Asian age-related macular degeneration: from basic science research perspective

Trends in the global disease burden of age-related macular degeneration from 1990 to 2021

AimTo investigate the global disease burden of age-related macular degeneration (AMD) from 1990 to 2021 using data from the Global Burden of Diseases 2021 database.MethodsWe recorded disability-adjusted life years (DALYs) and rates and estimated annual percentage changes (EAPCs) in AMD stratified by sex, age, sociodemographic index (SDI), geographic region, country, and risk factor.ResultsGlobally, the number of AMD-associated DALYs increased from 302,902 in 1990 to 578,020 in 2021, while the age-standardized rate (ASR) of DALYs decreased by 19.089% from 1990 to 2021, with an EAPC of -0.942 (95% CI, -1.010-0.873). During this period, males had fewer DALYs and lower ASRs than did females, and the ASR decreased with decreasing age. In 2021, the low-SDI region had the highest ASR (10.082 per 100,000 individuals) and the slowest ASR decrease (EAPC: -0.652, 95% CI, -0.708--0.595). East Asia had the most DALYs (154,300.168), and Western Sub-Saharan Africa had the highest ASR (14.735 per 100,000 individuals). From 1990 to 2021, all 21 regions experienced increased DALYs, while most regions, except for Central Sub-Saharan Africa and Southern Sub-Saharan Africa, experienced decreases in the ASR. China had the most DALYs (153,219.726) in 2021. The proportion of DALYs attributable to smoking in patients with AMD decreased globally and across all SDI regions from 1990 to 2021.ConclusionOver the past 32 years, AMD has remained a significant health concern, particularly affecting females, older individuals, and individuals living in lower-SDI regions, with a global decline in smoking-related AMD DALYs.

Enrolment characteristics in age-related macular degeneration clinical trials: a cross-sectional study

BACKGROUND/OBJECTIVES

To investigate demographic enrolment characteristics in age-related macular degeneration (AMD) trials.

SUBJECTS/METHODS

Clinicaltrials.gov was searched with "age-related macular degeneration" to identify RCTs with double, triple, or quadruple masking. Trial (e.g., study location, phase, masking, trial initiation year, and sponsor origin) and patient demographic data were collected. Sex-based AMD disease burdens were retrieved from the Global Burden of Disease database to calculate pooled female population-to-prevalence ratios (PPRs). Equitable trial enrolment was defined as PPR between 0.8-1.2. Demographic proportions were evaluated across trial characteristics using the Kruskal-Wallis test (alpha = 0.05) followed by post hoc comparisons. Secondary outcomes included absolute number of enrolled female, racial, and ethnic groups, and the association of trial characteristics with these demographics.

RESULTS

We included 106 trials (77,939 patients; 46.3% female), spanning 1990-2020. The pooled female PRR was 0.88 (95% confidence interval [CI]: 0.82, 0.94). PPR values were inconclusive studies with quadruple blinding; phase I, III, IV, or not applicable status; foreign (non-US) site; US-only and foreign-only sponsor; and an initiation year before 2010. There was no significant difference in PPR between sublevels of analysed trial characteristics. Of the 74 (69.8%) trials that adequately detailed race, White participants comprised the largest group (N = 57,917; 82% of total participants). Thirty-seven (34.9%) trials adequately detailed ethnicity. The absolute enrolment of race and ethnic groups did not generally exhibit significant difference between sublevels of analysed trial characteristics.

CONCLUSIONS

Female enrolment was commensurate to their disease burden across all trial characteristics. Race and ethnicity were under-reported. Future trials should prioritise equitable study enrolment strategies.

Switching to faricimab from the current anti-VEGF therapy: evidence-based expert recommendations

Dual inhibition of the angiopoietin (Ang)/Tie and vascular endothelial growth factor (VEGF) signalling pathways in patients with retinal diseases, such as neovascular age-related macular degeneration (nAMD) and diabetic macular oedema (DME), may induce greater vascular stability and contribute to increased treatment efficacy and durability compared with treatments that only target the VEGF pathway. Faricimab, a bispecific intravitreal agent that inhibits both VEGF and Ang-2, is the first injectable ophthalmic drug to achieve treatment intervals of up to 16 weeks in Phase 3 studies for nAMD and DME while exhibiting improvements in visual acuity and retinal thickness. Data from real-world studies have supported the safety, visual and anatomic benefits and durability of faricimab, even in patients who were previously treated with other intravitreal agents. These evidence-based expert recommendations from a panel of retina specialists consolidate current evidence with clinical experience for the optimal use of faricimab in patients with nAMD or DME, with a focus on switching from an anti-VEGF agent to faricimab.

Light-Activated Anti-Vascular Combination Therapy against Choroidal Neovascularization

Choroidal neovascularization (CNV) underlies the crux of many angiogenic eye disorders. Although medications that target vascular endothelial growth factor (VEGF) are approved for treating CNV, their effectiveness in destroying new blood vessels is limited, and invasive intravitreal administration is required. Additionally, other drugs that destroy established neovessels, such as combretastatin A-4, may have systemic side effects that limit their therapeutic benefits. To overcome these shortcomings, a two-pronged anti-vascular approach is presented for CNV treatment using a photoactivatable nanoparticle system that can release a VEGF receptor inhibitor and a vascular disrupting agent when irradiated with 690 nm light. The nanoparticles can be injected intravenously to enable anti-angiogenic and vascular disrupting combination therapy for CNV through light irradiation to the eyes. This approach can potentiate therapeutic effects while maintaining a favorable biosafety profile for choroidal vascular diseases.

α-Klotho prevents diabetic retinopathy by reversing the senescence of macrophages

BACKGROUND

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus (DM) and a significant cause of acquired blindness in the working-age population worldwide. Aging is considered as an important risk factor for DR development. Macrophages in aged mice bear typical M2 marker proteins but simultaneously express a pro-inflammatory factor profile. This may explain why the level of intraocular inflammation does not decrease during proliferative diabetic retinopathy (PDR) despite the occurrence of neovascularization and fibrosis (M2 activation). α-Klotho (KL) was originally discovered as a soluble anti-aging factor, which is mainly expressed in kidney tubular epithelium, choroid plexus in the brain and secreted in the blood. However, the role of KL in DR pathophysiology has not been previously reported.

METHODS

Type 1 (streptozotocin [STZ]-induced) and type 2 (a high-fat diet along with a low dose of STZ) diabetic mouse models were established and injected with or without KL adenovirus via the tail vein for 12 weeks. Vldlr-/- mice were injected intravitreally with or without soluble KL protein from P8 to P15. The retinal structure and function were analyzed by electroretinogram and optical coherence tomography. The neovascular lesions were analyzed by retinal flat mount and RPE flat mount. The senescence markers, macrophage morphology, and KL expression levels were detected by immunofluorescence staining. A cell model was constructed using RAW264.7 cells stimulated by 4-hydroxynonenal (4HNE) and transfected with or without KL adenovirus. The senescence-associated secretory phenotypes were detected by qRT-PCR. Senescence was detected by SA-β-Gal staining. Serum, aqueous humor, and vitreous humor KL levels of proliferative diabetic retinopathy (PDR) patients were measured by enzyme-linked immunosorbent assay. Quantitative proteomics and bioinformatics were applied to predict the change of proteins and biological function after overexpression of KL in macrophages. The effects of KL on the HECTD1 binding to IRS1 were analyzed by bioinformatics, molecular docking, and Western Blot.

RESULTS

Serum, aqueous humor, and vitreous humor KL levels were lower in patients with PDR than in those with cataracts. KL relieved the retinal structure damage, improved retina function, and inhibited retinal senescence in diabetic mice. KL administration attenuated the neovascular lesions in VLDLR-/- mice by decreasing the secretion of VEGFA and FGF2 from macrophages. KL also protected RAW264.7 cells from 4HNE-induced senescence. Additionally, it inhibited E3 ubiquitin ligase HECTD1 expression in both diabetic mouse peripheral blood mononuclear cells and 4HNE-treated RAW264.7 cells. KL inhibited HECTD1 binding to IRS1 and reduced the ubiquitination of IRS1.

CONCLUSIONS

Macrophage aging is involved in DM-induced retinopathy. KL alleviates DM-induced retinal macrophage senescence by downregulating HECTD1 and decreasing IRS1 ubiquitination and degradation. Meanwhile, KL administration attenuated the neovascular lesions by altering the activation state of macrophages and decreasing the expression of VEGFA and FGF2.

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.

Analysis of OCT Scanning Parameters in AMD and RVO

Optical coherence tomography (OCT) is an extensively used imaging tool for disease monitoring in both age-related macular degeneration (AMD) and retinal vein occlusion (RVO). However, there is limited literature on minimum requirements of OCT settings for reliable biomarker detection. This study systematically investigates both the influence of scan size and interscan distance (ISD) on disease activity detection. We analyzed 80 OCT volumes of AMD patients and 12 OCT volumes of RVO patients for the presence of subretinal fluid (SRF), intraretinal fluid (IRF), and pigment epithelium detachment (PED). All volume scans had a scan size of 6 × 6 mm and an ISD of 125 µm. We analyzed both general fluid distribution and how biomarker detection sensitivity decreases when reducing scan size or density. We found that in AMD patients, all fluids were nearly normally distributed, with most occurrences in the foveal center and concentric decrease towards the periphery. When reducing the scan size to 3 × 3 and 2 × 2 mm, disease activity detection was still high (0.98 and 0.96). Increasing ISD only slightly can already compromise biomarker detection sensitivity (0.9 for 250 µm ISD against 125 µm ISD).

Contribution of common and rare variants to Asian neovascular age-related macular degeneration subtypes

Neovascular age-related macular degeneration (nAMD), along with its clinical subtype known as polypoidal choroidal vasculopathy (PCV), are among the leading causes of vision loss in elderly Asians. In a genome-wide association study (GWAS) comprising 3,128 nAMD (1,555 PCV and 1,573 typical nAMD), and 5,493 controls of East Asian ancestry, we identify twelve loci, of which four are novel ([Formula: see text]). Substantial genetic sharing between PCV and typical nAMD is noted (rg = 0.666), whereas collagen extracellular matrix and fibrosis-related pathways are more pronounced for PCV. Whole-exome sequencing in 259 PCV patients revealed functional rare variants burden in collagen type I alpha 1 chain gene (COL1A1; [Formula: see text]) and potential enrichment of functional rare mutations at AMD-associated loci. At the GATA binding protein 5 (GATA5) locus, the most significant GWAS novel loci, the expressions of genes including laminin subunit alpha 5 (Lama5), mitochondrial ribosome associated GTPase 2 (Mtg2), and collagen type IX alpha 3 chain (Col9A3), are significantly induced during retinal angiogenesis and subretinal fibrosis in murine models. Furthermore, retinoic acid increased the expression of LAMA5 and MTG2 in vitro. Taken together, our data provide insights into the genetic basis of AMD pathogenesis in the Asian population.

Differences in Central and Peripheral Choroidal Thickness among the Subtypes of Age-Related Macular Degeneration in an Asian Population

Age-related macular degeneration (AMD) causes visual impairment in individuals who are >50 years of age. However, no study has investigated AMD when using ultra-wide-field swept-source optical coherence tomography (UWF SS-OCT). We aimed to evaluate central and peripheral choroidal thicknesses using UWF SS-OCT, and to compare these across the AMD subtypes. We included 75 eyes of patients with typical AMD (tAMD), 56 with polypoidal choroidal vasculopathy (PCV), 29 with pachychoroid neovasculopathy (PNV), and 12 with retinal angiomatous proliferation (RAP). To compare choroidal thicknesses in the central and peripheral choroids, we established subfields of <3 mm, <9 mm, and 9-18 mm from the fovea. PNV patients were significantly younger than those with tAMD (p = 0.01). The choroidal thicknesses of PNV were significantly greater than that of tAMD in all subfields (p < 0.01), and choroidal thickness significantly correlated with age and axial length in all subfields (p < 0.05). Even after adjusting for age and axial length, the choroidal thickness in PNV was significantly greater than that in tAMD (p < 0.05). In addition, the ratio of the posterior <9 mm to a peripheral 9-18 mm choroidal thickness in PNV was significantly greater than that in tAMD (p < 0.01). A thickened choroid in PNV was more pronounced in the posterior choroid than in the periphery.

The Past and Present Lives of the Intraocular Transmembrane Protein CD36

Cluster of differentiation 36 (CD36) belongs to the B2 receptors of the scavenger receptor class B family, which is comprised of single-chain secondary transmembrane glycoproteins. It is present in a variety of cell types, including monocytes, macrophages, microvascular endothelial cells, adipocytes, hepatocytes, platelets, skeletal muscle cells, kidney cells, cardiomyocytes, taste bud cells, and a variety of other cell types. CD36 can be localized on the cell surface, mitochondria, endoplasmic reticulum, and endosomes, playing a role in lipid accumulation, oxidative stress injury, apoptosis, and inflammatory signaling. Recent studies have found that CD36 is expressed in a variety of ocular cells, including retinal pigment epithelium (RPE), retinal microvascular endothelial cells, retinal ganglion cells (RGC), Müller cells, and photoreceptor cells, playing an important role in eye diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma. Therefore, a comprehensive understanding of CD36 function and downstream signaling pathways is of great significance for the prevention and treatment of eye diseases. This article reviews the molecular characteristics, distribution, and function of scavenger receptor CD36 and its role in ophthalmology in order to deepen the understanding of CD36 in eye diseases and provide new ideas for treatment strategies.

Early Stages of Age-Related Macular Degeneration: Racial/Ethnic Differences and Proposal of a New Classification Incorporating Emerging Concept of Choroidal Pathology

The progression of age-related macular degeneration (AMD) is determined by environmental and genetic factors, and phenotypic or molecular risk factors have been investigated extensively. Interestingly, risk factor profiles for advanced AMD differ among individuals, and one of the causes of variation may be explained by their ethnic background. Recent advances in retinal imaging technology have led to the identification of previously unrecognized risk factors for advanced AMD on optical coherence tomography (OCT) and OCT angiography, which expands the concept of traditional imaging risk factors such as drusen and pigmentary abnormalities visible on color fundus photographs. This OCT imaging modality has identified novel pathognomonic changes for early AMD, including the associated photoreceptor, retinal pigment epithelium, and underlying choroidal changes. Regarding features of multimodal imaging associated with the presence or progression of geographic atrophy, there is an international expert consensus classification system; however, features associated with the progression of macular neovascularization (MNV) are still obscure. To make a consensus towards understanding features associated with the risk of MNV, this review focuses on the early stages of AMD by summarizing imaging characteristics and early signs and classifications in view of advanced multimodal imaging technology. Recent evidence suggests that neovascular AMD is not a single disease entity but a heterogeneous disease characterized by MNV. Besides drusen, OCT features associated with pigment abnormalities, such as shallow irregular RPE elevation (SIRE, also known as double-layer sign), pachychoroid pigment epitheliopathy, and choriocapillaris ischemia, seem to confer a high risk of MNV developing, especially for Asian populations.

Association between inflammatory cytokines in the aqueous humor and hyperreflective foci on optical coherence tomography in patients with neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

Purpose

To investigate the associations between cytokine levels in the aqueous humor (AH) and hyperreflective foci (HF) on spectral-domain optical coherence tomography (SD-OCT) in neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV).

Methods

The prospective study included 63 eyes with nAMD, 44 with PCV, and 43 with cataracts (Controls). AH samples were obtained before anti-vascular endothelial growth factor (VEGF) therapy or cataract surgery. Cytokines interleukin 6 (IL-6), IL-8, IL-10, interferon-inducible protein 10 (IP-10), monocyte chemotactic protein 1 (MCP-1), and VEGF were measured by multiplex bead assay. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and the number of HF were evaluated at baseline and 1 month after anti-VEGF treatment.

Results

No significances difference in IL-6 and IL-8 levels were noted among the three groups (P = 0.370 and P = 0.067). VEGF, IP-10, and IL-10 levels were significantly higher in nAMD and PCV groups than in Controls (all P &lt; 0.05). In nAMD, HF was positively correlated with VEGF (rs = 0.300, P = 0.025) and in eyes with HF group, VEGF and IL-10 were significantly higher than those without HF (P = 0.008 and P = 0.022). In PCV, no correlation was observed between HF and cytokines (all P &gt; 0.05). After anti-VEGF treatment, patients with HF in nAMD and PCV were predisposed to worse visual outcomes (P = 0.022 and P = 0.015) and a significantly greater reduction in CMT (P = 0.001 and P = 0.057). And nAMD patients with HF were more sensitive to anti-VEGF treatment than those without HF (P = 0.029).

Conclusions

In the nAMD group, HF was positively correlated with VEGF. Patients in nAMD with HF had elevated levels of VEGF and IL-10 and responded favorably to anti-VEGF. HF might serve as an inflammatory biomarker and a predictive factor for therapeutic efficacy in patients with nAMD.

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.

Analysis of the aqueous humor lipid profile in patients with polypoidal choroidal vasculopathy

This study aimed to investigate the lipid profiles of aqueous humor from polypoidal choroidal vasculopathy (PCV) patients and identify potential biomarkers to increase the understanding of PCV pathomechanism. An ultra-high performance liquid chromatography-tandem mass spectrometry based untargeted lipidomic analysis was performed to acquire lipid profiles of aqueous humor of PCV patients and control subjects. Differentially expressed lipids were identified by univariate and multivariate analyses. A receiver operator characteristic curve (ROC) analysis was conducted to confirm the potential of identified lipids as biomarkers. Sixteen PCV patients and twenty-eight control subjects were enrolled in this study. In total, we identified 33 lipid classes and 639 lipid species in aqueous humor using the LipidSearch software. Of them, 50 differential lipids were obtained by combining univariate and multivariate statistical analyses (VIP>1 and P < 0.05), and 19 potential lipid biomarkers were identified by ROC analysis. In addition, significant alterations were found in several metabolic pathways, including glycerophospholipid, glycerolipid, and glycosylphosphatidylinositol-anchor biosynthesis. This study is the first to systematically characterize the alterations in lipid profiles in aqueous humor of PCV patients and screen for the potential lipid biomarkers for PCV diagnosis and treatment intervention. The results of this study are likely to broaden our understanding of the pathogenesis of PCV and contribute to improvements in the diagnosis and treatment of the disease.

Comparison of Peripheral Blood Inflammatory Indices in Patients with Neovascular Age-related Macular Degeneration and Haemorrhagic Polypoidal Choroidal Vasculopathy

PURPOSE

To compare the differences in peripheral blood inflammatory indices between patients with neovascular age-related macular degeneration (nAMD) and haemorrhagic polypoidal choroidal vasculopathy (PCV).

METHODS

Retrospective, best corrected visual acuity (BCVA), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR), were analysed across the nAMD, PCV and normal control (NCG) groups of patients. The ratios' cut-off values for nAMD were calculated.

RESULTS

nAMD had a significantly longer duration and better BCVA than PCV (all P < .05). The NLR, MLR and PLR were significantly higher in nAMD than in PCV and NCG (all P < .01), no significant differences between PCV and NCG (all P > .05). The ROC curve analysis revealed that the cut-off values for NLR and MLR were 1.98 and 0.24, respectively, for nAMD.

CONCLUSION

NLR, MLR and PLR are significantly high in patients with nAMD. The ability of these inflammatory indicators to distinguish nAMD and PCV is unclear.

Hyaluronidase-1-mediated glycocalyx impairment underlies endothelial abnormalities in polypoidal choroidal vasculopathy

Background

Polypoidal choroidal vasculopathy (PCV), a subtype of age-related macular degeneration (AMD), is a global leading cause of vision loss in older populations. Distinct from typical AMD, PCV is characterized by polyp-like dilatation of blood vessels and turbulent blood flow in the choroid of the eye. Gold standard anti-vascular endothelial growth factor (anti-VEGF) therapy often fails to regress polypoidal lesions in patients. Current animal models have also been hampered by their inability to recapitulate such vascular lesions. These underscore the need to identify VEGF-independent pathways in PCV pathogenesis.

Results

We cultivated blood outgrowth endothelial cells (BOECs) from PCV patients and normal controls to serve as our experimental disease models. When BOECs were exposed to heterogeneous flow, single-cell transcriptomic analysis revealed that PCV BOECs preferentially adopted migratory-angiogenic cell state, while normal BOECs undertook proinflammatory cell state. PCV BOECs also had a repressed protective response to flow stress by demonstrating lower mitochondrial functions. We uncovered that elevated hyaluronidase-1 in PCV BOECs led to increased degradation of hyaluronan, a major component of glycocalyx that interfaces between flow stress and vascular endothelium. Notably, knockdown of hyaluronidase-1 in PCV BOEC improved mechanosensitivity, as demonstrated by a significant 1.5-fold upregulation of Krüppel-like factor 2 (KLF2) expression, a flow-responsive transcription factor. Activation of KLF2 might in turn modulate PCV BOEC migration. Barrier permeability due to glycocalyx impairment in PCV BOECs was also reversed by hyaluronidase-1 knockdown. Correspondingly, hyaluronidase-1 was detected in PCV patient vitreous humor and plasma samples.

Conclusions

Hyaluronidase-1 inhibition could be a potential therapeutic modality in preserving glycocalyx integrity and endothelial stability in ocular diseases with vascular origin.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01244-z.

Effectiveness of Current Treatments for Wet Age-Related Macular Degeneration in Japan: A Systematic Review and Pooled Data Analysis

Purpose

We conducted a systematic review to investigate the effectiveness of clinical treatments for wet age-related macular degeneration (wAMD) in Japanese patients in the decade since anti-vascular endothelial growth factor (VEGF) therapies were introduced.

Methods

PubMed was searched for articles published in English between 1 January 2008 and 30 September 2018 using a multistring search strategy. Reviews were scanned for additional relevant studies and select gray literature was evaluated. Mean and/or median for the logarithm of the minimum angle of resolution (logMAR) visual acuity (VA), central retinal thickness (CRT), and the number of injections after 12 months of treatment were calculated using extracted data. Data were stratified by disease type and treatment modality.

Results

Of 335 studies identified, 94 were selected for data extraction (147 treatment arms; typical AMD, n = 25; polypoidal choroidal vasculopathy [PCV], n = 85). Mean (median) logMAR VA was 0.44 (0.32) for typical AMD and 0.34 (0.31) for PCV; the respective mean number of anti-VEGF injections was 5.6 and 4.6. The mean CRT was approximately 220 μm for both groups. For typical AMD, anti-VEGF monotherapy resulted in better VA outcomes than photodynamic therapy (PDT) alone. For PCV, anti-VEGF monotherapy or anti-VEGF plus PDT combination therapy resulted in better VA and CRT outcomes than PDT monotherapy. Combination therapy required fewer injections than anti-VEGF monotherapy (PCV, 3.2 versus 5.3).

Conclusion

wAMD treatment has advanced dramatically in the years since anti-VEGF drugs were introduced in Japan. Discrete patient populations may benefit from differing management regimens, including the fewer injections required with combination therapy.

Pigmentary abnormality without significant drusen as a risk factor for late age-related macular degeneration

We investigated the incidence and risk factors of late age-related macular degeneration (AMD) in the fellow eye (FE) without significant drusen of patients with unilateral exudative macular neovascularization (MNV). In this retrospective study, 241 eligible patients who were followed-up for more than 3 years were enrolled. We analyzed the incidence and hazard ratios (HRs) of late AMD in the FE according to demographic and ophthalmologic variables. Hypopigmentation on color fundus photography (CFP) corresponds to shallow irregular RPE elevation (SIRE), so-called "double-layer sign" and/or "attenuation or disruption of RPE and/or ellipsoid zone" on OCT. The 5-year incidence of FE exudative MNV conversion was 8.6%. The 5-year incidence of FE exudative MNV of large hypopigmentation (≥ 0.5 disc area; DA) and small hypopigmentation (< 0.5 DA) on CFP, and SIRE (≥ 1000 µm) and small RPE elevation (< 1000 µm) on OCT were 36.2%, 14.2%, 55.0%, and 15.6%, respectively. The multivariate Cox proportional hazard model revealed that large hypopigmentation, small hypopigmentation, SIRE, and small RPE elevation showed HRs of 23.230, 8.037, 132.589, and 41.823 for FE exudative MNV occurrence, respectively. Hypopigmentation on CFP and SIRE on OCT could represent the same lesion. Even small hypopigmentation and small RPE elevation were significant risk factors for progression to exudative MNV.

An Objective Perimetry Study of Central Versus Peripheral Sensitivities and Delays in Age-Related Macular Degeneration

Purpose

The purpose of this study was to compare central versus peripheral retinal sensitivities and delays in neovascular age-related macular degeneration (nAMD) using US Food and Drug Administration (FDA)-cleared multifocal pupillographic objective perimetry (mfPOP).

Methods

We recruited 18 patients with nAMD and commenced Pro re nata intravitreal anti- vascular endothelial growth factor (VEGF) injection. We compared macular (±15 degrees) and wide-field (±30 degrees) mfPOP variants. We examined temporal correlations between treated and untreated fellow eyes. We fitted linear models to selected treatment patterns, and compared the ability of central versus peripheral responses to predict the need for treatment.

Results

Central sensitivity decreased by -2.23 ± 0.051 dB/month (P < 0.0002) in treated eyes, and -0.17 ± 0.07 dB/month (P = 0.033) in untreated eyes. Treated eyes showed quicker central responses by 13.08 ± 3.77 ms than untreated eyes (P = 0.001). Based on peripheral responses, we identified two eye-types. Among positive-eyes peripheral sensitivity increased by 9.88 ± 4.41 dB (P = 0.042) before treatment; delays increased by 3.49 ± 1.75 ms/month (P = 0.049). For negative-eyes peripheral delays were shorter a month before treatment by 9.38 ± 3.59 ms (P = 0.013). Correlations between treatment and peripheral sensitivities or delays peaked at 1 to 2 months post-treatment. Peripheral data significantly determined treatment frequency and final acuity (all P < 0.044).

Conclusions

Peripheral macular function of treated and untreated eyes divided eyes into positive and negative groups. Those peripheral responses determined outcomes; changes preceding active disease by 1 to 3 months. Overall, mfPOP may provide potential biomarkers to assist nAMD management.

Translational Relevance

Objective perimetry may identify the requirement for treatment in nAMD that accords with the decision of a skilled clinician based on optical coherence tomography (OCT) and clinical findings.

Association of Dietary Nutrient Intake with Early Age-Related Macular Degeneration in Japanese-Americans

Lifestyle factors may be associated with the development of age-related macular degeneration (AMD), in addition to demographic and genetic factors. The purpose of this cross-sectional study is to elucidate the association between nutrient intake and AMD in the Japanese-American population living in Los Angeles. We conducted a medical survey of Japanese immigrants and their descendants living in Los Angeles, including interviews on dietary habits, fundus photography, and physical examinations. Participants were classified into early AMD and control groups on the basis of fundus photographic findings. Consequently, among the 555 participants, 111 (20.0%) were diagnosed with early AMD. There were no late-stage AMD participants. Multivariate logistic regression analysis showed that the intake of animal fat and saturated fatty acids (SFA) was positively associated with early AMD (p for trend = 0.01 for animal fat, p for trend = 0.02 for SFA), and the intake of vegetable fat, total carbohydrate, simple carbohydrate, sugar, and fructose was inversely associated with early AMD (p for trend = 0.04 for vegetable fat, p for trend = 0.046 for carbohydrate, p for trend = 0.03 for simple carbohydrate, p for trend = 0.046 for sugar, p for trend = 0.02). Our findings suggest that excessive animal fat and SFA intake increases the risk for early AMD in Japanese-Americans whose lifestyles have been westernized.

Effects of cataract surgery in Japanese patients with neovascular age-related macular degeneration

Purpose

To investigate the effects of cataract surgery in Japanese patients with neovascular age-related macular degeneration (nAMD).

Methods

The primary endpoint in this prospective, observational study was patient satisfaction at 6 months after cataract surgery in patients with nAMD. Secondary endpoints comprised changes in best-corrected visual acuity (BCVA), M-chart score, central retinal thickness (CRT), AMD status, and number of AMD treatments. All examinations were performed before surgery, and at 1, 3, and 6 months postoperatively.

Results

Fifty patients (52 eyes) were included in this study (32 men; mean age, 76.1 ± 7.1 years). Thirty-nine patients (75.0%) reported satisfaction with cataract surgery. BCVA significantly improved at all postoperative timepoints (all p < 0.0001), whereas differences in M-chart scores were not statistically significant. The number of eyes with BCVA ≤ 0.3 logarithm of the minimum angle of resolution (logMAR) increased from 21 to 38; however, CRT did not change. The number of AMD treatments did not change during follow-up. All questionnaire scores showed postoperative improvement. Univariate and multivariate analyses revealed that final BCVA ≤ 0.3 logMAR was significantly associated with patient satisfaction.

Conclusion

Cataract surgery significantly improved vision in Japanese patients with nAMD, without affecting AMD status. Patients were satisfied with cataract surgery, especially with respect to improvement of distance vision.

Dietary Saturated Fatty Acid Intake and Early Age-Related Macular Degeneration in a Japanese Population

Purpose

To assess the association of dietary saturated fatty acid (SFA) intake with the presence of early AMD in a Japanese population.

Methods

The population-based Tsuruoka Metabolomics Cohort Study enrolled general population individuals aged 35 to 74 years from among participants in annual health check-up programs that included fundus photographs in Tsuruoka, Japan. A total of 4010 individuals participated in the baseline survey. After excluding nonresponders to a dietary survey and participants with suboptimal fundus image quality, 3988 participants (median age, 62.4 years) were included in this cross-sectional analysis. Dietary intake was assessed by a validated food frequency questionnaire. Fatty acids intake was adjusted for total energy intake by the residuals method. The association between fatty acid intake and presence of early AMD was assessed by logistic regression models.

Results

Median daily SFA intake was 11.3 g (interquartile range, 9.6, 13.0 g). After adjustments for potential confounding factors, participants in the highest quartile of SFA intake were less likely to have early AMD, compared with the lowest quartile (odds ratio, 0.71; 95% confidence interval: 0.52–0.96). A significant trend for decreased risk of early AMD with increasing SFA intake was noted (P = 0.011). There was no significant association between poly-unsaturated fatty acid (PUFA) including n3-PUFA intake and early AMD.

Conclusions

We found that increased SFA intake was associated with reduced risk of early AMD in a Japanese population with low SFA intake. Adequate fatty acid intake may be required to maintain retinal homeostasis and prevent AMD.

APOE2 promotes the development and progression of subretinal neovascularization in age-related macular degeneration via MAPKs signaling pathway

Background

Neovascular age-related macular degeneration (nvAMD) is one of the main pathological features of wet AMD. Apolipoprotein E2 is involved in the formation of nvAMD but the molecular mechanism has not been reported.

Methods

The APOE alleles in AMD patients were detected by genotyping. Mouse models were divided into 4 groups according to transfection different gene segments and laser-induced treatment. APOE2, VEGF, PDGF-BB, b-FGF and inflammatory cytokines (including p-NF-κB, TNF-α, IL-1β and IL-6) were tested by ELISA in mice retinal lysate. The formation of nvAMD in the indicated treatment groups at 3rd, 7th and 14th day after laser-induced damage were detected by FFA. Besides, qRT-PCR was used to determine the mRNA levels of p38, JNK and ERK in ARPE-19 cells. Finally, the inflammatory cytokines and MAPK proteins (including P38, p-P38, JNK, p-JNK, ERK and p-ERK) were detected by western blot.

Results

The statistics of APOE alleles showed that APOE2 allele carriers were more likely to nvAMD. VEGF, PDGF-BB, b-FGF and related inflammatory cytokines were up-regulated significantly after treatment with APOE2, which were reduced after silencing the MAPK family genes, however. Further, the expression levels of neovascular growth factors and inflammatory cytokines were highly consistent between mouse models and ARPE-19 cells. Besides, the phosphorylation levels of p38, JNK and ERK were affected by APOE2.

Conclusion

nvAMD was affected directly by the overexpression of VEGF, PDGF-BB and b-FGF, which were regulated by APOE2 through activating MAPKs pathway.

Pachychoroid disease: a new perspective on exudative maculopathy

BACKGROUND

Pachychoroid, or the structural and functional abnormalities of the choroid, is one of the most important causes of exudative maculopathies. The purpose of this article is to review the current definitions of pachychoroid and their potential consequences. Most publications are from Asian countries. Although no consensus diagnosis has been reached, pachychoroid is defined by thickened choroid and choroidal vascular hyperpermeability, pachyvessels with inner choroidal attenuation; it is closely linked to pachydrusen. Although some studies suggest choroidal congestion may play a role in its pathogenesis, the exact causes of this condition are still unknown. Pachychoroid is associated with exudative maculopathies including central serous chorioretinopathy, pachychoroid neovasculopathy and polypoidal choroidal vasculopathy (PCV). It is widely accepted that macular neovascular membranes may develop secondary to pachychoroid. Recent clinical observations illustrate the importance of pachychoroid in the etiology of macular neovascularization including neovascular age-related macular degeneration (nAMD).

CONCLUSION

Pachychoroid is an important cause of exudative maculopathies. Both drusen and pachychoroid are increasingly recognized as important causes of macular neovascularization, and eyes formally categorized as typical nAMD or PCV can be further sub-categorized based on the presence or absence of pachychoroid and drusen. There is a need to develop a consensus definition, which will greatly enhance our understanding of pachychoroid and facilitate the development of individual interventions in pachychoroid diseases.