Vessel Density Of Superficial Capillary Plexus Research Articles

Effects of B12 Deficiency Anemia on Radial Peripapillary and Macular Vessel Density: An Optical Coherence Tomography Angiography (OCTA) Study.

To evaluate the macular and optic disc vascular changes in vitamin B12 deficiency anemia. A total of 24 patients with vitamin B12 deficiency anemia and 24 healthy controls were involved in this study. All participants were evaluated for central macular thickness (CMT), peripapillary retina nerve fiber layer (RNFL) thickness, foveal avascular zone (FAZ) area, macular vessel density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP), choriocapillaris flow area, and optic disc radial peripapillary capillary (RPC) VD using optic coherence tomography (OCT) and optic coherence tomography angiography (OCTA). Metabolic parameters were also noted. Temporal RNFL thickness significantly decreased in the B12 deficiency anemia group (p = 0.04). Choriocapillaris flow area (p = 0.045) and macular vessel density in both SCP (p = 0.022) and DCP (p = 0.018) markedly declined in the study group. Optic disc RPC VD in the B12 deficiency anemia group was lower in all regions compared to that of the control group, but the difference was not statistically significant (p > 0.05). There were significant positive correlations between choriocapillaris flow area, macular VD, vitamin B12, and hemoglobin. Retinal vascular alterations were observed in B12 deficiency anemia, and OCTA may be beneficial in the diagnosis and follow-up of ocular complications in these cases.

Nonperfusion Area and Other Vascular Metrics by Wider Field Swept-Source OCT Angiography as Biomarkers of Diabetic Retinopathy Severity.

PurposeTo study the wider field (WF) swept-source OCT angiography (SS-OCTA) metrics, especially the nonperfusion area (NPA), in the diagnosing and staging of diabetic retinopathy (DR).DesignCross-sectional observational study (November 2018 to September 2020).ParticipantsA total of 473 eyes of 286 patients (69 eyes of 49 control patients and 404 eyes of 237 diabetic patients).MethodsWe imaged using 6 × 6 mm and 12 × 12 mm angiograms on WF SS-OCTA. Images were analyzed using the ARI Network and FIJI ImageJ. Mixed effects multiple regression models and receiver operating characteristic (ROC) analysis were used for statistical analyses.Main Outcome MeasuresQuantitative metrics such as vessel density (VD); vessel skeletonized density (VSD); foveal avascular zone (FAZ) area, circularity, and perimeter; and NPA in DR and their relative performance for its diagnosis and grading.ResultsAmong patients with diabetes (median age, 59 years), 51 eyes had no DR, 185 eyes (88 mild, 97 moderate-severe) had nonproliferative DR (NPDR), and 168 eyes had proliferative DR (PDR). Trend analysis revealed a progressive decline in superficial capillary plexus (SCP) VD and VSD, and increased NPA with increasing DR severity. Additionally, there was a significant reduction in deep capillary plexus (DCP) VD and VSD in early DR (mild NPDR), but the progressive reduction in advanced DR stages was not significant. The NPA was the best parameter to diagnose DR (area under the curve [AUC], 0.96), whereas all parameters combined on both angiograms efficiently diagnosed (AUC, 0.97) and differentiated between DR stages (AUC range, 0.83–0.97). The presence of diabetic macular edema was associated with reduced SCP and DCP VD and VSD within mild NPDR eyes, whereas increased VD and VSD in SCP were observed in the moderate-severe NPDR group.ConclusionsOur work highlights the importance of NPA, which can be measured more readily and easily with WF SS-OCTA compared with fluorescein angiography. It is quick and noninvasive, and thus can be an important adjunct for DR diagnosis and management. In our study, a combination of all OCTA metrics on both 6 × 6 mm and 12 × 12 mm angiograms had the best diagnostic accuracy for DR and its severity. Further longitudinal studies are needed to assess NPA as a biomarker for progression or regression of DR severity.

Evaluation of subclinical retinal microvascular changes in systemic lupus erythematosus patients using optical coherence tomography angiography and its relationship with disease activity.

This study aimed to investigate subclinical retinal microvascular changes with optical coherence tomography angiography (OCTA) in patients with systemic lupus erythematosus (SLE) and healthy controls (HCs), and to evaluate the relationship between OCTA findings and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K). In this study, 47 eyes of SLE and 41 eyes of healthy control (HC) were evaluated. The SLE patients were divided into two subgroups: low disease activity (LDA) (SLEDAI≤5) and high disease activity (HDA) (SLEDAI>6). The results of OCTA were compared between SLE patients and HCs as well as the SLE subgroups. The relationship between OCTA results and SLEDAI-2K was evaluated. There were no differences in foveal avascular zone (FAZ) areas between the SLE patients and HCs. Central foveal thickness (CFT) was lower in SLE patients (p = .046). Superficial capillary plexus (SCP) vessel density (VD) in SLE patients was significantly lower only in the foveal area compared to that in HCs (p = .006). Deep capillary plexus (DCP) VD in SLE patients was significantly lower in all areas except the temporal parafoveal area compared to that in the HCs. There was no statistically significant difference between SLE groups with LDA and HDA in FAZ or any of the other areas, including SCP and DCP. When the correlation between OCTA findings and SLEDAI-2K was examined, both SCP and DCP VD were found to be negatively correlated. It was observed that DCP VDs were affected in SLE patients with LDA, and SCP VDs were also affected in addition to DCP with HDA. This suggests that DCP may be the first capillary plexus to be comprised in SLE. VDs were negatively correlated with disease activity. It was concluded that OCTA can be a useful tool in assessing subclinical retinal microvascular pathology and disease activity in patients with SLE.

Changes in optical coherence tomography angiography in patients with vitamin D deficiency.

25-hydroxyvitamin D [25(OH)D] sufficiency has critical biological importance for the human body. Although there are several studies on the association between serum 25(OH)D levels and macular structure, the data in this regard are limited. This study mainly aimed to investigate macular microvascular structure using optical coherence tomography angiography (OCTA) in 25(OH)D deficiency. Prospective, single-center, clinical study. The study included 82 eyes of 82 patients with 25(OH)D deficiency (Group I) and 50 eyes of 50 healthy subjects (Group II). All participants underwent OCTA examinations. The foveal avascular zone (FAZ) and superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density (VD) measurements of the participants were statistically compared between the patients and healthy subjects. The mean 25(OH)D levels measured from the venous blood samples of the participants were 7.61 ± 3.27 ng/mL in Group I and 25.39 ± 4.16 ng/mL in Group II, and the difference between these values was statistically significant (p < 0.0001). The FAZ measurement was significantly higher in Group I. The VDs of the SCP and DCP measurements were significantly higher in Group II. When the central macular thickness values of the participants were compared, Group II had a significantly higher value, but there was no significant difference in the central macular volume and retinal nerve fiber layer thickness analyses. The results showed that the FAZ area was significantly higher and the VDs of SCP and DCP were significantly lower in the patients with 25(OH)D deficiency. We found that 25(OH)D deficiency affected macular microvascular architecture.

Response to 1-Year Fixed-Regimen Bevacizumab Therapy in Treatment-Naïve DME Patients: Assessment by OCT Angiography.

Purpose To evaluate the effectiveness of intravitreal bevacizumab treatment in patients with diabetic macular edema (DME) by assessing retinal changes using optical coherence tomography angiography (OCT-A). Methods This prospective study was performed in patients with treatment-naïve DME. The eyes of patients were imaged using a swept-source OCT system with a scan area of 6 × 6 mm. The DME patients with a central macular thickness (CMT) of ≥300 μm received nine bevacizumab injections within 12 months. The demographic, systemic, and ocular parameters, including the best-corrected visual acuity (BCVA), CMT, microaneurysm (MA) count, and foveal avascular zone (FAZ) area in both superficial capillary plexus (SCP) and deep capillary plexus (DCP), as well as vessel density in SCP, were assessed in the patients. In addition, the response (good or poor) of the DME eyes to bevacizumab treatment and the final visual acuity (BCVA of 75 letters) were analyzed. Results Seventy-seven eyes of DME patients were subjected to the final analysis. Bevacizumab treatment reduced CMT from 425.06 μm (±77.15) to 350.25 μm (±82.04) and improved BCVA by about 8.61 letters (from 64.73 to 73.34) in the patients. The mean number of MAs in SCP decreased from 3.51 ± 2.07 to 2.31 ± 1.15 (p < 0.001) and in DCP from 17.12 ± 11.56 to 12.21 ± 6.99 (p < 0.001), whereas the area of FAZ increased in SCP from 328.22 ± 131.38 to 399.70 ± 156.98 (p < 0.001) and in DCP from 571.13 ± 396.01 to 665.89 ± 412.77 (p = 0.001). The final BCVA letter score and CMT were statistically significant in both poor and good responders, as well as in BCVA < 75 and BCVA ≥ 75 groups. Conclusion The fixed-regimen intravitreal bevacizumab therapy was effective in treating DME. Apart from noninvasive visualization of microvascular damage, OCT-A showed limited usefulness in predicting treatment response. Although the study showed that the number of MAs was significantly reduced during treatment, which is an OCT-A predictor of a good response to bevacizumab treatment at a 12-month visit, commonly observed artifacts may reduce the usefulness of OCT-A.

OCT-Angiography Changes in Patients with Diabetic Macular Edema Treated with Intravitreal Dexamethasone Implant.

PurposeTo evaluate, using optical coherence tomography angiography (OCTA), the impact of intravitreal dexamethasone (DEX) implant on quantitative vascular measurements in patients with diabetic macular edema (DME).MethodsProspective, randomized, and open-label study. Primary endpoints were mean changes in vessel density (VD) and vascular perfusion (VP) in superficial capillary plexus (SCP) and VP in deep capillary plexus (DCP) and peripapillary capillary plexus (PCP).ResultsThirty-four eyes from 19 patients were included. Mean age was 67.4±7.3 years and 24 (76.5%) were men. VD in SCP in the 6 mm × 6 mm perifoveal ring was significantly decreased from 15.2±2.7 mm/mm2 at baseline to 13.5±3.1 at month-2, p, 0.0029. VP in SCP in the 6 mm × 6 mm perifoveal ring decreased significantly from baseline to month-2 (mean change −3.8%; 95% confidence-interval: −7.7% to −1.7%, p, 0.0028). Compared to baseline, the VP in DCP was significantly reduced at month 2 in the perifoveal ring of the 6 mm × 6 mm scan (p, 0.0063), and in the parafoveal ring of the 6 mm × 6 mm scan (p, 0.0048). Foveal avascular zone (FAZ) area did not change throughout the study. Central macular thickness significantly decreased from baseline in 210.3 µm (149.9–270.8 µm) and 201.8 µm (140.4–263.3 µm), p < 0.0001 each at month-2 and month-3, respectively.ConclusionsBesides functional and anatomical improvements, DEX implant significantly reduced VD and VP in DME patients.

Comparison of retinal layer thickness and microvasculature changes in patients with diabetic retinopathy treated with intravitreous bevacizumab vs panretinal photocoagulation

To compare changes in retinal layers and microvasculature in diabetic retinopathy (DR) patients after bevacizumab therapy and panretinal photocoagulation (PRP). This prospective study divided patients into two groups: patients treated with bevacizumab and those treated with PRP. Patients visited our retinal clinic at 1, 3, and 6 months after treatment. Retinal layer thickness and vessel density (VD) using optical coherence tomography angiography were analyzed. 37 eyes in the bevacizumab group and 36 eyes in the PRP group were enrolled. In the bevacizumab group, the parafoveal RNFL, GCL, and IPL thicknesses significantly decreased (P < 0.001, P = 0.013, and P = 0.017, respectively), whereas the thicknesses in the PRP group showed an increasing tendency over time (P = 0.087, P = 0.005, and P = 0.003, respectively). The VD of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the bevacizumab group did not show significant changes, whereas the VD in the PRP group significantly increased over time (both P < 0.001). Additionally, RNFL (P = 0.001) and GCL thicknesses (P = 0.035) were significant factors affecting changes in BCVA, whereas the VDs of SCP and DCP did not. Patients who received bevacizumab therapy did not show a significant change in macular VD, whereas the VD of patients after PRP significantly increased after treatment. The increased macular VD in patients after PRP would be associated with the increased inner retinal layer thickness after treatment, which was significantly related to the impairment in visual acuity.

Macular Microvasculature Features of the Eyes of Healthy Korean Children Using Optical Coherence Tomography Angiography

Purpose: We used optical coherence tomography angiography to analyze the macular microvasculature of normal eyes of healthy Korean children; we derived normative data stratified by age.Methods: We retrospectively analyzed the medical records of 68 children (126 eyes) aged from 3 to 15 years. Optical coherence tomography angiography was performed on 3-mm2 regions centered on the fovea. The vascular densities of the superficial and deep capillary plexuses and the foveal avascular zone were determined, and analyzed by age. We sought correlations between age, gender, axial length, and the spherical equivalent.Results: The foveal, superficial capillary plexus vessel densities were 17.41 ± 5.41, 20.53 ± 4.76, 21.78 ± 5.73, and 22.95 ± 3.91% in children aged 3-5, 6-8, 9-11, and 12-15 years, respectively. The vessel densities of the foveal deep capillary plexus were 30.20 ± 6.59, 34.54 ± 7.16, 35.81 ± 6.02, and 37.38 ± 5.16% in those aged 3-5, 6-8, 9-11, and 12-15 years, respectively. Significant differences by age were apparent (p = 0.002, p &lt; 0.001, respectively). The foveal vessel densities of the superficial and deep capillary plexuses were positively correlated with axial length (R2 = 0.153, p &lt; 0.001; R2 = 0.158, p &lt; 0.001, respectively) and the foveal avascular zone area was negatively correlated with axial length (R2 = 0.085, p &lt; 0.001).Conclusions: The vessel densities of the superficial and deep capillary plexuses measured via optical coherence tomography angiography in normal eyes of healthy Korean children differed by age, and correlated significantly with axial length.

Retinal Microvasculature Changes in Patients With Coronary Total Occlusion on Optical Coherence Tomography Angiography.

Background: Retinal microvasculature has been associated with coronary artery disease (CAD), but the exact contributory role in coronary total occlusion (CTO) is unclear. We aimed to investigate whether retinal vasculature is associated with CTO and could provide incremental value in the assessment of CTO.Methods: A total of 218 CAD patients including 102 CTO and 116 non-CTO were enrolled. Retinal vasculature was measured by optical coherence tomography angiography (OCTA) for all patients. Receiver operating characteristic (ROC) curve was used to assess the performance of retinal vasculature in differentiating CTO from non-CTO patients.Results: In non-CTO CAD patients, vessel density (VD) of mean superficial capillary plexus (SCP) and parafovea SCP were 49.85 and 52.56%, respectively; in CTO patients, VD of mean SCP and parafovea SCP were 47.77, and 49.58%, respectively. After multiple adjustment, VD in the SCP was significantly lower in CTO patients compared to non-CTO patients. VD of superior hemi in the parafovea SCP combined with the clinical variates showed the best ability to predict CTO from CAD with an area under the curve (AUC) of 0.812 (specificity of 89.0% and sensitivity of 65.9%).Conclusions: In CTO patients, retinal VD was significantly decreased, and microvascular damage might specifically target to arterioles than capillaries. Retinal vasculature could thus be a surrogate for detecting the microvascular damage and assist in the assessment of CTO patients. OCTA examination could be suggested to monitor the process of coronary arteries lesions.

Associations Between Diabetic Retinal Microvasculopathy and Neuronal Degeneration Assessed by Swept-Source OCT and OCT Angiography.

Purpose: To provide clinical evidence of the associations between retinal neuronal degeneration and microvasculopathy in diabetic retinopathy (DR).Methods: This case-control study included 76 patients (76 eyes) with type 2 diabetes mellitus (DM), and refraction error between −3.0 and +3.0 D. The eyes were assigned into DM (without DR), non-proliferative DR (NPDR), and proliferative DR (PDR) groups. Age-, sex-, and refractive error-matched normal subjects were enrolled as controls. The mean retinal thickness (mRT), the relative mean thickness of the retinal nerve fiber layer (rmtRNFL, mtRNFL/mRT), ganglion cell layer (rmtGCL), ganglion cell complex (rmtGCC) layer, foveal avascular zone area (FAZa), FAZ perimeter (FAZp), FAZ circularity index (FAZ-CI), and vessel density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP) were assessed by swept-source optical coherence tomography (OCT) and OCT angiography (OCTA). Group comparison and Spearman's partial correlation coefficient analysis were applied to evaluate the correlation between these morphological parameters.Results: rmtRNFL, FAZa, and FAZp in SCP and DCP increased with the DR severity (prmtRNFL < 0.001; pFAZa, SCP = 0.001; pFAZa, DCP = 0.005; pFAZp, SCP < 0.001; pFAZp, DCP < 0.001). The rmtGCL, FAZ-CI in SCP and DCP, and VD in DCP decreased with the DR severity (prmtGCL = 0.002, pFAZ−CI, SCP = 0.002; pFAZ−CI, DCP < 0.001, pVD, DCP < 0.001). After controlling age, sex, duration of diabetes, and hypertension, the rmtRNFL, FAZa in SCP and DCP, and FAZp in SCP and DCP were correlated with the severity of DR (p < 0.05), while VD in SCP and DCP, FAZ-CI, and rmtGCL were negatively correlated with the severity of DR (p < 0.05). The rmtGCL was negatively correlated with the FAZa in SCP (r = −0.34, p = 0.002) and DCP (r = −0.23, p = 0.033), and FAZp in SCP (r = −0.37, p = 0.001) and DCP (r = −0.32, p = 0.003), but positively correlated with VD in SCP (r = 0.26, p = 0.016), VD in DCP (r = 0.28, p = 0.012), and FAZ-CI in DCP (r = 0.31, p = 0.006).Conclusions: rmtRNFL, FAZ-CI in SCP and DCP, and FAZp in SCP are strong predictors of the severity of DR. The ganglion cell body loss is highly correlated with increased FAZp and FAZa, decreased FAZ-CI, and reduced VD with the severity of DR.

The role of OCT- angiography in predicting anatomical and functional recovery after endoscopic endonasal pituitary surgery: A 1-year longitudinal study.

PurposeThe purpose of this study was to investigate the changes in structural spectral-domain optical coherence tomography (SD-OCT), OCT Angiography (OCTA) parameters, and visual acuity, 1 year after endoscopic endonasal approach for the removal of an intra-suprasellar pituitary adenoma compressing optic chiasm and compare outcomes with 48 hours postoperative data.MethodsSixteen eyes of eight patients (4 males, 4 females, mean age 52 ± 11 years) were enrolled in this prospective study. The primary outcome was to evaluate the changes over time before and after surgery, analyzing the Best Corrected Visual Acuity (BCVA), Ganglion Cell Complex (GCC), Retinal Nerve Fiber Layer (RNFL) thicknesses, the retinal vessel density (VD) of Superficial Capillary Plexus (SCP), Deep Capillary Plexus (DCP), Radial Peripapillary Capillary (RPC) and the Foveal Avascular Zone (FAZ). The secondary outcome was to identify potential biomarkers that could predict visual acuity changes after 1-year follow-up.ResultsWhen comparing SD-OCT and OCTA measurements obtained after 1 year with those observed 48 hours after surgery, GCC and RNFL were significantly improved. After a significant reduction at 48 hours, GCC thickness showed a significant increase at 1 year after surgery (p = 0.007), while a significant restoration of RNFL thickness was found at 1 year (p = 0.005), as well as the VD of SCP, DCP, and RPC values. FAZ area did not change over time. BCVA significantly improved at each time after surgery (p = 0.037, p = 0.013). A statistically significant correlation was found between the preoperative BCVA, VD of SCP, DCP, RPC, and the postoperative BCVA at 1 year (p = 0.017, p = 0.029, p = 0.031, p = 0.023).ConclusionSD-OCT and OCTA provide helpful information to identify the retinal structural and vascular improvements 1 year after surgery. OCTA parameters could serve as potential predictive markers for visual acuity recovery at long-term follow-up.

Retinal optical coherence tomography angiography findings of acute anterior uveitis.

To evaluate the changes in retinal microvasculature in eyes with anterior uveitis (AU) using optical coherence tomography angiography. Foveal avascular zone (FAZ) of superficial capillary plexus (SCP) and deep capillary plexus (DCP), vessel density (VD) of SCP, DCP, and choriocapillaris, and central macular thickness (CMT) and central foveal thickness (CFT) were calculated from 34 healthy and 41 uveitic eyes. The parameters were compared between the two groups. The deep FAZ was significantly smaller in the eyes with AU during the attack than after recovery and the control group (p = 0.001 and p = 0.003, respectively). The VD in deep capillary plexus (DCP) in eyes with AU during the attack was significantly higher than the control group (p = 0.048). The VD in the foveal sector of DCP in eyes with AU during the attack and after recovery was significantly higher than the control group (p = 0.001 and p = 0.031, respectively). There was no significant difference regarding CMT, CFT, VDs of each segment and each sector, and superficial and deep FAZ between eyes with first uveitis attack and those with recurrent uveitis during the attack and after recovery (p > 0.05). The results of this study show that there is a reduction in the FAZ and an increase in the VD of the DCP of the retina during active AU, and these findings are reversible. Acute AU may affect the macular microvasculature, which is usually temporary, especially in the DCP.

Normative data assessment of age-related changes in macular and optic nerve head vessel density using optical coherence tomography angiography

ObjectiveTo investigate macular and optic nerve head vessel density in healthy individuals using optical coherence tomography angiography (OCTA), and determine their relationship with age. MethodThis retrospective study included 153 eyes of 153 individuals aged between 20 and 80 years, who had no systemic diseases, optic disk, or retinal pathologies. The retinal (6 × 6 mm) and optic disk (4.5 × 4.5 mm) OCTA images were evaluated for superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillary plexus (RPCP) vessel density, foveal avascular zone (FAZ) area, and choriocapillaris flow area and compared among 5 age groups. ResultsThe SCP vessel density was significantly associated with age for the whole image (P = 0.001), parafovea (P = 0.038), and perifovea (P/ce:italic>= 0.001). The DCP vessel density significantly varied with age in the whole image (P = 0.004), parafovea (P = 0.001), and perifovea (P = 0.002). The SCP and DCP vessel densities were significantly lower in the older age groups, and more prominently so after 50 years of age. The FAZ area increased with age; however, this finding was not statistically significant (P = 0.660). The choriocapillaris flow area decreased with age (P = 0.002). The RPCP vessel density in the inside disk significantly decreased with age (P = 0.038). ConclusionAge should be taken into consideration when using OCTA in the diagnosis and follow-up of retinal and optic nerve diseases. It is believed that the results here in can be used as a reference baseline for future studies.

Effects of Hydroxychloroquine on Retinal Vessel Density in Patients with Rheumatoid Arthritis over One-Year Follow-Up: A Pilot Study

Background: To employ optical coherence tomography angiography (OCTA) to evaluate the effects of hydroxychloroquine (HCQ) on the superficial capillary plexus (SCP) and deep retinal capillary plexus (DCP) in patients affected by rheumatoid arthritis (RA). Methods: Patients with recent diagnosis of “definite RA”, based on 2010 Rheumatoid Arthritis Classification Criteria, were included in a prospective, observational imaging study carried out by the G.B. Bietti Foundation between March 2019 and January 2020. Vessel density (VD) of SCP and DCP, central foveal thickness (CFT) and foveal avascular zone (FAZ) values were collected by OCTA. The primary outcome measure was the VD alteration of SCP and DCP in RA-patients after one year of HCQ treatment. Results: OCTA data analysis showed no statistically significant reduction in the mean VD of SCP and DCP, including the mean global area, central subfield, inner ring and temporal, superior, nasal, and inferior sectors, as well as in the mean CFT and FAZ areas. Conclusions: OCTA demonstrated no early change in the VD in the SCP and DCP, in RA-patients after one year of HCQ treatment. A longer monitoring period would more precisely establish the treatment’s effect on the VD and its correlation with HCQ toxicity.

Retinal Vascular Response to Hyperoxia in Patients with Diabetes Mellitus without Diabetic Retinopathy

Purpose To evaluate the retinal vascular response to hyperoxia in patients with diabetes at the preclinical stage of diabetic retinopathy (DR) and to quantify the changes in comparison with normal subjects using optical coherence tomography angiography (OCTA). Methods In this prospective study, 40 eyes of 20 participants comprising 10 diabetic patients with no diabetic retinopathy (NDR) and 10 normal subjects were recruited. OCTA images were acquired in the resting position and were repeated after a hyperoxic challenge using a nasal mask connected to a reservoir bag supplying 100% oxygen at the rate of 15 L per minute for 5 minutes. The changes of mean parafoveal vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), the foveal avascular zone (FAZ) size, and the outer retina flow index were compared between two conditions in each group and between the two study groups. The statistical significance of differences in the means was evaluated using Student's t-test for unpaired samples with consideration of the generalized estimating equations (GEE) for intereye correlation. Results At baseline, the mean parafoveal VD of SCP and DCP were significantly lower in the NDR participants compared to the healthy subjects (P < 0.001 and P = 0.006, respectively). After induction of the hyperoxic challenge in healthy participants, mean parafoveal VD reduced at both the SCP and DCP, but reached a statistical significance only in DCP (P = 0.006). However, following induction of hyperoxic challenge in patients with NDR, no significant decline was noticed in mean parafoveal VD of SCP and DCP. The degree of change in mean parafoveal VD of DCP was statistically significantly more pronounced in healthy subjects compared to the NDR group (P = 0.034). The change in FAZ size and the outer retina flow index were comparable between the two study groups. Conclusion Retinal capillary layers responded differently to hyperoxia-induced challenge, and in normal subjects, the autoregulatory mechanism was mostly effective in the parafoveal DCP. Retinal vascular reactivity was impaired in SCP and DCP at the preclinical stage of DR. OCTA as a noninvasive modality was able to quantify the retinal vascular response to the hyperoxic challenge.

Evaluation of early retinal vascular changes by optical coherence tomography angiography in children with type 1 diabetes mellitus without diabetic retinopathy.

To evaluate macular and peripapillary vascular changes by optical coherence tomography angiography (OCTA) in children with type 1 diabetes mellitus (T1DM) without diabetic retinopathy (DR). This study included 46 patients with T1DM and 46 age-sex matched healthy subjects. All participants were evaluated in terms of macular and optic disk parameters by using AngioVue. Foveal avascular zone (FAZ) area, macular and optic disk vessel density (VD) were analyzed. The correlation of these parameters with metabolic factors such as disease duration, mean hemoglobin A1c (HbA1c), insulin-like growth factor 1 (IGF-1) standard deviation score (SDS), homocysteine (Hcy) level, body mass index (BMI) SDS and daily insulin dose was also investigated in T1DM group. No significant difference was found in FAZ area and optic disk radial peripapillary capillary (RPC) VD comparing diabetic and control groups. In all macular regions, VD was significantly lower in T1DM versus control group both in superficial capillary plexus (SCP) and deep capillary plexus (DCP). None of the metabolic parameters was correlated with FAZ area and optic disk RPC-VD. Vascular density in SCP was negatively correlated with mean HbA1c and positively correlated with IGF-1 SDS. Homocysteine level was negatively correlated with DCP-VD in all areas. In children with T1DM without clinically apparent DR, VD in SCP and DCP was decreased and OCTA is a valuable imaging technique for detecting early vascular changes. The metabolic parameters such as mean HbA1c, IGF-1 SDS and Hcy affect the macular VD in diabetic children. 2011-KAEK-2, 2021/4, Trial registration date: 02.04.2021.

Optical coherence tomography angiography is an efficient tool to assess optic nerve perfusion

Background Glaucoma is the neuropathy of the optic nerve with accelerated apoptosis of the retinal ganglion cells. Optical coherence tomography angiography provides valuable information about the optic nerve and the retinal circulation as an auxiliary tool for glaucoma diagnosis and optic nerve saving. Purpose To evaluate the performance of optical coherence tomography angiography in distinguishing primary open-angle glaucoma from healthy eyes by measuring the radial peripapillary capillary (RPC) vessel density (VD)% and macular superficial capillary plexus (SCP) VD%. Patients and methods A descriptive prospective cross-sectional case–control study was conducted on 60 participants, who were categorized into two groups: group A (30 patients with primary open-angle glaucoma and group B (30 healthy controls of matched age and sex with group A). Structural (retinal nerve fiber layer and ganglion cell complex thickness), functional (the mean deviation, and pattern standard deviation), and vascular parameters [the VD of RPC in scan 4.5×4.5 mm (in whole image, and the peripapillary region) and macular SCP in scan 6×6 mm] were compared between the two groups. Results Statistically significant decreases of VD of RPC of the whole disk, the peripapillary region, and the macular superficial plexus layer were observed in glaucoma eyes compared with controls (all P&lt;0.001). As for the VD of the RPC of the whole disk, the mean value in the healthy control was (51.83±2.31) and in the glaucoma group was (46.21±2.98). For the VD of the RPC of the peripapillary region, the mean value in the healthy control was (52.56±0.2.61), while it was (46.9±3.1) in glaucoma eyes. Regarding VD of the macular superficial plexus layer, the mean value in healthy controls was 47.53±2.1, while it was 43.91±2.81 in glaucoma eyes. Structural, regarding the comparison of the retinal nerve fiber layer thickness between the two groups, the glaucoma patients had a significant (P=0.0001) lower mean value (81.34±0.11) than healthy controls (103.85±0.6.2). Also, for comparing the ganglion cell complex thickness between the two groups, the glaucoma patients had a significant (P=0.0001) lower mean value (80.72±6.9) than healthy controls (99.67±5.8). Functional, significant statistical differences (P=0.0001) of both, the mean deviation [between healthy control (0.18±0.86) and glaucoma group (−4.2±1.9)] and the mean of pattern deviation (P=0.0001) [between healthy control (1.22±0.91) and glaucoma group (4.6±1.72)] were determined. Conclusion Quantitative assessment of the VD of RPC and superficial macular capillary plexus is a promising tool for glaucoma decision making. As compared with healthy controls, the VD of RPC and SCP in glaucoma patients is reduced.

Comparison of the Effect of Pan-Retinal Photocoagulation and Intravitreal Conbercept Treatment on the Change of Retinal Vessel Density Monitored by Optical Coherence Tomography Angiography in Patients with Proliferative Diabetic Retinopathy.

Background: This study compares the changes in retinal vessel density (VD) after pan-retinal photocoagulation (PRP) and intravitreal conbercept (IVC) treatment in proliferative diabetic retinopathy (PDR) eyes by optical coherence tomography angiography (OCTA). Methods: A total of 55 treatment-naïve PDR eyes were included in this retrospective study. Of these, 29 eyes were divided into a PRP group, and 26 eyes were divided into an IVC group based on the treatment they received. OCTA was performed to measure macular and papillary VD at each follow-up in both groups. Results: The macular VD for superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC) and papillary VD for radial peripapillary capillary (RPC) between the two groups demonstrated no significant difference at baseline and month 12 (p > 0.05). The paired t-test results showed that the macular VD for SCP, DCP, CC and papillary VD for the RPC at month 12 did not differ to the baseline in each group (p > 0.05). Conclusions: During the 12-month follow-up, there was no significant change of macular and papillary VD between the PRP and IVC treatment in PDR eyes. Additionally, compared to the baseline, there were no significant changes of macular and papillary VD after either the PRP or IVC treatment. Considering the decrease in VD as DR progress, both treatment modalities can potentially prevent macular and papillary VD loss in PDR.

Evaluation of Retinal Microvascular Perfusion Changes in Patients with Celiac Disease

ABSTRACT Purpose We aimed to determine whether there are retinal microvascular changes in patients with celiac disease (CD). Methods A total of 30 patients with CD (group 1) and 30 healthy controls (group 2) were included in this study. AngioVue optical coherence tomography angiography (OCTA) device was used to evaluate the retinal microvascular structure. Results Some of the values of both optic nerve head (ONH) vessel density (VD) and radial peripapillary capillary VDs were found to be significantly lower in group 1 than in group 2. These 2 groups were similar except for one of the parameters of superficial capillary plexus VD (SCP-VD), whereas it was found that deep capillary plexus VD (DCP-VD) was lower in group 1 than in group 2 except for the foveal area. Conclusion It was determined that some VDs obtained from the ONH and DCP-VD obtained from most areas of the macular region were significantly lower.

Improved Retinal Microcirculation After Cardiac Surgery in Patients With Congenital Heart Disease

Background: Microcirculatory changes in congenital heart disease (CHD) patients undergoing cardiac surgery are not fully understood. We aimed to investigate the changes of retinal microcirculation in CHD patients after cardiac surgery by optical coherence tomography angiography (OCTA) and explore the association between retinal microcirculation and surgical outcome.Methods: This prospective observational study consisted of 71 CHD patients aged ≥6 years undergoing cardiac surgery including 19 cyanotic CHD (CCHD) and 52 acyanotic CHD (ACHD). Optical coherence tomography angiography (OCTA) was used to measure vessel density (VD) and capillary density (CD) of radial peripapillary capillary (RPC) and peripapillary, VD of superficial capillary plexus (SCP) and deep capillary plexus (DCP), thickness of retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) preoperatively and 1 month postoperatively. Transthoracic echocardiography was conducted to measure macrocirculation.Results: In CCHD patients, VD and CD of RPC and peripapillary increased postoperatively (all P < 0.05). In ACHD patients, VD of peripapillary, CD of RPC and peripapillary, and RNFL thickness increased postoperatively (all P < 0.05). VD of SCP and DCP, and GCC thickness did not change significantly in CHD patients after surgery. Lower preoperative retinal microvascular density was associated with longer cardiopulmonary bypass (CPB) time and postoperative length of stay (PLOS). No correlation was found between microcirculatory and macrohemodynamic parameters (all P > 0.05).Conclusions: Improved retinal microcirculation was observed after congenital cardiac surgery and impaired preoperative retinal microvasculature was associated with prolonged CPB time and PLOS, which might provide potential information about the outcome of congenital cardiac surgery.