Retinal vein occlusion (RVO) is a serious retinal vascular disease, often accompanied by systemic cardiovascular and cerebrovascular diseases, with ocular changes such as macular oedema, retinal ischemia, and even neovascularisation formation, which, as a common slow disease of the fundus, seriously affects people's vision and quality of life. With the development of optical coherence tomography, the research on the role of the choroid in RVO's onset and progression has gradually attracted people's attention. Currently, observational metrics for changes in the choroidal layer of the RVO eyes have expanded from two-dimensional thickness to three-dimensional parameters such as volume, blood flow density, and blood flow velocity. Some studies have also incorporated artificial intelligence algorithm technologies. In the future, there remains a need to further enrich data on the choroidal layer of the fundus of the RVO eyes to enhance comprehensive understanding of RVO, providing new insights for its clinical prevention and treatment.
Objective To observe the hemodynamic changes of posterior polar and peripheral retina and choroid in patients with rheogenic retinal detachment （RRD） after scleral buckling surgery. MethodsA prospective clinical observational study. A total of 25 eyes of 25 patients with RRD who underwent scleral buckle surgery in Tianjin Eye Hospital from February to April 2024 were included in the study. Among them, 10 were male and 15 were female. Age was 17-68 years old. All cases were monocular. The surgical eye and the contralateral healthy eye were divided into the affected eye group and the contralateral healthy eye group respectively. Best corrected visual acuity （BCVA）, scanning source optical coherence tomography angiography （SS-OCTA）, and axial length （AL） measurements were performed 3 months after surgery. SS-OCTA examination of macular area was performed by VG200 of Visual Microimaging （Henan） Technology Co., LTD. Scanning range 21 mm×26 mm. According to the partitioning method of the early treatment group of glycosuria retinopathy, the retina within 21 mm of the macular fovea was divided into concentric circles with the macular fovea as the center and diameters of 1-3, 3-6, 6-12, 12-21 mm, respectively. The built-in software of the device was used to record the central area （12 mm×12 mm in the fovea of the macula） and the peripheral area （12-21 mm range） retinal superficial capillary plexus （SCP）, deep capillary plexus （DCP）, radial peripapillary capillaries （RPC） blood density and choroidal vascular index （CVI）, choroidal vascular volume （CVV）, and 1-3, 3-6, 6-12, 12-21 mm above concentric circles （S）, nasal side （N）, temporal side （T）, and lower side （I） SCP, DCP, and RPC blood flow density. Quantitative data between the two groups were compared by independent sample t test or Wilcoxon signed rank test. The correlation between retinal and choroid blood flow parameters and postoperative BCVA was analyzed by Spearman correlation analysis. ResultsCompared with the opposite healthy eye group, SCP blood density in the central area （Z=－4.372）, DCP blood density in the central area （Z=－2.829）, and CVI in the peripheral area （Z=－2.138） were decreased in the affected eye group, and the differences were statistically significant （P＜0.05）. SCP: in the affected eye group, the blood flow density in T3-6 mm, T6-12 mm, N6-12 mm and T12-21 mm regions decreased, while the blood flow density in I6-12 mm regions increased, with statistical significance （P＜0.05）. DCP: blood flow density in S6-12 mm, I6-12 mm, S12-21 mm and I12-21 mm regions decreased significantly, and the differences were statistically significant （P＜0.05）. RPC: blood flow density decreased significantly in T6-12 mm and I12-21 mm, and the differences were statistically significant （P＜0.05）. CVI: T6-12 mm, S12-21 mm, T12-21 mm, I12-21 mm significantly decreased, and T1-3 mm, S12-21 mm significantly increased, the differences were statistically significant （P＜0.05）. Correlation analysis showed that AL growth was positively correlated with CVV in central region （r=0.408, P=0.040）. The number of pad pressure was negatively correlated with the blood density of central DCP （r=－0.422, P=0.030）. ConclusionsAfter scleral buckling operation, the blood flow density and choroidal blood flow parameters in RRD affected eyes were lower than those in contralateral healthy eyes in some areas. The increase of AL was positively correlated with CVV in the central region, and the wider the range of pad pressure, the worse the recovery of DCP blood density.