ObjectiveTo observe and analyze the macular microvascular system changes in unilateral pediatric uveitis (PU) and healthy contralateral eyes. MethodsA cross-sectional case-control study. From January 2019 to July 2021, 21 eyes of 21 patients with PU diagnosed in one eye (PU group), 21 unaffected contralateral eyes (contralateral eye group), and 21 age-matched volunteers with 21 eyes (NC group) during the same period were examined in Peking Union Medical College Hospital. Optical coherence tomography angiography was used to scan the 6 mm × 6 mm fundus macular area in the three groups of selected eyes to measure the vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the retina, the area of the avascular zone (FAZ) in the fovea of the macula, the choroidal thickness under the fovea (SFCT), and the retinal thickness in the fovea of the macula (CRT). The device comes with a software choriocapillary flow measurement tool, which can obtain the macula's choriocapillary density (CCD) with the fovea as the center and the diameter of the annular area of 1.0 mm, 1.5 mm, and 3.0 mm, respectively. They were recorded as CCD-1.0, CCD-1.5, and CCD-3.0. The measurement data of multiple groups were compared by analysis of variance; if the variance of the three groups of data was not uniform, the Kruskal-Wallis test was used. Multiple linear regression analysis was used to evaluate the potentially related factors of CCD. ResultsCompared with the contralateral eye group and the NC group, the vessel density of SCP (H=－13.857, －25.500; P=0.043, P<0.001), DCP (H=－15.333, －31.595; P=0.007, P<0.001) and CCD-1.0 (H=－14.000, －16.214; P=0.040, 0.012) of the clinically quiescent PU group were significantly decreased. CRT and FAZ were not statistically different between PU and NC groups (F=0.955; P=1.000, 0.661). Compared with the NC group, the mean vessel density of SCP and DCP in the contralateral eye group decreased, and the difference in DCP vessel density was statistically significant (H=－16.262, P=0.004). There was no statistically significant difference between the CCD of two groups (P=1.000). The SFCT of the PU group was significantly thicker than that of the NC group (F=5.552, P=0.004), however, difference was not statistically significant from the fellow eye group (F=5.552, P=0.270). The results of multiple linear regression analysis revealed that the CCD-1.0, CCD-1.5, and CCD-3.0 showed a linear correlation with the area of FAZ (β=－0.494, －0.527, －0.566; P=0.015, 0.009, 0.010) and CRT (β=－0.322, －0.466, －0.342; P=0.026, 0.002, 0.028). CCD-1.0 and CCD-1.5 showed a linear correlation with the vessel density of DCP (β=0.277, 0.275; P=0.047, 0.045). ConclusionBoth retinal and choroidal microvasculature are abnormal in resting eyes with PU, and macular circulation disorders may be present in the unaffected fellow eye.
In experimental study on pigs was designed to evaluate the changes of the vessel density of super thin skin flaps.By means of stratified sampling, isotropic uniform random section, the vessel density of the supor thin skin flap was obeerved under the MIAS-200 image analyzer. The results showed that the remarkable changes of vascular density were found to begin on the 5th day after operation and was first appeared in the distal port of the survived flap,then,it proceeded gradually from the distal proximally.
ObjectiveTo investigate short-term changes in retinal and choroidal microcirculation in healthy adults after voluntary blood donation. MethodsA prospective observational clinical study. Nine healthy volunteers (18 eyes) who donated blood voluntarily at Tianjin Medical University Eye Hospital in August 2025 were included. Among them, 5 were male (10 eyes) and 4 were female (8 eyes); their age was (38.00±12.33) years old. Optical coherence tomography angiography was used to scan the macular area within a 6 mm×6 mm range. The software of the instrument automatically divided the scanning area into three concentric circular regions centered on the fovea centralis: the central fovea region with a diameter of 1 mm, the perifoveal central fovea region ranging from 1 to 3 mm, and the perifoveal area surrounding the fovea with a diameter of 3 to 6 mm. Measurements of blood flow density in the fovea centralis region, perifoveal central fovea region, and perifoveal area surrounding the fovea at different retinal layers (the entire retinal layer, the choroidal capillary layer, and the medium choroidal blood vessel layer) were conducted 30 minutes before blood donation and 30, 120 minutes after blood donation. Diastolic blood pressure (DBP), systolic blood pressure (SBP), and intraocular pressure were recorded, and ocular perfusion pressure (OPP) was calculated. Repeated measurement data were analyzed using one-way analysis of variance. ResultsThere was no statistically significant difference in SBP, DBP, OPP and intraocular pressure among different blood donors at different measurement time points (P＞0.05). There was also no statistically significant difference in SBP, DBP and intraocular pressure among overall blood donors at different time points (P＞0.05); however, OPP significantly decreased at 120 minutes after blood donation, and the difference was statistically significant (F=5.380, P=0.02). Compared with 30 minutes before blood donation, the temporal blood flow density in the periphery of the paracentral fovea, the superior part and the surrounding area of the fovea in the peripheral area decreased significantly at 30 minutes after blood donation (F=3.920, 3.45,0 4.200; P=0.03, 0.04, 0.02), and recovered by 120 minutes. There was no statistically significant difference in the blood flow density of the entire retinal layer in the macular area and the large blood vessel layer in the choroid at different measurement time points among overall blood donors (P＞0.05). The correlation analysis results showed that there was no significant correlation between OPP at 30 minutes and 120 minutes after blood donation and the temporal blood flow density of the choroidal capillary layer in the temporal part of the periphery of the paracentral fovea, the superior part and the surrounding area of the fovea (r=0.037, 0.047, 0.187, ?0.027, 0.056, 0.156; P＞0.05). ConclusionsThere is no significant correlation between the blood flow density in the macular area of the retina and choroid and OPP. The mild and reversible changes in the choroidal microcirculation could occur.