Deep Vascular Network Research Articles

In Vivo Assessment of Deep Vascular Patterns in Murine Colitis Using Optoacoustic Mesoscopic Imaging.

The analysis of vascular morphology and functionality enables the assessment of disease activity and therapeutic effects in various pathologies. Raster-scanning optoacoustic mesoscopy (RSOM) is an imaging modality that enables the visualization of superficial vascular networks in vivo. In murine models of colitis, deep vascular networks in the colon wall can be visualized by transrectal absorber guide raster-scanning optoacoustic mesoscopy (TAG-RSOM). In order to accelerate the implementation of this technology in translational studies of inflammatory bowel disease, an image-processing pipeline for TAG-RSOM data has been developed. Using optoacoustic data from a murine model of chemically-induced colitis, different image segmentation methods are compared for visualization and quantification of deep vascular patterns in terms of vascular network length and complexity, blood volume, and vessel diameter. The presented image-processing pipeline for TAG-RSOM enables label-free in vivo assessment of changes in the vascular network in murine colitis with broad applications for inflammatory bowel disease research.

Vascular changes in the retinal capillary network in fellow eye of the patients with central retinal artery occlusion.

We aimed to evaluate the retinal vascular changes in the superficial and deep retinal vascular networks in the fellow eye of patients with central retinal artery occlusion (CRAO) and compare them with controls using optical coherence tomography angiography (OCT-A). In a cross-sectional study, 27 patients with CRAO and 189 normal controls were included. Ophthalmic examination and OCT-A images were performed on all participants. The total vascular density of the superficial capillary network in the 6-mm scan was significantly lower in the fellow eye of patients with CRAO than in the control group (p = 0.02). No significant difference was observed in the FAZ area of the affected eyes and their fellow eyes compared with the controls. Total vascular density at 300 microns around the fovea was lower in the fellow eye compared with the control group (p = 0.034). The retinal vascular network changes in the fellow eyes of patients with CRAO suggest that persistent microvascular changes may be present before the onset of CRAO. This finding indicates that such changes could serve as an early diagnostic window for systemic vascular changes before catastrophic vascular events occur.

An advanced 3D lymphatic system for assaying human cutaneous lymphangiogenesis in a microfluidic platform

The human cutaneous lymphatic system strictly controls lymphatic functions by coordinating with skin cells. The lymphatic system plays important roles in removing cell waste, residual proteins, various antigens, and immune cells from tissues to maintain homeostasis and activate the immune system through the drainage of interstitial fluid1,2. The skin protects our body from external stimuli such as pathogens through the cutaneous lymphatic system3,4. Herein, to develop an in vitro human cutaneous lymphatic model, we present two 3D microfluidic platforms: a lymphangiogenesis model with a precollecting lymphatic vessel-like structure and an advanced lymphangiogenesis model with a functional cutaneous barrier and a precollecting lymphatic vessel-like structure. In addition, we rapidly analyzed prolymphangiogenic effects using methods that incorporate a high-speed image processing system and a deep learning-based vascular network analysis algorithm by 12 indices. Using these platforms, we evaluated the pro-lymphangiogenic effect of Lymphanax, a natural product derived from fresh ginseng. As a result, we demonstrated that Lymphanax induces robust lymphangiogenesis without any structural abnormalities. In conclusion, we suggest that these innovative platforms are useful for studying the interaction between the skin and lymphatic system as well as evaluating the prolymphangiogenic effects of drugs and cosmetics.

Dynamics of morphological changes in the cellular layers of retina in the long-term experimental opioid exposure

Relevance of research. There is enough information in the foreign and domestic specialized literature on the issue of morphological reorganization of cells and tissues during experimental opioid exposure and other types of toxic effects on the body today. At present, the issue of structural reorganization in the layers of the retina and disruption of its blood supply processes during subchronic and chronic periods of experimental opioid exposure remains unclear. That is why we decided to supplement, expand and deepen information about these processes by conducting our own research in this direction. The purpose of the study is to clarify the dynamics of pathomorphological changes in the layers of the retina and the links of its hemomicrocirculatory channel in the long term of experimental opioid exposure.Material and methods. The research material was sexually mature, outbred, white male rats, 56 animals in number, weighing 160-270 g, aged 4.5-7.5 months. The initial dose of nalbuphine during the first 2 weeks was 0.212 mg/kg, the next 2 weeks (III-IV weeks) – 0.225 mg/kg, the next (V-VI weeks) – 0.252 mg/kg, the next (VI-VIII weeks ) – 0.260 mg/kg, the next (VIII – X weeks) – 0.283 mg/kg, the next (X – XII weeks) – 0.3 mg/kg, and during (XII – XIV weeks) – 0.45 mg/ kg. Before taking the material of the experimental site, the animal was removed from the experiment with the help of diethyl ether. Rat eyeballs were used as a material for ultrastructural research, considering the preservation of the topographic ratio of the eye membranes. Ultrastructural preparations were prepared according to the generally accepted method. Research results. At the end of the eighth week and the tenth week, persistent hyperemia of the choroidal vessels, degenerative and necrotic changes in the cells of the pigment layer, degeneration of the outer segments of photoreceptors, shortening and fragmentation of mitochondrial cristae of the inner segments of photoreceptors, necrotic changes in the nuclei of individual photoreceptors, degeneration of axons of the outer and inner reticular layers, as well as degenerative and necrotic changes of bipolar and amacrine cells, hypertrophy of processes of Müller cells, degeneration of ganglion cells, hyperemia and perivascular edema of vessels of the outer and inner reticular layers were revealed. After twelve and fourteen weeks, the initial stages of development with subsequent progression of sclerotic changes of Bruchʹs membrane were first detected. The phenomena of degenerative and necrotic changes in the cells of the pigment layer, destruction of the membrane of the outer segments of photoreceptors, degenerative changes in the axons of the outer and inner reticular layers and the layer of nerve fibers, degenerative and necrotic changes in bipolar and amacrine cells, hypertrophic changes in processes of Muller cells, hyperemia and stasis gradually increased, perivascular swellings in the vessels of the inner reticular layer, ganglionic layer and layer of nerve fibers, reactive changes in Muller cells and protoplasmic astrocytes. Conclusion. In the long-term course of experimental opioid exposure, irreversible pathomorphological changes occurred and subsequently progressed, which were caused by an increase in dyscirculatory manifestations in the superficial and deep vascular networks of the retina, causing the deepening of edema phenomena with further compression and hypoxia in the thickness of the retinal layers.

Case Report: Optical coherence tomography angiography findings in radiation retinopathy

We report the observation of a 31-year-old patient followed for a nasopharyngeal carcinoma since 2009, treated by locoregional radiotherapy, with a cumulative dose of 70 Gray. This case presented all ocular complications of radiotherapy; radiation retinopathy (RR), which is the most severe complication, could be diagnosed earlier and have a better prognosis if optic coherence tomography angiography (OCTA) was performed. She presented with a progressive decline in bilateral visual acuity. Ophthalmologic examination revealed bilateral posterior subcapsular cataract, radiation retinopathy, and optic neuropathy. The OCT B-scan showed more pronounced macular edema in the right eye. The OCTA revealed enlargement of the central avascular zone and loss of the deep and superficial retinal vascular network. The patient received three consecutive monthly intravitreal injections of anti-vascular endothelial growth factor (VEGF), without improvement in visual acuity. The aim of this case report is to present the contribution of OCT-A in the diagnosis of radiation maculopathy, and attribute these changes to ischemia at the level of the retinal vascular network.

Case Report: Optical coherence tomography angiography findings in radiation retinopathy

We report the observation of a 31-year-old patient followed for a nasopharyngeal carcinoma since 2009, treated by locoregional radiotherapy, with a cumulative dose of 70 Gray. This case presented all ocular complications of radiotherapy; radiation retinopathy (RR), which is the most severe complication, could be diagnosed earlier and have a better prognosis if optic coherence tomography angiography (OCTA) was performed. She presented with a progressive decline in bilateral visual acuity. Ophthalmologic examination revealed bilateral posterior subcapsular cataract, radiation retinopathy, and optic neuropathy. The OCT B-scan showed more pronounced macular edema in the right eye. The OCTA revealed enlargement of the central avascular zone and loss of the deep and superficial retinal vascular network. The patient received three consecutive monthly intravitreal injections of anti-vascular endothelial growth factor (VEGF), without improvement in visual acuity. The aim of this case report is to present the contribution of OCT-A in the diagnosis of radiation maculopathy, and attribute these changes to ischemia at the level of the retinal vascular network.

Optical coherence tomography angiography of central serous chorioretinopathy: quantitative evaluation of the vascular pattern and capillary flow density

BackgroundThis study aimed to evaluate the vascular pattern and capillary flow density (CFD) map on optical coherence tomography angiography (OCTA) images of patients affected by central serous chorioretinopathy (CSC).MethodsIn this retrospective cohort study, OCTA (AngioVue RTVue XR Avanti, Optovue) 3 × 3 mm macula scans of both eyes of patients with CSC were taken at baseline; the images were segmented and compared with OCTA scans of fellow eyes without CSC as well as age-matched healthy subjects. OCTA images were processed by quantitative textural analysis (ImageJ software) to provide an objective grading of choroidal capillary alterations. The texture of OCTA images was examined by the autocorrelation method.ResultsIn eyes with CSC (40 eyes), we found six different morphological patterns of the choriocapillaris layer vasculature (CCL), likely corresponding to different grades of OCT choroidal hyporeflectivity and OCTA reduction of the decorrelation signal. Moreover, the OCTA capillary flow density map revealed capillary depletion in the superficial capillary plexus (p value = 0.0023), in the deep vascular network (p value = < 0.0001), and in the CCL (p value = 0.0001). Such findings were not observed in healthy subjects (13 eyes).ConclusionsOCTA in CSC is a useful tool that allows the identification of the clinical type of CSC by means of specific CCL patterns. Moreover, CFD depletion is observed in association with the inner retinal layers, pointing to an involvement of the inner blood retinal barrier in CSC. According to our results, it is plausible that the patterns observed herein may correlate to the different clinical subtypes of the disease.

Evaluation of retinal and optic nerve vasculature by optic coherence tomography angiography in Migraine with Aura

This study aimed to evaluate the retina by optic coherence tomography angiography (OCTA) in patients with migraine with aura (MA) in comparison with healthy controls. A total of 60 patients with MA and 56 control subjects who applied to the Ophthalmology Clinic of Dicle University between January 2020 and February 2020 were included in this study. In all patients, the vascular density (VD) of the radial peripapillary capillaries (RPCs) and optic nerve head (ONH), the VD of deep and superficial macular vascular networks, and foveal avascular zone (FAZ) were measured. Patients with MA showed reduced VD measurements of the nasal and inferotemporal ONH, inferonasal RPCs, and deep macular plexus. No statistically significant difference was observed in the superficial macular VD values between the study groups. The majority of patients with MA showed hypertrophy in the deep FAZ. There was a decrease in VD measurements in the deep macular capillary plexus, ONH, and peripapillary capillaries and hypertrophy in the deep FAZ in patients with MA. According to these results, patients with MA may have an increased risk of developing ocular and systemic vascular complications. Therefore, OCTA can be used to evaluate systemic and ocular hypoperfusion in patients with MA.

Evaluation of Ocular Hypoperfusion in Patients with Acromegaly by Using Optical Coherence Tomography Angiography

ABSTRACT Purpose This study aimed to evaluate the retinal blood vessel parameters and the foveal avascular zone (FAZ) area using optical coherence tomography angiography (OCTA) in patients with acromegaly in comparison with healthy controls. Methods A total of 45 patients with acromegaly and 45 healthy controls were included in this study. In all patients, the vessel density (VD) of the deep and superficial macular vascular networks and the foveal avascular zone (FAZ) were measured using OCTA. The correlation of insulin-like growth factor 1 (IGF-1) level and disease duration with deep macular VD and FAZ values was analyzed. All parameters were registered. Results were assessed and compared between the two groups. Results Deep macular plexus VD values were lower in patients with acromegaly compared to the control group. No significant differences in VD values in the superficial segment, except for that in the inferior parafovea (P = .01) were found between the two groups. Furthermore, patients with acromegaly showed enlargement in the superficial (P = .30) and deep FAZ areas (P < .001). IGF-1 level and disease duration showed a significant negative correlation with the deep whole image (R = −0.216, P = .041, R = −0.339, P = .001, respectively), deep parafovea (R = −0.271, P = .01; R = −0.372, P < .001, respectively), deep parafovea superior hemi (R = −0.342, P = .001; R = −0.350, P = .001, respectively), deep parafovea temporal (R = −0.224, P = .034; R = −0.234, P = .026, respectively), deep parafovea nasal (R = −0.320, P = .002; R = −0.361, P < .001, respectively), and deep parafovea superior VD values (R = −0.293, P = .005; R = −0.307, P = .003, respectively) and a significant positive correlation with the deep FAZ area values (R = 0.244, P = .02; R = 0.329, P = .002, respectively). Conclusion VD values in the deep macular capillary plexus were lower in patients with acromegaly, and the superficial and deep FAZ area enlarged. Patients with acromegaly may have an increased risk of developing ocular vascular complications. OCTA can be used to evaluate retinal blood VD in patients with acromegaly.

Comparison between the Foveal Avascular Zone and Macular Capillary Network Density in Diabetic Retinopathy and Normal Retina

Background: Diabetic retinopathy (DR) is mostly a vascular disease where the development of macular oedema and proliferative retinopathy are major causes of visual impairment. Enlargement of the foveal avascular zone (FAZ) is associated with visual deterioration in patients with diabetic retinopathy. Objective: To evaluate the foveal avascular zone (FAZ) and perifoveal capillary network density in the superficial retinal layer (SRL) and deep retinal layer (DRL) in patients with varying severities of diabetic retinopathy (DR). Patients and methods: This is a prospective comparative randomized case-control study consisting of 77 eyes divided into two groups, each group underwent imaging using OCT-A device. Group one: 37 healthy control eyes, and group two: 40 eyes with DM of different degrees of diabetic retinopathy. Subjects were imaged between September 2019 and February 2020 at Kasr El-Ainy Teaching Hospital. Results: The FAZ area at the levels of the superficial and deep vascular networks of eyes with DR were found to be larger compared with those of age-matched healthy controls, and as would be expected, control eyes had higher vascular density in both networks compared with the diabetic eyes. Furthermore, eyes with worse DR stage showed larger FAZ area and lower vascular density values. This study also showed that angiographic parameters, namely FAZ area and vessel density (VD) correlated with best corrected visual acuity. Conclusion: Our study revealed that vascular density and FAZ area can be quantified in DR eyes in a rapid, automated, and noninvasive manner with OCTA. Also foveal avascular zone area and vascular density as measures of DMI correlate with visual acuity in patients with DR.

Comparison between the Foveal Avascular Zone and Macular Capillary Network Density in Diabetic Retinopathy and Normal Retina

Background: Diabetic retinopathy (DR) is mostly a vascular disease where the development of macular oedema and proliferative retinopathy are major causes of visual impairment. Enlargement of the foveal avascular zone (FAZ) is associated with visual deterioration in patients with diabetic retinopathy. Objective: To evaluate the foveal avascular zone (FAZ) and perifoveal capillary network density in the superficial retinal layer (SRL) and deep retinal layer (DRL) in patients with varying severities of diabetic retinopathy (DR). Patients and methods: This is a prospective comparative randomized case-control study consisting of 77 eyes divided into two groups, each group underwent imaging using OCT-A device. Group one: 37 healthy control eyes, and group two: 40 eyes with DM of different degrees of diabetic retinopathy. Subjects were imaged between September 2019 and February 2020 at Kasr El-Ainy Teaching Hospital. Results: The FAZ area at the levels of the superficial and deep vascular networks of eyes with DR were found to be larger compared with those of age-matched healthy controls, and as would be expected, control eyes had higher vascular density in both networks compared with the diabetic eyes. Furthermore, eyes with worse DR stage showed larger FAZ area and lower vascular density values. This study also showed that angiographic parameters, namely FAZ area and vessel density (VD) correlated with best corrected visual acuity. Conclusion: Our study revealed that vascular density and FAZ area can be quantified in DR eyes in a rapid, automated, and noninvasive manner with OCTA. Also foveal avascular zone area and vascular density as measures of DMI correlate with visual acuity in patients with DR.

Irregular vascular network identified with OCT-A in angioid streaks: A probable predictor of active choroidal neovascularization (case series).

To evaluate the risk of active choroidal neovascularization (CNV) in presence of deep irregular vascular network (IVN) in eyes with angioid streaks (AS). Observational case series including three treatment-naive eyes with angioid streaks and IVN, without CNV. Patients were followed-up during 18 months with multimodal imaging including structural optical coherence tomography (OCT) and OCT Angiography (OCT-A) to detect possible neovascular complication. On OCT-A, IVN was detected as a peripapillary and/or macular high-flow lesion, filling the spaces between the angioid streaks in the outer retina slab. Repeated OCT-A could detect an active CNV emerging from the IVN, as a high-flow rich anastomotic vascular network with a perilesional dark halo. Patient was treated with intravitreal injections of Bevacizumab on a Pro Re Nata regimen, with a decreased CNV area and lower vascular density on control OCT-A. OCT-A shown to be helpful in detecting the presence of IVN in asymptomatic eyes with AS during a routine examination. In our series, the IVN seems to be predictor of active CNV, needing a close surveillance and frequent follow-up to allow early treatment upon CNV activation.

Morphological changes in and quantitative analysis of macular retinal microvasculature by optical coherence tomography angiography in hypertensive retinopathy.

Hypertension is a serious global health problem. Hypertensive retinopathy is generally considered to be a predictor of vascular disease elsewhere in the human body. In the past few decades, a variety of grading systems have been proposed for hypertensive retinopathy. However, these grading systems have some limitations. This study utilized optical coherence tomography angiography (OCTA) to investigate the morphological changes and macular retinal microvasculature in depth among 100 patients with hypertensive retinopathy and 66 healthy participants. Five main pathological changes were discovered in hypertensive retinopathy, as follows: focal capillary sparsity, scattered microangioma, focal macular arch ring defects, focal capillary disorder, and focal capillary nonperfusion at the levels of the superficial and deep vascular networks. In addition, we have found that the number of various pathological changes shows an increasing trend as hypertensive retinopathy progresses and may be related to renal damage. Finally, deep vessel density tended to decrease with progressive stages of hypertensive retinopathy and could be the best indicator to predict the risk of hypertensive retinopathy. Our study, therefore, proposes 3 stages of hypertensive retinopathy without macular edema according to the pathophysiology found by OCTA: stage 1 (only focal capillary sparsity), taking the place of KWB grade I; stage 2 (focal capillary sparsity and scattered microangioma), taking the place of KWB grade II; and stage 3 (focal capillary sparsity, scattered microangioma, focal capillary disorder, and nonperfusion), taking the place of KWB grade III. Hence, OCTA may be a potentially useful tool for evaluating the pathophysiology and staging of hypertensive retinopathy. Further longitudinal prospective studies are needed to confirm our findings.

Retinal structural and vascular changes in posterior microphthalmos

BackgroundPosterior microphthalmos (PM) is a rare developmental disorder characterised by high hyperopia, short axial length, presence of retinal papillomacular fold and relatively normal anterior segment findings. The study objective is to describe the retinal structural and vascular changes in eyes with PM with spectral domain optical coherence tomography, optical coherence tomography angiography and multicolour imaging.MethodsIn this retrospective, comparative case series, 10 eyes of five patients with PM as cases and 10 eyes of five age‐ and sex‐matched controls were included. Structural changes, namely inner and outer retinal layer thicknesses, were measured using optical coherence tomography. Multicolour imaging findings were noted. Perifoveal vascular changes with qualitative and quantitative assessments were analysed using optical coherence tomography angiography.ResultsThe foveal dip was absent in all 10 eyes (100 per cent) with PM. There was an elevated retinal papillomacular fold in six eyes (60 per cent) and intraretinal cystoid spaces in two eyes (20 per cent) with PM. The inner retinal layers were thicker in PM. On multicolour imaging, foveal avascular zone and retinal wrinkles were identified in eyes with retinal papillomacular fold in blue and green reflectance images. Perifoveal vascular changes in optical coherence tomography angiography included foveal area size reduction in superficial and deep vascular networks. The foveal capillary vessel densities were higher in PM compared to the controls in both superficial (46.3 ± 3.7 per cent; p = 0.000) and deep (54.7 ± 3.5 per cent; p = 0.000) capillary plexuses. Flow areas in superficial (p = 0.693) and deep (p = 0.088) capillary plexuses were not statistically relevant.ConclusionThe study suggests that in PM, retinal foreshortening occurs in one meridian leading to secondary changes such as loss of foveal dip, posterior bowing of the outer layers of the eye, thickening of the inner retina and ultimately, retinal papillomacular fold formation. The findings of the study need further validation in a larger series of patients with PM.

Automated quantification of foveal avascular zone and vascular density in Behçet's disease.

To measure the vascular density (VD) and foveal avascular zone (FAZ) area in patients with Behçet's disease (BD) obtained by optical coherence tomography angiography (OCTA). VD and FAZ area in the deep and superficial retinal vascular networks were measured in all eyes. Thirty BD and 31 control subjects were included in the study. The mean overall VD measured in the entire scan was lower in BD compared with control group in both the superficial (49.52 ± 6.54 vs 53.57 ± 2.87%, respectively; p = 0.003) and deep (53.44 ± 7.44 vs 58.41 ± 3.01%, respectively; p = 0.002) areas. The FAZ in the BD group was significantly increased at the level of the superficial (0.52 ± 0.67 vs 0.28 ± 0.1mm2, respectively; p = 0.05) and deep (0.91 ± 1.25 vs 0.39 ± 0.14mm2, respectively; p = 0.024) areas compared with those of the control group. The deep and the superficial FAZ areas were positively correlated with disease duration and negatively with VA. In the patients with BD, OCTA showed decreased VD in both the superficial and deep retinal vascular networks. Besides, the VA was correlated with the VD and FAZ.

Anatomic basis and clinical application of perforator flap thinning of posterior tibial artery

Objective To explore the anatomic basis of the thinning of the free posterior tibial artery perforator flaps and the clinical effect of repairing wound on hand or foot due to trauma. Methods From November, 2016 to December, 2017, 10 cases of lower extremity cadaver specimens perfused with red ralex were dissected, which were perfused through the amputated femoral artery. Five of them were left and the rest were right. All cases were males. The number, diameter, branches and distribution of the perforator was observed. From September, 2012 to September, 2017, there were 13 cases of clinical application, which were 5 cases of hand wound and 8 cases of foot wound. The size of the wound was 3.0 cm × 2.0 cm to 6.0 cm × 4.0 cm, and the flap area was 3.5 cm × 2.2 cm to 6.5 cm × 4.5 cm. The repairing procedure was suitable for the wound associated with tendon, bone, joint capsule exposure. Results The number of posterior tibial artery perforating branches that more than 0.50 mm in diameter was 4 to 6, and the mean diameter was (0.87±0.26) mm. The perforating branch penetrated into the fat layer and was divided into 3 layers of vascular network: deep fat vascular network, superficial fat vascular network and subdermal vascular network. The perforating branch was located according to the positional relationship from deep to shallow, and vessel diameter become smaller step by step. The perforating branch trunk gave off branches to the deep vascular network, and the superficial vascular network had the same origin or shared with the deep blood vessels. The subdermal vascular network issued from the superficial vascular network or directly from the perforating branch trunk. There was no or few communicating branch between the deep vascular network and superficial ones, besides the vessel pedicle. So trimming deep fat layer will not affect the blood supply of superficial vascular network and neither will affect the flap blood supply. Most of the deep fat tissue was trimmed in 13 cases. The superficial and subdermal fat vascular network was preserved, and the same to the trunk and branches of the pedicle. All the flaps survived. Of which, 1 appeared arterial crisis on the 2nd day after operation, and relieved by the local injection of papaverine. There was 1 case of venous crisis on the 3rd day, and improved by stitches, local release of congestion. Followed-up time was ranged from 2 to 12 months. All flaps were soft with good blood supply and good appearance, and did not need a second thinning surgery. Flaps restored the protective feeling 6 months later. Conclusion The microdissection of perforator flap of posterior tibial artery provides a theoretical basis for the perforator flap thinning, and the thinning of perforator flap is a good method to repair the appearance and function of the wound after foot and hand injuries. Key words: Posterior tibial artery perforator flap; Applied anatomy; Wound; Repair; Microsurgical operation

Anatomical basis of the V-Y advancement flap based on the dorsal carpal perforators

Objective To provide anatomical basis for the design of the V-Y advancement flap and investigate the morphological characters of the dorsal carpal perforators. Methods From August, 2017 to October, 2018, 30 sides adult specimens of hand were perfused with red latex. The following contents were observed under surgical magnifier: ①The origin, courses, branches, and distribution of the dorsal carpal perforators. ②The characters of dorsal carpal perforators in agreement with the antebrachial and dorsal metacarpal vascular net. Results The dorsal carpal vascular network was composed of deep vascular network (bone and joint network) and superficial vascular network (fasciocutaneous network). The deep vascular network was located at the deep aspect of the extensor tendons and was commonly formed by dorsal carpal branch of radial artery, dorsal carpal branch of anterior interosseous artery, ascending branch of the dorsal carpal perforator from the deep palmar arch, and dorsal carpal branch of ulnar artery. The superficial vascular network was located on the surface of the extensor tendons and was mainly formed by dorsal carpal branch of radial artery, dorsal carpal branch of ulnar artery, dorsal carpal branch of anterior interosseous artery, radial and ulnar myocutaneous branches of posterior interosseous artery, and the perforators from the deep vascular network. The 3rd and 4th perforators puncturing out from the ulnar and radial margins of the extensor tendon had a constant occurrence rate (100%) with an outer diameter of (0.7±0.3) mm and (0.6±0.2) mm, respectively, and a length of (1.1±0.4) cm and (0.9±0.4) cm, respectively. They were divided into the ascending branch, descending branch, and collateral branch. And finally anastomosis with antebrachial and dorsal metacarpal perforators. Conclusion The V-Y advancement flap based on the dorsal carpal perforators can be a good choice for restoring the dorsal metacarpal defects. Key words: The dorsal carpal perforators; Perforator flap; Advancement flap; Applied anatomy

OCT‐angiography: deep irregular vascular network predictor of neovascular complication in angioid streaks

OCT‐angiography: deep irregular vascular network predictor of neovascular complication in angioid streaks

Association Between Optic Nerve Head Deformation and Retinal Microvasculature in High Myopia

To evaluate the retinal microvasculature of peripapillary and macular regions in highly myopic eyes and investigate the association between the vascular parameters and optic nerve head (ONH) deformation. Cross-sectional study. Seventy-one subjects with highly myopic eyes and 26 subjects with emmetropic eyes were included. Horizontal B-scan images of the ONH were obtained using optical coherence tomography (OCT) and horizontal tilt angles were measured. Integrated automated algorithms in the Avanti OCT angiography were used to quantify the peripapillary vessel density and area of the foveal avascular zone (FAZ) at the level of superficial and deep vascular networks. Association between horizontal disc tilt and the vascular parameters was evaluated. The mean axial length and horizontal tilt angle were 26.73 ± 0.63mm and 9.77 ± 3.00 degrees in the highly myopic group and 23.46 ± 0.55mm and 5.95 ± 3.48 degrees in the emmetropic group, respectively. Highly myopic eyes exhibited significantly lower average peripapillary vessel density (P= .010) and larger superficial and deep FAZs (P= .001 and P < .001, respectively) compared with emmetropic eyes. Linear regression analyses showed that horizontal tilt angle significantly correlated the average peripapillary vessel density (P= .037) and the areas of superficial (P<.001) and deep (P < .001) FAZs. The retinal microvasculature was significantly different in highly myopic eyes according to the degree of horizontal optic disc tilt. In addition to peripapillary vessel density, FAZ can be affected by the degree of optic disc tilt.

Quantification of Diabetic Macular Ischemia Using Optical Coherence Tomography Angiography and Its Relationship with Visual Acuity

To quantify foveal avascular zone (FAZ) area and macular vascular density objectively using optical coherence tomography angiography (OCTA) and to examine correlations with visual acuity in eyes with diabetic retinopathy (DR) in the absence of diabetic macular edema. Retrospective observational case series. Eighty-four eyes from 55 patients with DR and 34 control eyes from 27 age-matched healthy participants. All eyes underwent OCTA (RTVue-XR Avanti; Optovue, Inc, Fremont, CA). Integrated automated algorithms were used to quantify FAZ area and macular vascular density. FAZ area, vessel area density (VAD), vessel length density (VLD), and visual acuity. In each study eye, DR was classified as mild nonproliferative DR (NPDR; n= 32 [38%]), moderate-to-severe NPDR (n= 31 [37%]), or proliferative DR (n= 21 [25%]). Mean FAZ area was greater in diabetic eyes compared with control eyes both in the superficial (0.427 mm2 vs. 0.275 mm2; P < 0.001) and deep (0.616 mm2 vs. 0.372 mm2; P < 0.001) vascular networks. Mean VAD was lower in diabetic eyes compared with control eyes in both the superficial (49.44% vs. 55.09%; P < 0.001) and deep (56.65% vs. 61.32%; P < 0.001) networks. Mean VLD was also lower in diabetic eyes compared with control eyes in both the superficial (17.68mm-1 vs. 21.55 mm-1; P < 0.001) and deep (21.19 mm-1 vs. 24.38 mm-1; P < 0.001) networks. In all eyes, there was a statistically significant negative correlation between the logarithm of the minimum angle of resolution (logMAR) visual acuity and the vascular density in both the superficial (VAD, ρ=-0.52; VLD, ρ=-0.54; P < 0.001) and deep (VAD, ρ=-0.50; VLD, ρ=-0.50; P < 0.001) networks. A positive correlation was found between logMAR visual acuity and FAZ area in both the superficial (ρ= 0.29; P<0.01) and deep (ρ= 0.48; P < 0.001) networks. Automated quantitative algorithms allow for objective assessment of retinal vascular changes in eyes with DR that are correlated to visual acuity. These methods may prove useful in monitoring disease progression and identifying parameters that affect visual function.