Evaluation of insomnia effect on ganglion cell complex, middle retina, and choroid.

PURPOSE: Insomnia is a common psychiatric disorder that has oxidative and degenerative effects on the brain. It is thought that the brain's processes affect the retina through their synaptic connections. However, the effects of sleep disorders on the retina and choroid are not fully understood. We aimed to investigate the impact of insomnia on retinal nerve fiber layer (RNFL), central foveal thickness, retinal layers, and choroidal thickness. METHODS: The right eye of 16 healthy controls and 15 patients with insomnia complaints for 3 months, no history of psychiatric drug use, and an Insomnia Severity Index (ISI) score of 15 or higher were included in the study. The retinal layers and RNFL analyses were performed using optical coherence tomography (OCT), and choroidal layers were analyzed using enhanced depth imaging OCT. RESULTS: Nasal and temporal ganglion cell complex thicknesses were significantly lower in patients with insomnia compared to the controls (97 µm vs. 111 µm P = 0.004; 94 µm vs. 105 µm P = 0.012, respectively). A significant negative correlation was detected between the ISI score and global RNFL thickness (rho, P = 0.03) Additionally, pachychoroid-like vascular structures were observed in choroidal images. CONCLUSION: These changes in the retina and the choroid layers due to insomnia may be precursors to retinal degenerative conditions, such as age-related macular degeneration that may occur in the future. Multicenter studies including more patients are needed to demonstrate the importance of quality sleep for eye health.

Characterization of Vortex Vein Drainage System in Healthy Individuals Imaged by Ultra-Widefield Optical Coherence Tomography Angiography.

Purpose: The purpose of this study was to investigate the choroidal characteristics of vortex vein (VV) drainage systems in healthy individuals using ultra-widefield optical coherence tomography angiography. Methods: The mean choroidal thickness (ChT) and choroidal vascularity index (CVI) of each VV quadrant (24 × 20 mm2 scan mode; superotemporal [ST], superonasal [SN], inferonasal [IN], and inferotemporal [IT] quadrants) were calculated. Furthermore, intervortex venous anastomosis (IVA) was classified into temporal, superior, inferior, and nasal types. Results: A total of 207 healthy eyes were analyzed to find that the ST quadrant had the thickest choroidal layer and highest CVI (all P < 0.05). Among the four VV drainage quadrants, the mean ChT and CVI decreased in the sequence of ST, SN, IT, and IN (all P < 0.05). Moreover, men had a higher CVI than women in all VV quadrants (all P < 0.05). IVA was observed in all VV quadrants of 91 eyes (43.96%), and in the macular region of 33 eyes (15.94%). Conclusions: The ST drainage system was identified as the preferred VV drainage route in healthy eyes. Among the four VV drainage quadrants, the drainage system adhered to the ST-SN-IT-IN order of descending perfusion. Furthermore, age- and sex-related differences were noted in the choroidal VV drainage systems of healthy eyes. Additionally, almost half of the healthy eyes had IVA in their choroidal vessel networks. Translational Relevance: The VV drainage system may be considered a novel imaging biomarker for ocular diseases.

Analysis of choroidal features to predict surgical prognosis of idiopathic macular hole.

OBJECTIVE: To investigate choroidal features of idiopathic macular hole (IMH) and determine their relationship with surgical outcomes. MATERIALS AND METHODS: Patients above stage II unilateral IMH who received pars plana vitrectomy (PPV) with the internal limiting membrane (ILM) peeling were enrolled for the retrospective observational study. Preoperative choriocapillaris perfusion (CCP), central choroidal thickness (CCT), base/minimum diameters (BD/MD) and height (HH) of MH were analyzed by optical coherence tomography angiography (OCTA). At 1, 3 and 6 months after PPV, CCT, central foveal thickness (CFT) and maximum parafoveal thickness (MPT) of closed MH were measured. Best-corrected visual acuity (BCVA) was assessed at every visit. The correlations between preoperative characteristics and surgical outcomes were assessed. RESULTS: Twenty-seven patients were evaluated. All eyes (100%) showed successful MH closure after the primary surgery. Until postoperative 6 months, BCVA continued to improve significantly (p < 0.001), while CFT and CCT progressively thinned (p < 0.001, p < 0.001). On correlation tests, final postoperative BCVA was associated with preoperative BCVA (R = 0.506, p = 0.007) and CCP (R = -0.475, p = 0.012), while final CFT was related with preoperative CCT (R = 0.392, p = 0.043). Multiple regression analysis revealed that preoperative CCP was significantly related with final postoperative BCVA (ß = -0.403, p = 0.049). CONCLUSION: Preoperative CCP and CCT were respectively associated with functional and anatomical prognosis of IMH after PPV.

[Diagnosis of choroidal nevus following multiple intravitreal anti-VEGF injections (case study)]. / Diagnostika nevusa khorioidei posle mnogokratnykh intravitreal'nykh in"ektsii anti-VEGF-preparata (klinicheskoe nablyudenie).

This article describes a clinical case of a female patient with choroidal nevus, who was previously diagnosed in another clinic with "subretinal neovascular membrane as a result of central serous chorioretinopathy" and subsequently underwent multiple intravitreal anti-VEGF injections. Based on the analysis of OCT angiography images, the macular changes in this case were interpreted as a polypoidal form of neovascularization in a patient with subfoveolar choroidal nevus.

MICROVASCULAR CHANGES IN TREATMENT-NAÏVE NONEXUDATIVE MACULAR NEOVASCULARIZATION COMPLICATED BY EXUDATION.

PURPOSE: To assess differences in choriocapillaris (CC) and macular neovascularization (MNV) optical coherence tomography angiography quantitative parameters between long-term persistently nonexudative MNVs (NE-MNVs) and long-term activated NE-MNVs in age-related macular degeneration. METHODS: Age-related macular degeneration patients with treatment-naïve NE-MNVs with >2 years of follow-up and no evidence of exudation within the first 6 months from diagnosis were retrospectively recruited. Two groups were considered according to the occurrence (EX group) or not (NE group) of exudation within the first 2 years of follow-up. Segmentation of the MNV and of the perilesional CC were obtained from enface optical coherence tomography angiography acquisitions at diagnosis and at 6-month follow-up. OCT B-scan images of the MNV were also collected. Fractal ratio was defined as the ratio between MNV fractal dimension (FrD) and CC FrD. RESULTS: Fifty (50) eyes were included (20 EX group and 30 NE group). EX group showed higher flow deficit density and flow deficit number at the 6-month follow-up. It also showed higher MNV FrD, lower CC FrD, and higher fractal ratio at the 6-month follow-up. The fractal ratio significantly increased at 6-month acquisitions in the EX group, showing an area under the ROC curves of 0.887 (95% CI 0.869-0.922). CONCLUSION: Fractal ratio at 6 months can predict exudation risk of MNV within 2 years from diagnosis. This suggests increased structural complexity of the NE-MNV accompanied by progressive capillary rarefaction of the perilesional CC as a key driving factor for the development of exudation in NE-MNV.

Anatomic changes in asymptomatic pachychoroid spectrum diseases after cataract surgery.

Pachychoroid spectrum disease (PSD) involves various chorioretinal pathologies associated with increased choroidal blood flow. Theoretically, PSD could worsen after cataract surgery since the choroidal thickness tends to increase after surgery. Therefore, we evaluated the prevalence of asymptomatic PSD in patients who underwent cataract surgery and compared the clinical characteristics according to the presence of PSD. The subretinal fluid (SRF) development risk was evaluated using the Cox proportional hazard model. Of 924 eyes, 184 (19.9%) showed asymptomatic PSD. Patients with asymptomatic PSD were older, predominantly male, hyperopic, and showed thicker choroid (P < 0.001, 0.001, < 0.001, and < 0.001). Seven (3.8%) of 184 eyes with asymptomatic PSD developed SRF. The Cox proportional hazard model showed that the flat, irregular pigment epithelial detect (FI-PED; HR 37.337, 95% CI 3.880-359.9300, P = 0.002) was the sole indicator for the SRF development after adjustment of age, sex, and axial length. The SRF-developed PSD group experienced a profound and prolonged increase in the choroidal thickness (P = 0.001, 0.002, and 0.002 at 1, 3, and 12 months). Meticulous preoperative evaluation for FI-PED and postoperative monitoring for choroidal thickness would predict SRF development after cataract surgery in eyes with asymptomatic PSD.

VEGFA may be a potential marker of myopic choroidal thickness and vascular density changes.

To evaluate the changes of choroidal thickness (CT) and blood flow related to myopia, and its effects of vascular endothelial growth factor (VEGFA) on choroidal vessels in myopia. Subjects were included and divided into emmetropia (EM), non-high myopia (Non-HM) and high myopia (HM) groups. we measured choroidal thickness (CT), choriocapillaris vessel density (VD), and VEGFA content in tears in humans (137 subjects for CT, VD and 84 for tear) and detected the role of VEGFA in the choroid in form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs were divided into control and FDM groups, and the expression changes of choroidal vessels and VEGFA were observed and compared using immunohistochemistry and Western blotting. Twenty-one guinea pigs were divided into control, FDM + Vehicle and FDM + Conbercept groups. The changes of diopter, axis length and choroidal vessels after intravitreal injection of Conbercept were observed. There were significant differences in CT and VD among the three groups (p < 0.05). VEGFA levels in tears were significantly lower in the myopic groups, with a decreasing trend from EM to Non-HM to HM. The choroidal vascular area fraction of FDM decreased compared to the control group. FDM guinea pigs exhibited reduced choroidal vasculature and significant downregulation of VEGFA expression. Following intravitreal injection of conbercept, the FDM + Conbercept group showed greater myopia, longer axial length, and lower choroidal vascular area fraction compared to the control group. VEGFA may participate in the regulation of choroidal blood vessels and blood flow in the progression of myopia. The reduction in VEGFA may accelerates the progression of myopia.

ChoroidSeg-ViT: A Transformer Model for Choroid Layer Segmentation Based on a Mixed Attention Feature Enhancement Mechanism.

Purpose: To develop a Vision Transformer (ViT) model based on the mixed attention feature enhancement mechanism, ChoroidSeg-ViT, for choroid layer segmentation in optical coherence tomography (OCT) images. Methods: This study included a dataset of 100 OCT B-scans images. Ground truths were carefully labeled by experienced ophthalmologists. An end-to-end local-enhanced Transformer model, ChoroidSeg-ViT, was designed to segment the choroid layer by integrating the local enhanced feature extraction and semantic feature fusion paths. Standard segmentation metrics were selected to evaluate ChoroidSeg-ViT. Results: Experimental results demonstrate that ChoroidSeg-ViT exhibited superior segmentation performance (mDice: 98.31, mIoU: 96.62, mAcc: 98.29) compared to other deep learning approaches, thus indicating the effectiveness and superiority of this proposed model for the choroid layer segmentation task. Furthermore, ablation and generalization experiments validated the reasonableness of the module design. Conclusions: We developed a novel Transformer model to precisely and automatically segment the choroid layer and achieved the state-of-the-art performance. Translational Relevance: ChoroidSeg-ViT could segment precise and smooth choroid layers and form the basis of an automatic choroid analysis system that would facilitate future choroidal research in ophthalmology.

Evaluation of choroidal thickness and optic disc parameters in patients with chronic phase gout.

PURPOSE: This study aims to assess the disparities in choroidal thickness and optic disc parameters between individuals diagnosed with chronic gout and an age- and gender-matched control cohort. METHODS: This cross-sectional study involved 30 gout patients receiving treatment at the Rheumatology clinic, alongside 30 healthy control individuals matched for age and gender. A comprehensive ophthalmological assessment, encompassing visual acuity measurement, intraocular pressure evaluation, slit-lamp biomicroscopy, and dilated fundus examination, was conducted for all participants. Peripapillary retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and subfoveal choroidal thickness (SFCT) were quantified utilizing Spectral Domain Optical Coherence Tomography. RESULTS: The mean age within the study group was 54.53 ± 9.43 years, while the control group's mean age was 53.20 ± 10.36 years. In both the gout and control cohorts, there were 28 men and 2 women. No significant differences were observed in age and gender between the groups. Gout patients manifested thinner RNFL and GCC across all quadrants; however, statistically significant thinning was only evident in the nasal and inferior quadrants for RNFL. Despite a thinner SFCT observed in gout patients compared to controls, this discrepancy did not attain statistical significance. CONCLUSION: Chronic phase gout patients may display alterations in optic disc and macular parameters, alongside potential variations in choroidal thickness. Nevertheless, more controlled studies encompassing a larger participant pool are imperative to substantiate our findings.

Central serous chorioretinopathy and the sclera: what we have learned so far.

Central serous chorioretinopathy (CSC) is a common disorder characterized by serous retinal detachment. Several studies using indocyanine green angiography (ICGA) have revealed that choroidal filling delay, choroidal vascular dilation, and choroidal vascular hyperpermeability are the characteristic findings of CSC. These ICGA findings confirm that choroidal circulatory disturbances are the primary factors in the pathogenesis of CSC. With advancements in optical coherence tomography (OCT), choroidal thickness has been found to be significantly greater in eyes with CSC than in normal eyes. Dilated large choroidal vessels reportedly account for the thickened choroid in eyes with CSC. Although many possible mechanisms and risk factors have been suggested, the pathophysiologic features of choroidal circulatory disturbances and choroidal thickening in eyes with CSC have not yet been fully elucidated. Recently, using anterior segment OCT, we proposed that the sclera may induce choroidal circulatory disturbances since CSC eyes have significantly thicker sclera than do normal eyes. This review summarizes updated information on the close relationship between CSC pathogenesis and the sclera.

Presentation and Clinical Features of Stargardt Disease in a Series of Nigerian Patients.

Stargardt disease (SD) is a common inherited macular dystrophy. It exhibits a high degree of phenotypic and genotypic heterogeneity. Yellow-white flecks are often found in the posterior pole in the early stages of the disease with a reduction in central vision from foveal atrophy as it progresses. A characteristic dark choroid appearance is seen on fundus fluorescein angiography (FFA) in many cases, with occasional reports of choroidal neovascular membranes. We report a series of four Nigerian patients, with varied presentations diagnosed with SD in our facility. One patient had good vision, while the other three had variable degrees of reduced vision. All patients had macular atrophy and flecks, while three patients had a dark choroid appearance on FFA and one patient developed a choroidal neovascular membrane in one eye.

RésuméLa maladie de Stargardt (SD) est une dystrophie maculaire héréditaire courante. La maladie de Stargardt (SD) est une dystrophie maculaire héréditaire courante. Il présente un haut degré d'hétérogénéité phénotypique et génotypique. Il présente un haut degré d'hétérogénéité phénotypique et génotypique. Des taches jaune-blanc sont souvent trouvées dans le pôle postérieur aux premiers stades de la maladie avec une réduction de la vision centrale due à l'atrophie fovéale au fur et à mesure de sa progression. au fur et à mesure de sa progression. Une apparence choroïde foncée caractéristique est observée sur l'angiographie à la fluorescéine du fond d'œil (AFL) dans de nombreux cas, avec des rapports de membranes néovasculaires choroïdiennes. Nous rapportons une série de quatre patients Nigérians, avec des présentations variées diagnostiquées avec SD chez notre établissement. Un patient avait une bonne vision, tandis que les trois autres avaient des degrés variables de vision réduite. Tous les patients présentaient une atrophie maculaire et des taches, tandis que trois patients avaient une apparence choroïde foncée sur FFA et qu'un patient a développé une membrane néovasculaire choroïdienne dans un œil.

Shear-wave elastographic imaging in choroidal melanomas: clinical and hemodynamic correlations.

PURPOSE: This study evaluated the role of shear wave elastography imaging (SWEΙ) in uveal melanomas and the associations between SWEI and clinical and hemodynamic findings. STUDY DESIGN: Prospective, clinical study METHODS: Twelve patients with uveal melanomas, scheduled to undergo Ru-106 brachytherapy, were prospectively recruited from the Department of Ophthalmology of the University Hospital of Heraklion (September-December 2022). B-mode, hemodynamic and SWEI ultrasonography examinations were performed with the HiScan (OPTIKON 2000) and the LOGIQ E9 (GE Healthcare) sonographic systems, respectively. Differences in SWEI scores (kPa) between tumor (TS) and adjacent non-affected choroid (CS), as well as between TS and orbital fat (FS) were examined. Correlations between SWEI and intra-tumoral hemodynamic parameters, including peak systolic and end diastolic velocities and resistivity index (RI) were also examined. RESULTS: TS was significantly correlated with intra-tumoral RI (Pearson's bivariate correlation coefficient 0.681, p=0.015) and with maximal tumor height (Pearson's bivariate correlation coefficient 0.620, p=0.031). TS was significantly higher than both FS and CS scores (paired-samples t-test, p=0.003 and p=0.006, respectively). CONCLUSIONS: SWEI score is applicable as a quantitative biomechanical marker in the assessment of choroidal melanoma. Choroidal melanomas are stiffer than both adjacent choroid and orbital fat. Moreover, choroidal melanomas with higher RI as well as those with higher apical elevations display higher SWEI scores.

Comparison of One-Year Outcome of Intravitreal Aflibercept with or without Photodynamic Therapy for Polypoidal Choroidal Vasculopathy.

Background and Objectives: Our study compared the visual and anatomical outcomes of polypoidal choroidal vasculopathy (PCV) patients receiving intravitreal aflibercept (IVA) with or without photodynamic therapy (PDT) over 12 months. Materials and Methods: This retrospective study was performed for 60 eyes from 60 patients with treatment-naïve PCV. Thirty eyes were treated using IVA monotherapy (IVA group), and thirty eyes were treated using a combination of IVA with PDT (IVA/PDT group). The baseline characteristics, treatment outcomes, and retreatment rates were compared between the two groups over a one-year follow-up period. Results: The best-corrected visual acuity (BCVA) was found to have improved significantly in the IVA/PDT group at every 3-month visit. However, no significant BCVA improvement was observed in the IVA group. A significantly lower retreatment rate and higher dry macula rate were found in the IVA/PDT group than that in the IVA group. In the entire population of the study, a better baseline vision and younger age were associated with better final visual outcomes. Retreatment was associated with poor baseline BCVA and IVA monotherapy. Conclusions: The combination of IVA and PDT may offer superior visual improvement and a higher dry macula rate compared to IVA monotherapy in the treatment of PCV patients while requiring fewer retreatments over 12 months.

Choriocapillaris in Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is a multifactorial disease characterized by progressive alterations of different retinal structures ultimately leading to vision loss. Among these, the choriocapillaris (CC) has been found to be affected in different stages of AMD. In this review we provide a discussion on the different stages of AMD, focusing particularly on the alterations involving the CC. This has been possible thanks to the introduction of optical coherence tomography-angiography, a recently developed imaging technique which allows the detection of blood flow in choroidal vessels. Therefore, the aim of this review is to provide a description of the various alterations involving the CC in the different stages of AMD.

Association of outer retinal and choroidal alterations with neuroimaging and clinical features in posterior cortical atrophy.

BACKGROUND: Posterior cortical atrophy (PCA) is a rare condition characterized by early-onset and progressive visual impairment. Individuals with PCA have relatively early-onset and progressive dementia, posing certain needs for early detection. Hence, this study aimed to investigate the association of alterations in outer retinal and choroidal structure and microvasculature with PCA neuroimaging and clinical features and the possible effects of apolipoprotein E(APOE) ε4 allele on outer retinal and choroidal alterations in participants with PCA, to detect potential ocular biomarkers for PCA screening. METHODS: This cross-sectional study included PCA and age- and sex-matched healthy control participants from June 2022 to December 2023. All participants with PCA completed a comprehensive neurological evaluation. All participants were recorded baseline information and underwent an ophthalmic evaluation. Quantitative analyses were performed using swept-source optical coherence tomography (SS-OCT) and angiography (SS-OCTA). Adaptive optics scanning laser ophthalmoscopy (AO-SLO) was performed in some patients. In participants with PCA, the influence of APOE ε4 on outer retinal and choroidal alterations and the correlation of outer retinal and choroidal alterations with PCA neuroimaging and clinical features in participants with PCA were investigated. RESULTS: A total of 28 participants (53 eyes) with PCA and 56 healthy control participants (112 eyes) were included in the current study. Compared with healthy control participants, participants with PCA had significantly reduced outer retinal thickness (ORT) (p < 0.001), choriocapillaris vessel density (VD) (p = 0.007), choroidal vascular index (CVI) (p = 0.005) and choroidal vascular volume (CVV) (p = 0.003). In participants with PCA, APOE ε4 carriers showed thinner ORT (p = 0.009), and increased choriocapillaris VD (p = 0.004) and CVI (p = 0.004). The PCA neuroimaging features were positively associated with the ORT, CVI and CVV. Furthermore, differential correlations were observed of PCA clinical features with the CRT, CVV and CVI. CONCLUSIONS: Our findings highlighted the association of outer retinal and choroidal alterations with PCA neuroimaging and clinical features in participants with PCA. Noninvasive SS-OCT and SS-OCTA can provide potential biomarkers for the diagnosis and management of PCA, improving awareness of PCA syndrome among ophthalmologists, neurologists, and primary care providers.

Choroidal and retinal exudative changes following extensive endolaser pan retinal photocoagulation.

BACKGROUND: In this report, we describe a case of proliferative diabetic retinopathy that developed into exudative changes confusing with central serous chorioretinopathy (CSCR) following extensive endolaser pan retinal photocoagulation. CASE DESCRIPTION: A 49-year-old male patient with diabetic retinopathy in both eyes presented with vitreous hemorrhage and 6/60 visual acuity in his left eye. Optical coherence tomography (OCT) scans at presentation revealed serous PEDs in both eyes. On day 10 after vitreoretinal surgery and complete peripheral endolaser PRP for the left eye, there was serous retinal detachment (SRD) and an increase in PED heights, mimicking CSCR. No additional treatment was considered. At the three-week post-operative visit, OCT scans revealed that the SRD had resolved and the PED heights had decreased without rupture. At the final follow-up visit, 12 weeks after surgery, the SRD had not recurred, and the PEDs had stabilized. Despite no additional ocular therapy for the right eye, the serous PED height had decreased. The choroidal thickness (CT) at the fovea at various points during the follow-up visits revealed a reduction in both eyes. CONCLUSION: This case demonstrated the course of SRD, PED, and CT following extensive PRP. These changes may be associated with intraocular VEGF changes. In the presence of SRD and serous PED, the PED morphology may help differentiate the condition from CSCR. Although caution should be exercised when performing PRP during surgery or as an outpatient procedure, the SRD usually resolves without problem.

Melanopsin in the human and chicken choroid.

The choroid embedded in between retina and sclera is essential for retinal photoreceptor nourishment, but is also a source of growth factors in the process of emmetropization that converts retinal visual signals into scleral growth signals. Still, the exact control mechanisms behind those functions are enigmatic while circadian rhythms are involved. These rhythms are attributed to daylight influences that are melanopsin (OPN4) driven. Recently, OPN4-mRNA has been detected in the choroid, and while its origin is unknown we here seek to identify the underlying structures using morphological methods. Human and chicken choroids were prepared for single- and double-immunohistochemistry of OPN4, vasoactive intestinal peptide (VIP), substance P (SP), CD68, and α-smooth muscle actin (ASMA). For documentation, light-, fluorescence-, and confocal laser scanning microscopy was applied. Retinal controls proved the reliability of the OPN4 antibody in both species. In humans, OPN4 immunoreactivity (OPN4-IR) was detected in nerve fibers of the choroid and adjacent ciliary nerve fibers. OPN4+ choroidal nerve fibers lacked VIP, but were co-localized with SP. OPN4-immunoreactivity was further detected in VIP+/SP + intrinsic choroidal neurons, in a hitherto unclassified CD68-negative choroidal cell population thus not representing macrophages, as well as in a subset of choroidal melanocytes. In chicken, choroidal nerve fibers were OPN4+, and further OPN4-IR was detected in clustered suprachoroidal structures that were not co-localized with ASMA and therefore do not represent non-vascular smooth-muscle cells. In the choroidal stroma, numerous cells displayed OPN4-IR, the majority of which was VIP-, while a few of those co-localized with VIP and were therefore classified as avian intrinsic choroidal neurons. OPN4-immunoreactivity was absent in choroidal blood vessels of both species. In summary, OPN4-IR was detected in both species in nerve fibers and cells, some of which could be identified (ICN, melanocytes in human), while others could not be classified yet. Nevertheless, the OPN4+ structures described here might be involved in developmental, light-, thermally-driven or nociceptive mechanisms, as known from other systems, but with respect to choroidal control this needs to be proven in upcoming studies.

Non-endothelial expression of endomucin in the mouse and human choroid.

Endomucin (EMCN) is a 261 amino acid transmembrane glycoprotein that is highly expressed by venous and capillary endothelial cells where it plays a role in VEGF-mediated angiogenesis and regulation of immune cell recruitment. However, it is better known as a histological marker, where it has become widespread due to the commercial availability of high-quality antibodies that work under a wide range of conditions and in many tissues. The specificity of EMCN staining has been well-validated in retinal vessels, but while it has been used extensively as a marker in other tissues of the eye, including the choroid, the pattern of expression has not been described in detail. Here, in addition to endothelial expression in the choriocapillaris and deeper vascular layers, we characterize a population of EMCN-positive perivascular cells in the mouse choroid that did not co-localize with cells expressing other endothelial markers such as PECAM1 or PODXL. To confirm that these cells represented a new population of EMCN-expressing stromal cells, we then performed single cell RNA sequencing in choroids from adult wild-type mice. Analysis of this new dataset confirmed that, in addition to endothelial cells, Emcn mRNA expression was present in choroidal pericytes and a subset of fibroblasts, but not vascular smooth muscle cells. Besides Emcn, no known endothelial gene expression was detected in these cell populations, confirming that they did not represent endothelial-stromal doublets, a common technical artifact in single cell RNA seq datasets. Instead, choroidal Emcn-expressing fibroblasts exhibited high levels of chemokine and interferon signaling genes, while Emcn-negative fibroblasts were enriched in genes encoding extracellular matrix proteins. Emcn expressing fibroblasts were also detected in published datasets from mouse brain and human choroid, suggesting that stromal Emcn expression was not unique to the choroid and was evolutionarily conserved. Together, these findings highlight unique fibroblast and pericyte populations in the choroid and provide new context for the role of EMCN in the eye.

CBX7 promotes choroidal neovascularization by activating the HIF-1α/VEGF pathway in choroidal vascular endothelial cells.

Vascular endothelial growth factor (VEGF) signaling is crucial for choroidal neovascularization (CNV), a major pathological feature of neovascular age-related macular degeneration (nAMD). Gene transcription of VEGF is mainly regulated by hypoxia-inducible factor 1-alpha (HIF-1α). The chromobox (CBX) family polycomb protein (Pc) subgroup includes CBX2, CBX4, CBX6, CBX7, and CBX8. CBX4 enhances hypoxia-induced VEGF expression and angiogenesis in hepatocellular carcinoma (HCC) cells by increasing HIF-1α's transcriptional activity. The objective of the study was to examine the functions of members of the CBX family Pc subgroup in choroidal vascular endothelial cells (CVECs) during CNV. CBX4 and CBX7 expression was up-regulated in hypoxic human choroidal vascular endothelial cells (HCVECs). In HCVECs, CBX7 facilitated HIF-1α transcription and expression, while CBX4 did not. In HCVECs, CBX7 stimulated HIF-1α's nuclear translocation and transcriptional activity, which in turn stimulated VEGF transcription and expression. The CBX7/HIF-1α/VEGF pathway promoted the migration, proliferation, and tube formation of HCVECs. The CBX7/HIF-1α/VEGF pathway was up-regulated in CVECs and in the mouse model with laser-induced CNV. Mouse CNV was lessened by the blockade of CBX7 through the down-regulation of HIF-1α/VEGF. In conclusion, CBX7 enhanced pro-angiogenic behaviors of hypoxic CVECs by up-regulating the HIF-1α/VEGF pathway, which contributing to the formation of mouse laser-induced CNV.