design of effective therapies for PCV.

DISTINGUISHING POLYPOIDAL CHOROIDAL VASCULOPATHY FROM TYPICAL NEOVASCULAR AGE-RELATED MACULAR DEGENERATION BASED ON SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY

PURPOSE

To investigate the sensitivity and specificity of spectral domain optical coherence tomography in distinguishing polypoidal choroidal vasculopathy (PCV) from typical neovascular age-related macular degeneration (nAMD).

METHODS

One hundred and eighty-eight eyes in 156 patients with active PCV or typical nAMD were enrolled prospectively. Three spectral domain optical coherence tomography manifestations, pigment epithelium detachment, double-layer sign, and thumb-like polyps were estimated in all the eyes. A diagnostic test to differentiate PCV from nAMD based on spectral domain optical coherence tomography was performed. Furthermore, the sensitivity and specificity was validated in a retrospective series of patients.

RESULTS

Pigment epithelium detachment, double-layer sign, and thumb-like polyps were more common in PCV eyes than in nAMD eyes. When the cutoff point was set as at least 2 positive signs out of 3 in the diagnostic test, the sensitivity was 89.4% and specificity was 85.3%. The results of the validation test further confirmed the strategy, with satisfying sensitivity (87.5%) and specificity (86.2%).

CONCLUSION

Spectral domain optical coherence tomography is sensitive and specific in distinguishing PCV from nAMD. From these results, the presence of at least two out three signs (pigment epithelium detachment, double-layer sign, and thumb-like polyps) indicates a positive test and is therefore suggested to be the screening strategy for PCV.

Central serous chorioretinopathy in primary hyperaldosteronism

Purpose

To describe ophthalmological characteristics of 13 patients with primary hyperaldosteronism (PA).

Methods

Cross-sectional study. All patients underwent extensive ophthalmological examination.

Results

Thirteen PA patients (9 male, 4 female) were diagnosed with arterial hypertension for 11.0 ± 11.2 years. Ophthalmological imaging revealed macular serous subretinal fluid (SRF) on optical coherence tomography in 2 patients (15 %). In one of these patients, bilateral chronic central serous chorioretinopathy (CSC) with polypoidal choroidal neovasculopathy was diagnosed, which was effectively treated with full-dose photodynamic therapy. In the other patient with SRF and bilateral diffuse hyperfluorescent areas on fluorescein angiography, the SRF had decreased spontaneously after 6 weeks of follow-up. In 5 of the remaining patients (38 %), retinal pigment epithelium alterations resembling findings characteristic for CSC were seen on multimodal imaging. The mean subfoveal choroidal thickness was 290.2 ± 65.0 μm.

Conclusions

Retinal abnormalities resembling (subclinical) CSC are common in patients with PA. These findings indicate that mineralocorticoid-mediated pathways are involved in the pathogenesis of CSC. In CSC patients with hypertension of unknown origin, a diagnosis of PA should be considered.

HTRA1 promoter variant differentiates polypoidal choroidal vasculopathy from exudative age-related macular degeneration

Exudative age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) share similar abnormal choroidal vasculature, but responses to treatments are different. In this study, we sequenced the whole HTRA1 gene and its promoter by direct sequencing in a Hong Kong Chinese PCV cohort. We identified rs11200638, c.34delCinsTCCT, c.59C>T, rs1049331 and rs2293870 significantly associated with PCV. Notably, rs2672598 was significantly associated with exudative AMD (p = 1.31 × 10(-4)) than PCV (p = 0.11). Logistic regression indicated that rs2672598 (p = 2.27 × 10(-3)) remained significant after adjusting for rs11200638 in exudative AMD. Moreover, the rs11200638-rs2672598 joint genotype AA-CC conferred higher risk to exudative AMD (43.11 folds) than PCV (3.68 folds). Promoter analysis showed that rs2672598 C-allele showed higher luciferase expression than wildtype T-allele (p = 0.026), independent of rs11200638 genotype (p = 0.621). Coherently, vitreous humor HTRA1 expression with rs2672598 CC genotype was significantly higher than that with TT genotype by 2.56 folds (p = 0.02). Furthermore, rs2672598 C-allele was predicted to alter the transcription factor binding sites, but not rs11200638 A-allele. Our results revealed that HTRA1 rs2672598 is more significantly associated with exudative AMD than PCV in ARMS2/HTRA1 region, and it is responsible for elevated HTRA1 transcriptional activity and HTRA1 protein expression.

T-helper-associated cytokines expression by peripheral blood mononuclear cells in patients with polypoidal choroidal vasculopathy and age-related macular degeneration

Background

Immune responses play a key role in the pathogenesis and progression of polypoidal choroidal vasculopath (PCV) and age-related macular degeneration (AMD). In this study, we determined the Th cell-associated immune responses by measuring the cytokine expression of peripheral blood mononuclear cells (PBMC) in both PCV and neovascular AMD (nAMD) patients.

Methods

Twenty-seven nAMD patients, 33 PCV patients and a gender- and age-matched group of 18 healthy individuals were involved in this study. The Th-cell cytokine profiles including levels of interferon-gamma (INF-γ), interleukin (IL)-17A and IL-4 in cultures of PBMCs were determined by enzyme-linked immunosorbent assay (ELISA).

Results

IFN-γ,IL-17A and IL-4 production was significantly increased after stimulation with PHA. The levels of IFN-γ and IL-4 in PHA-stimulated cultures were higher in PCV and nAMD patients than that in healthy controls (P = 0.038,P = 0.014), while no difference was found between PCV and nAMD (all P > 0.05). No significant difference in IL-17A level in PHA-stimulated cultures was found among PCV, nAMD and control groups (P > 0.05).

Conclusions

These findings suggest that circulating IFN-γ and IL-4 producing Th1 and Th2 cells may involve in the pathogenesis of PCV and nAMD. PCV may have the similar immune responses with nAMD.

Four complement factor H gene polymorphisms in association with AMD: A meta-analysis

AIM

To investigate the possible association between CFH gene polymorphisms -543G>A (rs1410996), A473A (rs2274700), -257C>T (rs3753394), IVS15 (rs1329428) and AMD risk.

METHODS

We searched the published literature in the Medline and Scopus from inception to May 2015. A meta-analysis was performed by the programs RevMan 5.1 and Stata 12.0, and the Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated in fixed or random effect model based on heterogeneity test among studies.

RESULTS

Nineteen studies with a total of 10,676 subjects were included in the present meta-analysis. A statistical significant association was observed between AMD risk and CFH -543G>A polymorphism with OR of 1.77 (95% CI, 1.47-2.12), 2.24 (95% CI, 1.71-2.94), 0.49 (95% CI, 0.38-0.62) and 0.25 (95% CI, 0.18-0.37) in additive, dominant, recessive and codominant models, respectively. Similar results were obtained in polymorphisms A473A, -257C>T, IVS15. Furthermore, stratified analysis for ethnicity showed a significantly strong association between -543G>A, A473A polymorphisms and AMD risk.

CONCLUSION

The present meta-analysis suggested that CFH -543G>A, A473A, -257C>T, and IVS15 polymorphisms might be moderately associated with AMD risk. This conclusion warrants confirmation by further studies.

Investigating the choriocapillaris and choroidal vasculature with new optical coherence tomography technologies

The body of knowledge of in vivo investigation of the choroid has been markedly enhanced by recent technological advances in optical coherence tomography (OCT). New insights elucidating the morphological features of the choriocapillaris and choroidal vasculature, in both physiological and pathological conditions, indicate that the choroid plays a pivotal role in many posterior segment diseases. In this article, a review of the histological characteristics of the choroid, which must be considered for the proper interpretation of in vivo imaging, is followed by a comprehensive discussion of fundamental principles of the current state-of-the-art in OCT, including cross-sectional OCT, en face OCT, and OCT angiography using both spectral domain OCT and swept source OCT technologies. A detailed review of the tomographic features of the choroid in the normal eye is followed by relevant findings in prevalent chorioretinal diseases, focusing on major causes of vision loss such as typical early and advanced age-related macular degeneration, polypoidal choroidal vasculopathy, central serous chorioretinopathy, pachychoroid spectrum disorders, diabetic choroidopathy, and myopia.

Characteristics of Neovascular Age-Related Macular Degeneration in Brazilian Patients

Purpose: To report features of neovascular age-related macular degeneration (AMD) in Brazilian patients. Procedures: Data were prospectively collected from patients diagnosed with neovascular AMD. Eyes were classified as having typical neovascular AMD, polypoidal choroidal vasculopathy (PCV), or retinal angiomatous proliferation (RAP). Results: In total, 265 eyes of 207 patients of predominantly Caucasian ancestry were included; 166 (62.6%) eyes had typical neovascular AMD, 65 (24.5%) eyes had PCV, and 34 (12.8%) eyes had RAP. RAP demonstrated a higher percentage of bilateral cases (p = 0.015). The mean foveal subfield thickness was significantly lower in eyes with PCV (p < 0.001). Cases with typical neovascular AMD had a higher percentage of predominantly classic and minimally classic lesions on fluorescein angiography (FA; p = 0.005). Conclusions: In Brazilian patients, PCV and RAP represented 24.5 and 12.8% of neovascular AMD cases. Neovascular AMD subtypes differ in relation to clinical features, mean foveal subfield thickness and FA presentation.

COL8A1 rs13095226 polymorphism shows no association with neovascular age-related macular degeneration or polypoidal choroidal vasculopathy in Chinese subjects

PURPOSE

Age-related macular degeneration (AMD) is the main cause of visual impairment and legal blindness in older individuals. COL8A1 rs13095226 variants have recently been implicated associated with neovascular age-related macular degeneration (nAMD) and Polypoidal Choroidal Vasculopathy (PCV) in American studies. The aim of this study was to investigate the association between the COL8A1 rs13095226 Polymorphism and neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) in Chinese people.

METHODS

900 Chinese subjects-300 cases with nAMD, 300 cases with PCV and 300 controls, were enrolled in a cross-sectional observational study. The diagnoses of nAMD and PCV were confirmed by Fundus photography, Fluorescence Fundus Angiography (FFA) and Indocyanine Green Angiography (ICGA). Genomic DNA was extracted from venous blood leukocytes and genotypes of rs13095226 were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Differences in allele distribution between cases and controls were tested by chi-square tests, with age and gender adjusted by logistic regression analysis.

RESULT

The COL8A1 rs13095226 polymorphism was not statistically significantly different from the nAMD or PCV to the normal controls (P>0.05) in Chinese Population. The association remained insignificant after adjustment for age and gender differences (P>0.05).

CONCLUSIONS

This case-control study indicated that the COL8A1 rs13095226 polymorphism is not associated with nAMD or PCV, which suggesting this gene maybe not a susceptibility gene locus for nAMD or PCV in Chinese subjects.

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

TOPIC

A systematic review and meta-analysis of the genetic association with polypoidal choroidal vasculopathy (PCV) and the genetic difference between PCV and neovascular age-related macular degeneration (nAMD).

CLINICAL RELEVANCE

To identify genetic biomarkers that are potentially useful for genetic diagnosis of PCV and for differentiating PCV from nAMD.

METHODS

We performed a literature search in EMBASE, PubMed, Web of Science, and the Chinese Biomedical Database for PCV genetic studies published before February 6, 2015. We then conducted a meta-analysis of all polymorphisms that had sufficient genotype/allele data reported in ≥2 studies and estimated the summary odds ratio (OR) and 95% confidence intervals (CIs) for PCV. We also compared the association profiles between PCV and nAMD, and performed a sensitivity analysis.

RESULTS

A total of 66 studies were included in the meta-analysis, involving 56 polymorphisms in 19 genes/loci. In total, 31 polymorphisms in 10 genes/loci (age-related maculopathy susceptibility 2 [ARMS2], high-temperature requirement factor A1 [HTRA1], complement factor H [CFH], complement component 2 [C2], CFB, RDBP, SKIV2L, CETP, 8p21, and 4q12) were significantly associated with PCV. Another 25 polymorphisms in 13 genes (ARMS2, HTRA1, C2, CFB, ELN, LIPC, LPL, ABCA1, VEGF-A, TLR3, LOXL1, SERPING1, and PEDF) had no significant association. Twelve polymorphisms at the ARMS2-HTRA1 locus showed significant differences between PCV and nAMD. The sensitivity analysis validated the significance of our analysis.

CONCLUSIONS

This study revealed 31 polymorphisms in 10 genes/loci that contribute to PCV susceptibility. Among them, ARMS2-HTRA1 also showed allelic diversity between PCV and nAMD. Our results confirm the gene variants that could affect the phenotypic expressions of PCV and nAMD.

Gene-gene interaction of CFH, ARMS2, and ARMS2/HTRA1 on the risk of neovascular age-related macular degeneration and polypoidal choroidal vasculopathy in Chinese population

PURPOSE

To evaluate the association and interaction of five single-nucleotide polymorphisms (SNPs) in three genes (CFH, ARMS2, and ARMS2/HTRA1) with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) in Chinese population.

METHODS

A total of 300 nAMD and 300 PCV patients and 301 normal subjects participated in the present study. The allelic variants of rs800292, rs2274700, rs3750847, rs3793917, and rs1065489 were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Gene-gene interactions were evaluated by the data mining approach multifactor-dimensionality reduction (MDR) method.

RESULTS

The risk alleles of CFH rs800292, rs2274700, ARMS2 rs3057847, and ARMS2/HTRA1 rs3793917 showed significant difference between nAMD or PCV patients and controls (all P<0.01). The homozygosity of risk alleles for rs800292, rs2274700, rs3750847, and rs3793917 were significantly different between nAMD patients and controls (all P<0.01), and predisposed to PCV patients (all P<0.01). After cross-validation consistency (CVC) and permutation tests, the two-locus model rs2274700_rs3750847 has a balanced accuracy of 64.37% in predicting nAMD disease risk. The one-marker model, rs3750847, and two-locus model rs2274700_rs3750847 has a balanced accuracy of 66.07% and 65.89% in predicting PCV disease risk, respectively. Furthermore, CFH rs1065489 did not show significant association with nAMD (P>0.01), but was strongly associated with PCV in Chinese patients (P<0.001).

CONCLUSIONS

In this study, we found that the interaction of ARMS2 and ARMS2/HTRA1 is significantly associated with nAMD, and the interaction of CFH and ARMS2 is pronounced in PCV development in Chinese population.

Ethnic differences in the association of SERPING1 with age-related macular degeneration and polypoidal choroidal vasculopathy

Neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) are leading causes of irreversible blindness in developed countries. In this study, we investigated the association of single nucleotide polymorphisms (SNPs) in the serpin peptidase inhibitor, clade G, member 1 (SERPING1) gene with neovascular AMD and PCV. Two haplotype-tagging SNPs, rs1005510 and rs11603020, of SERPING1 were genotyped in 708 unrelated Chinese individuals: 200 neovascular AMD, 233 PCV and 275 controls. A meta-analysis was also performed for all reported associations of SERPING1 SNPs with AMD and PCV. None of the tagging SNPs had a significant association with neovascular AMD or PCV (P > 0.05) in our study cohort. The meta-analyses showed that the most-studied SNP rs2511989 was not significantly associated with all forms of AMD, neovascular AMD, or PCV in East Asians (P = 0.98, 0.93 and 0.30, respectively) but was associated with AMD in Caucasians (P = 0.04 for all AMD and 0.004 for neovascular AMD). Therefore, the results of our study and meta-analysis suggest that SERPING1 is not a major genetic component of AMD or PCV in East Asians but is a genetic risk factor for AMD in Caucasians, providing evidence for an ethnic diversity in the genetic etiology of AMD.

C2 rs547154 polymorphism and polypoidal choroidal vasculopathy susceptibility: a meta-analysis

Previous studies have indicated the association between C2 rs547154 polymorphism and polypoidal choroidal vasculopathy (PCV) risk, while the results are controversial and inconsistent. Herein, we perform a meta-analysis to gain a precise estimation of the association using 5 eligible studies involving 4076 subjects, of which 1220 were PCV cases, 1073 were age-related macular degeneration (AMD) cases and 1783 were controls. Allelic frequencies of C2 rs547154 polymorphism between PCV and AMD were also compared. Both crude and adjusted odds ratios (OR) with their 95% confidence interval (CI) were included to assess the strength of the association. The pooled OR in random-effect model for allele T versus G was 0.64 (95% CI, 0.52–0.80; p < 0.0001), for genotype TG versus GG was 0.65 (95% CI, 0.52–0.83; p, 0.0004), and for genotype TT + TG versus GG was 0.64 (95% CI, 0.51–0.80; p, 0.0002). No difference in allelic frequency was observed between PCV and AMD (OR, 0.86; 95% CI, 0.64–1.16; p, 0.32). Sensitivity analysis proved the robustness of our data. No significant ethnic divergence was suggested by subgroup analysis, and no publication bias was detected via Egger's test. In conclusion, our data indicate that C2 rs547154 polymorphism plays a protective role in the development of PCV.

Stereotactic radiotherapy for polypoidal choroidal vasculopathy: a pilot study

PURPOSE

To evaluate low-voltage X-ray stereotactic radiotherapy (SRT) delivered in conjunction with intravitreal ranibizumab for the treatment of active macular polypoidal choroidal vasculopathy (PCV).

METHODS

At baseline, all eyes received an intravitreal injection of ranibizumab, followed by 16-Gy X-ray SRT to the macula. Further ranibizumab injections were given pro re nata. The primary outcome measure was regression of the polyps assessed by indocyanine green angiography. Secondary outcome measures were best-corrected visual acuity (BCVA) and central foveal thickness (CFT) changes on optical coherence tomography. Local or systemic adverse events were evaluated as well.

RESULTS

We examined 12 eyes of 12 patients with PCV. At month 12, an angiographic regression of the polyps was observed in 10 of the 12 eyes. The mean BCVA improved by 7.6 letters: from 65.08 ± 11.4 to 72.7 ± 14.75 letters on the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The mean CFT decreased from 372.3 ± 79.6 to 215.9 ± 57.9 µm (p < 0.01). No local or systemic adverse events were reported.

CONCLUSIONS

The preliminary data support the safety of low-voltage X-ray SRT for the treatment of macular PCV and show polyp closure, reduction in CFT and improvement in the mean BCVA. Additional research is warranted to confirm the efficacy and longer-term safety of this therapy in this population.

Pilot study of inactive polypoidal lesions in polypoidal choroidal vasculopathy

PURPOSE

This pilot study was conducted to describe the angiographic characteristics of inactive polypoidal lesions that were observed during indocyanine green angiography (ICGA) in polypoidal choroidal vasculopathy (PCV).

METHODS

This was a retrospective study involving 40 eyes of 39 consecutive Chinese patients with PCV with inactive polypoidal lesions. All patients underwent fundus fluorescein angiography and ICGA examinations. We used ICGA to make a definitive diagnosis of PCV in each patient. The clinical and angiographic characteristics of inactive polypoidal lesions were recorded and analyzed.

RESULTS

In the 40 eyes that were studied, the time between receiving an injection of indocyanine green and the initial appearance of inactive polypoidal lesions ranged from 8.2 minutes to 25.1 minutes, with a mean time of 15.1 ± 5.6 minutes. Inactive polypoidal lesions were divided into 4 groups: 5 eyes (12.5%) in the asymptomatic group; 8 eyes (20.0%) in the atrophic and/or cicatricial group; 24 eyes (60.0%) in the combined group (coexisting with active polypoidal lesions); and 3 eyes (7.5%) in the mixed group (coexisting with choroidal neovascularization). Twelve of the 40 eyes were followed up for 9 to 29 months (mean 12.4 ± 5.3 months). Over this time period, inactive polypoidal lesions completely regressed (not observed in ICGA) in 3 eyes (25.0%), partially regressed in 3 eyes (25.0%), and were stable (the same as the first visit) in 6 eyes (50.0%).

CONCLUSIONS

Inactive polypoidal lesions in patients with PCV most commonly appeared during the middle phase of ICGA and were manifested in 4 groups. These lesions represented the sites of PCV in a regressed or quiescent stage.

Spectral-domain optical coherence tomography findings in polypoidal choroidal vasculopathy suggest a type 1 neovascular growth pattern

PURPOSE

To report spectral-domain optical coherence tomography (SD-OCT) findings in polypoidal choroidal vasculopathy (PCV).

PATIENTS AND METHODS

Seventeen eyes of 15 consecutive patients diagnosed with PCV based on typical clinical and angiographic findings were imaged with macular SD-OCT including line scans passing through the polyps.

RESULTS

SD-OCT findings included typical and atypical retinal pigment epithelial (RPE) detachments and subretinal and intraretinal fluid in all eyes. In the areas corresponding to the polypoidal lesions, well-delineated round-oval, sub-RPE cavities were present and were adherent to the posterior surface of the detached RPE above Bruch membrane. No retinal or choroidal connections to the cavities were noted.

CONCLUSION

These SD-OCT findings document that the vascular lesions in PCV are not located in the inner choroid, but in the sub-RPE space, suggesting that PCV is a variant of type 1 choroidal neovascularization rather than a distinct clinical entity as initially thought.

Associations of complement factor B and complement component 2 genotypes with subtypes of polypoidal choroidal vasculopathy

BACKGROUND

We previously reported on subtypes of polypoidal choroidal vasculopathy (PCV), and categorized PCV as polypoidal choroidal neovascularization (CNV) and typical PCV. The aim of this study was to clarify whether complement component 2 (C2) and complement factor B (CFB) genotypes are associated with subtypes of polypoidal choroidal vasculopathy, such as polypoidal CNV and typical PCV.

METHODS

First, we categorized 677 patients into typical age-related macular degeneration (tAMD; 250 patients), PCV (376) and retinal angiomatous proliferation (RAP; 51). Second, we categorized 282 patients with PCV as having polypoidal CNV (84 patients) or typical PCV (198) based on indocyanine green angiographic findings. In total, 274 subjects without AMD, such as PCV and CNV, served as controls. A SNP (rs547154) in the C2 gene and three SNPs (rs541862, rs2072633, rs4151667) in the CFB gene were genotyped, and case-control studies were performed in subjects with these PCV subtypes.

RESULTS

In tAMD, no SNPs were associated with allele distributions. In PCV, rs547154 and rs2072633 were associated with allele distributions. RAP was only associated with rs2072633. After logistic regression analysis with adjustment for confounding factors, tAMD, PCV and RAP were found to be associated with rs2072633.As to PCV subtypes, there were significant differences in the distributions of rs547154, rs541862 and rs2072633 in the case-control studies for polypoidal CNV, but not between the typical PCV and control groups. Logistic regression analysis with adjustment for confounding factors showed the distributions of rs547154, rs541862 and rs2072633 to differ significantly between the controls and polypoidal CNV cases and that these SNPs were protective. The A/A genotype of rs2072633 was significantly more common in the polypoidal CNV than in the typical PCV group (p = 0.03), even with adjustment for polyp number and greatest linear dimension.

CONCLUSIONS

PCV might be genetically divisible into polypoidal CNV and typical PCV. The C2 and CFB gene variants were shown to be associated with polypoidal CNV. Typical PCV was not associated with variants in these genes.

[Personalized molecular medicine: new paradigms in the treatment of cochlear implant and cancer patients]

OBJECTIVES

To evaluate present options for the indication of cochlear implants (CI) and new forms of treatment for head and neck cancer, melanomas and basal cell carcinomas, with emphasis on future perspectives.

METHODS

A literature search was performed in the PubMed database. Search parameters were "personalized medicine", "individualized medicine" and "molecular medicine".

RESULTS

Personalized medicine based on molecular-genetic evaluation of functional proteins such as otoferlin, connexin 26 and KCNQ4 or the Usher gene is becoming increasingly important for the indication of CI in the context of infant deafness. Determination of HER2/EGFR mutations in the epithelial growth factor receptor (EGFR) gene may be an important prognostic parameter for therapeutic decisions in head and neck cancer patients. In basal cell carcinoma therapy, mutations in the Hedgehog (PCTH1) and Smoothened (SMO) pathways strongly influence the indication of therapeutic Hedgehog inhibition, e.g. using small molecules. Analyses of c-Kit receptor, BRAF-600E and NRAS mutations are required for specific molecular therapy of metastasizing melanomas. The significant advances in the field of specific molecular therapy are best illustrated by the availability of the first gene therapeutic procedures for treatment of RPE65-induced infantile retinal degradation.

CONCLUSION

The aim of personalized molecular medicine is to identify patients who will respond particularly positively or negatively (e.g. in terms of adverse side effects) to a therapy using the methods of molecular medicine. This should allow a specific therapy to be successfully applied or preclude its indication in order to avoid serious adverse side effects. This approach serves to stratify patients for adequate treatment.

Polypoidal choroidal vasculopathy and history of central serous chorioretinopathy

PURPOSE

To evaluate the possible causative role of central serous chorioretinopathy (CSC) in the development of exudative age-related macular degeneration (AMD).

METHODS

In a cross-sectional study at an institutional setting, 150 control subjects who had senile cataract or nasolacrimal duct stenosis and who were older than 50 years were enrolled. The background data for 89 patients with typical AMD (tAMD) and 138 patients with polypoidal choroidal vasculopathy (PCV) were used for comparison. Their medical records were taken for history of CSC, hypertension, systemic steroid use, and smoking. The fundus was also evaluated for signs of atrophic retinal pigment epithelial (RPE) tract and for focal photocoagulation scars in the macula.

RESULTS

After adjusting for age, gender, and history of hypertension, systemic steroid use, and smoking, history of CSC was significantly more frequent (P<0.0001) in patients with PCV (15 patients, 10.9%) compared with patients with tAMD (2 patients, 2.2%) or control subjects (0 patients). On fundoscopy, an atrophic RPE tract (seven patients) or a focal photocoagulation scar (one patient) was observed only in patients with PCV (eight patients, 5.8%), and the frequency was statistically significant compared with that with tAMD (P=0.0143) or control subjects (P=0.0143). The laterality of CSC and AMD involved the same eye in 9 of 10 patients among those who had unilateral AMD and a reported unilateral CSC history.

CONCLUSION

A history of CSC may be a predisposing factor for the development of PCV in the Japanese population.

Genes in the high-density lipoprotein metabolic pathway in age-related macular degeneration and polypoidal choroidal vasculopathy

PURPOSE

To investigate the associations of genetic variants in the high-density lipoprotein (HDL) metabolism pathway with neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV).

DESIGN

Cross-sectional, case-control association study.

PARTICIPANTS

A Chinese case-control group of 200 neovascular AMD patients, 233 PCV patients, and 275 control subjects.

METHODS

Eight single nucleotide polymorphisms (SNPs) from 6 genes of the HDL metabolism pathway and 2 known AMD-associated SNPs, rs800292 (from complement factor H [CFH]) and rs11200638 (from HtrA serine peptidase 1 [HTRA1]), were genotyped in all study subjects using the TaqMan genotyping technology (Applied Biosystems, Foster City, CA).

MAIN OUTCOME MEASURES

Allele and genotypic frequencies of selected SNPs.

RESULTS

The SNP rs3764261 in the cholesteryl ester transfer protein (CETP) gene was associated significantly with neovascular AMD (P = 1.82×10(-4); odds ratio [OR], 1.89) and PCV (P = 4.04×10(-4); OR, 1.80). The associations remained significant after adjusting for the CFH SNP rs800292 and the HTRA1 SNP rs11200638. A significant interaction between the CETP SNP rs3764261 and the CFH SNP rs800292 existed in both neovascular AMD and PCV, the rs800292 G allele conferring a significantly increased risk of the diseases only in individuals carrying the risk allele T of rs3764261. A borderline association was detected between the ATP-binding cassette, subfamily G, member 1 (ABCG1) gene SNP rs57137919 and PCV (P = 0.03).

CONCLUSIONS

Our results showed that CETP is a susceptibility gene for neovascular AMD and PCV and that ABCG1 a putative gene for PCV. CETP exerts a modifying effect on CFH in the genetic risk. Our data suggest a link of the HDL metabolism pathway with neovascular AMD and PCV.

Early-onset stroke and vasculopathy associated with mutations in ADA2

BACKGROUND

We observed a syndrome of intermittent fevers, early-onset lacunar strokes and other neurovascular manifestations, livedoid rash, hepatosplenomegaly, and systemic vasculopathy in three unrelated patients. We suspected a genetic cause because the disorder presented in early childhood.

METHODS

We performed whole-exome sequencing in the initial three patients and their unaffected parents and candidate-gene sequencing in three patients with a similar phenotype, as well as two young siblings with polyarteritis nodosa and one patient with small-vessel vasculitis. Enzyme assays, immunoblotting, immunohistochemical testing, flow cytometry, and cytokine profiling were performed on samples from the patients. To study protein function, we used morpholino-mediated knockdowns in zebrafish and short hairpin RNA knockdowns in U937 cells cultured with human dermal endothelial cells.

RESULTS

All nine patients carried recessively inherited mutations in CECR1 (cat eye syndrome chromosome region, candidate 1), encoding adenosine deaminase 2 (ADA2), that were predicted to be deleterious; these mutations were rare or absent in healthy controls. Six patients were compound heterozygous for eight CECR1 mutations, whereas the three patients with polyarteritis nodosa or small-vessel vasculitis were homozygous for the p.Gly47Arg mutation. Patients had a marked reduction in the levels of ADA2 and ADA2-specific enzyme activity in the blood. Skin, liver, and brain biopsies revealed vasculopathic changes characterized by compromised endothelial integrity, endothelial cellular activation, and inflammation. Knockdown of a zebrafish ADA2 homologue caused intracranial hemorrhages and neutropenia - phenotypes that were prevented by coinjection with nonmutated (but not with mutated) human CECR1. Monocytes from patients induced damage in cocultured endothelial-cell layers.

CONCLUSIONS

Loss-of-function mutations in CECR1 were associated with a spectrum of vascular and inflammatory phenotypes, ranging from early-onset recurrent stroke to systemic vasculopathy or vasculitis. (Funded by the National Institutes of Health Intramural Research Programs and others.).

Systematic review and meta-analysis of the association between complement factor H I62V polymorphism and risk of polypoidal choroidal vasculopathy in Asian populations

Purpose

To investigate whether the polymorphism rs800292 (184G>A, I62V) in the complement factor H gene is associated with polypoidal choroidal vasculopathy (PCV) and the genetic difference between PCV and neovascular age-related macular degeneration (nAMD), in Asian populations.

Methods

A comprehensive literature search was performed in PubMed, Medline, Web of Science, and reference lists. A system review and meta-analysis of the association between I62V and PCV and/or nAMD were performed from 8 studies involving 5,062 subjects. The following data from individual studies were extracted and analyzed: 1) comparison of I62V polymorphisms between PCV and controls; 2) comparison of I62V polymorphisms between PCV and nAMD. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed-effects models. The Q-statistic test was used to assess heterogeneity, and Egger’s test was used to evaluate publication bias. Sensitivity analysis and cumulative meta-analysis were also performed.

Results

The I62V polymorphism showed a significant summary OR₁ for genotype GA+GG versus homozygous genotype AA was 3.18 (95% CI, 2.51–4.04, P<0.00001), the OR₂ of heterozygous genotype GA versus AA was 2.29 (95% CI: 1.79–2.94, P<0.00001), the OR₃ of homozygous genotype GG versus AA was 4.42 (95% CI: 3.45–5.67, P<0.00001), and the OR₄ of allele G versus A was 2.04 (95% CI: 1.85–2.26, P<0.00001). Sensitivity analysis indicated the robustness of our findings, and evidence of publication bias was not observed in our meta-analysis. Cumulative meta-analysis revealed that the summary ORs were stable. There was no significant difference in every genetic model between PCV and nAMD (n = 5, OR₁ = 0.92, OR₂ = 0.96, OR₃ = 0.90, OR₄ = 0.94).

Conclusions

Our analysis provides evidence that the I62V polymorphism is associated with an increased risk of PCV. The variant of I62V could be a promising genetic biomarker of PCV in Asian populations.

Lack of polypoidal lesions in patients with myopic choroidal neovascularization as evaluated by indocyanine green angiography

OBJECTIVE

To investigate the prevalence of polypoidal choroidal vasculopathy (PCV) in patients with myopic choroidal neovascularization (CNV) using indocyanine green angiography (ICGA).

DESIGN

Retrospective cross-sectional study.

METHODS

A total of 297 eyes (255 patients) who presented with treatment-naive myopic CNV between January 2005 and December 2011 at Yonsei University Medical Center in Seoul, South Korea, were reviewed. Fluorescein angiography (FA) images obtained from the patients were analyzed to detect CNV presence and classify disease type. ICGA images were reviewed to detect polypoidal lesions. The main outcome measure was the prevalence of polypoidal lesions in patients with myopic CNV.

RESULTS

All 297 eyes with myopic CNV were type 2 CNV, and mean age at diagnosis was 47.32 ± 14.69 years. The mean refractive error was -11.95 ± 5.88 diopters, and the mean axial length was 29.39 ± 2.02 mm in the affected eyes. Among the myopic CNV eyes, 141 eyes (118 patients) were older than 50 years of age (mean 60.48 ± 7.34 years). No eyes with myopic CNV showed polypoidal lesions on ICGA at initial presentation. After treatments for myopic CNV, 243 eyes (206 patients) completed at least 12 months of follow-up, and 86 eyes (35.4%) showed at least one recurrence of CNV during follow-up. The follow-up imaging studies, FA, and ICGA, showed no polypoidal lesions associated with recurred myopic CNV.

CONCLUSIONS

ICGA analysis demonstrated no polypoidal component in myopic eyes with CNV.

Association between complement factor H Val62Ile polymorphism and age-related macular degeneration susceptibility: a meta-analysis

BACKGROUND

An increasing body of studies has assessed the contribution of Val62Ile polymorphism to age-related macular degeneration (AMD) risk, but the exact association still remains uncertain. This meta-analysis was undertaken in order to further characterize the potential association between Val62Ile polymorphism and AMD risk in four different ethnic populations.

METHODS

A meta-analysis was performed using data available from 16 case-control studies evaluating correlation between the Val62Ile polymorphism and AMD in Caucasian, Chinese, Japanese and South Korean populations. Data extraction and study quality assessment were performed in duplicate. Summary odds ratios (ORs) and 95% confidence intervals (CIs) of allele contrast and genotype contrast were estimated using the random-effects model. The Q-statistic test was used to identify heterogeneity, and the funnel plot was adopted to evaluate publication bias.

RESULTS

Sixteen studies involving a total of 11,400 subjects based on the search criteria were included in the meta-analysis. In overall populations, the Val62Ile polymorphism seemed to be associated with AMD (ORAA vs. GG=0.40, 95% CI=0.28-0.59; ORAA+GA vs. GG=0.72, 95% CI=0.64-0.80; ORAA vs. GC+GG=0.50, 95% CI=0.36-0.70; ORA vs. G=0.68, 95% CI=0.58-0.78; ORGA vs. GG=0.71, 95% CI=0.65-0.77). Similarly, subgroup analysis also revealed that this polymorphism was related to AMD in all ethnicities.

CONCLUSIONS

This meta-analysis suggested that Val62Ile polymorphism was associated with susceptibility to AMD.

Polypoidal choroidal vasculopathy: clinical features and genetic predisposition

Polypoidal choroidal vasculopathy (PCV) is currently recognized as a phenotype of age-related macular degeneration (AMD). PCV is believed to be a type of choroidal neovascularization, although some cases of PCV show a distinct vascular abnormality of the choroidal vessels. PCV often shows several unique clinical manifestations which are apparently different from typical neovascular AMD (tAMD). In addition, the natural course and response to treatment are often different between tAMD and PCV. Moreover, recent genetic studies suggested a possible difference in the genetic susceptibility to disease between tAMD and PCV, as well as the existence of heterogeneity among PCV cases. In viewing the accumulation of knowledge about PCV, we have summarized the recent literature regarding PCV in this review article to improve the understanding of this clinical entity including possible susceptibility genes. We will also discuss the optimal treatment strategies for PCV in accordance with the results of recent clinical and genetic studies.

Polypoidal choroidal vasculopathy in Caucasian patients with presumed neovascular age-related macular degeneration and poor ranibizumab response

Aims

To determine the prevalence of polypoidal choroidal vasculopathy (PCV) in patients with presumed neovascular age-related macular degeneration (AMD) who were considered poor responders to ranibizumab.

Methods

Caucasian patients with suspected neovascular AMD, presumed to be choroidal neovascularisation, previously treated with ≥8 intravitreal injections of ranibizumab 0.5 mg (Lucentis; Novartis AG, Basel, Switzerland) administered as required during optical coherence tomography-guided dosing were retrospectively included. Eyes were categorised according to the time from injection 1 to injection 6 (group 1: <12 months; group 2: ≥12 months). Indocyanine green angiography (ICGA) was used to re-evaluate eyes for PCV. Suitable candidates received reduced-fluence photodynamic therapy/ranibizumab combination therapy supplemented by ranibizumab monotherapy, as required.

Results

202 eyes were included (group 1: 73.8%; group 2: 26.2%). The prevalence of PCV in group 1 (21.5%) was significantly higher than in group 2 (3.8%; p=0.003). After initiation of combination therapy, 16 eyes with PCV received 3.1±2.5 ranibizumab injections/year vs 8.4±2.4 injections/year before initiation of combination therapy (p<0.001).

Conclusions

In Caucasian patients with presumed neovascular AMD, PCV prevalence is increased in eyes that respond poorly to ranibizumab monotherapy. ICGA improved PCV diagnosis in poor responders; combination therapy may be beneficial for eyes with PCV.

TOMM40 rs2075650 polymorphism shows no association with neovascular age-related macular degeneration or polypoidal choroidal vasculopathy in a Chinese population

PURPOSE

Age-related macular degeneration (AMD) and Alzheimer disease (AD) are age-related neurodegenerative diseases that share similar environmental risk factors, cellular pathologies, and genetic backgrounds. Recently, the rs2075650 single nucleotide polymorphism in the translocase of outer mitochondrial membrane 40 homolog (TOMM40) gene was identified as a risk factor for AMD and Alzheimer disease. We aimed to examine the associations between the TOMM40 rs2075650 polymorphism and neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) in a Chinese population.

METHODS

The study consisted of 900 subjects, including 300 controls, 300 cases with nAMD, and 300 cases with PCV. Genomic DNA was extracted from venous blood leukocytes. The allelic variant of rs2075650 was determined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Differences in the observed genotypic distributions between the case and control groups were tested using chi-square tests, with age and gender adjusted using logistic regression analysis.

RESULTS

The TOMM40 rs2075650 polymorphism was not statistically significantly associated with the nAMD or PCV phenotype (p>0.05). The difference remained insignificant after correction for age and gender differences based on the logistic regression models (p>0.05).

CONCLUSIONS

Our data provide no evidence to support an association of rs2075650 in TOMM40 with nAMD or PCV, suggesting that this gene is unlikely to be a major AMD and PCV susceptibility gene locus in the Chinese population.

The age-related maculopathy susceptibility 2 polymorphism and polypoidal choroidal vasculopathy in Asian populations: a meta-analysis

OBJECTIVE

To assess the role of the age-related maculopathy susceptibility 2 (ARMS2) A69S polymorphism as a risk factor for polypoidal choroidal vasculopathy (PCV) in Asian populations.

METHODS

We performed a meta-analysis of the association of the A69S variant with PCV in Asian populations using data available from 14 case-control studies involving 6552 subjects. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed- and random-effects models. Sensitivity analysis also was performed.

MAIN OUTCOME MEASURES

Understanding the relationship between the A69S variant and PCV is essential to provide new insights into pathophysiology and potential targets for intervention of PCV.

RESULTS

The pooled OR in random-effects models for genotype TG+TT versus wild homozygous genotype GG is 2.39 (95% CI, 1.98-2.89), the OR of heterozygous genotype TG versus GG is 1.66 (95% CI, 1.37-2.00), the OR of homozygous genotype TT versus GG is 4.74 (95% CI, 3.94-5.70), and the OR of allele T versus G is 2.14 (95% CI, 1.79-2.56). A sensitivity analysis indicated the robustness of our findings.

CONCLUSIONS

Our analysis provides evidence that the A69S variant is associated with an increased risk of PCV in Asian populations. The variant of A69S could be a promising genetic biomarker of PCV.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.