Elevated C-Reactive Protein Levels in Patients with Polypoidal Choroidal Vasculopathy and Patients with Neovascular Age-Related Macular Degeneration

Neuroretinal degeneration in a mouse model of systemic chronic immune activation observed by proteomics

Blindness or vision loss due to neuroretinal and photoreceptor degeneration affects millions of individuals worldwide. In numerous neurodegenerative diseases, including age-related macular degeneration, dysregulated immune response-mediated retinal degeneration has been found to play a critical role in the disease pathogenesis. To better understand the pathogenic mechanisms underlying the retinal degeneration, we used a mouse model of systemic immune activation where we infected mice with lymphocytic choriomeningitis virus (LCMV) clone 13. Here, we evaluated the effects of LCMV infection and present a comprehensive discovery-based proteomic investigation using tandem mass tag (TMT) labeling and high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS). Changes in protein regulation in the posterior part of the eye, neuroretina, and RPE/choroid were compared to those in the spleen as a secondary lymphoid organ and to the kidney as a non-lymphoid but encapsulated organ at 1, 8, and 28 weeks of infection. Using bioinformatic tools, we found several proteins responsible for maintaining normal tissue homeostasis to be differentially regulated in the neuroretina and the RPE/choroid during the degenerative process. Additionally, in the organs we observed, several important protein pathways contributing to cellular homeostasis and tissue development were perturbed and associated with LCMV-mediated inflammation, promoting disease progression. Our findings suggest that the response to a systemic chronic infection differs between the neuroretina and the RPE/choroid, and the processes induced by chronic systemic infection in the RPE/choroid are not unlike those induced in non-immune-privileged organs such as the kidney and spleen. Overall, our data provide detailed insight into several molecular mechanisms of neuroretinal degeneration and highlight various novel protein pathways that further suggest that the posterior part of the eye is not an isolated immunological entity despite the existence of neuroretinal immune privilege.

Serum Amyloid A 4 as a Common Marker of Persistent Inflammation in Patients with Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Background

Neovascular age-related macular degeneration (nAMD) and its subtype, polypoidal choroidal vasculopathy (PCV), are common choroidal vasculopathies. Although they share many common clinical manifestations and treatment strategies, a lack of comprehensive analysis of these conditions means that it is difficult for researchers to further explore the common pathomechanisms of nAMD and PCV. The aim of this study was to characterize aqueous humor (AH) proteome alterations and identify a novel biomarker related to both nAMD and PCV.

Methods

Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) was adopted to analyze the AH proteomes of nAMD, PCV and controls. The target protein was validated using the enzyme-linked immunosorbent assay (ELISA) and subjected to receiver operating characteristic (ROC) curve analysis.

Results

A total of 737 different proteins were identified in all the groups, of which 544 were quantifiable. The bioinformatics analysis suggested that immune response activation is the essential event in both nAMD and PCV. Serum amyloid A (SAA) 4 is closely associated with a number of chronic inflammatory diseases, and it was enriched as the hub protein. ROC analysis showed that SAA4 could distinguish both nAMD and PCV from the controls.

Conclusion

This comprehensive study provides insights into, and furthers our understanding of, the pathological mechanism of nAMD and PCV. Additionally, the SAA4 level alteration may serve as a common biomarker of nAMD and PCV.

Canonical correlation analysis for multi-omics: Application to cross-cohort analysis

Integrative approaches that simultaneously model multi-omics data have gained increasing popularity because they provide holistic system biology views of multiple or all components in a biological system of interest. Canonical correlation analysis (CCA) is a correlation-based integrative method designed to extract latent features shared between multiple assays by finding the linear combinations of features-referred to as canonical variables (CVs)-within each assay that achieve maximal across-assay correlation. Although widely acknowledged as a powerful approach for multi-omics data, CCA has not been systematically applied to multi-omics data in large cohort studies, which has only recently become available. Here, we adapted sparse multiple CCA (SMCCA), a widely-used derivative of CCA, to proteomics and methylomics data from the Multi-Ethnic Study of Atherosclerosis (MESA) and Jackson Heart Study (JHS). To tackle challenges encountered when applying SMCCA to MESA and JHS, our adaptations include the incorporation of the Gram-Schmidt (GS) algorithm with SMCCA to improve orthogonality among CVs, and the development of Sparse Supervised Multiple CCA (SSMCCA) to allow supervised integration analysis for more than two assays. Effective application of SMCCA to the two real datasets reveals important findings. Applying our SMCCA-GS to MESA and JHS, we identified strong associations between blood cell counts and protein abundance, suggesting that adjustment of blood cell composition should be considered in protein-based association studies. Importantly, CVs obtained from two independent cohorts also demonstrate transferability across the cohorts. For example, proteomic CVs learned from JHS, when transferred to MESA, explain similar amounts of blood cell count phenotypic variance in MESA, explaining 39.0% ~ 50.0% variation in JHS and 38.9% ~ 49.1% in MESA. Similar transferability was observed for other omics-CV-trait pairs. This suggests that biologically meaningful and cohort-agnostic variation is captured by CVs. We anticipate that applying our SMCCA-GS and SSMCCA on various cohorts would help identify cohort-agnostic biologically meaningful relationships between multi-omics data and phenotypic traits.

Analysis of Systemic and Serum Risk Factors in Patients with Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

INTRODUCTION

It remains controversial whether polypoidal choroidal vasculopathy (PCV) represents a subtype of neovascular age-related macular degeneration (nAMD) or is a distinct disease entity. This study aimed to compare and analyze systemic and serum risk factors for nAMD and PCV in an aging Chinese population.

METHODS

A retrospective study was performed on 108 patients with nAMD, 131 patients with PCV, and 219 control subjects. Serum levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), apolipoprotein A1 (APOA1), apolipoprotein B (APOB), complement 3 (C3), and complement 4 (C4) together with data on systemic risk factors, including hyperlipidemia, hypertension, diabetes mellitus (DM), coronary artery disease (CAD), and asthma, were collected. Chi-square tests, independent-samples t tests, and binary logistic regression analyses were performed to evaluate the associations of risk factors with nAMD and PCV.

RESULTS

Patients with PCV and those with nAMD were likely to have hyperlipidemia (P < 0.001). CAD (P = 0.020) and hypertension (P = 0.006) correlated significantly with nAMD and PCV, respectively. Although no association of age and asthma with PCV or nAMD was found (P > 0.05), DM was associated with PCV development (OR = 0.535, P = 0.044). Regarding serum risk factors, HDL, LDL, TG, APOB, and C3 were significantly associated with nAMD (OR < 0.001, P < 0.001; OR = 0.028, P < 0.001; OR = 0.175, P < 0.001; OR = 0.922, P = 0.022; OR < 0.001, P < 0.001) and PCV (OR = 0.001, P = 0.001; OR = 0.097, P = 0.003; OR = 0.410, P = 0.037; OR = 0.895, P = 0.001; OR = 0.001, P < 0.001). Compared with nAMD, higher levels of HDL (P = 0.003) and LDL (P = 0.016) and lower levels of TG (P = 0.039) were found in patients with PCV, but the association of systemic risk factors between the two diseases was not significant (P > 0.05).

CONCLUSION

Our findings indicate that hyperlipidemia is significantly associated with both nAMD and PCV. Serum lipid and complement levels have an effect on the pathogenesis of nAMD and PCV, and consideration of the differences between systemic and serum risk factors should be taken into account in clinical management.

Polypoidal Choroidal Vasculopathy Based on Non-ICGA Criteria in White Patients With Neovascular Age-Related Macular Degeneration

PURPOSE

To determine prevalence of probable polypoidal choroidal vasculopathy (PCV) among White patients with neovascular age-related macular degeneration (nAMD) using non-indocyanine green angiography (ICGA) criteria DESIGN: Multicenter, multinational, retrospective, cross-sectional study.

METHODS

A total of 208 treatment-naive eyes from Hispanic and non-Hispanic White individuals diagnosed with nAMD were included. All underwent color fundus photography (CFP), optical coherence tomography (OCT), and fluorescein angiography (FFA). De-identified images of study eyes were sent to 2 groups of graders. Group 1 reviewed CFP, OCT, and FFA to confirm nAMD diagnosis. Group 2 reviewed CFP and OCT to determine highly suggestive features for PCV. Probable PCV diagnosis defined as the presence of ≥2 of 4 highly suggestive features for PCV: notched or fibrovascular pigment epithelial detachment (PED) on CFP, sharply-peaked PED, notched PED, and hyperreflective ring on OCT.

RESULTS

Eleven eyes were excluded because of poor image quality (6) or non-nAMD diagnosis (5). Of 197 eligible eyes (197 patients), the mean age (SD) was 78.8 years (8.9), 44.2% were men, 26.4% were Hispanic, and 73.6% were non-Hispanic White individuals; 41.1%, 23.4%, 9.1%, and 2.5% had ≥1, ≥2, ≥3, and 4 highly suggestive features. Results showed that 23.4% (95% CI, 17.6%-29.9%) had probable PCV diagnosis. Predominantly occult CNV was more frequently found in probable PCV than nAMD subgroup (84.8% vs 64.9%, P = .01). Hispanic White individuals had a lower prevalence of probable PCV than non-Hispanic White individuals (9.6% vs 28.2%, P = .006) CONCLUSIONS: These findings suggest that probable PCV occurs between 17.6% and 29.9% in White individuals with nAMD, and more commonly in non-Hispanic than in Hispanic White individuals.

Age-related macular degeneration and myeloproliferative neoplasms - A common pathway

DANSK RESUMÉ (DANISH SUMMARY): Aldersrelateret makuladegeneration (AMD) er den hyppigste årsag til uopretteligt synstab og blindhed i højindkomstlande. Det er en progredierende nethindesygdom som gradvist fører til ødelaeggelse af de celler som er ansvarlige for vores centralsyn. De tidlige stadier er ofte asymptomatiske, imens senstadie AMD, som opdeles i to former, neovaskulaer AMD (nAMD) og geografisk atrofi (GA), begge udviser gradvist synstab, dog generelt med forskellig hastighed. Tidlig AMD er karakteriseret ved tilstedevaerelsen af druser og pigmentforandringer i nethinden mens nAMD og GA udviser henholdsvis karnydannelse i og atrofi af nethinden. AEtiologien er multifaktoriel og udover alder omfatter patogenesen miljø- og genetiske risikofaktorer. Forskning har specielt fokuseret på lokale forandringer i øjet hvor man har fundet at inflammation spiller en betydelig rolle for udviklingen af sygdommen, men flere studier tyder også på at systemiske forandringer og specielt systemisk inflammation spiller en vaesentlig rolle i patogenesen. De Philadelphia-negative myeloproliferative neoplasier (MPNs) er en gruppe af haematologiske kraeftsygdomme med en erhvervet genetisk defekt i den tidlige pluripotente stamcelle som medfører en overproduktion af en eller flere af blodets modne celler. Sygdommene er fundet at udvikle sig i et biologisk kontinuum fra tidligt cancerstadie, essentiel trombocytose (ET) over polycytaemi vera (PV) og endelig til det sene myelofibrose stadie (PMF). Symptomer hos disse patienter skyldes isaer den aendrede sammensaetning af blodet, hyperviskositet, kompromitteret mikrocirkulation og nedsat vaevsgennemblødning. Den øgede morbiditet og mortalitet beror i høj grad på tromboembolier, blødninger og leukemisk transformation. En raekke mutationer som driver MPN sygdommene er identificeret, bl.a. JAK2V617F-mutationen som medfører en deregulering JAK/STAT signalvejen, der bl.a. har betydning for cellers vaekst og overlevelse. Et tidligere stort registerstudie har vist at patienter med MPNs har en øget risiko for neovaskulaer AMD og et pilotstudie har vist øget forekomst af intermediaer AMD. Dette ønsker vi at undersøge naermere i et større studie i dette Ph.d.- projekt. Flere studier har også vist at kronisk inflammation spiller en vigtig rolle for både initiering og udvikling af den maligne celleklon hos MPNs og herfra er en "Human Inflammationsmodel" blevet udviklet. Siden er MPN sygdommene blevet anvendt som "model sygdomme" for en tilsvarende inflammationsmodel for udvikling af Alzheimers sygdom. I dette Ph.d.-projekt vil vi tilsvarende forsøge at undersøge systemisk inflammation i forhold til forekomst af druser. Det vil vi gøre ved at sammenligne systemiske immunologiske markører som tidligere er undersøgt hos patienter med AMD og sammenligne med MPN. Specielt er vi interesseret i systemiske immunologiske forskelle på patienter med MPN og druser (MPNd) og MPN med normale nethinder (MPNn). Denne afhandling består af to overordnede studier. I Studie I, undersøgte vi forekomsten af retinale forandringer associeret med AMD hos 200 patienter med MPN (artikel I). Studie II, omhandlede immunologiske ligheder ved AMD og MPN, og var opdelt i yderligere tre delstudier hvor vi undersøgte hhv. systemiske markører for inflammation, aldring og angiogenese (artikel II, III og IV). Vi undersøgte markørerne i fire typer af patienter: nAMD, intermediaer AMD (iAMD), MPNd og MPNn. Undersøgelsen af forskelle mellem MPNd og MPNn, vil gøre det muligt at identificere forandringer i immunsystemet som kunne vaere relevante for AMD-patogenesen. Vi vil endvidere sammenholde resultaterne for patienter med MPN med patienter som har iAMD og nAMD. I studie I (Artikel I) fandt vi at patienter med MPN har en signifikant højere praevalens af store druser og AMD tidligere i livet sammenlignet med estimater fra tre store befolkningsundersøgelser. Vi fandt også at forekomst af druser var associeret med højere neutrofil-lymfocyt ratio, hvilket indikerer et højere niveau af kronisk inflammation i patienterne med druser sammenlignet med dem uden druser. I studie II (Artikel II, III og IV) fandt vi flere immunologiske forskelle mellem patienter med MPNd og MPNn. Da vi undersøgte markører for inflammation, fandt vi en højere grad af systemisk inflammation i MPNd end MPNn. Dette blev vist ved en højere inflammationsscore (udregnet på baggrund af niveauer af pro-inflammatoriske markører), en højere neutrofil-lymfocyt ratio, samt indikationer på et dereguleret komplementsystem. Ved undersøgelse af aldringsmarkører fandt vi tegn på accelereret immunaldring hos MPNd i forhold til MPNn, hvilket kommer til udtryk ved en større procentdel af "effector memory T celler". Endelig fandt vi en vaesentlig lavere ekspression af CXCR3 på T celler og monocytter hos patienter med nAMD sammenlignet med iAMD, MPNd og MPNn. Dette er i overensstemmelse med tidligere studier hvor CXCR3 ekspression er fundet lavere end hos raske kontroller. Derudover fandt vi en faldende CXCR3 ekspression på monocytter over det biologiske MPN-kontinuum. Disse studier indikerer en involvering af CXCR3 i både nAMD og PMF, begge sygdomsstadier som er karakteriseret ved angiogenese og fibrose. Ud fra resultaterne af denne afhandling kan vi konkludere at forekomsten af druser og AMD hos MPN er øget i forhold til baggrundsbefolkningen. Endvidere viser vores resultater at systemisk inflammation muligvis spiller en vaesentlig større rolle i udviklingen af AMD end tidligere antaget. Vi foreslår derfor en AMD-model (Figur 18) hvor inflammation kan initiere og accelerere den normale aldersafhaengige akkumulation af affaldsstoffer i nethinden, som senere udvikler sig til druser, medførende øget lokal inflammation og med tiden tidlig og intermediaer AMD. Dette resulterer i den øgede risiko for udvikling til de invaliderende senstadier af AMD. ENGLISH SUMMARY: Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss and blindness in high-income countries. It is a progressive retinal disease leading to damage of the cells responsible for central vision. The early stages of the disease are often asymptomatic, while late-stage AMD, which is divided into two entities, neovascular AMD and geographic atrophy (GA), both show vision loss, though generally with different progression rates. Drusen and pigmentary abnormalities in the retina characterise early AMD, while nAMD and GA show angiogenesis in and atrophy of the retina, respectively. The aetiology is multifactorial and, in addition to ageing, which is the most significant risk factor for developing AMD, environmental- and genetic risk factors are implicated in the pathogenesis. Research has focused on local changes in the eye where inflammation has been found to play an essential role, but studies also point to systemic alterations and especially systemic inflammation to be involved in the pathogenesis. The Philadelphia-negative myeloproliferative neoplasms (MPN) are a group of haematological cancers with an acquired genetic defect of the pluripotent haematopoietic stem cell, characterised by excess haematopoiesis of the myeloid cell lineage. The diseases have been found to evolve in a biological continuum from early cancer state, essential thrombocythemia, over polycythaemia vera (PV), to the advanced myelofibrosis stage (PMF). The symptoms in these patients are often a result of the changes in the blood composition, hyperviscosity, microvascular disturbances, and reduced tissue perfusion. The major causes of morbidity and mortality are thromboembolic- and haemorrhagic events, and leukemic transformation. A group of mutations that drive the MPNs has been identified, e.g., the JAK2V617F mutation, which results in deregulation of the JAK/STAT signal transduction pathway important, for instance, in cell differentiation and survival. A previous large register study has shown that patients with MPNs have an increased risk of neovascular AMD, and a pilot study has shown an increased prevalence of intermediate AMD. We wish to study this further in a larger scale study. Several studies have also shown that systemic inflammation plays an essential role in both the initiation and progression of the malignant cell clone in MPNs. From this knowledge, a "Human inflammation model" has been developed. Since then, the MPNs has been used as model diseases for a similar inflammation model for the development of Alzheimer's disease. In this PhD project, we would like to investigate systemic inflammation in relation to drusen presence. We will do this by comparing systemic immunological markers previously investigated in patients with AMD and compare with MPN. We are primarily interested in systemic immunological differences between patients with MPN and drusen (MPNd) and MPN with normal retinas (MPNn). This thesis consists of two main studies. Study I investigated the prevalence of retinal changes associated with AMD and the prevalence of different AMD stages in 200 patients with MPN (paper I). Study II examined immunological similarities between AMD and MPNs. This study was divided into three substudies exploring systemic markers of inflammation, ageing and angiogenesis, respectively. This was done in four types of patients: nAMD, intermediate AMD (iAMD), MPNd and MPNn. Investigating, differences between MPNd and MPNn, will make it possible to identify changes in the immune system, relevant for AMD pathogenesis. Additionally, we will compare patients with MPNs with patients with iAMD and nAMD. In study I (Paper I), we found that patients with MPNs have a significantly higher prevalence of large drusen and consequently AMD from an earlier age compared to the estimates from three large population-based studies. We also found that drusen prevalence was associated with a higher neutrophil-to-lymphocyte ratio indicating a higher level of chronic low-grade inflammation in patients with drusen compared to those without drusen. In study II (papers II, III and IV), we found immunological differences between patients with MPNd and MPNn. When we investigated markers of inflammation, we found a higher level of systemic inflammation in MPNd than MPNn. This was indicated by a higher inflammation score (based on levels of pro-inflammatory markers), a higher neutrophil-to-lymphocyte ratio, and indications of a deregulated complement system. When examining markers of ageing, we found signs of accelerated immune ageing in MPNd compared to MPNn, shown by more senescent effector memory T cells. Finally, when exploring a marker of angiogenesis, we found a lower CXCR3 expression on monocytes and T cells in nAMD compared to iAMD, MPNd and MPNn, in line with previous studies of nAMD compared to healthy controls. Further, we found decreasing CXCR3 expression over the MPN biological continuum. These studies indicate CXCR3 involvement in both nAMD and PMF, two disease stages characterised by angiogenesis and fibrosis. From the results of this PhD project, we can conclude that the prevalence of drusen and AMD is increased in patients with MPN compared to the general population. Further, our results show that systemic inflammation may play a far more essential role in AMD pathogenesis than previously anticipated. We, therefore, propose an AMD model (Figure 18) where inflammation can initiate and accelerate the normal age-dependent accumulation of debris in the retina, which later evolve into drusen, resulting in increased local inflammation, and over time early- and intermediate AMD. This results in the increased risk of developing the late debilitating stages of AMD.

Current Trends in Clinical Characteristics, Diagnosis, and Treatment of Polypoidal Choroidal Vasculopathy: A Perspective from Vietnam

Polypoidal choroidal vasculopathy (PCV) is a common choroidal disease in the Asian population including Vietnam and is characterized by subretinal red-orange nodules, pigmented epithelium detachment, and massive subretinal hemorrhage. The recent focus on PCV in Vietnam can be attributed to advancements in PCV diagnosis and treatment. However, there is a scarcity of published literature and clinical data on PCV in the Vietnamese population, highlighting a key knowledge gap in this region. In order to address this gap, we gathered the opinions of experienced clinicians and retinal experts in Vietnam and reviewed available medical literature with the aim of: (i) providing an overview of PCV in the Vietnamese population—in terms of epidemiology, clinical characteristics, and management; (ii) tailoring international/national guidelines for the diagnosis and management of PCV, in line with available resources and medical equipment in Vietnam; and (iii) identifying gaps in clinical data in order to guide future PCV research in Vietnam and other countries with similar clinical conditions. The present review will enable healthcare providers and researchers to gain insight into current clinical practices and the limitations of PCV management in Vietnam and provide optimal and effective solutions.

Cytokine profiles of macular neovascularization in the elderly based on a classification from a pachychoroid/drusen perspective

PURPOSE

To classify macular neovascularization (MNV) based on pachychoroid and drusen features and to examine the aqueous humor cytokine signatures of each group.

METHODS

In total, 106 consecutive eyes with treatment-naïve MNV and 104 control eyes were examined. The aqueous humor concentrations of 15 cytokines were compared among the MNV groups classified based on the presence of drusen and/or pachychoroid features. Multidimensional scaling analysis was used to visualize the similarity level of the MNV subtypes according to their cytokine profiles.

RESULTS

Thirty-one, 18, 43, and 10 eyes were classified into the pachychoroid-associated, drusen-associated, pachychoroid/drusen-associated, and non-drusen/non-pachychoroid MNV groups, respectively. Compared with the control group, cytokines were differently upregulated among the MNV groups. CRP and CXCL12 were significantly upregulated in all MNV groups, whereas CXCL13 and IL-8 were significantly upregulated in three MNV groups, excluding the non-pachychoroid/non-drusen-associated MNV group. Ang-2 was significantly upregulated in three MNV groups except the drusen-associated MNV group. PlGF was significantly upregulated in the pachychoroid-associated and drusen-associated MNV groups. CCL-2 was significantly upregulated in the pachychoroid-associated and pachychoroid/drusen-associated MNV groups. VEGF was downregulated in the pachychoroid-associated and drusen-associated MNV groups, respectively. Multidimensional scaling analysis showed a distinct cytokine profile for each MNV group.

CONCLUSION

All MNV groups showed distinct cytokine profiles. Eyes with "neovascular age-related macular degeneration with drusen and concomitant pachychoroid" may share a similar etiology to those with "pachychoroid neovasculopathy" and "choroidal neovascularization with drusen," but have a distinct etiology to those without these. These findings suggest the importance of evaluating drusen and the choroid during the diagnosis of neovascular age-related macular degeneration.

Association between C-reactive protein and polypoidal choroidal vasculopathy: a systematic review and meta-analysis

Aetiological processes of polypoidal choroidal vasculopathy (PCV) remains poorly understood, but several studies indicate that immunity may play a role and report elevated levels of systemic C-reactive protein (CRP). In this systematic review and meta-analysis, we summarize available evidence in the field. We searched the databases PubMed/MEDLINE, EMBASE, Web of Science and the Cochrane Central on 19 March 2020. Two independent authors reviewed the studies and extracted data. Two independent authors reviewed the studies, extracted data and evaluated risk of bias within individual studies. Studies were reviewed in the text qualitatively and measures of association were included for quantitative analyses. Results from univariate analyses and multivariate-adjusted analyses were included for separate meta-analyses to evaluate whether the association was only due to factors associated with PCV. Four studies (246 patients with PCV and 2861 control individuals) were identified and included for a qualitative and quantitative analysis. Increased CRP was associated with PCV when pooling both univariate measures (OR 3.54, 95% CI: 2.13-5.89, p < 0.0001) and multivariate-adjusted measures (OR 3.05, 95% CI: 1.56-5.98, p = 0.0011). Sensitivity analyses confirmed robustness of the results. Increased CRP is associated to PCV, even after adjusting for demographics, lifestyle factors and co-morbidities. Clinical value of CRP in relation to PCV remains unclear, but the association gives much needed insight into the aetiology of a poorly understood disease.

Physics-based modeling of Age-related Macular Degeneration-A theoretical approach to quantify retinal and choroidal contributions to macular oxygenation

We developed a mathematical model to characterize how macular oxygenation may be affected by abnormalities in the retinal and choroidal oxygen supplies. The macular region is modeled as a layered structure including: ganglion cell and nerve fiber layers, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, inner segment of photoreceptors layer and retinal pigmented epithelium. Each layer is characterized by specific levels of oxygen consumption. The vitreous and the choroid are located at the macula boundary and provide oxygen via boundary conditions of Dirichlet type. The three capillary plexi (superficial, intermediate, and deep) of the retinal circulation pierce the macular layers and provide oxygen via a volumetric source that depends on the retinal blood flow. Oxygen profiles through the macular tissue are calculated by simulating the balance among oxygen supply, consumption and diffusion in: (a) physiological baseline conditions; (b) retinal blood flow reduced by 10%, 30% and 50% with respect to baseline; (c) choroidal oxygen level diminished by 10%, 30% and 50% with respect to baseline. Model simulations predict that: (1) the oxygenation of the foveal avascular zone is not affected by reduction in retinal blood flow; (2) a reduction in choroidal oxygen supply significantly affects the outer layers, especially the photoreceptors and outer nuclear layers; (3) the impact of reduction in choroidal oxygen supply is larger in the region more proximal to the macular center; (4) the impact of reduction in retinal blood flow is larger in the region more proximal to the macular periphery. The proposed mathematical model suggests that changes in retinal and choroidal oxygen supplies impact the oxygenation of the macular tissue differentially. These results may help better understand the pathogenesis of macular degeneration.

Associations between seven-year C-reactive protein trajectory or pack-years smoked with choroidal or retinal thicknesses in young adults

Inflammation and cigarette smoking predispose to macular diseases, and choroidal and retinal thinning. We explored the choroidal and retinal thicknesses in young adults against their 7-year C-reactive protein (CRP) level trajectory and pack-years smoked. Participants from the Raine study, a longitudinal cohort study, had serum CRP levels analysed at the 14-, 17-, and 20-year follow-ups. Group-based trajectory modelling was used to classify participants according to their 7-year CRP levels. At the 20-year follow-up (at 18–22 years old), participants completed questionnaires on their smoking history, and underwent optical coherence tomography imaging to obtain their choroidal and retinal thicknesses at the macula. Three CRP trajectories were identified: consistently low CRP levels (78% of sample), increasing (11%), or consistently high (11%). 340 and 1035 participants were included in the choroidal and retinal thickness analyses, respectively. Compared to those in the “Low” trajectory group, participants in the “Increasing” and “High” groups had 14–21 μm thinner choroids at most macular regions. Every additional pack-year smoked was linked with a 0.06–0.10 μm thinner retina at the inner and outer macular rings, suggesting a dose-dependent relationship between smoking and thinner retinas. These associations may suggest that an increased risk of future visual impairment or eye disease associated with these risk factors may be present since young adulthood.

Idiopathic polypoidal choroidal vasculopathy: a review of literature with clinical update on current management practices

PURPOSE

Polypoidal choroidal vasculopathy is a major cause of visual disability in a vast majority of Asian population due to exudative maculopathy. Although it is a distinctive disease entity with characteristic pathophysiology, genetics, immunology and clinical features, but it is still misdiagnosed as neovascular age related macular degeneration as both the diseases are a part of pachychoroid spectrum and have some similar features. Also, there are varied options for the management of this disease, but there are no clear recommendations. So, a detailed review of the literature has been done along with special attention to the recent therapeutic advances to help the readers get a better understanding of the disease and its current management practices.

METHOD

Detailed review of literature regarding polypoidal choroidal vasculopathy was done. The disease pathophysiology, genetics, risk factors, diagnostic modalities along with current treatment guidelines were extensively studied and compiled.

RESULT

A comprehensive clinical update on polypoidal choroidal vasculopathy was compiled with special emphasis on the recent diagnostic modalities and treatment guidelines.

CONCLUSION

Polypoidal choroidal vasculopathy is a distinct clinical entity which can be diagnosed based on indocyanine green angiography and optical coherence tomography. Treatment includes various options like photodynamic therapy, anti VEGF agents and thermal laser ablation. A review of literature has been done and recent diagnostic modalities with management practices have been compiled for the better understanding of the disease.

Systemic levels of C-reactive protein in patients with age-related macular degeneration: A systematic review with meta-analyses

Ageing of the retina is associated with the gradual accumulation of basal deposits and the formation of drusen. However, in some individuals this process is exacerbated and causes development of age-related macular degeneration. Late features of age-related macular degeneration include geographic atrophy of the neuroretina or choroidal neovascularization. Such changes lead to blurred vision, metamorphopsia, and scotoma, and is the leading cause of vision loss in developed countries. Chronic low-grade inflammation has been investigated because of its relationship to ageing and its role in the gap between chronological and biological ageing. Here, we systematically reviewed studies investigating systemic C-reactive protein in patients with age-related macular degeneration. We identified 53 studies with 60,598 participants (10,392 patients and 38,901 controls). Our meta-analyses revealed that early age-related macular degeneration was not associated to systemic C-reactive protein (Cohen's d = 0.03 [-0.04 to 0.10]; OR = 1.06 [0.93-1.20]; P = 0.39) whereas late age-related macular degeneration (Cohen's d = 0.38 [0.24 to 0.51]; OR = 1.99 [1.55-2.52]; P < 0.0001), and neovascular age-related macular degeneration (Cohen's d = 0.40 [0.24 to 0.56]; OR = 2.07 [1.55-2.76]; P < 0.0001) was associated with a small-to-moderate increase in systemic C-reactive protein. Our review provides an overview of this extensively studied field, provide summary estimates that provide insight into when and to what extent systemic C-reactive protein is associated with age-related macular degeneration, and help in distinguishing the potentially reversible disease processes from that of irreversible retinal ageing.

Association of CRP levels with ARMS2 and CFH variants in age-related macular degeneration

PURPOSE

To investigate whether plasma high sensitivity C-reactive protein (hs-CRP) level is associated with exudative age-related macular degeneration (AMD) as well as variants of ARMS2 A69S and CFH I62V in patients with exudative AMD.

METHODS

A case-control study was done comparing CRP among patients with exudative AMD including those with polypoidal choroidal vasculopathy, typical AMD and retinal angiomatous proliferation, and CRP were also compared between cases and controls. Plasma CRP was measured from peripheral blood using latex nepherometry for all participants. Genotyping of ARMS2 A69S and CFH I62V was performed for all patients with exudative AMD using TaqMan technology.

RESULTS

Among 125 patients with exudative AMD, including 31 with typical neovascular AMD, 73 with PCV and 21 with RAP lesions and 150 controls, CRP levels were higher in exudative AMD than in controls. (P = 2.7 × 10^-5) There was not a significant difference in hs-CRP levels among AMD subtypes. Neither variants of ARMS2 nor CFH was associated with hs-CRP level in patients with exudative AMD. A multiple regression analysis revealed that gender male, presence of exudative AMD and presence of cardiovascular diseases were associated with increased plasma hs-CRP.

CONCLUSIONS

Plasma hs-CRP was elevated independent of variants of ARMS2 A69S and CFH I62V in patients with exudative AMD.

Plasma levels of inflammatory chemokines in patients with polypoidal choroidal vasculopathy

PURPOSE

Chemokines are a group of cytokines that guide immune cell migration. We studied plasma levels of inflammatory chemokines in patients with polypoidal choroidal vasculopathy (PCV) and compared with healthy age-matched control individuals.

METHODS

This was a clinic-based prospective case-control study of participants (n = 60) with either PCV (n = 26) or age-matched healthy controls (n = 34). We sampled fresh venous blood and isolated plasma for analysis. We used U-PLEX Human Assays to quantify concentrations of the inflammatory chemokines MCP-1/CCL2, RANTES/CCL5, eotaxin/CCL11, IP-10/CXCL10 and fractalkine/CX3CL1.

RESULTS

Plasma levels of fractalkine was significantly higher in patients with PCV when compared to healthy controls (mean ± SD: 7291 ± 2461 pg/ml versus 5879 ± 2001 pg/ml; p = 0.021). Plasma levels of MCP-1 (p = 0.846), RANTES (p = 0.288), eotaxin (p = 0.496) and IP-10 (p = 0.352) did not differ significantly between the groups. To evaluate possible biomarker quality of fractalkine, we used a ROC analysis and found a positive but weak discriminatory ability (AUC = 0.68).

CONCLUSION

Patients with PCV have a higher plasma level of fractalkine. Although the differences do not possess strong biomarker qualities, they inform on disease processes of a poorly understood disease and suggest that the fractalkine-CX3CR1 axis may be involved. As this study did not investigate local chemokine concentrations, we are unable to confirm or disprove any local chorioretinal interaction, and our findings should be interpreted with such caution.

Latest Developments in Polypoidal Choroidal Vasculopathy: Epidemiology, Etiology, Diagnosis, and Treatment

Polypoidal choroidal vasculopathy (PCV) is a condition characterized by multiple, recurrent, serosanguineous pigment epithelial detachments, and neurosensory retinal detachments due to abnormal aneurysmal neovascular lesions. It is generally considered as a variant of neovascular age-related macular degeneration, but there are some differences between the clinical presentation, natural history, and treatment response between patients with PCV and typical neovascular age-related macular degeneration patients. Over the past decade, new research and technological advancements have greatly improved our understanding of the PCV disease process and the management of PCV. This review aims to summarize the recent research findings to highlight the epidemiology, pathogenesis, genetics, the application of various diagnostic tools for PCV, and the available treatment options for PCV.

Polypoidal Choroidal Vasculopathy in Congolese Patients

Purpose

Polypoidal choroidal vasculopathy (PCV) is a visually debilitating disease that mostly affects people of African and Asian heritage. Indocyanine green angiography (ICGA) is the recommended exploratory method for definitive diagnosis. The disease has been extensively described in Asians and Caucasians, but not in Africans. This study was conducted to document the clinical presentation and optical coherence tomography features of polypoidal choroidal vasculopathy (PCV) in Congolese patients.

Methods

A prospective case series of patients with PCV was performed between January 2017 and June 2019. Routine ocular examination was performed including best corrected visual acuity measurement, slit-lamp examination, dilated direct fundoscopy, and spectral domain optical coherence tomography (OCT). The diagnosis was based on a combination of clinical and OCT signs.

Results

Fourteen patients were diagnosed with PCV during this period. The average age was 64.7 ± 6.9 years. There were 8 females. Ten (71.4%) patients had systemic hypertension. Most patients (n = 9, 64.3%) had bilateral involvement. Blurred vision was the most common complaint (71.4%). The main clinical presentation was subretinal exudates, seen in 19 (82.6%) eyes of 11 (78.6%) patients and subretinal hemorrhage in 10 (43.5%) eyes. Macular localization was found in 16 eyes (69.5%) of 12 (85.7%) patients. Drusen were observed in 35.7% of the patients. On OCT imaging, thumb-like pigment epithelial detachment and subretinal exudation were the most frequent features, observed in 92.9% and 71.4% of the patients, respectively.

Conclusions

PCV in Congolese patients showed features that are more similar to those observed in Caucasians. In this setting where indocyanine green angiography is not available, OCT facilitates the diagnosis of PCV.

Associations of systemic, serum lipid and lipoprotein metabolic pathway gene variations with polypoidal choroidal vasculopathy in China

BACKGROUND

To investigate the association of systemic, serum lipids and genetic variants in the high-density lipoprotein (HDL) metabolic pathway with polypoidal choroidal vasculopathy (PCV) in China.

METHODS

The case-control study was included 150 controls and 66 cases with PCV. Serum levels of total cholesterol (TC), low-density lipoprotein (LDL), HDL, triglycerides (TG), apolipoprotein A1 (APOA1), apolipoprotein B (APOB) together with systemic risk factors including gender, hyperlipidemia, diabetes mellitus (DM), hypertension, coronary artery disease (CAD) and asthma were identified. All subjects were genotyped for four single nucleotide polymorphisms (SNPs) from three genes in the HDL metabolic pathway: rs10468017 of hepatic lipase (LIPC), rs12678919 of lipoprotein lipase (LPL), rs3764261 and rs173539 of cholesterol ester transfer protein (CETP) with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Student's t-tests, chi-square tests, anova and logistic regression were used to evaluate associations.

RESULTS

Hyperlipidemia was a risk factor (odds ratio (OR) = 1.19, P = 0.001) for PCV. HDL, LDL and APOB levels were associated with PCV (OR = 0.001, P = 0.004; OR = 0.099, P = 0.010; OR = 0.839, P = 0.018). Higher level of TC was potently associated with increased risk of PCV (OR = 109.8, P = 0.000). LIPC rs10468017 was a risk factor for PCV (OR = 11.68, P = 0.000). CETP rs3764261 conferred a decreased risk for PCV (OR = 0.08, P = 0.000). No associations of LPL rs12678919 or CETP rs173539 with PCV were found. Mean level of HDL increased with T allele of the CETP gene (p = 0.026): 1.24 mmol/L (±0.31) for the GG genotype and 1.66 mmol/L (±0.54) for the TT genotype. Additionally, T allele was associated with the following increase in APOA1: 136.78 mg/dl (±20.53) for the CC genotype and 149.57 mg/dl (±22.67) for the TT genotype of LIPC and 137.91 mg/dl (±20.36) for the GG genotype and 162.67 mg/dl (±22.50) for the TT genotype of CETP gene.

CONCLUSION

Our study suggested that the significant association was found between hyperlipidemia, the serum levels of TC, HDL, LDL and APOB and PCV. The result of present study also showed that the association of LIPC rs10468017 and CETP rs3764261 with PCV.

Cytokine Profiling in Patients With Exudative Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Purpose

The purpose of this study was to investigate the cytokine profiles in plasma and aqueous humor of patients with choroidal neovascularization (CNV) due to exudative AMD and polypoidal choroidal vasculopathy (PCV).

Methods

In this cross-sectional study, 16 patients clinically diagnosed with AMD, 18 patients with PCV, and 50 age- and sex-matched cataract patients without AMD/PCV (controls) were enrolled. Study subjects were treatment naïve, and 200 μL undiluted aqueous humor and 5 mL peripheral venous blood were collected from the study subjects. Clinical samples were analyzed for 41 different cytokines by Luminex bead-based multiplex assay. Cytokines concentrations with detection rates of 50% or more were included for the analysis, and the differences in plasma and aqueous humor cytokines levels between each group were analyzed.

Results

The age of the patients with AMD and PCV was 70.62 ± 10.15 (mean ± SD) and 71.48 ± 9.08 years, respectively, and that in the control group was 62.8 ± 10.67 years. Aqueous humor cytokines growth-regulated oncogene (GRO), macrophage-derived chemokine (MDC), and macrophage inflammatory protein (MIP)-1α were significantly higher in AMD patients than controls (all P < 0.04), and GRO, MDC, MIP-1α, IL-8, IFN-γ-inducible protein 10, and monocyte chemotactic protein levels were significantly higher in PCV patients than controls (all P < 0.03). Soluble CD40 ligand and platelet-derived growth factor-AA levels were higher in plasma of healthy controls compared with AMD subjects. No significant differences in cytokine levels were observed between AMD and PCV patients for both plasma and aqueous humor.

Conclusions

In AMD and PCV patients, our data suggest that the pathologic changes are primarily driven by dysregulation of local immune factors in the eye, whereas the plasma cytokine levels are not elevated.

Polypoidal choroidal vasculopathy: a comprehensive clinical update

Polypoidal choroidal vasculopathy as a disease is yet to be comprehended completely. The clinical features consisting of huge serosanguineous retinal pigment epithelial and neurosensory layer detachments, although unique may closely mimick neovascular age-related macular degeneration and other counterparts. The investigative modalities starting from indocyanine angiography to optical coherence tomography angiography provide diagnostic challenges. The management strategies based on the available therapies are plenty and not vivid. A detailed review with clarifying images has been compiled with an aim to help the readers in getting a better understanding of the disease.

Polypoidal Choroidal Vasculopathy

Purpose of review

The aim of this review is to summarize developments in the treatment of active polypoidal choroidal vasculopathy (PCV). PCV is associated with a poor visual prognosis as a consequence the condition's hallmark polypoidal dilatation and a branching network resulting in recurrent hemorrhages and serous leakage.

Recent findings

Recent research has provided new insights into the pathogenesis of PCV. While still considered a subtype of age-related macular degeneration, suggestions that PCV belongs to a spectrum of conditions that present with a pachychoroid are increasingly well accepted. Treatment remains challenging. Combination therapy (photodynamic therapy (PDT) and intravitreal anti-vascular endothelial growth factor (VEGF)) is associated with higher polyp closure rate, but polyp closure rate has not been correlated with superior visual outcomes. Current data points to non-inferiority of anti-VEGF alone versus combined with PDT when final vision acuity is the study outcome.

Summary

PCV remains a clinical challenge. Classification and treatment of the condition continues to evolve. Combination therapy may not be superior to anti-VEGF treatment alone in terms of visual acuity outcome, however data on long-term recurrence should be compared in formulating preferred treatment plans.

Plasma markers of chronic low-grade inflammation in polypoidal choroidal vasculopathy and neovascular age-related macular degeneration

PURPOSE

Ageing is the strongest predictor of neovascular age-related macular degeneration (AMD), where neuroinflammation is known to play a major role. Less is known about polypoidal choroidal vasculopathy (PCV), which is an important differential diagnosis to neovascular AMD. Here, we report plasma markers of inflammation with age (inflammaging) in patients with PCV, patients with neovascular AMD and a healthy age-matched control group.

METHODS

We isolated plasma from fresh venous blood obtained from participants (n = 90) with either PCV, neovascular AMD, or healthy maculae. Interleukin(IL)-1β, IL-6, IL-8, IL-10 and tumour necrosis factor receptor 2 (TNF-R2) were measured using U-PLEX Human Assays. Routine plasma C-reactive protein (CRP) was measured using Dimension Vista 1500.

RESULTS

Patients with PCV had plasma levels of IL-1β, IL-6, IL-8, IL-10 and TNF-R2 similar to that in healthy controls. Patients with neovascular AMD had significantly higher plasma IL-1β, IL-6 and IL-10 than healthy controls, whereas no significant differences were observed for plasma IL-8 and TNF-R2. Differences between plasma IL-1β, IL-6 and IL-10 possessed a positive but weak ability in discriminating neovascular AMD from PCV. Both patients with PCV and patients with neovascular AMD had significantly higher levels of routine plasma CRP.

CONCLUSION

Patients with PCV differ from patients with neovascular AMD in terms of plasma inflammaging profile. Apart from increased CRP, no signs of inflammaging were observed in patients with PCV. In patients with neovascular AMD, we find a specific angiogenesis-twisted inflammaging profile.

Polypoidal Choroidal Vasculopathy Complicating Retinal Laser in Quiescent Uveitis

A 58-year-old Afro-Caribbean gentleman with a diagnosis of quiescent systemic lupus erythematosus- (SLE-) related occlusive retinal vasculitis was previously treated with sector pan-retinal photocoagulation in his right eye to control temporal retinal neovascularization. At routine review he was found to have a focal area of subretinal fluid in the temporal macula sparing an ischaemic fovea. Fundus fluorescein angiography and indocyanine green angiography confirmed a branching vascular network (BVN) and terminal polys (i.e., polypoidal choroidal vasculopathy (PCV)). Interestingly, the BVN arose within an old laser scar. To our knowledge this is the first report of PCV in uveitis in an Afro-Caribbean patient and of the lesions arising within a laser scar.

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.

Systemic inflammation and eye diseases. The Beijing Eye Study

Purpose

Systemic inflammation is potentially associated with ocular diseases such as late age-related macular degeneration (AMD). Using the serum concentration of high-sensitive C-reactive protein (hs-CRP) as surrogate of systemic inflammation, we examined potential associations between the serum hs-CRP concentration and the presence and degree of eye diseases.

Methods

The population-based Beijing Eye Study included 3468 Chinese individuals. The study participants underwent a standardized interview and a detailed ophthalmic examination. The serum concentration of hs-CRP was determined.

Results

Out of 3468 participants, 2452 (70.7%) individuals (mean age:63.4±9.4 year; range:50–91 years) had hs-CRP measurements (mean:1.96±4.07mg/L). In multivariate analysis, higher serum concentration of hs-CRP was significantly (regression coefficient r: 0.21) associated with a higher level of diabetic retinopathy (P = 0.007; standardized regression coefficient beta:0.06; non-standardized regression coefficient B:1.35; 95% confidence interval (CI):0.37,2.22) and polypoidal choroidal vasculopathy (P = 0.002;beta:0.06;B:6.22;95%CI:2.24,10.2) after adjusting for higher serum concentration of high-density lipoproteins (P<0.001;beta:-0.12;B:-1.31;95%CI:-1.77,-0.85), higher body mass index (P = 0.01;beta:0.06;B:0.06;95%CI:0.01, 0.11), lower level of education (P = 0.04;beta:-0.06;B:-0.22;95%CI:-0.42,-0.02), lower cognitive function score (P = 0.01;beta:-0.07;B:-0.08;95%CI:-0.13,-0.02). If the presences of other ocular diseases were added to the model, the presence of glaucoma (P = 0.99), open-angle glaucoma (P = 0.80), angle-closure glaucoma (P = 0.67), pseudoexfoliation (P = 0.18), nuclear cataract (P = 0.30), cortical cataract (P = 0.15), subcapsular cataract (P = 0.59), retinal vein occlusions (P = 0.33), central serous choroidopathy (P = 0.44), early stage of age-related macular degeneration (AMD) (P = 0.46), intermediate stage of AMD (P = 0.20) and late stage of AMD (P = 0.91) including geographic atrophy (P = 0.60) or neovascular AMD (P = 0.68) were not significantly associated with the serum concentration of hs-CRP.

Conclusions

In Chinese aged 50+ years, higher serum concentration of hs-CRP was significantly associated with a higher level of diabetic retinopathy and higher frequency of polypoidal choroidal vasculopathy. Other major ocular disorders, namely glaucoma including open-angle glaucoma and angle-closure glaucoma, pseudoexfoliation, nuclear, cortical or subcapsular cataract, retinal vein occlusions, central serous choroidopathy, early, intermediate or late stage of AMD including geographic atrophy, were not significantly associated with hs-CRP serum concentrations. It suggests that these diseases, in contrast to diabetic retinopathy and polypoidal choroidal vasculopathy, were not associated with a major systemic inflammatory component.

Macular degeneration and occupational risk factors: a systematic review

Purpose

Macular degeneration is a multi-factorial disease, leading cause of blindness for people over 50 years old in developed countries. To date, the knowledge on possible occupational factors involved in the development of the disease is scant.

Method

We performed a systematic scientific literature search on the association between macular degeneration and occupational risk factors searching the MedLine and Scopus databases.

Results

We examined 158 articles and, according to the inclusion criteria, 13 peer-reviewed studies evaluating occupational risk factors for macular degeneration or reporting the frequency of the disease in specific groups of workers were included in the review. Ten on thirteen articles evaluated the presence of macular degeneration in workers exposed to solar radiation. Only one study found that non-specific history of occupational chemical exposure was associated with the disease. Two studies showed an association between macular degeneration and the general category of “blue-collar” workers, but they did not identify the specific risk factors involved.

Conclusions

To date few studies have examined occupational risk factors for macular degeneration. Nevertheless, available data indicate that long-term occupational solar radiation exposure, in particular for its blue-light component, is associated with macular degeneration in outdoor workers.

Electronic supplementary material

The online version of this article (10.1007/s00420-018-1355-y) contains supplementary material, which is available to authorized users.

Periocular triamcinolone acetonide injection for treating polypoidal choroidal vasculopathy concurrent with hemorrhagic retinal detachment

To investigate the clinical efficiency of periocular triamcinolone acetonide (TA) injection for treating polypoidal choroidal vasculopathy (PCV) concurrent with hemorrhagic retinal detachment (HRD).Twenty-two cases confirmed with PCV concurrent with HRD characterized by massive subretinal hemorrhage and exudation presented to our department from January 2015 to May 2017 were included in this study. The initial vision varied from counting finger to 0.2. All cases were randomly divided into TA group (n = 12), which received periocular TA injection per month, and anti-VEGF group (n = 10), which were treated by anti-VEGF intravitreous injection per month. The patients were followed up for 6 months, in which fundus examination and visual acuity along with optical coherence tomography (OCT) were carried out.The treatment effect is divided into the following categories. Cure was defined as the elimination of subretinal hemorrhage and exudation accompanied by retinal edema and choroidal neovascularization (CNV) extinction and rise of visual acuity. Improvement was characterized by alleviation of subretinal hemorrhage and exudation accompanied by retinal edema and CNV reduction and rise of visual acuity. Ineffective means remained subretinal hemorrhage and exudation in fundus and no improvement of visual acuity, and polypoid lesions in OCT images. Among the 12 cases in TA group, 1 case was treated by periocular injection of TA twice, and 11 cases were treated by 3 times injection. After that, 3 cases (25%) were cured, 8 cases (66.7%) got improvement, and only 1 case (8.3%) showed no response. Although among 10 cases in the anti-VEGF group, 3 cases were treated by anti-VEGF intravitreous injection twice. Seven cases were treated by 3 times injection. After that, 4 cases (40%) got improvement, and the other 6 case (60%) showed no response. All patients showed no recurrence in the 6-month follow-up. No complications were noticed under periocular injection or intravitreous injection.Periocular TA injection is effective for treating PCV concurrent with HRD.

A comparison of risk factors for age-related macular degeneration and polypoidal choroidal vasculopathy in Chinese patients

PURPOSE

Neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) are important vision-threatening diseases worldwide. For effective treatment, the risk factors for the diseases merit investigation. This study aimed to compare the risk factors for nAMD vs. PCV in Chinese patients.

METHODS

A total of 946 participants were recruited in this case-control study, including 281 patients with nAMD, 306 patients with PCV, and 359 controls. All participants underwent comprehensive ophthalmic examinations. Information on risk factors were collected by questionnaire. Multivariate logistic regression analyses were performed to investigate the difference in risk factors between nAMD and PCV. In a subgroup of subjects, serum lipid data were obtained and analyzed.

RESULTS

Risk factors for nAMD included older age (OR 1.03, P = 0.001), male gender (OR 1.55, P = 0.020), asthma (OR 2.50, P = 0.028), smoking (OR 1.92, P = 0.001), and family history (OR 6.82, P = 0.001), while smoking (OR 1.67, P = 0.013) was the only risk factor for PCV. Compared to patients with PCV, patients with nAMD were more likely to be older and suffer from hyperlipidemia, coronary artery disease, rheumatism, and tumor. Interestingly, higher levels of high-density lipoprotein were positively associated with PCV in the subgroup analysis (OR 7.74, P = 0.011). Besides, results were quite different between the combination of patients with nAMD and PCV and patients with nAMD or PCV alone.

CONCLUSIONS

The risk factors for nAMD and PCV is varying with the exception of smoking. Our findings suggest that different strategies might be applied in the clinical management and scientific research on nAMD and PCV.

Evaluating Polypoidal Choroidal Vasculopathy With Optical Coherence Tomography Angiography

Purpose

We observed and analyzed the morphologic characteristics of polypoidal lesions and abnormal branching vascular network (BVN) in patients with polypoidal choroidal vasculopathy (PCV) by optical coherence tomography angiography (OCTA).

Methods

A retrospective observational case series was done of patients with PCV. All patients were scanned with a 70-kHz spectral-domain OCT system using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm to distinguish blood flow from static tissue. The OCTA images of these patients were compared to those from indocyanine green angiography (ICGA). Semiautomated segmentation was used to further analyze the polypoidal lesion and the BVN.

Results

We studied 13 eyes of 13 patients 51 to 69 years old. A total of 11 patients were treatment-naive. Two patients had multiple anti-VEGF injections and one underwent photodynamic therapy (PDT). Optical coherence tomography angiography was able to detect the BVN in all cases. Using cross-sectional OCTA, BVN locations were shown to be in the space between the RPE and Bruch's membrane. Using en face OCTA, the BVN vascular pattern could be shown more clearly than by ICGA. Polypoidal lesions showed high flow signals in different patterns in 12 cases in the outer retina slab. Using cross-sectional OCTA, the polyps were shown to be just below the top of the pigment epithelial detachment (PED). In one case, the polypoidal lesion was not detectable at the outer retina slab.

Conclusions

Optical coherence tomography angiography is a noninvasive imaging tool for detecting vascular changes in PCV. Branching vascular networks showed more clearly on OCTA than on ICGA. Polypoidal lesions had variable patterns on OCTA and were not always detected. The OCTA patterns of the polypoidal lesions and the BVN are helpful in understanding the pathology of PCV.

Effects of photodynamic therapy plus intravitreal aflibercept with subtenon triamcinolone injections for aflibercept-resistant polypoidal choroidal vasculopathy

PURPOSE

To evaluate the outcome of triple therapy of photodynamic therapy combined with injections of intravitreal aflibercept (IVA) and subtenon triamcinolone acetonide for polypoidal choroidal vasculopathy (PCV) resistant to IVA.

METHODS

A retrospective chart review at a single institution was conducted to identify patients with PCV resistant to treatment with IVA who were switched to treatment with triple therapy. In total, 13 eyes from 13 patients were included in the study. Demographic data, visual acuities, central retinal thickness (CRT) and height of pigment epithelial detachment (PED) on optical coherence tomography (OCT), complications, and number of injections were reviewed.

RESULTS

The patients had a mean age of 68 years (range 53-83). The number of prior injections with IVA ranged from 5 to 10. At 12 months follow-up after triple therapy, there was a significant improvement in visual acuity (P = 0.0039), a significant decrease in CRT (P = 0.003), and a significant reduction of the height of PED (P = 0.015). Only one patient had retinal pigment epithelium tear.

CONCLUSIONS

Triple therapy improved visual and anatomical outcomes in patients with PCV with recurrent or resistant retinal fluid and PED after multiple injections with IVA.

Systemic and ocular fluid compounds as potential biomarkers in age-related macular degeneration

Biomarkers can help unravel mechanisms of disease and identify new targets for therapy. They can also be useful in clinical practice for monitoring disease progression, evaluation of treatment efficacy, and risk assessment in multifactorial diseases, such as age-related macular degeneration (AMD). AMD is a highly prevalent progressive retinal disorder for which multiple genetic and environmental risk factors have been described, but the exact etiology is not yet fully understood. Many compounds have been evaluated for their association with AMD. We performed an extensive literature review of all compounds measured in serum, plasma, vitreous, aqueous humor, and urine of AMD patients. Over 3600 articles were screened, resulting in more than 100 different compounds analyzed in AMD studies, involved in neovascularization, immunity, lipid metabolism, extracellular matrix, oxidative stress, diet, hormones, and comorbidities (such as kidney disease). For each compound, we provide a short description of its function and discuss the results of the studies in relation to its usefulness as AMD biomarker. In addition, biomarkers identified by hypothesis-free techniques, including metabolomics, proteomics, and epigenomics, are covered. In summary, compounds belonging to the oxidative stress pathway, the complement system, and lipid metabolism are the most promising biomarker candidates for AMD. We hope that this comprehensive survey of the literature on systemic and ocular fluid compounds as potential biomarkers in AMD will provide a stepping stone for future research and possible implementation in clinical practice.

ANGIOGRAPHIC FINDINGS OF RANIBIZUMAB-RESISTANT POLYPOIDAL CHOROIDAL VASCULOPATHY AFTER SWITCHING TO A TREAT-AND-EXTEND REGIMEN WITH INTRAVITREAL AFLIBERCEPT

PURPOSE

The aim of this study was to study the angiopathic findings of ranibizumab-resistant polypoidal choroidal vasculopathy after switching to a treat-and-extend regimen with intravitreal aflibercept.

METHODS

The authors retrospectively reviewed 17 eyes of 17 Japanese patients with polypoidal choroidal vasculopathy (10 men and 7 women, age: 73.8 ± 7.4 years) who were treated with intravitreal aflibercept (2 mg/0.05 mL) injections from February 2013 to August 2014 at Tokyo University Hospital. All patients had switched to aflibercept because their polypoidal choroidal vasculopathy had been refractory to ranibizumab.

RESULTS

The mean logMAR best-corrected visual acuity at baseline and after 12 months of therapy was 0.30 ± 0.29 (Snellen equivalent: 20/40) and 0.17 ± 0.26 (20/30) (paired t-test P < 0.001). Visual acuity remained stable in 5 cases (29%), deteriorated in 3 (18%), and improved in 9 (53%). Branching vascular networks persisted in all 17 eyes but shrank in 15 (88%). The mean lesion diameter was 3329 ± 1261 μm at baseline and 3180 ± 1247 μm after 12 months (P = 0.0002).

CONCLUSION

A treat-and-extend regimen with intravitreal aflibercept for ranibizumab-resistant patients resulted in branching vascular network shrinkage over a 1-year period.

The association of enzymatic and non-enzymatic antioxidant defense parameters with inflammatory markers in patients with exudative form of age-related macular degeneration

There are evidence that oxidative stress and inflammation are involved in the pathogenesis of the age-related macular degeneration (AMD). The aim of this study was to analyze the antioxidant defense parameters and inflammatory markers in patients with exudative form of AMD (eAMD), their mutual correlations and association with the specific forms of AMD. The cross-sectional study, included 75 patients with the eAMD, 31 patients with the early form, and 87 aged-matched control subjects. Significantly lower SOD, TAS and albumin values and higher GR, CRP and IL-6 were found in the eAMD compared to the early form (p<0.05). Significant negative correlations were found between GPx and fibrinogen (r = -0.254), TAS and IL-6 (r = -0.999) and positive correlations between uric acid and CRP (r = 0.292), IL-6 and uric acid (r = 0.398) in the eAMD. A significant association of CRP (OR: 1.16, 95% CI: 1.03-1.32, p = 0.018), fibrinogen (OR: 2.21, 95% CI: 1.14-4.85, p = 0.021), TAS (OR: 7.45, 95% CI: 3.97-14.35, p = 0.0001), albumin (OR: 1.25, 95% CI: 1.11-1.41, p = 0.0001) and uric acid (OR: 1.006, 95% CI: 1.00-1.02, p = 0.003) was found with the eAMD. In conclusion it may be suggested, there is a significant impairment of antioxidant and inflammatory parameter levels in eAMD patients. In addition, significant association exists between the tested inflammatory markers and antioxidant parameters with late-eAMD.

Three-year visual outcomes of intravitreal ranibizumab with or without photodynamic therapy for polypoidal choroidal vasculopathy

PURPOSE

To compare 3-year visual outcomes after intravitreal ranibizumab (IVR) monotherapy and combination therapy of photodynamic therapy (PDT) with IVR for polypoidal choroidal vasculopathy (PCV).

METHODS

Medical records for 45 eyes in 45 patients (34 men, 11 women; mean age, 73.8 years old; range, 62-86 years old) with treatment-naïve PCV were reviewed retrospectively. Of the 45 eyes, 20 were treated with IVR monotherapy and 25 with combination therapy. Mean change in best-corrected visual acuity, numbers of injections of IVR and length of treatment-free period from baseline at month 36 were observed. Adverse events were monitored.

RESULTS

The change in visual acuity after combination therapy was significantly better than that after IVR monotherapy (p = 0.0399). At 36 months, improvement in visual acuity was seen in five eyes (25.0%) in the IVR monotherapy group and 13 eyes (52.0%) in the combination therapy group. The treatment-free period was significantly longer in the combination therapy group (p = 0.0008). Additional IVR therapy was required significantly more frequently in the IVR monotherapy group (p = 0.0026). Post-treatment subretinal haemorrhage or retinal pigment epithelium tear occurred only in the IVR monotherapy group, in one eye (5.0%) and one eye (5.0%), respectively.

CONCLUSION

Initial therapy consisting of a single session of PDT combined with IVR improves vision in treatment-naïve PCV. Compared with IVR monotherapy, this combination therapy may be more effective for PCV.

C-reactive protein and complement factor H polymorphism interaction in advanced exudative age-related macular degeneration

PURPOSE

To determine the association of C-reactive protein (CRP) and complement factor H (CFH) gene with exudative age-related macular degeneration (AMD) and any possible interaction among these factors.

METHODS

In this case-control study, 139 unrelated patients with exudative AMD and 123 non-AMD controls were recruited. Blood sample was taken for analysis of the CRP levels and DNA testing. DNA fragments of CFH gene variants containing 4 single nucleotide polymorphisms including rs800292, rs1061170, rs2274700, and rs3753395 were assessed. A CRP level of ≥3 mg/L was considered as elevated. The association of elevated CRP and CFH gene variants polymorphism with exudative AMD was compared between the groups.

RESULTS

Mean age was 72.6 ± 6.4 for controls and 74.9 ± 7.4 for case group (P = 0.006). The difference between CRP levels in cases and controls was not statistically significant (P = 0.055). However, Y402H variant of CFH in both homozygous and heterozygous carriers C allele was significantly more frequent among exudative AMD patients than controls, 32.1 versus 6.5 % (P < 0.001). Evaluating various CRP levels in patients with CC and non-CC genotypes disclosed that in CC genotype group, higher CRP level (>3 mg/L) was associated with higher risk of developing exudative AMD (OR = 12.0, CI: 1.5-98.8) compared with the control group.

CONCLUSION

This study disclosed no difference in CRP levels per se between exudative AMD patients with control group. However, higher levels of CRP in the presence of C allele of Y402H might confer more risk for the development of exudative AMD.

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.

Risk factors and biomarkers of age-related macular degeneration

A biomarker can be a substance or structure measured in body parts, fluids or products that can affect or predict disease incidence. As age-related macular degeneration (AMD) is the leading cause of blindness in the developed world, much research and effort has been invested in the identification of different biomarkers to predict disease incidence, identify at risk individuals, elucidate causative pathophysiological etiologies, guide screening, monitoring and treatment parameters, and predict disease outcomes. To date, a host of genetic, environmental, proteomic, and cellular targets have been identified as both risk factors and potential biomarkers for AMD. Despite this, their use has been confined to research settings and has not yet crossed into the clinical arena. A greater understanding of these factors and their use as potential biomarkers for AMD can guide future research and clinical practice. This article will discuss known risk factors and novel, potential biomarkers of AMD in addition to their application in both academic and clinical settings.

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.

[Sensitivity and specificity of optical coherence tomography in diagnosing polypoidal choroidal vasculopathy]

OBJECTIVE

To establish the diagnostic criteria for polypoidal choroidal vasculopathy (PCV) based on spectral-domain optical coherence tomography (SD OCT) by evaluating the sensitivity and specificity of SD OCT in differentiating PCV from wet age-related macular degeneration (wAMD).

METHODS

The clinical data were reviewed for 62 patients (63 eyes) with the initial diagnosis of PCV or wAMD between August, 2012 and June, 2016. Twenty-four patients (25 eyes) were diagnosed to have PCV and 38 (38 eyes) had wAMD based on findings by fundus photography, fluorescein angiography (FFA) and indocyanine green angiography (ICGA). Among the 6 features of SD OCT, namely a sharp RPED peak, double-layer sign, multiple RPED, an RPED notch, a hyporeflective lumen representing polyps, and hyperreflective intraretinal hard exudates, findings of the first two features and at least one of the other features sufficed the diagnosis of PCV; in the absence of the first two features, the diagnosis of PCV was also made when at least 3 of the other features were present simultaneously. The sensitivity and specificity of SD OCT-based diagnosis were estimated by comparison with the gold standard ICGA-based diagnosis.

RESULTS

In the 25 eyes with an established diagnosis of PCV, 23 eyes (92.0%) met the diagnostic criteria based on SD OCT findings; in the 38 eyes with the diagnosis of wAMD, only 4 eyes (10.5%) met the criteria. The sensitivity and specificity of SD OCT-based diagnosis of PCV was 92.0% and 89.5%, respectively.

CONCLUSION

s We established the diagnostic criteria for PCV based on SD OCT findings with a high sensitivity and specificity. SD OCT shows a strong capacity for differentiating PCV from wAMD.

The Features of Inflammation Factors Concentrations in Aqueous Humor of Polypoidal Choroidal Vasculopathy

Purpose

To investigate the cytokine concentrations in the aqueous humor of patients with refractory polypoidal choroidal vasculopathy (PCV).

Methods

Three separate groups of patients were studied–refractory PCV (Group A, 41 eyes), stable PCV (Group B, 39 eyes) and senile cataract (Group C, 44 eyes). Aqueous humor samples were collected at two time points for Groups A and B–before the first intravitreal ranibizumab injection and before the last injection. Aqueous humor samples were collected prior to phacoemulsification in Group C. The cytokine concentrations of interleukin 2, 6, and 8 (IL-2, IL-6, and IL-8), tumor necrosis factor α (TNF-α), monocyte chemotactic protein 1 (MCP-1), and vascular endothelial growth factor (VEGF) were measured by cytometric bead array and flow cytometry.

Results

Before the first treatment, the MCP-1, VEGF, and TNF-α levels in Group A were significantly higher than those in Group C (P < 0.05), and the MCP-1 and VEGF levels in Group A were significantly higher than those in Group B (P < 0.05). Significantly higher MCP-1 and VEGF levels were seen in Group B compared to Group C (P < 0.05). Before the final treatment, the MCP-1, VEGF, and TNF-α concentrations in Group A were significantly higher than those in Group B (P < 0.05) and Group C (P < 0.05). IL-2 levels were significantly lower in Group A compared to Group B (P < 0.05) and Group C (P < 0.05).

Conclusion

Inflammatory cytokines such as MCP-1, VEGF, and TNF-α may be associated with the pathogenesis of both stable and refractory PCV.

Effect of High-Density Lipoprotein Metabolic Pathway Gene Variations and Risk Factors on Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy in China

Purpose

To investigate the effect of genetic variants in the high-density lipoprotein (HDL) metabolic pathway and risk factors on neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) in China.

Methods

A total of 742 Chinese subjects, including 221 controls, 230 cases with nAMD, and 291 cases with PCV, were included in the present study. Five single nucleotide polymorphisms (SNPs) from three genes in the HDL metabolic pathway (HDLMP) including cholesteryl ester transfer protein (CETP), hepatic lipase (LIPC) and lipoprotein lipase (LPL) were genotyped in all study subjects with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Risk factors including gender, hypertension, hyperlipidemia, diabetes mellitus, and coronary artery disease were identified. Chi-square tests or Fisher’s exact tests were applied to discover associations between SNPs and risk factors for PCV and nAMD. Gene-gene interactions and gene-environment interactions were evaluated by the multifactor-dimensionality reduction (MDR) method.

Results

CETP rs3764261 were significantly associated with an increased risk for PCV (odds ratio (OR) = 1.444, P = 0.0247). LIPC rs1532085 conferred an increased risk for PCV (OR = 1.393, P = 0.0094). We found no association between PCV and LPL rs12678919, LIPC rs10468017 or CETP rs173539. No association was found between five SNPs with nAMD. Regarding risk factors, females were found to have significantly decreased risks for both PCV and nAMD (P = 0.006 and 0.001, respectively). Coronary artery disease (CAD) was a risk factor in PCV patients but played a protective role in nAMD patients. Hyperlipidemia was associated with PCV but not with nAMD. Neither hypertension nor diabetes mellitus was associated with PCV or nAMD. The MDR analysis revealed that a three-locus model with rs12678919, rs1532085, and gender was the best model for nAMD, while a five-locus model consisting of rs10468017, rs3764261, rs1532085, gender, and hyperlipidemia was best for PCV.

Conclusion

Our large-sample study suggested that CETP rs3764261 conferred an increased risk for PCV. We also first found the association between rs1532085 and PCV. The result of present study also showed that gender and CAD are associated with PCV and nAMD. Significant association was found between hyperlipidemia and PCV but not nAMD.

Parainflammation, chronic inflammation, and age-related macular degeneration

Inflammation is an adaptive response of the immune system to noxious insults to maintain homeostasis and restore functionality. The retina is considered an immune-privileged tissue as a result of its unique anatomic and physiologic properties. During aging, the retina suffers from a low-grade chronic oxidative insult, which sustains for decades and increases in level with advancing age. As a result, the retinal innate-immune system, particularly microglia and the complement system, undergoes low levels of activation (parainflammation). In many cases, this parainflammatory response can maintain homeostasis in the healthy aging eye. However, in patients with age-related macular degeneration, this parainflammatory response becomes dysregulated and contributes to macular damage. Factors contributing to the dysregulation of age-related retinal parainflammation include genetic predisposition, environmental risk factors, and old age. Dysregulated parainflammation (chronic inflammation) in age-related macular degeneration damages the blood retina barrier, resulting in the breach of retinal-immune privilege, leading to the development of retinal lesions. This review discusses the basic principles of retinal innate-immune responses to endogenous chronic insults in normal aging and in age-related macular degeneration and explores the difference between beneficial parainflammation and the detrimental chronic inflammation in the context of age-related macular degeneration.

Interleukin-1β Level Is Increased in Vitreous of Patients with Neovascular Age-Related Macular Degeneration (nAMD) and Polypoidal Choroidal Vasculopathy (PCV)

Purpose

To examine the expression of pro-interleukin-1β (pro-IL-1β) and interleukin-1β (IL-1β) in the vitreous body of patients with neovascular age-related macular degeneration(nAMD), polypoidal choroidal vasculopathy (PCV), proliferative diabetic retinopathy (PDR), retinal vein occlusion (RVO) or Eales’ disease to further elucidate the role of IL-1β and inflammation in the pathogenesis of neovascular retinal disease.

Design

Prospective clinical laboratory investigation study.

Methods

All patients enrolled had vitreous hemorrhage due to nAMD, PCV, PDR, RVO or Eales’ disease that required vitrectomy. Patients were excluded for any history of active intraocular inflammation, or other ophthalmic surgery besides vitrectomy. Control samples were obtained from patients with idiopathic macular epiretinal membrane. A total of fifty vitreous samples were collected from patient during vitrectomy. Pro-IL-1β and IL-1β expression were measured by enzyme-linked immunosorbent assay (ELISA). Results were analyzed statistically using nonparametric tests.

Results

Expression of pro-IL-1β protein was increased by 2.83-fold and 9.19-fold in PCV and nAMD vitreous samples relative to control, respectively. Expression of IL-β protein was increased by 10-fold and 4.83-fold in PCV and nAMD vitreous samples relative to control, respectively.

Conclusions

Our results demonstrate that expression of pro-IL-1β and IL-1β proteins is higher in PCV and nAMD. The roles of pro-IL-1β and IL-1β as inflammatory mediators in the development of PCV and nAMD may be associated with photoreceptor degeneration and neovascularization which necessitates further study.

Polypoidal Choroidal Vasculopathy in Asians

Age related macular degeneration (AMD) in Asians has been suggested to differ from their Western counterparts in terms of epidemiology, pathogenesis, clinical presentation and treatment. In particular, polypoidal choroidal vasculopathy (PCV) appears to be the predominant subtype of exudative AMD in Asian populations, in contrast to choroidal neovascularization secondary to AMD (CNV-AMD) in Western populations. Epidemiological data on PCV has been largely limited to hospital-based studies and there are currently no data on the incidence of PCV. Similarities and differences in risk factor profile between PCV and CNV-AMD point to some shared pathogenic mechanisms but also differential underlying mechanisms leading to the development of each phenotype. Serum biomarkers such as CRP, homocysteine and matrix metalloproteinases suggest underlying inflammation, atherosclerosis and deranged extracellular matrix metabolism as possible pathogenic mechanisms. In addition, recent advances in genome sequencing have revealed differences in genetic determinants of each subtype. While the standard of care for CNV-AMD is anti-vascular endothelial growth factor (VEGF) therapy, photodynamic therapy (PDT) has been the mainstay of treatment for PCV, although long-term visual prognosis remains unsatisfactory. The optimal treatment for PCV requires further clarification, particularly with different types of anti-VEGF agents and possible benefits of reduced fluence PDT.

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.

Hyperhomocysteinemia in patients with polypoidal choroidal vasculopathy: a case control study

Purpose

To determine whether elevated plasma homocysteine and serum high sensitivity C-reactive protein (hsCRP) levels, two established risk factors of vascular diseases, are associated with polypoidal choroidal vasculopathy (PCV).

Design

Retrospective case-control study.

Methods

One hundred and nineteen consecutive patients with PCV and 119 matched controls were enrolled in a tertiary hospital from September 2008 to June 2013. Plasma homocysteine and serum hsCRP levels were measured. Associations among plasma homocysteine, serum hsCRP levels and PCV were further evaluated using multivariable logistic regression analysis.

Results

The median plasma homocysteine level was significantly higher in patients with PCV than in the controls (12.20 µmol/L vs. 9.80 µmol/L, p<0.001). The median serum hsCRP level was slightly higher in the PCV group (0.16 mg/dl vs. 0.11 mg/dl in control group, p = 0.07). After multivariable logistic regression analysis, each 1 µmol/L increase of plasma homocysteine was associated with a 1.5-fold increase in likelihood of having PCV (OR, 1.54; 95% confidence interval (CI), 1.33–1.79, p<0.001).

Conclusions

Hyperhomocysteinemia was associated with PCV and might play a role in the pathogenesis of PCV.