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Lipid Emulsion–Based OCT Angiography for Ex Vivo Imaging of the Aqueous Outflow Tract
摘要： PURPOSE. Contrast agents applicable for optical coherence tomography (OCT) imaging are rare. The intrascleral aqueous drainage system would be a potential application for a contrast agent, because the aqueous veins are of small diameter and located deep inside the highly scattering sclera. We tested lipid emulsions (LEs) as candidate OCT contrast agents in vitro and ex vivo, including milk and the anesthetic substance Propofol. METHODS. Commercial OCT and OCT angiography (OCTA) devices were used. Maximum reflectivity and signal transmission of LE were determined in tube phantoms. Absorption spectra and light scattering was analyzed. The anterior chamber of enucleated porcine eyes was perfused with LEs, and OCTA imaging of the LEs drained via the aqueous outflow tract was performed. RESULTS. All LEs showed a significantly higher reflectivity than water (P < 0.001). Higher milk lipid content was positively correlated with maximum reflectivity and negatively with signal transmission. Propofol exhibited the best overall performance. Due to a high degree of signal fluctuation, OCTA could be applied for detection of LE. Compared with blood, the OCTA signal of Propofol was significantly stronger (P ? 0.001). As a proof of concept, time-resolved aqueous angiography of porcine eyes was performed. The three-dimensional (3D) structure and dynamics of the aqueous outflow were significantly different from humans. CONCLUSIONS. LEs induced a strong signal in OCT and OCTA. LE-based OCTA allowed the ability to obtain time-resolved 3D datasets of aqueous outflow. Possible interactions of LE with inner eye's structures need to be further investigated before in vivo application.
关键词： lipid emulsion,propofol,optical coherence tomography angiography,aqueous flow
更新于2025-09-19 17:15:36
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VESSEL DENSITY OF SUPERFICIAL, INTERMEDIATE, AND DEEP CAPILLARY PLEXUSES USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY
摘要： Purpose: To provide values of retinal vessel density (VD) in the three retinal capillary plexuses, foveal avascular zone (FAZ) area, and retinal layer thickness in a cohort of healthy subjects. Methods: The optical coherence tomography angiography maps of 148 eyes of 84 healthy subjects, aged 22 to 76 years, were analyzed for measuring VD of the retinal capillary plexuses, using the Optovue device comprising a projection artifact removal algorithm. Foveal avascular zone metrics were measured, and the relationship between optical coherence tomography angiography findings and age, sex, and image quality was studied. Results: The deep capillary plexus showed the lowest VD (31.6% ± 4.4%) in all macular areas and age groups compared with the superficial vascular plexus (47.8% ± 2.8%) and intermediate capillary plexus (45.4% ± 4.2%). The mean VD decreased by 0.06%, 0.06%, and 0.08% per year, respectively, in the superficial vascular plexus, intermediate capillary plexus, and deep capillary plexus. Mean FAZ area, FAZ acircularity index, and capillary density in a 300-mm area around the FAZ were 0.25 ± 0.1 mm2, 1.1 ± 0.05, and 50.8 ± 3.4%, respectively. The yearly increase in FAZ area was 0.003 mm2 (P , 0.001). Conclusion: The deep capillary plexus, a single monoplanar capillary plexus located in the outer plexiform layer, has the lowest VD, a significant finding that might be used to evaluate retinal vascular diseases. Vascular density decreased with age in the three capillary plexuses.
关键词： retinal vessel density,OCTA,retina,retinal capillaries,retinal capillary plexus,optical coherence tomography angiography,deep capillary plexus,capillary density,intermediate capillary plexus
更新于2025-09-19 17:15:36
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Impact of near-infrared angiography on the quality of anatomical resection during video-assisted thoracic surgery segmentectomy
摘要： Background: The aim of the present study was to assess the impact of near-infrared angiography in guiding intraoperatively sublobar anatomical resection by video-assisted thoracic surgery (VATS). Methods: We retrospectively analyzed data from 67 patients who underwent segmentectomy by VATS from November 2014 to November 2017 at the University Hospitals of Geneva, Switzerland. The need to modify arterial or parenchymal resection based on intraoperative near-infrared imaging was considered the primary study outcome. Results: A total of 67 patients (28 men, 39 women, mean age 66±10 years) underwent anatomical pulmonary segmentectomy by VATS. Histological analysis revealed a primary lung tumor in 59 patients. The mean ± standard deviation (SD) operation time was 154±51 minutes. Identification of the intersegmental plane (ISP) with near-infrared angiography was achieved in 88% of patients and led to modification of the resection during segmentectomy in 7 patients (10%), avoiding inappropriate resection; 2 patients had distant tumor recurrences (3%). Conclusions: Near-infrared angiography during VATS segmentectomy is effective for identifying ISPs, with respect to the oncological margins, as well as for correcting the anatomical resection.
关键词： intersegmental plane (ISP),Near-infrared angiography,video-assisted thoracic surgery (VATS),anatomical resection,segmentectomy
更新于2025-09-19 17:15:36
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Comparison of choroidal neovascularization secondary to white dot syndromes and age-related macular degeneration by using optical coherence tomography angiography
摘要： Purpose: To characterize and compare choroidal neovascularization (CNV) secondary to white dot syndromes (WDS) and age-related macular degeneration (AMD) using optical coherence tomography angiography (OCT-A). Methods: This is a cross-sectional study in which we imaged patients with CNV secondary to WDS and AMD with either the Zeiss Angioplex OCT-A or Optovue AngioVue OCT-A. Relevant demographic and clinical characteristics were collected and analyzed. CNV area and vessel density (VD) were measured by three independent graders, and linear regression analysis was subsequently performed. Results: Three patients with multifocal choroiditis and panuveitis, one patient each with birdshot chorioretinopathy, presumed ocular histoplasmosis syndrome, and persistent placoid maculopathy, and eleven patients with AMD with sufficient image quality were included. CNV associated with WDS was significantly smaller than that secondary to AMD (0.56±0.32 vs 2.79±1.80 mm2, β=-2.22, P=0.01), while no difference in VD was detected (0.46±0.09 vs 0.44±0.09, β=0.02, P=0.71). Conclusion: CNV networks secondary to WDS appear to be smaller than those secondary to AMD but have similar VD. OCT-A is a powerful tool to investigate properties of CNV from various etiologies. Larger studies are needed for further characterization and understanding of CNV pathogenesis in inflammatory conditions.
关键词： uveitis,age-related macular degeneration,inflammation,choroidal neovascularization,white dot syndromes,optical coherence tomography angiography,choroidal neovascular membrane
更新于2025-09-19 17:15:36
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Assessment of the Dynamic Alteration of Choriocapillaris Vessel Density after Focal Laser Photocoagulation with OCT Angiography
摘要： Purpose. To evaluate the changes of choriocapillaris blood ?ow beneath laser lesions in noncenter-involved diabetic macular edema patients using optical coherence tomography angiography (OCTA). Methods. This was a retrospective case-series study. We used OCTA to analyze the characteristics of the choriocapillaris blood ?ow beneath laser lesions before laser treatment and at several intervals after treatment. The choriocapillaris vessel density (CCVD) beneath the laser lesions was based on the OCTA images and was de?ned as the proportion of ?ow pixels in the selected area calculated using FIJI software through automatic binarization processing based on threshold methods. Results. A total of 63 laser lesions in 8 eyes of 5 patients were included in this study. There was a signi?cant decrease in the CCVD at 1 hour and 1 day following laser treatment (24.25% ± 5.04% and 22.00% ± 4.71%, respectively) when compared with the baseline value (39.09% ± 3.71%, all p < 0.001). The CCVD was 31.82% ± 4.53% in 1 week after laser treatment, which was signi?cantly higher than that in 1 day after treatment (p < 0.001), and then continued to improve at 1 month after treatment (34.44% ± 4.16%). Additionally, in the group with smaller spot size and lower energy, the CCVD recovery at 1 month after laser was signi?cantly better than that in the group with larger spot size and higher energy (p ? 0.006). Conclusions. OCTA image analysis can re?ect changes in the choriocapillaris blood ?ow beneath laser lesions at di?erent times following laser treatment in vivo. Spot size and laser energy may a?ect blood ?ow recovery.
关键词： laser photocoagulation,choriocapillaris,diabetic macular edema,OCT angiography
更新于2025-09-19 17:13:59
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<p>Correlation between laser speckle flowgraphy and optical coherence tomography angiography measurements in normal and glaucomatous eyes</p>
摘要： Purpose: To investigate the relationship between laser speckle ?owgraphy (LSFG) and optical coherence tomography angiography (OCTA) measurements of the peripapillary retina and optic nerve head (ONH) in normal eyes and eyes with primary open-angle glaucoma (POAG). Patients and methods: One eye from each of 46 normal subjects and mild and moderate/advanced POAG patients were included. ONH blood ?ow acquired by LSFG, circumpapillary vessel density (cpVD, a 250 μm-wide elliptical annulus around the optic disc), and intra-papillary vessel density (ipVD, a 1.5×1.5 mm scan ?eld) acquired by OCTA were measured. Their values were compared among normal controls and patients at each stage of glaucoma using one-way ANOVA, and the correlation between measurements obtained by the two methods was examined by univariate regression analysis. Results: ONH tissue blood ?ow, tissue mean blur rate (MBR-T), and cpVD in the outer layer of the retina signi?cantly decreased with the progression of glaucoma stage, although the latter showed no signi?cant difference between normal subjects and mild-stage glaucoma patients. MBR-T was signi?cantly correlated with cpVD, but not with ipVD, in the retinal outer layer. Conclusion: A correlation was found only between MBR-T and cpVD in the retinal outer layer. A difference in MBR-T, but not in cpVD, was detected between normal controls and mild glaucoma patients.
关键词： optic nerve head,blood ?ow,laser speckle ?owgraphy,optical coherent tomography angiography
更新于2025-09-16 10:30:52
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Clinical efficacy of bowel perfusion assessment during laparoscopic colorectal resection using laser speckle contrast imaging: A matched case–control study
摘要： Introduction: Disadvantages of bowel perfusion assessment with indocyanine green fluorescence angiography include the need for a fluorophore and the subjective nature of the assessment. This study was performed to evaluate the clinical efficacy of bowel perfusion assessment using laser speckle contrast imaging (LSCI) during laparoscopic colorectal surgery. Methods: The study population comprised the first 27 consecutive patients who underwent laparoscopic left-sided colorectal resection with intraoperative perfusion assessment using LSCI. The operative outcomes of these patients were compared with those of a matched group of patients without perfusion assessment. We analyzed the flux data expressed in laser speckle perfusion units. Results: After propensity score matching, we found no significant between-group differences in the patients' characteristics with the exception of the cancer stage. No patients undergoing LSCI perfusion assessment developed anastomotic leakage, but five (18.5%) patients in the control group did, at a significantly higher rate in male patients (P = .042). There were no significant differences in other operative outcomes. The laser speckle perfusion unit values after ligating marginal vessels were significantly lower than before ligation (P < .01). Conclusions: With respect to anastomotic leakage, LSCI may improve patient outcomes after colorectal surgery. This technique appears to be a superior tool with the advantages of measurement repeatability and quantitativity and no need for a fluorophore.
关键词： fluorescence angiography,anastomotic leakage,colorectal cancer
更新于2025-09-12 10:27:22
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Mild accidental macular injury induced by picosecond Nd:YAG laser
摘要： Accidental laser-associated ophthalmic complications are rare disorders which were first described in 1965 by Rathkey as a ‘laser burn’ of the macula. Most reported ophthalmic complications have been induced by nanosecond neodymium-doped yttrium aluminium garnet (Nd:YAG) laser. Several studies have reported that most nanosecond Nd:YAG laser-associated ophthalmic complications are choroidal neovascularisation, macular hole, and vitreous haemorrhage. These complications also have been reported as poor prognosis of visual function. Few reports appear to have described picosecond Nd:YAG laser-associated ophthalmic complications. In this report, a case of mild ophthalmic complications of subretinal and choroidal haemorrhage due to accidental picosecond Nd:YAG laser irradiation is described.
关键词： optical coherence tomography,angiography,picosecond Nd:YAG laser,ophthalmic complications
更新于2025-09-12 10:27:22
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Microvasculature Changes of Myopic Choroidal Neovascularization and the Predictive Value of Feeder Vessel Disappearance after Ranibizumab Treatment Revealed Using Optical Coherence Tomography Angiography
摘要： Aim: To investigate vascular changes of myopic choroidal neovascularization (mCNV) after ranibizumab treatment using optical coherence tomography-angiography (OCTA). Methods: Consecutive subjects with a diagnosis of mCNV were included. Patients underwent intravitreal injection of ranibizumab treatment with a 6-month follow-up. All patients underwent a complete ophthalmological examination and OCTA evaluation. The 3 × 3 OCTA en face images were analyzed for the absence/presence of mCNV, CNV area, and CNV network morphology. In particular, the morphology of the mCNV was analyzed in order to detect the presence/absence of feeder vessels. Results: Eleven subjects were evaluated. At baseline, the mCNV was identified in all cases on OCTA. At 6 months, the mean mCNV area was not statically significantly reduced in comparison with baseline values (p > 0.05), while the morphologic analysis revealed a complete disappearance of the feeder vessel in 6 eyes. The subgroup analysis of these latter showed that the CNV area was significantly reduced, visual acuity had improved, and only one intravitreal injection was administrated over the entire follow-up period. Conclusions: OCTA allowed the detection of qualitative and quantitative vascular changes in mCNV. The disappearance of the feeder vessel was associated with better anatomical as well as functional outcomes at the last follow-up visit.
关键词： Myopic choroidal neovascularization,Pathologic myopia,Optical coherence tomography angiography
更新于2025-09-12 10:27:22
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SEVERE RECURRENT FIBROVASCULAR PROLIFERATION AFTER COMBINED INTRAVITREAL BEVACIZUMAB INJECTION AND LASER PHOTOCOAGULATION FOR AGGRESSIVE POSTERIOR RETINOPATHY OF PREMATURITY
摘要： To describe the clinical features of severe recurrent fibrovascular proliferation after combined intravitreal bevacizumab injections and laser photocoagulation for aggressive posterior retinopathy of prematurity. This retrospective, nonrandomized case series reviewed the medical and ophthalmic records in the referral hospital and our hospital. Four patients (seven eyes) with aggressive posterior retinopathy of prematurity. The patients were referred for vitrectomy with/without lensectomy for recurrent fibrovascular proliferation with a tractional retinal detachment after combined intravitreal bevacizumab injections and laser photocoagulation. Three patients were born at 22 weeks or 23 weeks’ gestational age and one patient at 29 weeks’ gestational age. Preoperatively, fluorescein angiography images showed all eyes had tractional retinal detachment from regrowth of fibrovascular proliferation 3 months to 5 months after the intravitreal bevacizumab injection and abnormal retinal vasculature; four eyes had a broad ischemic retina. Postoperatively, four eyes had retinal attachment and three eyes a total retinal detachment. Neovascular glaucoma developed in five of the seven eyes during the clinical course. Severe fibrovascular proliferation may recur due to widespread retinal ischemia with capillary dropout and abnormal vasculature after failed combined intravitreal bevacizumab and laser photocoagulation therapy as the initial treatment for aggressive posterior retinopathy of prematurity. Careful follow-up is important especially after anti–vascular endothelial growth factor treatment, with recognition that severe reactivation is possible.
关键词： intravitreal bevacizumab injection,vitrectomy,retinopathy of prematurity,fluorescein angiography,stage 5 ROP,vascular endothelial growth factor,stage 4 ROP,fibrovascular proliferation,laser photocoagulation,ROP surgery
更新于2025-09-12 10:27:22