Deep Vascular Plexus Research Articles

Comparison of Vessel Density and Retinal Sensitivity After Scleral Buckling and Phacovitrectomy in the Management of Macula-on Primary Rhegmatogenous Retinal Detachment.

The choice of surgical method for rhegmatogenous retinal detachment (RRD) may have a significant impact on the retina. In this study, we aimed to compare retinal function and structure after scleral buckling (SB) and phacovitrectomy (phaco-PPV) for macula-on RRD. This cross-sectional study included patients who underwent anatomically successful repair of macula-on RRD managed with SB (n=35) and phaco-PPV (n=35) between 2019-2023. All participants were examined within 6-20 months of surgery to evaluate the retinal structure using spectral domain optical coherence tomography (SD-OCT) and vessel density (VD) by OCT angiography (OCTA). Best-corrected visual acuity (BCVA) and microperimetry (MP) tests were used to assess the retinal function. Analysis of the microvascular network with OCTA between eyes after surgery and healthy eyes showed a decrease in VD. Significant changes in the superficial vascular plexus (SVP) and deep vascular plexus (DVP) were observed only in eyes after SB surgery (p <0.001 and p=0.02, respectively). Analysis of retinal function assessed by MP showed a significant decrease (p<0.05) in retinal sensitivity after phaco-PPV (24.81±2.25 dB) and SB (24.18±2.14 dB) operations compared to the healthy control group (25.97 ± 1.51 dB), whereas postoperative BCVA showed no differences (p>0.05). Changes in retinal sensitivity were accompanied by impairment of the microvascular network in the eyes after SB and phaco-PPV surgeries due to macula-on RRD. Disorders were more pronounced in eyes following SB surgery, possibly secondary to mechanical stress.

Optical coherence tomography (OCT) and OCT Angiography in Stages 3 and 4 proliferative sickle cell retinopathy

PurposeTo investigate macular findings in Goldberg stages 3 and 4 proliferative sickle cell retinopathy (PSCR) using optical coherence tomography (OCT) and OCT Angiography MethodsA case-control study using retrospective OCT and OCTA data from PSCR eyes (cases) and prospective data from age and sex-matched normal (controls). OCTA data included vessel density (VD) in the superficial capillary vascular plexus (SCP) and deep capillary vascular plexus (DCP), foveal avascular zone (FAZ) characterization, including the shape (in the SCP & DCP), size (area covered), and perimeter. OCT data were whole, superior, and inferior hemi-retina thickness for the superficial and deep retina. ResultsThere were 38 OCT / OCTA scans of PSCR eyes of 21 SCD patients; ten eyes were excluded for not meeting inclusion criteria. We analyzed nineteen (19) patients (ten unilateral and 9 bilateral), 28 eyes, nine SS eyes (32%), and nineteen SC eyes (68%). The controls consisted of 29 eyes of 16 normal subjects (three unilateral and 13 bilateral). The commonest FAZ shape in PSCR was “irregular” in 14 eyes (50%), followed by “round” in 11 eyes (39.3%) versus controls, the commonest shape “round” in 18 eyes (62%), followed by “irregular” 9 eyes (31%) (p = 0.165). FAZ area and perimeter were larger in PSCR (p > 0.05). The deep and superficial VD was reduced in PSCR. The mean whole deep VD for cases was 48.9 ± 6.1 versus 52.9 ± 6.4 for controls (p = 0.019). Mean whole superficial VD for cases was 47.4 ± 5.5 versus 49.8 ± 3.4 for controls (p = 0.058).Retina thickness in the whole, superior and inferior hemi-retina, for superficial and deep retina, was higher in PSCR compared to controls (p < 0.05). Superficial whole thickness for cases and controls were 287.0 µm [IQR 35.3 µm] versus 273.0 µm [IQR 18 µm] respectively (p = 0.008). Deep whole thickness for cases and controls was 287.0 µm [IQR 35.25 µm] versus 273.0 µm [IQR 18 µm] (p = 0.008).VD was reduced in SS compared to SC eyes (deep whole VD: 50.28 ± 6.01 vs 46.78 ± 5.80) (p = 0.139). Retina thickness in SS was reduced relative to SC. Peripheral retinal laser photocoagulation did not affect VD, though it was associated with a thinner macula. ConclusionOCT/OCTA of stage 3 and 4 PSCR revealed reduced VD in the DCP and SCP. Despite the thin temporal retina in SCD, there is a thicker whole, superior, and inferior hemiretina in both the superficial and deep retina. An irregularly shaped FAZ is common, a reflection of abnormal microcapillary loss in the perifoveal area.

Associations between the Vessel Density in Deep Vascular Plexus and Macular Edema Recurrences in Patients with Retinal Vein Occlusion

Introduction: The aim of this study was to study the relationships between vessel density (VD) in different retinal vascular plexus and retinal vein occlusion-macular edema (RVO-ME) recurrence using wide-field swept source optical coherence tomography angiography (OCTA). Methods: Patients with a history of central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO) with macular edema in the Department of Ophthalmology, Shanghai General Hospital, from May 25, 2020, to January 12, 2023, were retrospectively reviewed and recruited. All patients were followed up for at least 6 months and divided in the release group and the recurrence group. The optical coherence tomography and OCTA examination were performed. Demographics, retinal structural, and angiographic data were collected and compared between two groups. The ordinal logistic regression was performed to assess the risk factors for RVO-ME. Results: A total of 85 patients were enrolled in this study. Among them, 30 patients had CRVO, while 55 had BRVO. The VD in the 6–9 mm ring in deep vascular plexus (DVP) was significantly higher in the recurrence group (25.414 ± 6.068% in the release group vs. 27.574 ± 7.767% in the recurrence group, p = 0.036). More patients with mean VD of the 6–9 mm ring in DVP no less than 30% were observed in the recurrence group (observed n = 20, expected n = 14.4, p = 0.043). The ordinal logistic regression reported that patients with mean VD of the 6–9 mm ring in DVP ≥30% had risk of RVO-ME increased to 11.508 (95% CI: 1.745–75.944, p = 0.011), when compared to the patients with mean VD of the 6–9 mm ring in DVP <20%, even with RVO type, baseline central macular thickness weighed. Conclusion: High vessel density of the 6–9 mm ring in DVP, especially those ≥30%, was associated with macular edema recurrences in patients with retinal vein occlusion.

Neuronal and glial cell alterations involved in the retinal degeneration of the familial dysautonomia optic neuropathy.

Familial dysautonomia (FD) is a rare genetic neurodevelopmental and neurodegenerative disorder. In addition to the autonomic and peripheral sensory neuropathies that challenge patient survival, one of the most debilitating symptoms affecting patients' quality of life is progressive blindness resulting from the steady loss of retinal ganglion cells (RGCs). Within the FD community, there is a concerted effort to develop treatments to prevent the loss of RGCs. However, the mechanisms underlying the death of RGCs are not well understood. To study the mechanisms underlying RGC death, Pax6-cre;Elp1loxp/loxp male and female mice and postmortem retinal tissue from an FD patient were used to explore the neuronal and non-neuronal cellular pathology associated with the FD optic neuropathy. Neurons, astrocytes, microglia, Müller glia, and endothelial cells were investigated using a combination of histological analyses. We identified a novel disruption of cellular homeostasis and gliosis in the FD retina. Beginning shortly after birth and progressing with age, the FD retina is marked by astrogliosis and perturbations in microglia, which coincide with vascular remodeling. These changes begin before the onset of RGC death, suggesting alterations in the retinal neurovascular unit may contribute to and exacerbate RGC death. We reveal for the first time that the FD retina pathology includes reactive gliosis, increased microglial recruitment to the ganglion cell layer (GCL), disruptions in the deep and superficial vascular plexuses, and alterations in signaling pathways. These studies implicate the neurovascular unit as a disease-modifying target for therapeutic interventions in FD.

Evaluation of Long-term Posterior Segment Parameters in Children Who Had Recovered From Multisystem Inflammatory Syndrome.

To evaluate long-term posterior segment findings in children recovering from multisystemic inflammatory syndrome (MIS-C) associated with severe acute respiratory syndrome coronavirus 2. Our study included 22 patients who were admitted to an intensive care unit with a diagnosis of MIS-C between November 2021 and March 2022, and 25 healthy controls. The study included pediatric patients who had an eye examination an average of 12.35 ± 2.18 months after recovery from MIS-C. Detailed eye examinations and measurements of all participants were obtained retrospectively from patient files. Posterior segment parameters were measured using swept-source optical coherence tomography (OCT) and OCT-angiography (OCT-A); these parameters included peripapillary retinal nerve fiber layer (pRNFL) thickness, central macular thickness (CMT), subfoveal choroidal thickness (SCT), macular vascular densities (VD), and foveal avascular zone (FAZ) area. Mean age was 9.7 ± 3.6 years in the MIS-C group and 10.6 ± 2.8 years in the healthy control group (P = 0.316). There were no statistically significant differences between the MIS-C group and the healthy control group in terms of pRNFL thickness, CMT, and SCT. However, in the MIS-C group, the macular superficial vascular plexus and deep vascular plexus showed significantly lower VD in the superior, inferior, nasal, and temporal quadrants compared to the healthy controls (P < 0.05 for all). A comparison of the superficial and deep FAZ area parameters of both groups showed no statistically significant difference (P > 0.05). We showed that patients who had recovered from MIS-C had retinal vascular damage at the long-term follow-up. Following up with these patients after recovery with OCT and OCT-A, which are noninvasive methods commonly used in the detailed evaluation of the posterior segment of the eye, could be beneficial for understanding the long-term effects of MIS-C on retinal microvasculature. [Ophthalmic Surg Lasers Imaging Retina 2024;55:518-526.].

Vessel density, macula thickness and foveal avascular zone measurements in young African adults with moderate myopia: A pilot study.

The aim of this study was to investigate the association between macula thickness and vessel density in African myopic and emmetropic eyes through the use of Spectral Domain Optical Coherence Tomography (OCT). The study population comprised African adults aged 18-35 years old. The study was conducted at a University eye clinic located in Durban, South Africa. Purposive sampling was utilised to obtain 59 participants of whom 24 were myopes and 35 were emmetropes. Vessel density (VD), foveal avascular zone (FAZ) and retinal thickness (RT) were obtained using the Heidelberg Spectralis OCT with angiography. Thereafter, a multivariate linear regression was used to investigate associations between the spherical equivalent myopic refractive error and VD, FAZ and RT for the myopic group only. Myopic participants had a mean spherical equivalent (MSE) and standard deviation (SD) of -4.79 D (1.27) while the emmetropic group had an MSE (SD) of -0.32 D (0.46). Both superficial and deep VD were significantly decreased at the central fovea (radius (r) = 0.4 mm), peri-foveal (r = 1.10-1.45 mm) and para-foveal (r = 0.75-1.10 mm) sectors in myopes when compared with emmetropes. Myopes showed a significant reduction in RT in the inner retinal layer across the inferior and temporal zones of the peri-foveal region as well as the inferior and temporal zones of the para-foveal region when compared with emmetropes. A significantly smaller FAZ was found at both the superficial and deep vascular plexuses (p < 0.001). In African myopes, significant associations were not found between MSE and VD or FAZ and macula retinal thickness. Retinal vascular and thickness reduction may occur in young African adults with moderate myopia. A broad-based study targeting VD and IRT in African myopes is proposed to confirm preclinical myopic macula disruptions in adults of African ethnicity. OCT angiography should be considered when monitoring progressive myopia.

OCTA-based research on changes of retinal microcirculation in digestive tract malignancy

PurposeThis cross-sectional study measured retinal vessel density (VD) in patients with digestive tract malignancy by optical coherence tomography angiography (OCTA), and compared them with healthy controls to explore the retinal microcirculation changes in patients with digestive tract malignancy. Methods106 eligible participants were divided into three groups: gastric cancer (GC) group (36 individuals), colorectal cancer (CRC) group (34 individuals), and healthy control group (36 individuals). Angio 6 × 6 512 × 512 R4 and ONH Angio 6 × 6 512 × 512 R4 modes were performed to collect retinal vessel density data centered on fovea and papillary, respectively. The retina was automatically segmented into different layers (superficial vascular plexus (SVP), the inner retinal layer, radial peripapillary capillary plexus (RPCP), deep vascular plexus (DVP)) and areas to analyze. ResultsAt the optic nerve head (ONH) region, the VD of the inner retinal layer increased in both GC and CRC groups in all quadrants and areas. In the papillary area, VD in the inner retinal layer, SVP, and RPCP increased in the GC and CRC groups. In the parapapillary area, VD in the inner retinal layer increased in the GC and the CRC groups. Significant increase in the global VD were found in the GC group of the RPCP and SVP. Regarding the macular region, no statistical differences were observed in each layer. ConclusionsThe study suggested that retinal vessel density changed in patients with digestive tract malignancy, especially in the inner retinal layer of the ONH region, revealing the potential relevance of the relation between gastrointestinal cancer and retinal microcirculation.

OCT Angiography of the Retina and the Choroid in the Macula in Patients with Normal Tension Glaucoma and Primary Open Angle Glaucoma.

The aim of this study was to compare vessel density (VD) in the retina and choroid in eyes with primary open angle glaucoma (POAG), normal tension glaucoma (NTG) and controls. Patients with POAG, NTG and controls underwent OCT scanning of the macula and the disc followed by 6 × 6 mm macula OCT angiography (OCTA) imaging. Global and hemifield VD were recorded for the superficial (SVP) and deep (DVP) vascular plexus and the choriocapillaris (CC). The OCT thickness of the nerve fiber layer (NFL) and ganglion cell layer (GCC) was also measured. Data from 65 POAG, 33 NTG and 40 control eyes matched for age were analyzed. Mean SVP VD was lower in NTG and POAG eyes compared to controls (38.8 ± 5.3, 40.7 ± 6.8 and 48.5 ± 4.0%, p < 0.001). Mean DVP VD was lower in NTG and POAG eyes compared to controls (43.1 ± 6.1, 44.5 ± 7.6 and 48.6 ± 5.8%, p = 0.002). There was no difference in SVP VD or DVP VD between the glaucoma groups (p > 0.050). No difference was noted in CC VD between the groups (68.3 ± 2.3, 67.6 ± 3.7 and 68.5 ± 2.6%, p = 0.287). Lower SVP and DVP VD was seen in eyes with glaucoma compared to normal eyes. NTG and POAG eyes had similar VD loss. Eyes with glaucoma manifested similar CC VD compared to controls.

Spatially resolved imaging of human macular capillaries using adaptive optics-enhanced optical coherence tomography angiography

Documenting the organization of the retinal capillaries is of importance to understand the visual consequences of vascular diseases which may differentially affect the microvascular layers. Here we detailed the spatial organization of the macular capillaries in ten healthy human subjects using a prototypic adaptive optics-enhanced optical coherence tomography angiography (AO-OCTA) system. Within the central 6° × 6°, the radial peripapillary capillaries and the superficial, intermediate and deep vascular plexuses (SVP, IVP and DVP, respectively) were consistently resolved. In 8 out of the 10 eyes, the capillary segments composing the perifoveal arcade (PFA) were perfused only by the SVP, while drainage of the PFA showed more variability, comprising a case in which the PFA was drained by the DVP. Around the center, a distinct central avascular zone could be documented for each layer in 7 of the 10 cases; in three eyes, the IVP and SVP merged tangentially around the center. In all eyes, the foveal avascular zone was larger in the DVP than in the SVP and IVP. In one eye with incomplete separation of the inner foveal layers, there was continuity of both the SVP and the IVP; a central avascular zone was only present in the DVP. The diversity of perfusion and drainage patterns supported a connectivity scheme combining parallel and serial organizations, the latter being the most commonly observed in perifoveal vessels. Our results thus help to further characterize the diversity of organization patterns of the macular capillaries and to robustly analyze the IVP, which will help to characterize early stages of microvascular diseases.

Macular perfusion, thickness, and sensitivity in phacovitrectomy versus lens-sparing vitrectomy in rhegmatogenous retinal detachment

Purpose The aim of this study was to compare phacovitrectomy (phacoPPV) to lens-sparing pars plana vitrectomy (PPV) with respect to macular perfusion, thickness, and sensitivity in phakic patients with rhegmatogenous retinal detachment. Patients and methods This is a prospective, comparative, nonrandomized, interventional study that included 31 phakic eyes with primary rhegmatogenous retinal detachment. The patients were divided into two groups according to the preoperative lens status: group A who had significant cataract and group B who did not have significant cataract. Group A included 17 eyes for which phacoPPV was performed, while group B included 14 eyes for which lens-sparing PPV was performed. All patients were preoperatively evaluated clinically and with A-scan ultrasonography and were followed up for 4 months after surgery. Optical coherence tomography angiography (OCTA) and microperimetry were done at 2 and 4 months, postoperatively. Results The OCTA showed that the lens-sparing PPV was associated with significantly larger foveal avascular zone area (0.4±0.2 mm2) compared to the phacoPPV (0.2±0.1 mm2) at 2 months (P=0.048), as well as at 4 months (0.4±0.1 mm2vs. 0.2±0.1 mm2, respectively, P=0.044). However, the foveal avascular zone perimeter showed no statistically significant differences between the two groups at 2 and 4 months postoperatively. At 2 months, the deep vascular plexus (DVP) parafoveal vessel density was statistically significantly higher in the phacoPPV group (47.9±4.7%) compared to the PPV group (36.4±11.9%) (P=0.048), while at 4 months it was the DVP foveal vessel density that showed a significantly higher mean in the phacoPPV group (35.4±11.9%) compared to the PPV group (20.3±16.1%) (P=0.036). No other statistically significant intergroup differences were found with respect to other parameters for macular perfusion, and other DVP parameters. Similarly, the macular sensitivity, as well as the ganglion cell complex, and the central subfield thicknesses were comparable between the two groups. The visual outcome was also comparable at 2 and 4 months between the two groups. Conclusion PhacoPPV and lens-sparing vitrectomy were comparable with respect to OCTA, microperimetry, and visual acuity. The limited differences are too preliminary and the decision to do phacoPPV rather than lens-sparing PPV needs to be based on other determinants like the presence of preoperative lens opacity.

Variability of scan quality and perfusion density in longitudinal optical coherence tomography angiography imaging

Background/aimsOptical coherence tomography angiography (OCT-A) images are subject to variability, but the extent to which learning impacts OCT-A measurements is unknown. We determined whether there is a learning effect in...

Characteristics of Retinal Vascular Degeneration and the Expression of Vessel-Related Claudin Proteins in Retinal Degeneration Mouse.

This study aimed to investigate the characteristics of retinal vascular degeneration and the expression of vessel-related claudin (CLD) proteins in retinal degeneration mouse (Pde6βrd1/rd1 rd1 mouse). Retinas from wild-type (WT) mice and rd1 mice at postnatal day 3 (P3), P5, P8, P11, P13, P15, P18, and P21 were collected. Immunofluorescence staining was used to assess the retinal vascular plexus, cell proliferation, CLD expression, and retinal ganglion cells (RGCs). The distribution of retinal superficial and deep vessels was determined by isolectin B4 fluorescence staining of retinal flat mounts and frozen sections. Hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dNTP nick-end labeling were used to investigate retinal histological degeneration and apoptosis in rd1 mice, respectively. Quantitative real-time PCR and Western blot were used to measure the expression of vessel-related CLD-1, -2, -3, and -5, vascular endothelial growth factor A (VEGFA), and vascular endothelial growth factor receptor 2 (VEGFR2) in the retinas. Compared to the WT mice, the rd1 mice displayed delayed but completed progressive development in the retinal superficial vascular plexuses (SVPs) and deep vascular plexuses (DVPs). In the rd1 mice, the thickness of retinal layers gradually decreased and the retinas underwent progressive atrophy and degeneration. The deterioration got worse at the late developmental stage. The declined vessel density of SVP and DVP correlated with the decreased thickness of the full and inner parts of the retina and the reduced number of RGCs. DVP degeneration and the thinning of the outer nuclear layer exhibited an obvious reduction at P15. The expression levels of CLD-1, CLD-2, CLD-3, CLD-5, VEGFA, and VEGFR2 decreased and were consistently lower in the rd1 mice than in WT mice since P15. Rd1 mice exhibited progressive vascular degeneration of retinal SVP and DVP, the thinning and atrophy of retinal ONL and RGC, and the downregulation of vessel-related CLD proteins during the late developmental period. Thus, the rd1 mouse is a useful model of not only retinal neuro-degeneration but also retinal vascular degeneration.

The retina's neurovascular unit: Müller glial sheaths and neuronal contacts.

The neurovascular unit (NVU), comprising vascular, glial and neural elements, supports the energetic demands of neural computation, but this aspect of the retina's trilaminar vessel network is poorly understood. Only the innermost vessel layer - the superficial vascular plexus (SVP) - is ensheathed by astrocytes, like brain capillaries, whereas glial ensheathment in other layers derives from radial Müller glia. Using serial electron microscopy reconstructions from mouse and primate retina, we find that Müller processes cover capillaries in a tessellating pattern, mirroring the tiled astrocytic endfeet wrapping brain capillaries. However, gaps in the Müller sheath, found mainly in the intermediate vascular plexus (IVP), permit different neuron types to contact pericytes and the endothelial cells directly. Pericyte somata are a favored target, often at spine-like structures with a reduced or absent vascular basement lamina. Focal application of adenosine triphosphate (ATP) to the vitreal surface evoked Ca2+ signals in Müller sheaths in all three vascular layers. Pharmacological experiments confirmed that Müller sheaths express purinergic receptors that, when activated, trigger intracellular Ca2+ signals that are amplified by IP3-controlled intracellular Ca2+ stores. When rod photoreceptors die in a mouse model of retinitis pigmentosa (rd10), Müller sheaths dissociate from the deep vascular plexus (DVP) but are largely unchanged within the IVP or SVP. Thus, Müller glia interact with retinal vessels in a laminar, compartmentalized manner: glial sheathes are virtually complete in the SVP but fenestrated in the IVP, permitting direct neural-to-vascular contacts. In the DVP, the glial sheath is only modestly fenestrated and is vulnerable to photoreceptor degeneration.

Clinical Implications of Alternating Hypointense Bands on OCT Angiography in Retinal Vascular Occlusive Disease

PurposeTo demonstrate the relationship between alternating hypointense signal bands on optical coherence tomography-angiography (OCTA), real-time fluorescein angiography (FA), and structural OCT findings in patients with retinal vascular occlusive disease (RVOD). DesignRetrospective, consecutive case series. SubjectsConsecutive patients with a clinical diagnosis of acute RVOD and alternating bands of hypointense OCTA flow signal on en face projections. MethodsComplete ophthalmic examination and multimodal imaging, including color fundus photography (CFP), real-time FA, SD-OCT, and OCTA performed with different instruments having different scan speeds and acquisition protocols. Main Outcome MeasurementsThe primary outcomes were: Hypointense OCTA band characteristics (number, width, orientation, and location), OCTA acquisition characteristics (speed and scan direction), and FA findings including delayed arteriovenous (AV) transit and pulsatile flow. Secondary outcomes were: Structural OCT changes including retinal fluid, paracentral acute maculopathy lesion (PAMM), and a prominent middle limiting membrane (p-MLM) sign. ResultsOCTA-hypointense bands were detected in the superficial and deep vascular plexuses in 9 eyes of 9 patients with either partial CRAO or nonischemic RVO. When obtained on the same device, hypointense bands were thinner and more numerous at lower (100 kHz) scan speeds compared with higher (200 kHz) scan speeds. Band orientation was parallel to the OCTA scan direction, and their extent correlated with the area of delayed AV transit on FA. Structural OCT showed multiple PAMM lesions in 78% of cases and a p-MLM sign centered in the fovea in 44% of cases. ConclusionsOCTA-hypointense bands are a novel biomarker in RVOD indicating delayed AV transit and pulsatile filling without the need for dye angiography. Structural OCT often shows PAMM in these eyes, and less commonly, a p-MLM sign.

Optical Coherence Tomography Angiography Changes in Patients Diagnosed With Acute Coronary Syndrome: A Systematic Review and Meta-Analysis.

We conducted a systematic review and meta-analysis to assess the association between optical coherence tomography angiography (OCTA) parameters and acute coronary syndrome (ACS). Two independent reviewers searched the electronic databases (MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, Embase (Excerpta Medica Database), Cochrane Library, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform) from inception until April 2023. According to the inclusion criteria of this review, eligible were observational studies, randomized control trials, and registry/database studies that included the eyes of adult ACS patients and assessed OCTA parameters within the macula. The pooled standardized mean differences (SMD) between patients diagnosed with ACS and healthy controls with a confidence interval (CI) of 95% were calculated using the Hartung-Knapp-Sidik-Jonkman random-effects method. The heterogeneity was assessed by I2 and the Cochran Q and a random effects model was applied. Seven studies were eligible and included in our systematic review (n = 898), of which three were included in the meta-analysis (n = 341). The pooled SMD in the superficial vascular plexus (SVP), deep vascular plexus (DVP), and foveal avascular zone (FAZ) were -0.46 (95% CI: -0.94 to 0.01, p = 0.05, I2 = 0%, three studies), -0.10 (95% CI: -3.20 to 3.00, p = 0.75, I2 = 67%, two studies), and 0.43 (95% CI: -1.22 to 2.09, p = 0.38, I2 = 92%, three studies), respectively. Our findings suggest that there are no differences in OCTA metrics between ACS patients and healthy individuals.

Decreased retinal capillary density as a beneficial response to 24-week high-speed circuit resistant training in healthy older adults

PurposeTo determine the changes in retinal microvascular density after a 24-week high-speed circuit resistance training program (HSCT) in healthy older adults. MethodsThirty healthy older adults were recruited and randomly assigned to either a training group (HSCT) or a non-training (CON) group. Fifteen subjects (age 73.3 ± 7.76 yrs) in the HSCT group exercised three times per week on non-consecutive days for 24 weeks. Fifteen subjects in the CON group (age 72.2 ± 6.04 yrs) did not have formal physical training. Both eyes of each subject were imaged using optical coherence tomography angiography (OCTA) at baseline and at the 24-week follow-up. The vessel densities of the retinal vascular network (RVN), superficial vascular plexus (SVP), and deep vascular plexus (DVP) were measured. ResultsThere were no demographic differences between the study groups. There were significant decreases in the retinal vessel densities of RVN, SVP and DVP in the HSCT group (P < 0.05). However, there were no significant changes in all three vascular measurements in the CON group (P > 0.05), although the changes showed a decreasing trend. The decreased vessel densities were doubled in the HSCT group in comparison to the CON group. However, the differences between groups did not reach a significant level (P > 0.05). ConclusionsThis is the first study to reveal the decreased retinal vessel densities as a possible imaging marker for the beneficial effects of the 24-week HSCT program in older adults.

Оценка клинической эффективности нового способа адаптивного управления инфузией при факоэмульсификации

Reduction of the adverse effects of intraoperative intraocular pressure fluctuation referred to as post-occlusion surge on the intraocular structures is an important task for ensuring phacoemulsification safety. In this regard, the method to control infusion during phacoemulsification based on controlling the infusion and aspiration flow rates in combination with monitoring of vacuum parameters was developed. The study was aimed to provide comparative assessment of clinical and functional characteristics of the eye in patients after phacoemulsification using the new and already existing adaptive infusion control methods. A total of 38 patients aged 66.4 ± 7.8 years (15 males and 23 females) in the index group (Optimed Profi system with the use of new method) and 35 patients aged 68.7 ± 7.5 years (16 males and 19 females) in the control group (Centurion Vision System with Active Fluidics) underwent surgery due to cataract. The patients underwent comprehensive eye examination before surgery and on days 1, 7, 30, months 3, 6 after surgery. The smaller loss of corneal endothelial cells on months 3 and 6 after surgery was observed in patients of the index group with grade III and IV cataract (p &lt; 0.05). Comparison of macular microcirculation parameters revealed the reduced FAZ area by month 6 of postoperative follow-up in the index group, along with the increased total vascular density of the deep vasculature (p &lt; 0.001). A significant decrease in the total density of the superficial and deep vascular plexuses by month 6 of postoperative follow-up was observed in the control group (p &lt; 0.05). The use of new adaptive infusion control method contributes to effective phacoemulsification of cataracts of varying density with the lower percentage of the corneal endothelial cells lost in the late postoperative period.

The characteristics of acute macular neuroretinopathy following COVID-19 infection

BackgroundIn this study, we report a case series of acute macular neuroretinopathy (AMN) associated with COVID-19 infection.MethodsThis retrospective observational study was conducted at Beijing Tongren Hospital. We reviewed patients who were diagnosed with AMN within one month of testing positive for COVID-19 using real-time reverse transcription-polymerase chain reaction (RT-PCR).ResultsA total of 11 AMN patients (20 eyes) were included in the study. The mean age was 33.8 ± 12.6 years. The average interval between a positive COVID-19 PCR test and the onset of ocular symptoms was 2.8 ± 2.5 days. The mean follow-up period for the patients was 12.5 ± 3.8 weeks. Imaging characteristics of AMN patients following COVID-19 infection included areas of low reflectivity on near-infrared reflectance (NIR) imaging, hyperreflective lesions at the level of the outer plexiform layer (OPL) and outer nuclear layer (ONL) and disruption of the ellipsoid zone (EZ) on spectral domain optical coherence tomography (SD-OCT) B-scans. Visual field examinations revealed parafoveal scotomas that closely corresponded to the clinical lesions. Optical coherence tomography angiography (OCT-A) demonstrated impaired perfusion in the deep retinal vascular plexus. Fluorescein angiography (FA), indocyanine green angiography (ICGA), and spontaneous fundus autofluorescence showed no significant abnormalities. During follow-up, partial improvement in retinal lesions was observed in NIR imaging and SD-OCT in some patients, but a proportion of patients still exhibited persistent retinal damage and no improvement in visual field scotomas.ConclusionCOVID-19-related AMN share similar clinical and imaging features with AMN due to other causes, as evidenced by the persistent presence of visual field scotomas over a longer duration.Trail registrationhttps://www.chictr.org.cn/; identifier: ChiCTR2100044365

Retinal biomarkers in vascular occlusion

Objective: To clarify the diagnostic and prognostic values of the biomarkers detected by multimodal imaging procedures as coloured fundus imaging, fluorescein angiography, near infra‐red imaging, fundus Autofluorescence, SD‐OCT, and OCT angiography to predict the prognosis and the response to therapy in retinal vascular occlusions (artery or vein).Recently, there has been an interest in determining the prognostic value of changes on optical coherence tomography (OCT) in retinal vein occlusion as it allows both quantitative and qualitative analysis of imaging biomarkers such as central retinal thickness, choroidal thickness, intraretinal hyper‐reflective foci (HRF), disorganization of the inner retinal layers (DRIL), external limiting membrane (ELM) disruption, ellipsoid zone (EZ) disruption. Also classifying the intraretinal edema if sponge‐like or cystoid or serous retinal detachment (and detecting its height). Also signs of ischemia can be detected such as prominent middle limiting membrane (p‐MLM), paracentral acute middle maculopathy (PAMM), as well as hyperreflectivity of the inner retinal layers (HIRL) which is commonly seen in cases of acute retinal artery occlusion. Internal limiting membrane detachment (ILMD) which is a novel biomarker that can be detected in some cases of acute CRAO.OCT Angiography has added more information about the assessment of microvascular alterations, especially vessel density in the deep retinal vascular plexus, the foveal avascular zone and of areas with no capillary perfusion. Biomarkers of ultra‐widefield angiography, such as peripheral ischemia (ischemic index) and neovascularization are essential for retinal laser treatment decision.Finally, FAF has been a very useful tool in monitoring the disease progression and response to treatment.The speaker will present examples of multimodal imaging of different retinal biomarkers in retinal vascular occlusion that help in predicting the prognosis.

Retina hypoperfusion in multiple sclerosis: Is it only a consequence of atrophy?

Aims/Purpose: To study if there are vascular changes in patients with multiple sclerosis (MS) when compared healthy controls, analysing oct and OCT‐angiography findings (choroidal thickness and retinal vascular density) at the macular level.Methods: The study compared two groups (controls and patients) and it analysed whether there were statistically significant differences in the different parameters studied using OCT: choroidal thickness and in the vascular macular plexuses, using OCT‐angiography. Any patient has an optic neuritis history. It was also studied whether there was a statistically significant correlation between anatomical parameters (radial nerve fibre layer, RNFL and ganglion cell layer, GCL) and vascular parameters matching cases and controls by age and sex.Results: We found a statistically significant reduction in macular choroidal thickness in patients when compared to controls. The study of retinal vascular plexuses showed that the superficial and deep retinal vascular plexuses and the choriocapillaris plexus showed significantly lower vascular density in the patients group. Variations in anatomical parameters between anatomical parameters and in vascular parameters between vascular parameters pairing cases and controls show direct correlations. Regarding the correlation between the differences in anatomical versus vascular parameters, we only observed a low direct correlation between the difference in the papillary RFNL and that of the superficial macular vascular plexus between case and control group.Conclusions: The density of macular vascular plexus and choroidal thickness proved to be significantly lower in MS patients than in healthy subjects. To date, it is not known to what extent hypoperfusion in MS is a cause or consequence of the brain disease or whether it is a simply association. Vascular parameters could be used as useful markers in the diagnosis and follow‐up of MS.