Vessel Thickness Research Articles

Vascular changes in vascularized composite allotransplantation.

Allograft vasculopathy in vascularized composite allografts (VCA) remains understudied. This review explores the vascular changes in VCA, focused on recent literature. Allograft vasculopathy in VCA generally includes progressive concentric myointimal thickening and luminal narrowing of arterial vessels through endothelial deterioration and proliferation of smooth muscle cells. Microvascular changes are also noted, with thrombosis and lumen narrowing in microvessels of the skin even in the absence of large vessel vasculopathy. Histopathologic reports of skin containing VCA rejection document arteriosclerosis in deep vessels that are not always reflected in skin punch biopsies. The first revision of the Banff VCA scoring system 2022 was developed to include vascular changes in VCA. The scoring system for chronic changes and antibody mediated rejection continues to be under development. The study of vascular changes in VCA continues to progress. Important data and advances in experimental and clinical VCA have been reported and continue to take place. Challenges ahead include capture of clinical data that will evolve beyond transient report forms and approaching on the problem of graft failure well grounded in sound scientific methodology.

Peripheral arterial pathology and osteoarthritis of the knee: US examination of arterial wall stiffness, thickness, and flow characteristics

BackgroundOsteoarthritis (OA) is a widespread chronic joint disorder characterized by the degeneration of articular cartilage, extensive bone remodeling, ligamentous fibrosis, and synovial inflammation impacting millions. Shared factors like phenotypic similarities, hypofibrinolysis, and inflammation constitute similarities in pathophysiology and clinical manifestations between OA and peripheral vascular disease (PVD). This study investigated peripheral arterial flow characteristics, vascular wall thickness, and stiffness in knee OA to clarify a potential association with early atherosclerosis. MethodsThe OA cohort consisted of 35 knees with a mean age of 69 years. The control cohort consisted of 58 knees with a mean age of 68 years. Subjects underwent arterial ultrasound scanning of the common femoral, superficial femoral, and popliteal arteries. Data measured included peak systolic volumetric flow, intima-media thickness, systolic and diastolic vessel diameter, and simultaneous EKG and flow curves. Structural and functional vascular data were quantified using the incremental Young's modulus, pulse wave velocity (PWV), and distensibility. ResultsSignificantly elevated arterial volumetric flow, measures of arterial stiffness, and intima-media wall thickness were observed in those with OA compared to those without. PWV as calculated by the Bramwell-Hill equation were found to be significantly greater in all three vessels of patients with OA. ConclusionsThis study supports the association between peripheral arterial pathology and knee OA, consistent with shared clinical and phenotypic traits. The observed characteristics of early vascular pathology suggest potential pathophysiologic linkages between OA and PVD. This foundational framework provides avenues for mechanistic studies exploring the relationship between these two disease processes.

ERBB4 activation prevents microvascular dysfunction in a large animal model of hypertensive heart disease

Abstract Background Coronary microvascular dysfunction (CMD) participates in the pathophysiology of multiple cardiovascular diseases, but treatment options are limited. A new treatment option may include ERBB4 stimulation by neuregulin-1 (NRG1), which has anti-inflammatory, antifibrotic, and cardioprotective effects in models of heart failure. Objectives To assess the effect NRG1/ERBB4 stimulation on CMD in hypertensive heart disease. Methods Hypertensive heart disease was induced in 12 Aachener minipigs by implantation of deoxycorticosterone acetate (DOCA) pellets for 8 weeks and compared to 6 controls. The DOCA pigs were randomized to a weekly infusion of JK07, a NRG1 fusion protein with improved pharmacokinetic and pharmacodynamic properties, or vehicle. Microvascular resistance was measured using the bolus thermodilution method. Results DOCA significantly increased microvascular resistance compared to controls (from 14.5 to 19.9 mmHg.s, p = 0.028). This increase was abrogated by JK07 (11.3 mmHg.s, p = 0.018 vs DOCA). dP/dtmax increased by DOCA compared to controls (from 2415.5 to 4455.5 mmHg/s, p = 0.011), which was also abrogated by JK07 (3107.3 mmHg/s, p = 0.055 vs DOCA). Interstitial left ventricular fibrosis was significantly lower in JK07-treated pigs compared to DOCA only (2.1 vs. 5.4 %, p = 0.026), but without difference in perivascular fibrosis (p = 0.48). JK07 did not affect myocyte cross-sectional area, capillary density, pericyte coverage, or microvascular vessel thickness. Conclusions ERBB4 activation by JK07 is capable to prevent CMD in a DOCA hypertensive pig model. Functional rather than structural alterations may explain the protective effects of JK07 on microvascular resistance.Visual summaryJK07 decreases microvascular resistance

Towards a better understanding of xylem: Helical thickenings in vessels of woody angiosperms are associated with thinner cell walls and lower vessel diameter

Towards a better understanding of xylem: Helical thickenings in vessels of woody angiosperms are associated with thinner cell walls and lower vessel diameter

Damage-tolerance design for composite high-pressure hydrogen vessels when AE testing is applied

An approach was proposed to design high-pressure composite hydrogen vessels for fuel cell vehicles with damage tolerance. In addition, a stacking-sequence optimization method was developed, which was built upon the damage tolerance design. A no-growth approach, damage categorization, and residual strength requirements were proposed for the damage-tolerance design method for highpressure hydrogen vessels, which were implemented in the damage-tolerance design method for composite aircrafts. The initial burst pressure was set at 180% of normal working pressure (NWP) assuming that the structural health monitoring (SHM) system with acoustic emission (AE) testing would immediately detect the occurrence of fiber breakage. Stacking-sequence optimization was then conducted to minimize vessel thickness and meet the residual strength requirements. The results show that the thickness of the vessel can be reduced by introducing a damage-tolerant design. Moreover, the proposed method for an optimal design based on the damage-tolerance design method is effective.

Retinal vascular changes after Silicon Oil removal in the Eye with Rhegmatogenous Retinal detachment

BackgroundThis study aims to examine vessel density changes in the optic nerve and macula following silicone oil removal (SOR) surgery in eyes with rhegmatogenous retinal detachment (RRD) at different time points by Optical Coherence Tomography Angiography (OCTA) in compared to the contralateral eye.MethodsA total of 43 eyes from 43 patients with silicone oil in their eyes for 3–9 months underwent OCT-A using AngioVue and optic disc-associated vessel density (VD) and thickness, macular-associated VD and thickness, Foveal avascular zone (FAZ) area, FAZ perimeter (PERIM), Acircularity index (AI), vessel density within a 300 μm wide region of the FAZ were compared between eyes. OCTA scans were performed one week before SOR and one month and three months after SOR.ResultsThe mean age of participants was 52.8 years (SD = 15.85) and a median visual acuity was 0.8 (range: 0.5-1.0). Notably, male participants constituted 67.4% of the sample. The preoperative mean value BCVA (logMAR) of patients was 0.73, and 3 months post-oil removal was 0.7727. Regarding optic disc parameters, RNFL thickness and vessel density (VD) measurements Peripapillary, whole disc, inside disc, and Disc Angio (superior, Nasal, inferior, temporal) did not change.In analyzing macular thickness parameters, all of them (Whole and Fovea, parafoveal, and Perifovea) remained unchanged. Examining macular vessel density parameters revealed no significant changes across superficial and deep retinal layers. Finally, the comparison of the foveal avascular zone (FAZ) area and flow density (FD) parameters demonstrated consistent measurements with non-significant alterations observed in FAZ size (p = 0.6) and FD values (p = 0.49) over the monitored duration.ConclusionThere was no change in peripapillary VD and macular vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) after silicone oil removal. FAZ and full retinal thickness remained stable 3 month after SOR. Clinical trial number: Not applicable.

Obesity and atherosclerosis in children

<p>Atherosclerosis, one of the leading causes of death in developed countries is characterized by lumen reduction of blood vessels due to local thickening of internal blood vessels caused by plaque/atheroma. It begins in childhood, goes for a long time without manifesting symptoms, increasing with age it begins to seriously threaten health. The most important risk factors for the development of atherosclerotic disease are: hyperlipidemia, hypertension, smoking, diabetes, high fibrinogen, excessive weight, increased level of homocysteine, physical inactivity, heredity and immune response in some diseases. The primary intention of prevention is to preclude the occurrence of risk factors for atherosclerosis, and the secondary is to prevent the development or aggravation of the illness along with the reduction or control of existing risks. There is an increasing number of studies that show that children are overweight, which in adolescence is certainly a risk factor for the onset of many chronic diseases, namely: cardiovascular, type 2 diabetes, orthopedic, and psychological diseases. The obesity epidemic is one of the most serious health problems of today affecting individuals of all ages. Atherosclerosis demands action with the aim of early detection and treatment as well as the reduction of development of risk factors for coronary artery diseases. Finding the most effective preventive measures for obesity in each country requires precise epidemiological data on the number of obese children and youth, as well as on their eating and activity habits.</p>

51144 Optical Coherence Tomography-Measured Epidermal Thickness and Blood Vessel Characteristics in Healthy Skin

51144 Optical Coherence Tomography-Measured Epidermal Thickness and Blood Vessel Characteristics in Healthy Skin

End Connectors Stress Analysis for Horizontal Pressure Vessel

The gas and oil industry extensively utilizes horizontal pressure vessels to store its primary sources. These vessels are designed to withstand high levels of pressure and to release contents in a controlled manner. Although the sphere-shaped storage container is widely regarded as a better-engineered structure, the ease of manufacturing makes horizontal pressure vessels the preferred choice. This paper presents an in-depth analysis of stress distribution in horizontal pressure vessels with various end connections, including hemispherical, ellipsoidal, flat head, and tori-spherical configurations. The study involves analytical and finite element analysis (FEA) to compare the stress distribution across these above-mentioned end connections. Key vessel dimensions, such as internal diameter, vessel thickness, and end connections, have been determined through analytical design. A detailed structural analysis aided in determining which among the different end connectors is best suitable for industry usage.

Exploring the potential of two Pseudomonas species to produce vincristine from vinblastine via biotransformation

A biotransformation pair consisting of vinblastine: vincristine present in the Catharanthus roseus plant is of immense pharmacological significance. In this study, we successfully transformed vinblastine into vincristine outside the plant using Pseudomonas aeruginosa 8485 and Pseudomonas fluorescens 2421 and evaluated the antiangiogenic potential of thus produced vincristine through the CAM assay. The toxicity assay showed that both Pseudomonas spp. can tolerate varying concentrations (25–100 µl of 1 mg/ml) of vinblastine. The biotransformation was performed in a liquid nutrient broth medium containing vinblastine (25–100 µl), and Pseudomonas spp. inoculums (50–150 µl) by incubating at 30 °C and 37 °C, respectively for 8 days. The process was optimized for substrate and culture concentrations, pH, temperature, and rotation speed (rpm) for the highest conversion. Analysis using LC–MS/MS confirmed the presence of vincristine as a product of the vinblastine biotransformation by two Pseudomonas spp. P. fluorescens 2421 showed a faster conversion rate with 95% of vinblastine transformed within 24 h than P. aeruginosa 8485, which demonstrated a conversion rate of 92% on the 8th day. From LC–MS/MS analysis, the optimal conditions for the reaction were determined as vinblastine (25 µl), microbial inoculums (150 µl or 200 × 106 and 210 × 106 CFU/ml), pH 7.4, rotation speed of 180 rpm, and temperatures of 30 °C and 37 °C with incubation time of 8 days. The vincristine produced exhibited potent antiangiogenic activity in the CAM assay reducing the thickness and branching of blood vessels in a dose-dependent manner. The study concludes that both Pseudomonas spp. showed promise for vincristine production from vinblastine, without compromising its antiangiogenic properties.

The coffin-reliquary of the holy Serbian king Stefan of Dečani (fourteenth century): wood, pigments and metal surfaces

The coffin-reliquary for the relics of the holy Serbian king Stefan Uroš III of Dečani has been made around 1343 as a rectangular chest with a gable cover. The present study aimed to identify the wood this coffin-reliquary was made, as well as the pigments and metals found on its surface. The combination of anatomical traits (diffuse-porosity, distinct helical thickenings in vessels, simple perforation plates, 3- to 4-seriate noded rays and diffuse-in-aggregates axial parenchyma) showed that the wood belongs to linden, i.e., to the botanical genus Tilia L. (Malvaceae). The linden is one of the sacred trees in Serbian culture, and its wood could also be used due to its ease for joinery. X-ray fluorescence spectroscopy (XRF analyzer) was used for in situ determination of the material chemistry of the pigments, as well as the metals on the wooden surfaces of the coffin. Their elemental composition showed that wooden coffin-reliquary was painted with vermilion, malachite or copper resinate, orpiment, and lead white, while metal surfaces were shown to be gold and silver. Unlike a commonly used palette of earthy pigments, these coloring matters belong to precious noble pigments.

Evaluation of Choroidal Thickness and Retinal Vessel Density with Serum HIF-1α and TNF-α Level in Patients with OSAS

Purpose To reveal changes in choroidal thickness, retinal vessel density, and serum HIF-1α and TNF-α levels in obstructive sleep apnea syndrome (OSAS) and their correlation. Methods This prospective case-control study included 118 patients divided into mild-to-moderate OSAS (n = 40), severe OSAS (n = 39), and a control group (n = 39). Choroidal thickness was evaluated with OCT, vessel density with OCTA, AHI index with polysomnography, and serum HIF-1α and TNF-α levels were analyzed using the enzyme-linked immunosorbent assay. Results The serum HIF-1α values of the participants in the mild-moderate OSAS and severe OSAS groups were [893.25(406.7–2068) and 1027(453–2527), respectively], and were both significantly higher than the control group [(521.5(231.6–2741))] (p < 0.001). Serum TNF-α levels did not differ significantly between the groups (p = 0.051).). Subfoveal choroidal thickness (SFCT) values of the severe OSAS groups were significantly lower than the control group (p < 0.05). The superficial and deep capillary plexus vascular density (SVD and DVD) values of the severe OSAS group were lower than the control group (p < 0.05). Serum HIF-1α and TNF-α levels of all participants were negatively correlated with both their SVD values (p < 0.05, r: –0.220 and p < 0.05, r: –0.252, respectively) and their DVD values (p < 0.001, r: –0.324 and p = 0.001, r: –0.299, respectively). Conclusions Increased serum levels of inflammatory mediators (HIF-1α ve TNF-α) in OSAS cause a decrease in SFCT, SVD, and DVD, which is an indication of systemic vascular damage. Further research on developing treatment strategies to modulate TNF-α ve HIF-1α may help recede vascular morbidity in OSAS patients.

MicroRNA-210 mediates hypoxia-induced pulmonary hypertension by targeting mitochondrial bioenergetics and mtROS flux.

Chronic hypoxia is a common cause of pulmonary hypertension (PH). We test the hypothesis that microRNA-210 (miR-210) mediates hypoxia-induced PH by targeting mitochondrial metabolism and increasing reactive oxygen species (mtROS) production in the lungs. Adult wildtype (WT) or miR-210 knockout (KO) mice were exposed to hypoxia (10.5% O2) or normoxia for 4 weeks. We measured miR-210 levels, right ventricular systolic pressure (RVSP), and histological changes in heart and lung tissues. Mitochondrial bioenergetics and mtROS production were assessed in isolated lung mitochondria. Hypoxia increased right ventricular wall thickness and pulmonary vessel wall muscularization in WT, but not miR-210 KO mice. No sex differences were observed. In male mice, hypoxia increased miR-210 levels in the lung and RVSP, which were abrogated by miR-210 deficiency. Hypoxia upregulated mitochondrial oxygen consumption rate and mtROS flux, which were negated in miR-210 KO animals. In addition, chronic hypoxia increased macrophage accumulation in lungs of WT, but not miR-210 KO mice. Moreover, miR-210 overexpression in lungs of WT animals recapitulated the effects of hypoxia and increased mitochondrial oxygen consumption rate, mtROS flux, right ventricular wall thickness, pulmonary vessel wall muscularization and RVSP. MitoQ revoked the effects of miR-210 on lung mitochondrial bioenergetics, right ventricular and pulmonary vessel remodeling and RVSP. Our findings with loss-of-function and gain-of-function approaches provide explicit evidence that miR-210 mediates hypoxia-induced PH by upregulating mitochondrial bioenergetics and mtROS production in a murine model, revealing new insights into the mechanisms and therapeutic targets for treatment of PH.

Shock Response of Water-Protected Spherical Explosion Containment Vessels

Abstract Explosion containment vessels (ECVs) are important equipment used for underwater explosion experiment research. In this paper, a method is proposed to improve the blast resistance of the ECV by placing it in the water medium. The shock response caused by the underwater explosion in a spherical ECV is studied. The single-layer thin-walled spherical vessel shell submerged in an infinite domain water medium is deduced and simplified as a single-degree-of-freedom elastic vibration system with viscous damping. The underwater explosion shock wave is simplified to an exponential shock loading, and the analytical solutions of the radial shock vibration of the spherical shell are obtained using Duhamel's integrals. Compared with the numerical simulation results, the accuracy of the theoretical model is verified. The study results show that the water medium radiates out vibration energy and plays an important role in eliminating vibration through damping. It is found that the vibration damping ratio can be controlled by adjusting the vessel radius and thickness, so that the vibration of the shell can be controlled within three periods and the impact fatigue can be reduced. In addition, the radiation damping of the water medium greatly reduces the maximum radial displacement of the spherical shell, which significantly improves the blast resistance of the spherical shell.

Initial Factors Associated with Resistance to Intravitreal Aflibercept Injection in Polypoidal Choroidal Vasculopathy

Purpose: To identify initial factors contributing to the resistance against intravitreal aflibercept treatment in polypoidal choroidal vasculopathy (PCV) patients.Methods: This study included PCV patients initially treated with aflibercept. Resistance was defined when treatment did not reduce subretinal fluid (SRF) or intraretinal fluid (IRF) by 100 μm or more after three consecutive 4-week intervals, and the treatment interval could not be extended beyond 8 weeks. To identify initial factors associated with resistance to aflibercept treatment, we examined visual acuity and central choroidal thickness before initial treatment and after three treatments. Choroidal thickness was divided into the thickness of the large choroidal vessel layer and the layer that includes choriocapillaris and medium choroidal vessel thickness (termed medium choroidal vessel/choriocapillaris layer thickness, MCCT). Additionally, the volume of SRF, IRF, subretinal hyperreflective material, and pigment epithelial detachment in optical coherence tomography (OCT) images was investigated. The statistical significance of each factor was assessed through logistic regression analysis.Results: The study included 39 eyes showing no resistance to aflibercept and 37 eyes that exhibited resistance. Multiple logistic regression analysis, adjusted for age and sex, indicated that a lower initial ratio of MCCT to choroidal thickness at the fovea was associated with resistance to aflibercept.Conclusions: In patients with PCV treated with aflibercept, early OCT anatomical structures, such as the initial MCCT-choroidal thickness ratio at the fovea, may predict response to treatment injections.

Quantitative evaluation of lower limb varicose veins using photoacoustic imaging

PurposeVaricose veins in the lower extremities are dilated subcutaneous varicose veins with a diameter of ≥ 3 mm, caused by increased venous pressure resulting from backflow of blood due to venous valve insufficiency (Gloviczki in Handbook of venous disorders: guidelines of the American venous forum, Hodder Arnold, London, 2009). When diagnosing varicose veins, the shape and thickness of the blood vessels should be accurately visualized in three dimensions. In this study, we investigated a new method for numerical evaluation of vascular morphology related to varicose veins in the lower extremities, using a photoacoustic imaging (PAI) system, which can acquire high-resolution and three-dimensional images noninvasively.MethodsNine patients with varicose veins participated in the study, and their images were captured using an optical camera and PAI system. We visualized the vascular structure, created a blood presence density (BPD) heat map, and examined the correlation between BPD and location of varicose veins.ResultsThe obtained photoacoustic (PA) images demonstrated the ability of this method to visualize vessels ranging from as small as 0.2 mm in diameter to large, dilated vessels in three dimensions. Furthermore, the study revealed a correlation between the high-density part of the BPD heat map generated from the PAI images and the presence of varicose veins.ConclusionPAI is a promising technique for noninvasive and accurate diagnosis of varicose veins in the lower extremities. By providing valuable information on the morphology and hemodynamics of the varicose veins, PAI may facilitate their early detection and treatment.

Wide-field swept-source optical coherence tomography angiography (SS-OCTA) in the assessment of retinal vessel density and thickness in 4-to 16-year-old myopic children

PurposeTo analyze the characteristics of macular retinal vessel density and thickness in children with myopia. MethodsA cross-sectional study was conducted. A total of 228 children aged 4–16 years who visited the Ineye Hospital of Chengdu University of Traditional Chinese Medicine from September 2022 to November 2023 were included. Those with −0.5D < spherical equivalent (SE) < +2.0D were included in the non-myopia group (150 eyes), those with −3.0D < SE ≤ −0.5D were included in the low myopia group (246 eyes), and those with SE ≤ −3.0D were included in the moderate-to-high myopia group (60 eyes). All subjects underwent cycloplegic refraction, IOLmaster500, and Wide-field SS-OCTA (to exclude some peripheral retinal degeneration). Multiple linear regression analysis was used to analyze the correlation between macular ETDRS subfield of full retinal thickness (FRT), outer, inner retinal thickness (ORT, IRT), retinal vessel density (VD), deep and superficial retinal vessel density (DVD, SVD), and SE, axial length (AL). ResultsThere were statistically significant differences (P < 0.05) in FRT in the central fovea (1 mm diameter)and perifovea (Diameter 3 to 6 mm) among the non-myopia group, low myopia group, and moderate-to-high myopia group. The three groups also showed statistically significant differences (P < 0.05) in VD in the central fovea and parafovea with a diameter of 1 to 3 mm (except the lower part). In multiple linear regression analysis adjusted for gender and age, SE and AL were found to be correlated with FRT in all ETDRS regions (except the central fovea) (P < 0.01), and SE and AL were correlated with IRT in the central fovea and perifovea, respectively (β range −2.302 to 1.652; P < 0.05). SE and AL were also correlated with ORT in the parafovea and perifovea, respectively (β range −4.371 to −2.344; P < 0.05). AL was negatively correlated with VD in the central fovea and parafovea (except the inferior region) (P < 0.05), as well as with DVD in all ETDRS regions (β range −1.314 to −1.031; P < 0.05). AL was only negatively correlated with SVD in the parafoveal nasal region (β = −0.633, P < 0.05). Additionally, the correlation between AL and DVD, ORT was higher than that with SVD, IRT. ConclusionThe more severe the myopia, the longer the AL, the thinner the FRT in the perifovea, and the lower the VD in both the fovea and parafovea in children. In addition, DVD and ORT were more significantly correlated with AL, suggesting that they may be more closely related to the growth of AL.

Association between metformin use with circumpapillary retinal nerve fibre layer thickness and capillary vessel density in glaucoma

Background/aimsTo investigate the association between use of metformin and circumpapillary retinal nerve fibre layer (cpRNFL) thickness, as well as whole image capillary density (wiCD), in patients with glaucoma.MethodsThis cross-sectional study...

Takayasu arteritis presenting with large cerebral infarction in a 39-year-old Syrian woman: a case report

Introduction and importance: Takayasu Arteritis (TA) is a rare chronic inflammatory disease of unknown etiology that primarily affects large vessels, such as the aorta and its major branches. The disease typically presents with diverse symptoms, depending on the site and degree of arterial lesions. Delayed diagnosis is common, especially in younger populations. Case presentation: A 39-year-old Syrian female presented with an initial stroke. She had no prior medical history and was otherwise healthy. On examination, she had an absent left radial pulse, a carotid bruit, and muscle weakness. Blood tests showed an elevated ESR and CRP. Computed tomography of the brain revealed a right large cerebral infarction. Multislice computed tomography angiography showed diffuse arterial wall thickening, stenosis, and occlusion of several major vessels, including the left internal carotid artery, right internal carotid artery, and left subclavian artery. Clinical discussion: The patient was diagnosed with TA based on the American College of Rheumatology criteria. She was treated with prednisolone, methotrexate, and aspirin, and her symptoms improved significantly. Conclusion: This case highlights the importance of considering TA in the differential diagnosis of ischemic stroke, especially in young patients with atypical presentations. Early identification and management are essential to preclude critical sequelae.

Peripapillary microvasculature and retinal nerve fiber layer damage according to the severity of diabetic retinopathy.

To identify damage to the inner retinal layer and microvasculature in the peripapillary area according to the severity of diabetic retinopathy (DR). Patients were divided into four groups: control (group 1), type 2 diabetes (T2DM) without DR (group 2), mild to moderate nonproliferative DR (NPDR) (group 3), and severe NPDR (group 4). The peripapillary retinal nerve fiber layer (pRNFL) thickness and peripapillary vessel density (VD) were compared. Linear regression analysis was performed to identify factors associated with the DR severity. The average pRNFL thicknesses were 96.2 ± 7.1, 94.1 ± 9.6, 92.0 ± 9.9, and 90.3 ± 12.4μm in groups 1, 2, 3, and 4, respectively (P = 0.003) (post hoc analyses: group 1 vs. group 2, P = 0.529; group 2 vs. group 3, P = 0.627; group 2 vs. group 4, P = 0.172; group 3 vs. group 4, P = 0.823). The VDs of the outer ring were 18.9 ± 0.6, 18.4 ± 0.8, 17.9 ± 1.1, and 17.3 ± 1.6mm-1 in groups 1, 2, 3 and 4, respectively (P < 0.001) (all pairwise comparisons, P < 0.050). In multivariate analysis, the VD of the outer ring (B = - 0.35, P < 0.001) was significantly associated with the DR severity. The peripapillary microvasculature reflects retinal damage following DR progression better than the structure of the pRNFL.