In order to study effect of endothelin (ET-1) on hepatic blood flow in rats and effect of nitric oxide (NO) and prostacyclin (PGI2) on ET-1 biological function, 20 rats were randomized into control, ET-1, ET-1 plus nitric-Larginine, ET-1 plus prostacyclin and indomethen groups. The result showed that ET-1 decreased hepatic blood flow and lasted for longer time. NO and PGI2 may antagonize the biological action of ET-1 during endotoxemia. Therefore, the endothelium-derived vascular factors may regulate hepatic blood flow.
The development and progression of atherosclerosis and thrombosis are closely related to changes of hemodynamics parameters. Ultrasonic pulse wave Doppler technique is normally used for noninvasively blood flow imaging. However, this technique only provides one-dimensional velocity and depends on the angle between the ultrasound beam and the local velocity vector. In this study, ultrasonic particle image velocimetry method was used to assess whole field hemodynamic changes in normal blood vessels. By using the polynomial fitting method, we investigated the velocity gradient and assessed the shear in different blood flow velocity of 10 healthy rats. It was found that using four polynomial fitting could result in optimal measurement results. The results obtained by ultrasonic particle image velocimetry accorded with the results obtained using Doppler technique. The statistical average of cyclical vessel wall shear stress was positively related to the locational mean velocity. It is proven that ultrasonic particle image velocimetry method could be used to assess directly the real-time whole field hemodynamic changes in blood vessels and was non-invasively, and should be a good prosperous technique for monitoring complex blood flow in stenotic arteries.
ObjectiveTo observe the changes of microperimeter and OCT angiography (OCTA) in idiopathic macular hole (IMH) before and after operation, and to explore the correlation between the changes and visual acuity.MethodsFrom January 2018 to January 2019, 41 patients (41 eyes) with IMH who underwent pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) flap surgery in Tianjin Eye Hospital were included in this study. Among them, 8 patients (8 eyes) were male and 33 patients (33 eyes) were female. The average age was 64.02±6.46 years. The average course of disease was 7.00±8.85 months. BCVA, microperimeter and OCTA were performed. The retinal mean sensitivity (RMS) at 10 ° and fovea 2 ° fixation rate (P1) and binary contour ellipse area (63% BCEA) were measured by macular integrity assessment instrument. The central retinal thickness (CRT), choroidal blood flow area (CFA), superficial and deep retinal blood flow density (FAVD, FDVD), foveal avascular zone (FAZ) and blood flow densitywithin the width of FAZ 300 μm (FD-300) were measured by OCTA. Twenty one and 19 eyes with or without ILM flap operation were treated with 25G standard three incision PPV. The follow-up time was more than 6 months. Paired t-test was used to compare the indexes before and after operation. Pearson correlation analysis was performed for the correlation between logMAR visual acuity and microperimeter variables and OCTA variables. Nonparametric test was performed for paired comparison between affected eyes and contralateral eyes before and after operation.ResultsAt 6 months after operation, logMAR visual acuity (t=－12.33), RMS (t=7.94), P1 (t=3.21), 63% BCEA (t=－3.98), CRT (t=－9.17), CFA (t=8.14), FSVD (t=3.75), FDVD (t=3.88) were significantly improved compared with those before operation (P＜0.001). The difference of FAZ area (t=－1.40) and FD-300 (t=1.95) before and after operation were not statistically significant (P＞0.05). The results of correlation analysis showed that logMAR visual acuity 6 months after surgery was correlated with preoperative logMAR visual acuity, MIN, RMS, P1, 63% BCEA, FSVD, FDVD and FAZ (r=0.432、0.527、－0.410、－0.383、0.349、－0.406、－0.373、0.407; P＜0.05). At 6 months after operation, the indexes of the affected eyes were significantly improved compared with those before operation, but worse than those of the contralateral eyes (P＜0.05).ConclusionsPPV for IMH can effectively improve the visual acuity, retinal function and foveal microvascular circulation. Retinal function and blood circulation changes have a significant impact on postoperative visual acuity.
ObjectiveTo observe and analyze the correlation between macular microvascular parameters and urinary albumin to creatinine ratio (UACR) in patients with type 2 diabetes mellitus (T2DM). MethodsA cross-sectional study. From October 2017 to April 2018, 100 eyes of 100 patients (T2DM) and 27 eyes of 27 healthy controls (the control group) were enrolled in Xuzhou First People’s Hospital. All subjects underwent anterior segment examination via slit-lamp biomicroscopy, dilated fundus examination, 7-field fundus photographs, OCT angiography (OCTA), the fasting glucose test, glycosylated hemoglobin (HbA1c), urinary albumin, urinary creatinine and UACR levels determination. Height and weight measurement were taken for calculating body mass index (BMI). Diabetic retinopathy was ruled out by fundoscopic examinations and 7-field fundus photographs in T2DM patients. According to the UACR, patients in the T2DM group were subdivided into A1 group (UACR< 30 mg/g), A2 group (UACR 30-300 mg/g), and A3 group (UACR>300 mg/g), with 38 cases and 38 eyes respectively , 40 cases with 40 eyes, 22 cases with 22 eyes. A 6 mm×6 mm scanning area centered on the macular fovea were scanned for right eye using a frequency domain OCTA instrument, which were divided into three concentric circles centered on the macular fovea by the software automatically. The foveal zone was defined as a circular area measuring 1 mm in diameter, the parafoveal zone was described as a middle circle area measuring 1-3 mm in diameter, and the perifoveal zone was an outer circle area measuring 3-6 mm in diameter. The vessel density of superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular area (FAZ) and perimeter (PERIM), non-circularity index (AI) were measured. The correlation between the macular vessel density, FAZ and UACR was analyzed by Spearman correlation analysis. ResultsA1 group, A2 group, A3 group, and normal control group. The macular area SCP and DCP (F=13.722, 5.644), foveal area (F=4.607, 4.719), parafoveal area (H=23.142, F=2.904), the blood flow density of the area around the fovea (F=12.292, H=10.946), the difference was statistically significant (P＜0.05); with the increase of UACR, the blood flow density of each area of SCP and DCP showed a downward trend. The results of correlation analysis showed that the blood flow density of the whole SCP, parafoveal area, and surrounding area of T2DM patients was negatively correlated with UACR (r=－0.376, －0.240, －0.364, －0.347, P＜0.05). There were no correlation among fasting plasma glucose, HbAlc and UACR (r=0.179, 0.085, P＞0.05). There were no correlation among blood flow density in BMI, SCP foveal area, DCP and UACR (|r|＜0.3, P＞0.05). ConclusionThe whole, parafovea and perifovea vessel density values of SCP in T2DM eyes without DR are negatively correlated with UACR.
As a neurodegenerative disease of the retina, glaucoma can cause irreversible vision loss in patients. More and more evidences indicate that systemic blood flow abnormalities, decreased optic nerve blood flow, and retinal microcirculation disorders are related to the mechanism of glaucoma ganglion injury. Optical coherence tomography (OCTA) has the advantages of non-invasive, high resolution, quick inspection, three-dimensional imaging, and quantitative blood flow perfusion. Compared with other blood flow detection methods such as color ultrasound Doppler, laser speckle blood flow imaging, etc. it has higher performance and accuracy, and is easier to be applied in clinical practice. OCTA can not only be used for the early diagnosis and follow-up of glaucoma, but has a strong correlation with retinal nerve fiber layer thickness and visual field parameters; it can also provide objective data for the follow-up of patients with advanced glaucoma to assess the progress of the disease. In the future, OCTA is expected to become a routine detection method and follow-up method for the diagnosis of glaucoma.
Optical coherence tomography angiography (OCTA) base on OCT with an algorithm that can image a high-resolution picture of retinal circulation. OCTA has allowed quantifying the characteristic lesions of diabetic retinopathy (DR) in early stage, such as fovea avascular zone, retinal vascular density and the counts of retinal microaneurysm. In addition, OCTA can objectively evaluate the progression and prognosis of DR in late stage through imaging involved retinal neovascularization. Understanding OCT angiography features of DR lesions with different course of the disease may provide reference value for the diagnosis and treatment of DR.
ObjectiveTo observe the prevalence of fundus tessellation in college students with high myopia and analyze the relationship of fundus tessellation and ocular biological parameters.MethodsA cross-sectional study. A total of 202 eyes of 161 individuals were included in the study. Among them, there were 49 males and 112 females with the average age of 19.73 ± 1.12 years old, and the average spherical equivalent of －7.39 ± 1.12 D. All participants underwent computer optometry, non-mydriatic fundus photography, OCT, OCT angiography (OCTA) examination and axial length (AL) measurement. The non-mydriatic fundus camera was used to take the photo of fundus. Fundus tessellation was differentiated to no leopard eye fundus (grade 0), mild leopard eye fundus (grade 1) and middle leopard eye fundus (grade 2) and for severe leopard eye fundus (grade 3). The lenstar was used for eye axis measurement. The choroid, retinal thickness and microvessel density of the macular fovea at the posterior pole of the fundus were measured using a swept-frequency source optical coherence tomography scanner. According to the ETDRS, the choroid within 6 mm of the fovea was divided into 3 concentric circles centered on the macula, which were the central area with a diameter of 1 mm, the inner ring area of 1-3 mm and the outer ring area of 3-6 mm. The outer ring area of 3-6 mm included a total of 9 zones. The inner ring and outer ring 4 regions were superior, inferior, nasal and temporal, respectively. The distribution characteristics of choroid and retinal thickness in different regions and the density of superficial microvessels in the macular area of the retina were observed. Bivariate correlation analysis was used to analyze the relationship of fundus tessellation and ocular biological parameters.ResultsAmong 202 eyes, 37 eyes with leopard pattern fundus with 0 grade (18.32%, 37/202), 165 eyes with grade 1 to 3 (81.68%, 165/202), of which grade 1, 2 and 3 were respectively 125 (61.88%, 125/202), 28 (13.86%, 28/202), 12 (5.94%, 12/202) eyes. The thickness of the retina, both horizontally and vertically, increased first and then decreased from the nasal side to the central area, was lowest in the central area, then increased and then decreased; the overall thickness of the temporal side was slightly lower than that of the nasal side, and the overall thickness of the lower part was slightly lower than the upper part. The choroidal thickness gradually thickened from the nasal side to the temporal side in the horizontal direction; it gradually decreased in the vertical direction from the top to the central area, then increased and then decreased. The SCP blood flow density in the central area in the horizontal and vertical directions was lower than that in other areas. In multivariate regression analysis, Leopard-like fundus classification and AL (β=0.291, OR=1.338, 95%CI 1.064-1.682, P=0.013), SCP blood flow density in the central area of the macula (β=0.080, OR=1.084, 95% CI 1.006-1.167, P=0.034) and choroidal thickness (β=－0.033, OR=0.968, 95%CI 0.960-0.975, P＜0.001) were related.ConclusionsPatients with high myopia have a higher prevalence of tessellation. The deepening of tessellation is related to the thinning of the choroid thickness, the growth of the eye axis, and the larger density of the superficial microvessels in the fovea.
ObjectiveTo observe the changes of retinal blood flow density and thickness in the macular region of eyes with high myopia (HM) combined with peripapillary intrachoroidal cavitation (PICC). MethodsA cross-sectional study. From March 2019 to May 2021, 65 patients (65 eyes) diagnosed as PICC (HM+PICC group) in Eye Hospital, China Academy of Chinese Medical Sciences, sex-and age-matched 69 HM patients of 69 eyes (HM group) and 65 healthy people of 65 eyes (control group) were enrolled in this study. The optical coherence tomography angiography was used to scan macular areas in 3 mm×3 mm, and measure the macular fovea and optic disc on superior, inferior, nasal, temporal superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density in the foveal and parafoveal region, and macular retinal ganglion cell complex (mGCC) thickness, full retinal thickness. One-way analysis of variance were used to test the difference of the index values among three groups, and then two groups were compared with Bonferroni test. A paired t-test was used to test the difference of the macular vessel density and thickness between the superior and inferior hemifield in three groups. Pearson partial regression analysis was used to calculate the correlations between them at same sites. ResultsPICC was located most frequently at the inferior temporal disc border, followed by the inferior nasal region, superior temporal region, and superior nasal region in the HM+PICC group on 57(87.7%, 57/65), 25(38.5%, 25/65), 3(4.6%, 3/65) and 1(1.5%, 1/65 ) eye. There were significant differences in the global and regional full retinal thickness, mGCC thickness, SCP and DCP vessel density among 3 groups (F=29.097, 51.929, 16.253, 6.135; P＜0.001). The macular SCP and DCP vessel density except in the fovea, all regional macular full retinal thickness and mGCC thickness in the HM+PICC group were significantly lower than those in the normal group (P＜0.05). Compared to the HM group, the HM+PICC group had lower all regional mGCC thickness and SCP vessel density, as well as full retinal thickness in the inferior hemifield and DCP vessel density in the foveal region (P＜0.05). Macular vessel density and thickness in the inferior hemifield were significantly lower than those in the superior hemifield (t=6.356, 11.693, 6.212, 2.936; P＜0.01). Pearson partial regression analysis showed the SCP vessel density was positively correlated with corresponding mGCC thickness and full retinal thickness (r=0.584, 0.534, 0.592, 0.496, 0.485, 0.517; P＜0.001). However, there was no significant correlation between the DCP vascular density and mGCC thickness (P＞0.05), and only a weak positive correlation between the DCP vascular density and the full retinal thickness in the inferior hemifield (r=0.319, P=0.014). However, no association with average and superior full retinal thickness (r=0.066, 0.002, 0.125, 0.184, 0.016, 0.319; P＞0.05). ConclusionThe macular SCP vessel density, mGCC thickness and the full retinal thickness in the inferior hemifield in PICC eyes are lower than those in the HM eyes, especially the mGCC thickness and SCP vessel density in the inferior hemifield, and there is a strong positive correlation between them.
ObjectiveTo observe the imaging characteristics of optical coherence tomography angiography (OCTA) and the changes of choroidal capillary density (CCD) in the eyes of patients with high myopia choroidal neovascularization (mCNV). MethodsA case-control study. From January 2018 to October 2020, 50 cases of mCNV patients with 50 eyes (mCNV group) were included in the study. There were 18 males and 32 females; their age was 42.11±11.66 years old. Fifty eyes of 50 patients with normal fundus with matching myopia refractive power (≥6.00 D) were selected as the simple high myopia group, and 50 normal volunteers (refractive power －0.25-0.25 D) while 50 eyes were selected as the normal control group. There was no statistically significant difference in age (F=0.028) and gender composition ratio (χ2=0.136) among the three groups of patients (P＞0.05); the difference in best corrected visual acuity was statistically significant (F=14.762, P=0.004). Compared with mCNV group and pure high myopia group, the refractive index (t=－0.273) and axial length (t=0.312) of the examined eyes were not statistically significant (P＞0.05). OCTA instrument was used to measure the CCD in the macular area of the examined eye. Analysis of variance was used for comparison of measurement data among the three groups; χ2 test was used for comparison of categorical variables. The paired t test was performed to compare the CCD of the mCNV patient's eye and the contralateral eye. ResultsAmong the 50 eyes in the mCNV group, Ⅰ, Ⅱ, and mixed choroidal neovascularization (CNV) were 12 (24%, 12/50), 34 (68%, 34/50), and 4 (8%, 4/50) eyes, respectively. Corresponding to the OCTA cross-sectional image of the lesion, there was a clear “flower cluster”-like strong blood flow signal. Among them, the focal shape, the filament shape, and the group net shape were 6 (12%, 6/50), 8 (11%, 8/50), and 36 (72%, 36/50) eyes, respectively. The CCD of the eyes in the mCNV group, the pure high myopia group, and the normal control group were (57.39±3.24)%, (59.33±2.23)%, and (61.87±1.62)%, respectively. The CCD of the eyes in the mCNV group was significantly lower than that of the simple high myopia group (P=0.030) and the normal control group (P＜0.001). The CCD of the affected eye and the contralateral eye in the mCNV group were (57.39±3.24)% and (59.82±3.94)%, respectively; there was no statistically significant difference between the CCD of the affected eye and the contralateral eye (t=－0.496, P=0.100). The CCDs of eyes with Ⅰ, Ⅱ and mixed CNV were (57.38±3.31)%, (57.39±2.83)%, and (57.36±4.21)%, respectively. There were no statistically significant differences in CCD (F=1.476), age (F=0.274), sex ratio (χ2=0.825), and diopter (F=0.348) in different CNV types (P＞0.05). ConclusionThe mCNV is mostly type Ⅱ, and OCTA has a "bloom" appearance of abnormal reticular blood vessels; the CCD is significantly reduced, and it is bilateral.
ObjectiveTo assess changes of blood flow density of idiopathic choroidal neovascularization (ICNV) treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF).MethodsRetrospective case analysis. Sixteen eyes of 16 patients with ICNV diagnosed with FFA and OCT were included in this study. Among them, 12 were female and 4 were male. The mean age was 33.94±9.83 years. The mean course of diseases was 5.13±4.44 weeks. The BCVA, indirect ophthalmoscope, OCT and OCT angiography (OCTA) were performed at the first diagnosis in all patients. The BCVA was converted to logMAR. The macular fovea retinal thickness (CMT) was measured by OCT, and the selected area of CNV (CSA) and flow area of CNV (CFA) were measured by OCTA. The mean logMAR BCVA, CMT, CSA and CFA were 0.336±0.163, 268.500±57.927 μm, 0.651±0.521 mm2, 0.327±0.278 mm2 , respectively. All patients were treated with intravitreal ranibizumab (IVR, 10 mg/ml, 0.05 ml). Follow-up results including the BCVA, fundus color photography, OCT and OCTA were obtained 1 month after treatment. To compare the changes of BCVA, CMT, CSA, CFA of ICNV treated with anti-VEGF. Pearson method was used to analyze the correlation between logMAR BCVA and CMT, CSA and CFA before and after the treatment.ResultsOne month after treatment, the average logMAR BCVA, CMT, CSA and CFA were 0.176±0.111, 232.500±18.910 μm, 0.420±0.439 mm2, 0.215±0.274 mm2. The mean logMAR BCVA (t=5.471, P＜0.001), CMT (t=2.527, P=0.023), CSA (t=4.039, P=0.001), CFA (t=4.214, P=0.001) significantly decreased at 1 month after injection compared to baseline, and the difference had statistical significance. The results of correlation analysis showed that the post-logMAR BCVA was moderately positively correlated with pre-CSA and post-CSA (r=0.553, 0.560; P=0.026, 0.024), and strongly correlated with pre-CFA and post-CFA (r=0.669, 0.606; P=0.005, 0.013), but not correlated with pre-CMT and post-CMT (r=0.553, 0.560; P=0.026, 0.024).ConclusionThe blood flow density of ICNV measured by OCTA were significantly decreased in the treatment of anti-VEGF drugs.
