Changes In Vascular Density Research Articles

Analysis of the effect of congenital unilateral trochlear nerve paresis on retinal vascular density: a retrospective study.

To use swept-source optical coherence tomography angiography (SS-OCTA) to investigate the alterations in retinal vascular density (VD) in patients presenting with congenital unilateral trochlear nerve palsy. The medical records of patients diagnosed with congenital unilateral trochlear nerve palsy and those of a healthy control group were reviewed retrospectively. Comprehensive ocular examinations and SS-OCTA imaging were conducted. The study population was divided into three subgroups of eyes: paretic eyes, fellow eyes, and controls. All participants underwent comprehensive ophthalmic examinations, which included assessments of ocular motility, refraction under cycloplegia, and axial length measurement. Various strabismus tests-the cover-uncover test, prism and alternate cover test, Krimsky test, and Parks-Bielschowsky test-were conducted to confirm the diagnosis and evaluate the extent of the condition. A total of 34 patients and 39 healthy controls were included. Sex and age distributions were similar between groups. Significant differences were observed in central VD of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) between paretic eyes, fellow eyes, and control eyes. The fellow eye exhibited lower central VD compared to the paretic and control eyes. Inverse correlations between deviation angle and VD were noted in different SCP and DCP quadrants in paretic eyes. In our study cohort, there were significant changes in retinal VD in fellow eyes of patients with trochlear nerve palsy, which we speculate may be related to compensatory head position.

Structural and vascular density affection of macular and peripapillary areas in patients having multiple sclerosis versus neuromyelitis optica with previous optic neuritis

Purpose The aim of this study was to compare the peripapillary and macular vascular density changes in neuromyelitis optica spectrum disorders (NMOSD) patients to multiple sclerosis (MS) patients with previous history of optic neuritis and to correlate the loss in the retinal nerve fiber layer (RNFL) and the ganglion cell complex (GCC) with the vascular density. Patients and methods This observational cross-sectional retrospective study was carried out on 25 patients divided into two equal groups of eyes (20 eyes of 13 MS patients and 20 eyes of 12 NMOSD patients), aged 18–50 years of both sexes and 11 age-matched and sex-matched healthy individuals as a control group. The patients were evaluated by history taking, neurological examination, Symbol Digit Modalities Test, and ophthalmic examination including best-corrected visual acuity, Goldmann applanation tonometry (adjusted for central corneal thickness), and slit-lamp biomicroscopy, followed by spectral-domain optical coherence tomography, and optical coherence tomography angiography. Results The NMOSD patients were significantly older, with lower Symbol Digit Modalities Test score, more prevalence of temporal disc pallor, larger foveal avascular zone, and with higher Expanded Disability Status Scale compared to the MS patients and the control group (P<0.05). In the deep vascular plexus, the foveal density and the central macular thickness were significantly less in the NMOSD patients (P<0.05), while in the superficial vascular plexus (SVP), the whole image density, foveal density, parafoveal density, parafoveal superior hemi, parafoveal inferior hemi, and perifoveal density were significantly less in the NMOSD patients (P<0.05). In addition, in the radial peripapillary capillary density (RPCD %), the whole image, total peripapillary, peripapillary superior hemi, and peripapillary inferior hemi were significantly less in the NMOSD patients (P<0.05). The average, superior, and inferior RNFL and GCC were significantly thinner in the NMOSD patients compared to the other two groups (P<0.05). In the MS group, there were strong positive correlations between the RNFL thickness and the choriocapillaris flow area, most of the SVP density, and the RPCD parameters, and between the GCC thickness and most of the SVP density parameters and the whole image of RPCD %, while in the NMOSD group, the best-corrected visual acuity was correlated with duration, number of eye attacks, central macular thickness of the deep vascular plexus, most of the RPCD %, all RNFL and GCC parameters. Conclusion Subclinical primary retinal vasculopathy was detected more frequently in the NMOSD than in the MS disease. It has an essential impact on this disease and the Expanded Disability Status Scale may be a useful adjunct for differentiation between NMOSD and MS individuals who developed previous optic neuritis.

Retinal thickness and vascular density changes in Keratoconus: A systematic review and meta-analysis

Retinal thickness and vascular density changes in Keratoconus: A systematic review and meta-analysis

Effect of panretinal photocoagulation versus intravitreal bevacizumab injection on optic disc microcirculation in patients with diabetic retinopathy

BackgroundThis retrospective study aimed to compare optic disc vasculature changes in 1 and 3 months after treatment with either panretinal photocoagulation (PRP) or Intravitreal bevacizumab (IVB) in patients with diabetic retinopathy.MethodsA total of 50 eyes of 29 diabetic patients without severe complications were included in this comparative case series. Of these, twenty-eight eyes (15 patients) were assigned to the PRP group, while twenty-two eyes (14 patients) were treated with the biosimilar (IVB) (Stivant® CinnaGen Co., Iran). Optical tomography angiography (OCTA) was performed to measure optic disc vascular density (VD) as well as retinal nerve fiber layer (RNFL) thickness.ResultsThe mean age of the enrolled patients was 62.1 ± 8.3 years (40 to 78 years). During follow-up, whole disc VD, inside disc VD and peripapillary VD decreased significantly in the PRP group at month 1 (p = 0.032, p = 0.32, and p = 0.016, respectively) and month 3 (p = 0.004, p = 0.001 and p = 0.011, respectively). There was an insignificant and slight increase for these parameters in the IVB group. (p > 0.05 for all) A comparison of two treatment arms based on mean whole disc VD, inside disc VD, and peripapillary VD changes revealed a significant difference at month 1 (p = 0.009, p = 0.019, and p = 0.002, respectively) and month 3 (p = 0.002, p = 0.015, and p = 0.009, respectively). Peripapillary RNFL thickness increased in the PRP group at month 1 (p = 0.002) and then decreased at month 3 (p = 0.001). During three months of follow-up, the peripapillary RNFL thickness decreased significantly in the IVB group (p = 0.001). Peripapillary RNFL thickness changes were significantly different between treatment groups at month 1 and month 3. (p = 0.001 for both) The RNFL changes during the study did not significantly correlate with peripapillary VD changes in each group (p = 0.231 and p = 372, for PRP and IVB group, respectively).ConclusionThis study demonstrated that IVB and PRP treatments produced distinct short-term microvascular changes in the optic nerve of diabetic retinopathy patients. PRP treatment significantly reduced vascular density in the optic disc and peripapillary region over 3 months, with an initial increase in RNFL thickness followed by a decrease by month 3. In contrast, IVB treatment led to a slight increase in optic disc vascular density while significantly reducing RNFL thickness. No significant correlation was found between changes in RNFL thickness and peripapillary vascular density within either treatment group.

An endogenous aryl hydrocarbon receptor ligand induces preeclampsia-like phenotypes in rats.

Preeclampsia (PE) is a hypertensive disorder during human pregnancy. Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor. Exogenous and endogenous AhR ligands can induce hypertension in male rats and mice. Herein, using rats as a model, we tested the hypothesis that over-regulation of endogenous AhR ligands during pregnancy impairs vascular functions by disrupting the transcriptome in the placenta, contributing to the development of PE. Pregnant rats were injected daily with an endogenous AhR ligand, 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), from gestational day (GD) 10 to 19. Maternal mean blood pressure was measured on GD16-20. Proteinuria and uteroplacental blood flow were monitored on GD20. Placentas collected on GD20 were used to determine changes in vascular density and transcriptome. Compared with the vehicle control, ITE elevated maternal mean blood pressure by 22% and 16% on GD16 and 17, respectively. ITE increased proteinuria by 50% and decreased uteroplacental blood flow by 26%. ITE reduced the placental vascular density by 18%. RNA sequencing analysis revealed that ITE induced 1316 and 2020 differentially expressed genes (DEGs) in female and male placentas, respectively. These DEGs were enriched in pathways relevant to heart diseases, vascular functions and inflammation. Bioinformatics analysis also predicted that ITE altered immune cell infiltration in placentas depending on fetal sex. These data suggest that over-regulation of endogenous AhR ligands may lead to PE with impaired vascular functions and disrupted fetal sex-specific transcriptomes and immune cell infiltration in placentas. These AhR ligand-induced DEGs and pathways may represent promising therapeutic targets for PE-induced cardiovascular dysfunctions. KEY POINTS: An endogenous AhR ligand (ITE) elevated maternal blood pressure and proteinuria in pregnant rats, and decreased uteroplacental blood flow and fetal and placental growth, all of which are hallmarks of preeclampsia. ITE reduced vascular density and altered immune cell distribution in rat placentas. ITE dysregulated transcriptomes in rat placentas in a fetal sex-specific manner. These ITE-dysregulated genes and pathways are highly relevant to diseases of heart, vascular functions and inflammatory responses.

Microcirculatory parameters as risk factors for predicting progression of posterior staphyloma in highly myopic eyes: a case–control study

BackgroundTo assess the rate of macular blood flow decreasing in adults with and without posterior staphyloma (PS) using optical coherence tomography angiography (OCTA) and to identify risk factors associated with PS progression.MethodsThis longitudinal case-control study enrolled 122 eyes of 122 patients—64 patients with PS (PS group) and 58 patients without PS (NPS group). Participants underwent OCTA and clinical examinations at least twice, and those followed for at least one year were included in the analysis. Logistic regression analysis and machine learning were applied to explore the risk factors for PS and its progression.ResultsPatients in the PS group exhibited faster growth rates of spherical equivalent refraction (SER), axial length (AL), curvature index (CI), and posterior scleral height (PSH) as well as higher loss rates of choriocapillaris perfusion area (CCPA), choroid perfusion area (CPA) and choroidal vascularity index (CVI) compared to the NPS group (all P < 0.05). The baseline SER (B = − 1.291, OR = 0.275, P = 0.008), baseline subfoveal scleral thickness (B = − 1.621, OR = 0.198, P = 0.046), baseline PSH (B = 2.959, OR = 19.282, P = 0.001) and foveal CVI changes per year (B = − 2.776, OR = 0.062, P < 0.001) were the risk factors for PS. Baseline AL (B = 0.561, OR = 1.752, P = 0.033), parafoveal choroidal thickness changes per year (B = − 0.094, OR = 0.910, P = 0.032), foveal retinal vascular density changes per year (B = 0.104, OR = 1.110, P = 0.013) and foveal CCPA changes per year (B = − 0.214, OR = 0.807, P = 0.038) were the risk factors for the PS progression.ConclusionsDuring the progression of myopia in adults, changes in the morphology of the eye's posterior pole are not limited to axial lengthening alone; there also will be a phase of compensatory lateral expansion. Baseline AL and changes in the microcirculation can be utilized to predict the progression of PS.

Investigation of choroidal vascular alterations in eyes with myopia using ultrawidefield optical coherence tomography angiography

Background/aimsThe study aims to evaluate choroidal vascular changes in younger patients with myopia using ultrawidefield swept-source optical coherence tomography angiography (SS-OCTA).MethodsOverall, 724 eyes of 362 participants (177 males, 185 females,...

Microvascular alterations of the ocular surface and retina in connective tissue disease-related interstitial lung disease.

To examine the disparities in macular retinal vascular density between individuals with connective tissue disease-related interstitial lung disease (CTD-ILD) and healthy controls (HCs) by optical coherence tomography angiography (OCTA) and to investigate the changes in microvascular density in abnormal eyes. For a retrospective case-control study, a total of 16 patients (32 eyes) diagnosed with CTD-ILD were selected as the ILD group. The 16 healthy volunteers with 32 eyes, matched in terms of age and sex with the patients, were recruited as control group. The macular retina's superficial retinal layer (SRL) and deep retinal layer (DRL) were examined and scanned using OCTA in each individual eye. The densities of retinal microvascular (MIR), macrovascular (MAR), and total microvascular (TMI) were calculated and compared. Changes in retinal vascular density in the macular region were analyzed using three different segmentation methods: central annuli segmentation method (C1-C6), hemispheric segmentation method [uperior right (SR), superior left (SL), inferior left (IL), and inferior right (IR)], and Early Treatment Diabetic Retinopathy Study (ETDRS) methods [superior (S), inferior (I), left (L), and right (R)]. The data were analyzed using Version 9.0 of GraphPad prism and Pearson analysis. The OCTA data demonstrated a statistically significant difference (P<0.05) in macular retinal microvessel density between the two groups. Specifically, in the SRL and DRL analyses, the ILD group exhibited significantly lower surface density of MIR and TMI compared to the HCs group (P<0.05). Furthermore, using the hemispheric segmentation method, the ILD group showed notable reductions in SL, SR, and IL in the superficial retina (P<0.05), as well as marked decreases in SL and IR in the deep retina (P<0.05). Similarly, when employing the ETDRS method, the ILD group displayed substantial drops in superficial retinal S and I (P<0.05), along with notable reductions in deep retinal L, I, and R (P<0.05). In the central annuli segmentation method, the ILD group exhibited a significant decrease in the superficial retinal C2-4 region (P<0.05), whereas the deep retina showed a notable reduction in the C3-5 region (P<0.05). Additionally, there was an observed higher positive likelihood ratio in the superficial SR region and deep MIR. Furthermore, there was a negative correlation between conjunctival vascular density and both deep and superficial retinal TMI (P<0.001). Patients with CTD-ILD exhibits a significantly higher conjunctival vascular density compared to the HCs group. Conversely, their fundus retinal microvascular density is significantly lower. Furthermore, CTD-ILD patients display notably lower superficial and deep retinal vascular density in comparison to the HCs group. The inverse correlation between conjunctival vascular density and both superficial and deep retinal TMI suggests that detecting subtle changes in ocular microcirculation could potentially serve as an early diagnostic indicator for connective tissue diseases, thereby enhancing disease management.

Evaluation of Macular Vascular Density Changes Following Phacoemulsification by Optical Coherence Tomography Angiography

Evaluation of Macular Vascular Density Changes Following Phacoemulsification by Optical Coherence Tomography Angiography

Assessment of Changes in Vascular Density in the Layers of the Eye in Patients With Parkinson's Disease.

The retina is affected by Parkinson's disease (PD). We aimed to assess the anatomical and vascular deterioration of the retina in PD. Sixty-six patients with PD and 66 healthy volunteers were evaluated in this study. Choriocapillaris vessel density (CCVD), superficial vascular density (SVD), deep vascular densities (DVD), central macular thickness (CMT), retinal nerve fibre layer (RNFL), ganglionic cell layer (GCL), and choroidal thickness (CT) were assessed. RNFL, GCL, CMT, and CT were thinner than in HC, and also the differences between the groups were statistically significant (P < .05). SVD and DVD were not statistically different between the groups (P > .05). There was a decrease in vascular density in all quadrants of the choriocapillary layer. The decrease in vascular density was statistically significant in the nasal, inferior and central quadrants (P < .05). These results supported vascular thinning in the choroidal layer. Also showed that vascular and neural layers were affected together. It could help clinicians in the follow-up of Parkinson's patients.

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.

Assessment of conjunctival autograft reperfusion after pterygium surgery by optical coherence tomography angiography (OCT-A)

PurposeTo investigate the healing process of conjunctival autografts (CAG) following pterygium surgery using optical coherence tomography angiography (OCTA). MethodsTwenty-one eyes of 21 patients diagnosed with pterygium underwent pterygium excision with CAG without using Mitomycin-C. Over a 12-week follow-up period, changes in vascular density (VD), vascular density index (VDI), and vascular length density (VLD) were assessed at two distinct depths: superficial (<200 μm) and deep (>200 μm) using OCTA. Additionally, the revascularization rate and pattern were evaluated. ResultsDuring the first week, the CAG was edematous and no sign of neovascularization was observed. In 4th week edema decreased and early signs of vascular formation appeared. In the 12th week, the deep vasculature demonstrated a greater density of interconnectivity compared to the superficial layers. VD and VLD significantly increased during the follow-up period (P < 0.05). The CAG blood flow signals exhibited a chaotic pattern, deviating from the expected centrifugal vascular pattern in the surrounding normal conjunctiva. ConclusionOCTA imaging emerges as a reliable tool for the assessment of CAG vascularization, improving the monitoring of the healing process in the postoperative period. The evaluation of CAG revascularization patterns appears to be promising biomarkers that can predict the potential future recurrence.

Automatic wound closure system: closure of large wounds by stretching the skin around the wound.

Large-wound treatment often requires autologous skin grafting or skin flap transfer, causing iatrogenic secondary injuries. Thus, we have developed an automatic wound closure system that consists of a stretch module, microcontroller, and touch screen. Full-thickness wounds (8 × 14cm) on Bama miniature pigs were manually closed by direct suture in control animals and with three different tension levels performed by the automatic device in the experimental animals. Wound-closure conditions, post-closure healing, and scars were evaluated. Post-operative microscopic changes in collagen fibers, local cell apoptosis, and changes in vascular density were compared between the two wound-closure techniques. In the control group and the first experimental group, which used a traction force of 15 N, primary wound closure could not be achieved. The other two experimental groups used a traction force of 30 N and 60 N and all wounds achieved primary closure. Collagen-fiber stretching was observed histologically in all groups and collagen-fiber breakdown occurred in some wounds when the traction force was 60 N. Scar hyperplasia was significantly reduced in the automatic wound closure system groups. The collagen content decreased, cell apoptosis increased, and vascular density decreased in local tissues in the early post-closure stage, but eventually recovered to normal-skin levels. In summary, we developed an automatic wound closure system that effectively and safely stretches dermal-collagen fibers under an appropriate traction force (30 N) and stretch wound-peripheral skin to cover the wound, achieve primary closure, and reduce scar hyperplasia.

Retinal microvascular changes in patients with pancreatitis and their clinical significance

Acute pancreatitis, a common exocrine inflammatory disease affecting the pancreas, is characterized by intense abdominal pain and multiple organ dysfunction. However, the alterations in retinal blood vessels among individuals with acute pancreatitis remain poorly understood. This study employed optical coherence tomography angiography (OCTA) to examine the superficial and deep retinal blood vessels in patients with pancreatitis. Sixteen patients diagnosed with pancreatitis (32 eyes) and 16 healthy controls (32 eyes) were recruited from the First Affiliated Hospital of Nanchang University for participation in the study. Various ophthalmic parameters, such as visual acuity, intraocular pressure, and OCTA image for retina consisting of the superficial retinal layer (SRL) and the deep retinal layer (DRL), were recorded for each eye. The study observed the superficial and deep retinal microvascular ring (MIR), macrovascular ring (MAR), and total microvessels (TMI) were observed. Changes in retinal vascular density in the macula through annular partitioning (C1–C6), hemispheric quadrant partitioning (SR, SL, IL, and IR), and early diabetic retinopathy treatment studies (ETDRS) partitioning methods (R, S, L, and I). Correlation analysis was employed to investigate the relationship between retinal capillary density and clinical indicators. Our study revealed that in the superficial retinal layer, the vascular density of TMI, MIR, MAR, SR, IR, S, C2, C3 regions were significantly decreased in patients group compared with the normal group. For the deep retinal layer, the vascular density of MIR, SR, S, C1, C2 regions also reduced in patient group. The ROC analysis demonstrated that OCTA possesses significant diagnostic performance for pancreatitis. In conclusion, patients with pancreatitis may have retinal microvascular dysfunction, and OCTA can be a valuable tool for detecting alterations in ocular microcirculation in pancreatitis patients in clinical practice.

OCT angiographic evaluation of changes in macula and optic nerve head vessel density after a water drinking test in glaucomatous and healthy eyes.

To evaluate the effects of a water drinking test (WDT) on the intraocular pressure (IOP) and vascular density of the optic nerve head and macula in healthy individuals and those with primary open glaucoma using optical coherence tomography angiography. In this prospective comparative study, 30 healthy patients and 44 POAG subjects were divided into two groups. The study's outcome measures were the IOP and vessel density of the optic nerve and macular area. After ingesting 1000ml of water in 5min, the effect of the WDT on the IOP and the vascular density of the macular area and optic nerve head were measured at baseline and then 20, 40, and 60min later at intervals of 20min. The initial IOP in the healthy and glaucomatous eye groups was comparable (15.94 ± 2.6 and 16.87 ± 4.21mmHg, respectively, P = 0.506). The IOP of both groups peaked at 40' measurements. POAG eyes had significantly higher IOP elevation (4.34 ± 0.30 vs. 2.24 ± 0.30mmHg, P < 0.001). The glaucomatous eyes had lower radial peripapillary capillary (RPC) and whole macular superficial capillary plexus (SCP) densities at baseline (48.55 ± 5.99 vs. 51.33 ± 3.75) and (48.92 ± 3.41 vs. 45.29 ± 5.29), respectively (P < 0.001). After the WDT, the change in vessel density between groups in the RPC, whole superficial, and deep capillary plexuses was insignificant (SCP and DCP of 0.66 and 0.70, respectively, P = 0.16). The WDT caused a significant IOP jump in both glaucomatous and healthy eyes, but generally, the alterations in the glaucomatous eyes were more pronounced. The changes in vascular density in the macula and optic nerve head were similar between the groups.

Comparison of Changes in Retinal Vascular Density and Thickness After Using Low-Level Red Light and 0.01% Atropine in Premyopic Children.

To compare changes in superficial retinal vascular density (SRVD), deep retinal vascular density (DRVD), and retinal thickness (RT) of the macular zone after repeated low-level red light (RLRL) and 0.01% atropine exposure in premyopic schoolchildren. Prospective randomized trial. Sixty-nine schoolchildren with cycloplegic refraction >-0.75 D and ≤0.50 D were randomly assigned to RLRL and 0.01% atropine groups. SRVD, DRVD, and RT were measured using swept-source optical coherence tomography at baseline and six months. The macular zone was divided into three concentric rings (fovea, parafovea, and perifovea) using the Early Treatment Diabetic Retinopathy Study. After six months, the whole, parafoveal, and perifoveal SRVD significantly increased in the two groups (all P < 0.05). Multivariate regression analyses showed that none of these changes varied significantly between the two groups (all P > 0.05), whereas foveal SRVD remained stable in both groups (all P > 0.05). In the RLRL group, the whole and perifoveal DRVD increased significantly (all P < 0.05), whereas no statistical difference was observed in the foveal and parafoveal DRVD. DRVD remained stable in the 0.01% atropine group (all P > 0.05). No significant differences were observed in RT changes between the two groups (all P > 0.05). In comparison, there were no significant changes in SRVD, DRVD, or RT after six months in the placebo group in our previous study. SRVD increased similarly in the RLRL and 0.01% atropine groups, whereas DRVD increased only in the former group. There were no significant RT changes in either group after six months of treatment in premyopic schoolchildren. This research observed the effects of low-level red light and 0.01% atropine on retinal vasculature, offering valuable insights into myopia progression prevention.

Longitudinal evaluation of macular vascular density alterations in unilateral amblyopic children undergoing therapy: An optical coherence tomographic angiography study

ImportanceUnderstanding the pathophysiology of the macula in amblyopic eyes is an active research area. ObjectiveTo correlate macular retinal vascular density changes with best-corrected visual acuity changes following occlusion therapy for amblyopia in children. DesignA prospective cohort study of children visiting the Pediatric Ophthalmology Division of our institution between January 2020 and January 2022 was conducted. SettingA specialist eye hospital in Saudi Arabia. ParticipantsThirty children with unilateral amblyopia. ExposureOcclusion therapy for amblyopia.Main Outcome and Measures: Best corrected visual acuity (logMAR) before and at each of the four optical coherence tomographic angiographies was compared in amblyopic and fellow eyes. The effect of pretreatment determinants on the correlation between best-corrected visual acuity and retinal vascular density changes was reviewed. ResultsIn this cohort of 30 amblyopic and 30 fellow eyes from 30 children (mean age 8.7 ± 1.4 years; male: female 18:12. The best-corrected visual acuity improved from a median of 0.6 (interquartile range 0.5; 1.1) pretreatment to a median of 0.4 (interquartile range 0.2; 0.6) posttreatment in amblyopic eyes, and from a median of 0.1 to 0.05 in the fellow eyes. The total percentage change in retinal vascular density in the amblyopic eye was significantly higher than that in the fellow eye (Z = −1.92, P = 0.05). The change in best-corrected visual acuity in the amblyopic eye after a median of 98 months (interquartile range, 69–126 months) of intervention was significantly correlated with the refraction-adjusted change in retinal vascular density (B = −0.03, 95 % confidence interval −0.04, −0.02, P < 0.001) and was influenced by strabismus (B = −0.46, 95 % confidence interval −0.59, −0.34, P < 0.001), type of amblyopia (B = 0.24, 95 % confidence interval 0.12, 0.36, P < 0.001), duration of occlusion (B = −0.43, 95 % confidence interval −0.65, −0.22, P < 0.001), and occlusion compliance (B = 0.24, 95 % confidence interval 0.11, 0.36, P < 0.001). Conclusionsand Relevance: The RVD in amblyopic eyes in the first six months of therapy was significantly lower than that in fellow eyes, but not in subsequent assessments.

Investigating the Impact of Bariatric Surgery on Macular and Peripapillary Vessel Density in Obese Individuals without Metabolic Disease

Introduction: It is well established that microvascular structures are affected in obese people with metabolic disease. We aimed to evaluate the effect on microvascular structures by examining macular and peripapillary vessel density with optical coherence tomography angiography after bariatric surgery in obese individuals without metabolic disease. Methods: This prospective study included 96 eyes of 48 obese patients. Body mass index (BMI), macular vessel density in the superficial, intermediate, and deep capillary plexus, and peripapillary vessel density were measured before and 6 months after bariatric surgery. Results: BMI decreased significantly to 43.75 ± 4.4 kg/m2 postoperatively compared to 55.31 ± 5.1 kg/m2 preoperatively (p < 0.05). A significant increase was observed in macular vessel density in the deep capillary plexus postoperatively (p < 0.01). However, no significant postoperative increase occurred in macular vascular density in the superficial and intermediate capillary plexus (p > 0.05). Moreover, there was no change in peripapillary vascular density (p > 0.05). Postoperative thickening of the foveal, parafoveal, and perifoveal retinal layers was significant (p < 0.001). No significant correlation was detected between BMI change and macular and peripapillary vessel density changes (p > 0.05). Conclusion: An increase in macular vascular density, particularly in the deep capillary plexus, and retinal layer thickness has been observed following bariatric surgery performed on obese individuals without metabolic disease. This increase may indicate that microvascular structures are affected even in the absence of metabolic disease and that microperfusion improves with surgery.

Evaluation of macular vessel density with OCTA in patients undergoing inferior oblique muscle surgery

Aims: To evaluate pre- and postoperative macular vascular density changes in patients undergoing inferior oblique muscle surgery using optical coherence tomography angiography (OCTA). Methods: 28 eyes of 16 patients who underwent inferior oblique muscle surgery were included in the study. Measurements were taken preoperatively (T0) and one day (PO1), 15 days (PO15) and 6 weeks (PO6w) after surgery. The vessel densities of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CCL) were measured by OCTA. Results: This study included 28 eyes of 16 patients. The mean age of the patients was 8.07±5.5 years (4-23 years). SCP and DCP mean vascular densities decreased significantly at PO1 and PO15 compared to T0, but increased at PO6w, reaching their initial levels. Mean CCL levels were lower at PO1 compared to all other measurements and reached their preop values at PO6w. Conclusion: The inferior oblique muscle insertion is known to be close to the macula and surgical interventions for this muscle may cause changes in macular vascular density. In our study, macular vascular density decreased in all parameters at PO1 compared to T0, but almost reached its preop levels at PO6w.

Autocrine VEGF drives neural stem cell proximity to the adult hippocampus vascular niche.

The vasculature is a key component of adult brain neural stem cell (NSC) niches. In the adult mammalian hippocampus, NSCs reside in close contact with a dense capillary network. How this niche is maintained is unclear. We recently found that adult hippocampal NSCs express VEGF, a soluble factor with chemoattractive properties for vascular endothelia. Here, we show that global and NSC-specific VEGF loss led to dissociation of NSCs and their intermediate progenitor daughter cells from local vasculature. Surprisingly, though, we found no changes in local vascular density. Instead, we found that NSC-derived VEGF supports maintenance of gene expression programs in NSCs and their progeny related to cell migration and adhesion. In vitro assays revealed that blockade of VEGF receptor 2 impaired NSC motility and adhesion. Our findings suggest that NSCs maintain their own proximity to vasculature via self-stimulated VEGF signaling that supports their motility towards and/or adhesion to local blood vessels.