Radial Peripapillary Capillary Network Research Articles

Optical Coherence Tomography Angiography Assessment of Optic Nerve Head and Macula across the Primary Angle Closure Disease Spectrum.

The microvasculature of the optic disc and macula in eyes with acute primary angle closure and primary angle closure glaucoma was lower across the disease spectrum, but the significant difference was only observed in primary angle closure glaucoma. To assess the microvasculature in the optic nerve head (ONH) and macula across primary angle-closure disease (PACD) spectrum using optical coherence tomography angiography (OCTA). OCTA (AngioVue, Fremont, CA) imaging was performed on 122 PACD subjects. Flow area (FA) and vessel density (VD) in the ONH, radial peripapillary capillary (RPC) network, and superficial and deep capillary plexuses of the macula were calculated and compared across the PACD spectrum using linear regression models with generalized estimating equations adjusted for inter-eye correlation. A total of 234 eyes including 44 primary angle-closure suspects (PACS), 93 primary angle-closure (PAC), 79 primary angle-closure glaucoma (PACG) and 18 PAC with history of previous acute primary angle-closure (APAC) were included in the analysis. Compared to other groups, PACG eyes showed smaller FA in the ONH (1.35±0.02mm2), RPC (0.78±0.03mm2), and the superficial retinal layer (1.08±0.03mm2) (all P<0.05). Lower VD was also observed in the "whole image", "inside disc", and "peripapillary" regions of the ONH and RPC, and the "whole image" and "parafoveal" regions of the retinal layer in the PACG group when compared with other groups (all P<0.05). No significant differences were found for the other groups (all P>0.05). Lower VD in the ONH, RPC, and superficial retinal layer significantly correlated with worse visual field loss in PACG eyes (all P<0.05). Significant reduction in the microvasculature of the optic disc and macula in PACG suggests that glaucoma development may contribute to lower VD in these regions.

Optic nerve head alterations after COVID-19: an optical coherence tomography angiography-based longitudinal study.

To evaluate longitudinal changes in peripapillary vessel density (VD) following coronavirus disease 2019 (COVID-19) using optical coherence tomography angiography. As part of a prospective longitudinal observational study, we studied healthy individuals with a history of mild COVID-19 confirmed via real-time polymerase chain reaction. After recovery, we used the Optovue RTVue XR Avanti machine to perform optic nerve head (ONH) imaging. We also assessed the VD of all vessels and of small vessels in the disc and the radial peripapillary capillary (RPC) network at 1 and 3 months post-recovery. We included 17 patients (34 eyes; mean age: 36.9 ± 10.2 years, range: 24-62 years) who had recovered from COVID-19. No changes were observed in the ONH parameters. However, there was a noticeable trend of increased small vessel VD values in the RPC. These increases were significant for the peripapillary whole, superior hemifield, inferior-temporal, temporal-superior, and superior-temporal small vessels. Moreover, the evaluation of all vessel VD values in the RPC revealed a significant decrease in the inside disc and a significant increase in a grid-based inferior region. COVID-19 may affect VD of the RPC in the ONH, and should be considered in ONH evaluations.

Impact of dexmedetomidine as an adjuvant to peribulbar anesthesia on the retinal vasculature in glaucoma patients: an optical coherence tomography angiography study

Objectives To assess Dexmedetomidine’s effect as an adjuvant to peribulbar anesthesia on the retinal vasculature in patients with glaucoma undergoing cataract extraction surgery via optical coherence tomography angiography (OCT-A). Participants Thirty-nine glaucoma participants planned for phacoemulsification were allocated into two groups. A 10 ml mixture of peribulbar anesthesia was administered to group I. This anesthetic mixture consisted of 4.5 ml of lidocaine 2% mixed with 4.5 ml of bupivacaine 0.5%,1 ml of dexmedetomidine (50 µg), and 150 IU hyaluronidase. Group II was administered a peribulbar anesthetic mixture consisting of 4.5 ml of lidocaine 2% combined with 4.5 ml of bupivacaine 0.5%,150 IU of hyaluronidase, and 1 ml of normal saline, totaling 10 ml. Optical coherence tomography angiography was used 10 mi before and 10 min after injection to scan optic disc total vessel density, foveal superficial deep capillary plexuses (DCP) density, radial peripapillary capillary network density, and total vessel density plus foveal avascular zone (FAZ) diameter. We also checked the intraocular pressure (IOP) before and 10 min after the anesthetic injection. Results After the administration of the peribulbar anesthetic, group II demonstrated a notably higher significance in the DCP fovea median percent change (–43.7%) compared with group I (-2%) (P&lt;0.001). Additionally, group II experienced a considerably greater median percent change in DCP total density (–22.4%) postinjection compared to group I (–0.8%) (P value &lt; 0.001). The postinjection median percent changes in foveal total vessel density and superficial vessel density were −16.2% and −56.8% in group II, and −1% and −2.4% in group I, respectively, with a P value less than 0.001. Moreover, following the injection, the median percentage change in the diameter of the foveal avascular zone was significantly higher in group II (–40.6%) than in group I (–2.3%) (P value &lt; 0.001). Additionally, there was a noteworthy increase in the optic disc’s total vessel density and the median percentage shift in radial peripapillary capillary network density in group II (–13.1 and −13.7%, respectively) compared with group I (–1.2 and −1%, respectively, P value &lt; 0.001). IOP before and after injecting the anesthesia was insignificantly different between the studied groups (P =0.198 and 0.069, respectively). Conclusion The addition of dexmedetomidine to the peribulbar anesthesia demonstrates a protective effect on the retinal microvasculature against the ischemic impact of anesthetic drugs with no significant effect on the IOP. This effect holds significant implications for glaucoma patients.

Optical coherence tomography (OCT) and OCT-angiography in syndromic versus non-syndromic USH2A-associated retinopathy.

To compare non-syndromic and syndromic forms of USH2A-related retinitis pigmentosa (RP) by means of structural optical coherence tomography (OCT) and OCT-angiography (OCTA). Observational, cross-sectional, multicenter study. All patients underwent best corrected visual acuity (BCVA) measurement, OCT (Spectralis HRA + OCT, Heidelberg Engineering) and OCTA (OCT DRI Topcon Triton, Topcon Corporation). We compared subfoveal choroidal thickness (SCT), choroidal vascularity index (CVI), presence of cystroid macular edema (CME), macular vessel density (VD) at the superficial and deep capillary plexa, as well as VD of the radial peripapillary capillary (RPC) network, between syndromic and non-syndromic patients with USH2A-associated retinopathy. Thirty-four eyes from 18 patients (7 females) were included. Thirteen patients (72.2%) were affected by Usher syndrome type 2, whereas the remaining 5 subjects (27.8%) had non-syndromic retinitis pigmentosa (nsRP). Syndromic patients were younger than nsRP (p = 0.01) and had a worse visual acuity than those with the exclusively retinal phenotype. Patients with Usher syndrome type 2 had a higher prevalence of CME and a thicker choroid compared to nsRP, although these results were not statistically significant (p = 0.775 and p = 0.122, respectively). Similarly, none of the other quantitative OCT and OCTA parameters was statistically different between the two groups. Despite their younger age, patients with Usher syndrome type 2 displayed similar choroidal and microvascular changes compared to those with nsRP.

Optical Coherence Tomography Angiography Assessment of the Optic Nerve Head in Patients Hospitalized Due to COVID-19 Bilateral Pneumonia.

Background and objectives: We aimed to investigate changes in the radial peripapillary capillary (RPC) network using optical coherence tomography angiography (OCTA) in patients who recovered from coronavirus disease 2019 (COVID-19). Materials and Methods: This was a prospective study of patients hospitalized due to COVID-19 bilateral pneumonia between March and May 2021. The control group included healthy individuals matched for age and sex. Two months after discharge, the patients underwent ophthalmological examination, including optical coherence tomography (OCT) imaging. The RPC network and retinal nerve fiber layer (RNFL) of the optic disc (RNFL optic disc) were automatically evaluated and compared between the study groups. Additionally, the RPC parameters were compared between the men and women in the COVID-19 group, and correlations between the RPC and RNFL optic disc parameters were assessed. Results: A total of 63 patients (120 eyes) with bilateral pneumonia caused by severe acute respiratory syndrome coronavirus 2 infection were examined. No ophthalmic symptoms were reported by the patients. No significant differences were observed in the RPC parameters between the patients from the COVID-19 group and the 43 healthy controls. Moreover, the RPC parameters did not differ between the men and women in the COVID-19 group. A positive correlation was found between the RPC and RNFL optic disc parameters in the COVID-19 patients (p < 0.001). Conclusions: No changes in the RPC network were observed among the patients with COVID-19 bilateral pneumonia in the early period after hospital discharge. However, a longer follow-up is needed to monitor COVID-19-related changes in the microvasculature of the optic nerve head.

Comparison of peripapillary vascular density as measured by optical coherence tomography angiography between various types of open-angle glaucoma

The purpose of this study is to compare the peripapillary vascular density in patients with various types of open-angle glaucoma (primary open-angle glaucoma, pseudoexfoliative glaucoma and pigmentary glaucoma) with healthy subjects by optic coherence tomography angiography (OCTA). Twenty-seven eyes with diagnosed POAG, thirty-four eyes with diagnosed PXG, twenty eyes with diagnosed PG and thirty eyes of healthy individuals were included in our study. Peripapillary vessel density measurements were performed with all images; (AI-DD), intra-disc (ID-DD) and peripapillary (PP-DD); measurement of vascular density in the radial peripapillary capillary network was performed by OCTA. The Kruskal-Wallis test and post-hoc test were performed for statistical analysis. AI-DD was 50.76±2.07% in the healthy group, 47.12±2.57% in POAG, 39.71±6.64% in PXG, and 43.37±1.55% in PG. ID-DD was 50.49±3.74% in the healthy group, 49.51±6.83% in POAG, 38.42±13.46% in PXG, and 40.9±4.45% in PG. PP-DD was 51.26±3.12% in the healthy group, 50.13±3.04% in POAG, 42.31±7.31% in PXG, and 47.6±1.40% in PG. While it was found that all image and intra-disc vascular density measurements were statistically significantly lower in the PG and PXG group compared to the healthy group and the POAG (P<0.001), there was no significant difference between PXG and PG or between the control group and POAG. The lower radial peripapillary capillary density in PXG and PG compared to the POAG and healthy groups suggests that the blood flow around the optic disc is negatively affected in these patients.

Does thalassemia truly cause microvascular changes without us noticing? An optical coherence tomography angiography study of the children with beta-thalassemia.

It was aimed to evaluate the retinochoroidal microvascular alterations of pediatric beta-thalassemia patients and investigate the effect of blood transfusion on perfusion among transfusion-dependent thalassemia (TDT), by means of optical coherence tomography angiography (OCTA). In this multicentered, prospective, cross-sectional study, 56 TDT, 14 non-TDT (NTDT), and 63 healthy children were evaluated. The vessel density (VD) in superficial capillary plexus (SCP), deep capillary plexus, radial peripapillary capillarynetwork, choriocapillaris, and the foveal avascular zone area (FAZ) were evaluated by OCTA. Before and after transfusion values ​​of the TDT group were compared, and correlations were made with blood values ​​and iron accumulation. Foveal and parafoveal zones were significantly thinner among TDT patients, with larger FAZ area. Macula VD of SCP and ppVD was lowest in NTDT group. In the TDT group, a decrease in retinal nerve fiber thickness and ppVD values was detected ​​after transfusion. A negative significant relationship was found between both hemoglobin (Hb), hematocrit (Htc), and ppVD. OCTA provides a better insight into retinal and choriocapillaris vascular impairment influenced by tissue hypoxia and oxidative stress in different clinical phenotypes of beta-thalassemia.

Radial peripapillary capillary network in optic disc anomalies with abnormal tissues on disc surface.

Optic disc anomalies with abnormal tissue on the disc surface includes, myelinated nerve fiber, optic disc drusen, and Bergmeister papillae. Imaging the radial peripapillary capillary (RPC) network in optic disc anomalies with optical coherence tomography-angiography (OCTA) can give information on the RPC network in these conditions. This video describes the OCTA of optic nerve head and RPC network using the angio disc mode in cases of optic disc anomalies with abnormal tissue on the disc surface. This video presents characteristic features of RPC network in one eye each of myelinated nerve fiber, optic disc drusen, and Bergmeister papillae. OCTA in optic disc anomalies with abnormal tissue on the disc surface show a dense RPC microvascular network. OCTA is an effective imaging modality to study vascular plexus/RPC and their alteration in these disc anomalies. https://youtu.be/zlflgijy56c.

Evaluation of parafoveal and peripapillary vascular densities using optical coherence tomography angiography in children with thalassemia major.

Thalassemia major (TM) is an inherited anaemia caused by faulty haemoglobin synthesis. Reducing serum iron levels using iron chelating agents is an important step in the treatment of TM, and the effects on the eye of both the disease and these agents can be determined by regular eye examination. We evaluated macular and optic nerve vascular densities in children with TM and compared the results with healthy controls using optical coherence tomography angiography (OCTA). This is a prospective study. A total of 30 children with TM and 30 healthy controls were included in the study. The area of the foveal avascular zone (FAZ) and the vascular densities (VD) of the optic nerve head (ONH), radial peripapillary capillary (RPC) and deep and superficial retinal vascular networks were measured using OCTA. A statistically significant decrease in VD was observed in the whole image and the parafovea, superior hemi, superior and inferior parts of the superficial capillary plexus and in the whole image and the superior regions of the deep capillary plexus in the TM patient group compared with the control group (p < 0.05). A significant decrease in VD was also observed in the whole image and the inside disc, peripapillary, nasal, inferonasal and temporal regions of the ONH and in the whole image and the inside disc, peripapillary and inferonasal regions of the RPC network in patients with TM (p < 0.05). A significant positive correlation was observed between both serum ferritin levels and deferasirox dosage, on one hand, and both the superficial (p = 0.023 and p = 0.002, respectively) and deep FAZs (p = 0.015 and p = 0.045, respectively), on the other hand. A negative correlation was also found between the deferasirox dosage and the VDs of the superficial (p = 0.010) and deep (p = 0.001) foveal plexuses. Retinal VD and FAZ are affected in patients with TM. OCTA, which can noninvasively measure retinal VD in patients with TM, may be a useful tool for the early detection of retinal microvascular changes that may occur during the course of the disease.

Optic nerve head optical coherence tomography angiography findings in patients with thyroid eye disease: a case–control study

BackgroundTo evaluate changes in the vessel density (VD) of the optic nerve head (ONH) microvasculature in thyroid eye disease (TED) using optical coherence tomography angiography (OCTA). This study aimed to applicate the OCTA as a noninvasive modality in screening TED patients to assess sub-clinical changes.MethodsIn a cross-sectional study, the control group patients were healthy individuals with no ocular abnormalities and were euthyroid. All patients with TED had clinical features of the disease. We divided them into two groups using the clinical activity score (CAS). Patients with CAS scores 0–2 were categorized as group A, and scores three or more as group B. All vessels (AV) and small vessels (SV) VD inside disc and radial peripapillary capillary network were measured using the ONH-OCTA.ResultsWe evaluated 29 patients with TED and 28 healthy controls. The mean whole image AV VD (mean ± SD: 56.33 ± 2.56, p-value = 0.17) and the mean whole image SV VD (mean ± SD: 49.94 ± 2.56, p-value = 0.16) in the TED group had no statically significant difference compared with the control group (AV mean ± SD: 57.20 ± 20.22, SV mean ± SD: 50.84 ± 2.23). We found a non-significant decrease in AV and SV radial peripapillary capillary VD in the TED group. There was a significant decrease in the mean whole image AV VD (mean ± SD: 54.83 ± 3.07, p-value = 0.005) and the mean whole image SV VD (mean ± SD: 48.60 ± 3.18, p-value = 0.013) in CAS group B compared to group A (AV mean ± SD: 57.45 ± 1.33, SV mean ± SD: 50.95 ± 1.37).ConclusionOur study showed non-significant ONH vascular alterations in patients with TED, including reduced VD of ONH in the radial peripapillary capillary. Patients with higher CAS scores had a more noticeable decrease in ONH microvasculature.

Accuracy of peripapillary OCTA in patients with acute nonarteritic anterior ischemic optic neuropathy

ObjectifÉvaluer l'exactitude de la segmentation péripapillaire par angiographie-tomographie par cohérence optique (OCTA) dans des yeux présentant une neuropathie optique ischémique antérieure non artéritique (NOIANA) aiguë et dans des yeux sains. MéthodeDans le cadre de cette étude rétrospective, on a obtenu des images OCTA en face du disque optique d'yeux sains et d'yeux présentant une NOIANA aiguë unilatérale. Les délimitations de la bordure du disque optique et la segmentation du capillaire péripapillaire radial (RPC) ont été générées automatiquement par le logiciel de l'appareil et corrigées par 2 examinateurs spécialisés qui ont évalué la fréquence des erreurs de segmentation et leurs répercussions sur la mesure de la densité vasculaire et de l’épaisseur de la couche de fibres nerveuses (NFL). RésultatsAinsi, 38 yeux de 38 sujets (18 dans le groupe de témoins en bonne santé et 20 dans le groupe NOIANA aiguë) ont pris part à l’étude. Une mauvaise identification de la bordure du disque optique s'est produite dans 5 yeux sains (27,7 %) et dans 19 yeux présentant une NOIANA (95,0 %; p < 0,001). Une erreur de segmentation du RPC a été observée dans 6 yeux sains (33,33 %) et dans 19 yeux présentant une NOIANA (95,0 %; p < 0,001). Une fois les erreurs corrigées, l’épaisseur de la NFL et la densité du RPC n'ont pas varié de manière statistiquement significative dans ni l'un ni l'autre des groupes. ConclusionsL'identification erronée de la bordure du disque optique et les erreurs de segmentation de la couche de RPC sont fréquentes dans les images OCTA du disque optique. L'exactitude de l'imagerie OCTA en matière de délimitation de la bordure du disque optique et de segmentation du réseau de RPC est moindre lorsque le disque optique est œdématié en raison d'une NOIANA aiguë.

The use of optical coherence tomography angiography in patients with chiasmal compression (literature review)

Optical coherence tomography (OCT) is currently the leading method for the observation and evaluation of microstructural changes in the retina in vivo. In recent years, OCT has been used in clinical practice to monitor the progression of compressive optic neuropathy in patients with chiasmal-sellar region neoplasms. The results obtained in the course of the studies opened up new opportunities for studying the pathogenesis of the development of compressive optic neuropathy in patients of this group. The advent of OCT-angiography (OCTA), developed on the basis of OCT, made it possible to study changes in the blood flow of the radial peripapillary capillary network, superficial and deep capillary plexuses, which opens up many opportunities for further research into the pathogenesis of visual impairment in this group of patients, prognosis of the development of the disease, and selection optimal terms of treatment. The literature review presents and analyzes the currently available results of the use of OCTA in patients with chiasmal compression.

Quantitative OCT Angiography Assessment of the Effect of Peribulbar Anesthesia on Retinal Microvasculature in Primary Open-Angle Glaucoma Patients Undergoing Cataract Surgery.

ObjectiveTo assess the effect of peribulbar anesthesia on retinal microvasculature in primary open-angle glaucoma (POAG) patients undergoing cataract surgery using OCT Angiography.ParticipantsForty-nine patients undergoing cataract surgery were divided into two groups. Group I included patients with no history of glaucoma, while group II included patients previously diagnosed as POAG with controlled IOP. Each participant received 6 mL of peribulbar anesthetic injection of 4 mL lidocaine 2% containing 150 IU hyaluronidase and 2 mL bupivacaine 0.5%. They were scanned with the OCT-A 10 minutes before and 10 minutes after injection for foveal deep (DCP), superficial (SCP) capillary plexuses density and total vessel density, foveal avascular zone (FAZ) diameter, optic disc total vessel density, and radial peripapillary capillary (RPC) network density. In addition, IOP was checked before and 10 minutes after injection.ResultsMedian percent change in DCP post-injection was significantly greater in group II (−43%) than in group I (−2.5%) (P < 0.001). Also, DCP total density median percent change post-injection was significantly higher in group II (−21%) than in group I (−0.9%) (P < 0.001). Foveal SCP vessel density and total vessel density median percent change post-injection were −62.6% and −16.2%, respectively, in group II and were −2.6% and −1.1%, respectively, in group I, which are statistically significant (P < 0.001). The FAZ diameter median percentage change post-injection was higher in group II (40.6%) than in group I (2.5%) (P < 0.001). Optic disc total vessel density and radial peripapillary capillary (RPC) network density post-injection median percent change were significantly higher in group II (−13.6%) and (−13.1%) respectively than in group I (−1.1%) and (−1.25%) respectively (P < 0.001).ConclusionPeribulbar anesthesia harbors a deleterious ischemic effect on the retinal vascular tree of glaucoma patients, which could harmfully affect the vision and the visual field in those vulnerable patients.

Fundus Changes Evaluated by OCTA in Patients With Cerebral Small Vessel Disease and Their Correlations: A Cross-Sectional Study.

ObjectiveTo detect fundus changes in patients with cerebral small vessel disease (CSVD) using optical coherence tomography angiography (OCTA) and to investigate the correlations between CSVD and fundus changes.MethodsFrom January 2019 to January 2020, patients diagnosed with CSVD by magnetic resonance imaging (MRI) were enrolled in our study and received fundus examinations using OCTA. CSVD was defined as white matter hyperintensities, enlarged perivascular spaces, lacunes, or microbleeds on MRI. OCTA parameters included foveal avascular zone areas, retinal nerve fiber layer thickness, and capillary densities of the superficial retinal capillary plexuses, deep retinal capillary plexuses, and the radial peripapillary capillary network of the disc. Univariate and multivariate logistic regression analyses were performed to explore the correlation between CSVD and fundus changes.ResultsA total of 115 patients (40% male) were enrolled and analyzed, and the mean age was 65.11 ± 11.23 years. After multivariate logistic regression analysis, the radial peripapillary capillary network density was negatively correlated with severity of deep white matter lesions (OR: 0.909; 95% CI: 0.828–0.998; p = 0.046) and perivascular spaces (OR: 0.881; 95% CI: 0.779–0.995; p = 0.041). Parafoveal vessel densities of the superficial retinal capillary plexuses were independently correlated with lacunes (OR: 0.889; 95% CI: 0.817–0.967; p = 0.006).ConclusionOCTA parameters were correlated with CSVD, indicating that OCTA is a potential method for CSVD screening.

Analysis of Radial Peripapillary Capillary Density in Patients with Bietti Crystalline Dystrophy by Optical Coherence Tomography Angiography

ObjectiveWe wanted to investigate the radial peripapillary capillary (RPC) network in patients with Bietti crystalline dystrophy (BCD). MethodsWe compared RPC densities in the disk and different peripapillary regions, obtained using optical coherence tomography angiography in 22 patients with BCD (37 eyes) and 22 healthy subjects (37 eyes). The BCD group was then divided into Stage 2 and Stage 3 subgroups based on Yuzawa staging, comparing the RPC densities of the two. ResultsThe disk area RPC density was 38.8% ± 6.3% in the BCD group and 49.2% ± 6.1% in the control group (P < 0.001), and peripapillary region RPC density was significantly lower in the BCD group than in the control group (49.1% ± 4.7% and 54.1% ± 3.0%, respectively, P < 0.001). There were no significant RPC density differences between the tempo quadrant and inside disk of Stages 2 and 3 subgroups; the other areas showed a significantly lower RPC density in Stage 3 than in Stage 2 BCD. ConclusionThe BCD group RPC density was significantly lower than the control group. The reduction of RPC density in the tempo quadrant occurred mainly in the Stage 1 BCD. In contrast, the reduction of RPC density in superior, inferior, and nasal quadrants occurred mainly in Stage 2.

Quantitative changes in peripapillary, macular, and choriocapillaris microvasculature of patients with non-ocular Behçet's disease and relationship with systemic vascular involvement, an optical coherence tomography angiography study

BackgroundTo evaluate the changes in the peripapillary, macular and choriocapillaris microvasculatures in the eyes of patients with Behçet's disease (BD) without ocular involvement by optical coherence tomography angiography (OCT-A) and to investigate the relationship with systemic vascular involvement (SVI). MethodsThe study included 56 eyes of 33 patients with non-ocular BD and 61 eyes of 33 healthy subjects. The macular microvascular (MMV) vessel densities (VDs), FAZ parameters, Choriocapillaris flow area (CCFA), radial peripapillary capillary (RPC) VDs and optic nerve head (ONH) analyses were performed with OCT-A. MMV, RPC, ONH, and CCFA measurements were compared between the non-ocular BD patients and healthy controls. Then, the patient group was divided into two subgroups according to the presence of SVI. MMV, RPC, and CCFA measurements of these subgroups were compared with the healthy controls. ResultsWhile deep capillary plexus VD and foveal density decreased in MMV analysis in the BD group compared to the control group, CCFA was not different. In the RPC and ONH analysis, the VDs of the inside-disc small vessels and the VDs of the inside-disc all vessels were decreased while the cup/disk area ratio and cup volume were increased in the BD group compared to the healthy controls. Furthermore, the VDs of the inside-disc vessels were reduced in patients without SVI compared to those with SVI and healthy controls. ConclusionsThe RPC network, ONH and MMV architecture analysis by OCT-A revealed changes in the MMV, RPC, and ONH structures in non-ocular BD patients. Moreover, the decrease in RPC VDs and MMV VDs in patients without SVI suggested that the patients with BD without SVI had subclinical ocular involvement even in the absence of clinical ocular findings.

Improvement of Retinal Microcirculation after Pulmonary Vein Isolation in Patients with Atrial Fibrillation-An Optical Coherence Tomography Angiography Study.

Purpose: To evaluate retinal and optic nerve head (ONH) perfusion in patients with atrial fibrillation (AF) before and after catheter ablation of AF with pulmonary vein isolation (PVI). Methods: 34 eyes of 34 patients with AF and 35 eyes of 35 healthy subjects were included in this study. Flow density data were obtained using spectral-domain OCT-A (RTVue XR Avanti with AngioVue, Optovue, Inc, Fremont, California, USA). The data of the superficial and deep vascular layers of the macula and the ONH (radial peripapillary capillary network, RPC) before and after PVI were extracted and analysed. Results: The flow density in the superficial OCT-angiogram (whole en face) and the ONH (RPC) in patients with AF was significantly lower compared to healthy controls (OCT-A superficial: study group: 48.77 (45.19; 52.12)%; control group: 53.01 (50.00; 54.25)%; p < 0.001; ONH: study group: 51.82 (48.41; 54.03)%; control group: 56.00 (54.35; 57.70)%; p < 0.001;). The flow density in the ONH (RPC) improved significantly in the study group following PVI (before: 51.82 (48.41; 54.03)%; after: 52.49 (50.34; 55.62)%; p = 0.007). Conclusions: Patients with AF showed altered ocular perfusion as measured using OCTA when compared with healthy controls. Rhythm control using PVI significantly improved ocular perfusion as measured using OCT-A. Non-contact imaging using OCTA provides novel information about the central global microperfusion of patients with AF.

Evaluations of the radial peripapillary, macular and choriocapillaris microvasculature using optical coherence tomography angiography in patients with systemic sclerosis

To analyze the macular microvascular (MMV) architecture, radial peripapillary capillary (RPC) network and choriocapillaris using optical coherence tomography angiography (OCT-A) in patients with systemic sclerosis (SSc) without systemic comorbidities. The vessel densities (VDs) of the MMV, foveal avascular zone (FAZ) parameters, choriocapillaris flow areas (CCFAs), RPC VDs, and optic nerve head (ONH) parameters were measured by OCT-A. Retinal thickness and subfoveal choroidal thickness (SFCT) were measured by spectral-domain optical coherence tomography (SD-OCT). The SD-OCT and OCT-A measurements of 53 eyes of 30 SSc patients were compared with 61 eyes of 33 healthy controls. In the MMV analysis, a decrease in the VDs of the superficial capillary plexus and an increase in the FAZ area, FAZ perimeter and non-flow area were detected in the SSc group compared to the controls (P=0.007, P=0.001, P=0.029, P=0.018, and P=0.039, respectively). While there was a decrease in SFCT, no change was found in CCFA (P=0.001 and P=0.902, respectively). The RPC analysis revealed a decrease in the VDs of all vessels for the entire area and the intradisc area, as well as the VDs of the small vessels for the intradisc area (P=0.021, P=0.001, and P=0.003, respectively). In the ONH analysis, there was an increase in the C/D area ratios and cup volumes, and a decrease in the rim areas and nasal quadrant retinal nerve fiber layer thickness (P=0.004, P=0.004, P=0.013, and P=0.032, respectively). Decreases in RPC and MMV VDs and changes in ONH parameters were found in OCT-A measurements in patients with SSc.

Radial peripapillary capillary network microvascular changes in Alzheimer's disease, mild cognitive impairment, and cognitively healthy controls

AbstractBackgroundThe retinal and optic nerve head microvasculature may represent a non‐invasive, inexpensive biomarker for Alzheimer’s disease (AD) and mild cognitive impairment (MCI). In this study, we characterize microvascular changes at the optic nerve head (radial peripapillary capillary network) using optical coherence tomography angiography (OCTA).MethodOptic nerve head‐centered OCTA images were obtained from 66 eyes of 36 patients with AD, 119 eyes of 63 patients with MCI, and 513 eyes of 265 cognitively healthy controls in a cross‐sectional study (NCT03233646) using Zeiss Cirrus HD‐5000 OCTA. Exclusion criteria included diabetes, uncontrolled hypertension, glaucoma, non‐AD dementia, and other optic nerve pathology. Two metrics of vessel perfusion were calculated in a 2.5mm‐wide annulus centered on the optic nerve head using Zeiss AngioPlex (Version 11.0.0.29946) – capillary perfusion density (CPD) and capillary flux index (CFI). CPD represents the percentage of perfused capillaries in a unit scan area; CFI is a unitless ratio of perfused capillaries in a unit scan area weighted by intensity of flow signal. Retinal nerve fiber layer (RNFL) thickness was measured using a peripapillary optic disc cube scan. Groups were compared using multivariable generalized estimating equations, controlling for age and sex as covariates.ResultAverage CPD was significantly greater in AD vs controls (0.446 ± 0.015 vs 0.439 ± 0.017, p = 0.001) and in MCI vs controls (0.443 ± 0.020 vs 0.439 ± 0.017, p = 0.007) but not AD vs MCI (p = 0.69). CFI and average RNFL thickness did not significantly differ among groups (all p &gt; 0.05). Among all groups, average CPD differed significantly (p = 0.001), as did CPD in the nasal and inferior peripapillary quadrants (p &lt; 0.001 and p = 0.001, respectively).ConclusionPeripapillary CPD is increased in eyes of patients with AD or MCI compared to cognitively healthy controls, despite similar RNFL thickness between these groups. This finding represents a novel biomarker and contrasts with macular microvascular changes, which show decreased vessel and perfusion density in AD and MCI compared to controls. Integration of optic nerve head OCTA in models using retinal imaging to diagnose AD and MCI may improve specificity; further investigation is necessary.

Optic Nerve Head Optical Coherence Tomography Angiography Findings after Coronavirus Disease.

PurposeTo quantify the microvasculature density of the optic nerve head (ONH) using optical coherence tomography angiography (OCTA) analysis in patients recovered from Coronavirus Disease 2019 (COVID-19).MethodsIn a comparative cross-sectional, observational study, patients recovered from COVID-19 whose initial diagnosis was confirmed by a rRT-PCR of a nasopharyngeal sample were included in this study. OCTA of ONH was performed in included patients and normal controls. Vascular density (VD) of the all vessels (AV) and small vessels (SV) inside the disc and radial peripapillary capillary (RPC) network density were measured in COVID-19 recovered patients and compared with similar parameters in an age-matched group of normal controls.ResultsTwenty-five COVID-19 patients and twenty-two age-matched normal controls were enrolled in the study and one eye per participant was evaluated. The mean whole image SV VD in the COVID-19 group (49.31 1.93) was not statistically significantly different from that in the control group (49.94 . 2.22; P = 0.308). A decrease in RPC VD was found in all AV and SV VD measured, which became statistically significant in whole peripapillary SV VD, peripapillary inferior nasal SV VD, peripapillary inferior temporal SV VD, peripapillary superior nasal SV VD, and grid-based AV VD inferior sector (P 0.05). Inside disc SV VD in the COVID-19 group (49.43 4.96) was higher than in the control group (45.46 6.22) which was statistically significant (P = 0.021).ConclusionUnremarkable decrease was found in ONH microvasculature in patients who had recovered from COVID-19. These patients may be at risk of ONH vascular complications. Increase in inner disc SV VD may be an indicator of ONH hyperemia and edema.