Superficial Capillary Plexus Layers Research Articles

Clinical outcomes of posterior scleral reinforcement in Chinese high myopia children

We aim to observe the posterior scleral reinforcement (PSR) clinical outcomes of children with high myopia and analyze the retinal vessel alteration before and after PSR by using angiography optical coherence tomography (angio-OCT). Fifty-six pediatric participants (112 eyes) clinically diagnosed high myopia were recruited and were treated by PSR in Shanghai Children’s Hospital from June 1, 2021 to May 1, 2023. The average age ranged from 5.42 to 14.83 years (mean 8.83 years) and mean follow up duration was 8.7 months (3–24 months). The axial length (AL) was significantly shortened after PSR (p < 0.05). The spherical equivalent (SE) and the best-corrected visual acuity (BCVA) were also improved without severe rejection in the follow-up. Compared with baseline, angio-OCT parafoveal vessel indices including vascular area density (VAD) and vascular skeleton density (VSD) on the superficial capillary plexus layer (SCPL), as well as VAD and vessel perimeter index (VPI) on the deep capillary plexus layer (DCPL), were significantly increased after PSR surgery (p < 0.05). VPI on the SCPL, vascular diameter index (VDI) and VSD on the DCPL were also improved without statistical difference after PSR. The VSD on SCPL, VAD on DCPL of the right eyes and the VPI on SCPL of the left eyes were significantly increased after PSR (p < 0.05). PSR surgery can shorten the AL and can stable BCVA and SE in high myopia children. The angio-OCT parameters indicated that the retinal microcirculation supply was significantly improved after PSR.

Changes in OCTA-related parameters and their impact on retinal sensitivity after ILM flap inversion surgery in patients with IMH

Objective: To analyze the changes in optical coherence tomography angiography(OCTA)-related parameters before and after idiopathic macular hole (IMH) internal limiting membrane (ILM) flap inversion surgery and assess their impact on retinal sensitivity. Methods: A retrospective case series study was conducted, collecting clinical data of 30 patients (30 eyes) diagnosed with IMH who underwent vitrectomy combined with ILM flap inversion surgery at Shanxi Eye Hospital, affiliated with Shanxi Medical University, between January 2020 and December 2021. Visual acuity and best-corrected visual acuity were examined preoperatively and at 1, 3, and 6 months postoperatively. Microperimetry measured retinal sensitivity (RS), and OCTA measured retinal thickness (RT) as well as vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Statistical analysis was performed using t-tests, repeated measures analysis of variance, and Pearson correlation analysis. Results: Thirty patients with IMH (30 eyes) were included, with 3 males (3 eyes) and 27 females (27 eyes). The mean age was (62.5±3.0) years, and the follow-up time was (96.3±1.3) days, with a 100% closure rate of macular holes postoperatively. RT in the macular was significantly lower at 1, 3, and 6 months postoperatively compared to preoperative values (F=46.21, P<0.001). The RT in the upper macular region showed statistically significant differences at different time points (P<0.001). VD in the SCP layer showed no significant differences between the upper and lower macular regions at various time points (F=3.21, P=0.601). VD in the upper region of the DCP layer increased at 1, 3, and 6 months postoperatively (P<0.001). RS in the macular was higher at 1, 3, and 6 months postoperatively compared to preoperative values (F=52.01, P<0.001). RS in the lower macular region increased at 3 and 6 months postoperatively (P<0.001), while in the upper region, it increased only at 6 months postoperatively (P<0.001). There was a positive correlation between RS and RT at 1 and 3 months postoperatively, but not at 6 months postoperatively in the upper macular region (r=0.40, P=0.071). In the lower macular region, there was a positive correlation between RS and RT at 1 and 3 months postoperatively (P<0.001). There was no correlation between RS in the upper macular region at 6 months postoperatively and preoperative RT (r=0.43, P=0.072), but there was a positive correlation with RT at 3 months postoperatively (r=0.58, P=0.041). Conclusions: After idiopathic macular hole internal limiting membrane flap inversion surgery, the OCTA-related parameters have changed. There are transient changes in deep vascular parameters and thinning of the retinal layers at the ILM inversion site, leading to decreased sensitivity.

OCT-Angiography of deep and superficial retinal vascular density changes in diabetes without diabetic retinopathy

To analyze the vascular density values (VD) in the superficial and the deep retinal network and in all perimacular sectors of diabetic eyes without clinical retinopathy, comparing them to that of healthy, nondiabetic control eyes. We investigated the factors that may influence these values. This was a cross-sectional study including diabetics without diabetic retinopathy and healthy control subjects. All subjects underwent OCTA examination (RTVue-XR Avanti; Optovue, Fremont, CA, USA). The scanned area was 3×3mm and centered on the fovea. In the superficial and deep capillary plexus, we evaluated the total VD, parafoveal, temporal, nasal, superior and inferior sectors, as well as the superior and inferior hemi-sector VD. The sectors with the greatest area under the curve (AUC) were determined. We evaluated the correlation between certain risk factors and VD values. VD values in all sectors of the superficial capillary plexus layer and deep capillary plexus layer in the diabetic group were significantly lower than in the control group. Among all the parameters, the superficial total VD and superficial parafoveal VD had the greatest AUC (0.992 and 0.991 respectively). The sector with the greatest AUC was the temporal sector in both the SCP (0.990) and DCP (0.976). Age, creatinine clearance and hyperlipemia correlated with vascular density. Superficial and deep retinal VD are both decreased in diabetic patients without diabetic retinopathy. Our results suggest that OCTA might be a promising tool for diabetic retinopathy screening. Quantitative microvascular changes might precede clinical damage.

Retinal vascular density change in patients with heart failure

PurposeThe aim of this study is to assess choroid thickness, retinal vessel density in the superficial capillary plexus layer and deep capillary plexus layer in heart failure (HF) using optical coherence tomography angiography (OCT-A). Methods36 healthy participants (group 1), 33 patients with HF were assessed for this study. HF patients had a left ventricular ejection fraction (LVEF) <50%. HF patients were divided into 2 groups according to the New York Heart Association (NYHA). 15 patients were evaluated as group 2 according to NYHA and 18 patients as group 3 according to NYHA. Choroid thickness, superficial and deep capillary plexus perfusion were analyzed between groups using OCT-A. ResultsChoroid thicknesses were found to be significantly decrease in the HF groups. Superficial capillary plexus density was compared with the control group, no statistically significant difference was found between the HF groups. But among the HF groups, a statistically significant decrease was found in group 3 patients. Deep capillary plexus density was compared with the control group, a statistically significant decrease was found in group 3. In addition, deep capillary plexus density a statistically significant difference was found between the groups HF. ConclusionsPatients with HF showed decreased flow density compared with healthy controls. In addition, significant changes were found in flow densities among the HF groups. Retinal perfusion measured using OCT-A may give an idea about the hemodynamic status and microperfusion of HF patients.

The Impact of Chronic Heart Failure on Retinal Vessel Density Assessed by Optical Coherence Tomography Angiography in Children with Dilated Cardiomyopathy.

(1) Introduction: The aim of this study is to assess retinal vessel density (VD) in the superficial capillary plexus layer (SP) and deep capillary plexus layer (DP) in children with chronic heart failure (CHF) in the course of dilated cardiomyopathy (DCM) using optical coherence tomography angiography (OCTA). (2) Methods: Thirty children with CHF due to DCM lasting more than six months, with an enlarged left ventricle and impaired left ventricular systolic function (left ventricular ejection fraction (LVEF) ≤ 55%), were enrolled to have both their eyes assessed for this study. Mean age of the children was 9.9 ± 3.57 years. The control group consisted of an additional 30 children without CHF (mean age 11.27 ± 3.33 years) matched for age and gender against the study group. All participants underwent transthoracic echocardiography to measure LVEF using Simpson method. Blood serum was tested for N-terminal-pro-brain natriuretic peptide (NT-proBNP) marker value. All children underwent OCTA with evaluation of the foveal avascular zone (FAZ), whole superficial vessel density (wsVD), foveal superficial vessel density (fsVD), parafoveal superficial vessel density (psVD), whole deep vessel density (wdVD), foveal deep vessel density (fdVD), parafoveal deep vessel density (pdVD), whole thickness (WT), foveal thickness (FT), and parafoveal thickness (PFT). (3) Results: Retinal VD in SP was significantly lower in children with CHF as compared to the controls. The following SP parameters in the study group were statistically significantly lower than these same measurements for the control group. Details, with study group findings quantified first, include wsVD (46.2% vs. 49.83%, p < 0.05), fsVD (18.07% vs. 24.15%, p < 0.05), and psVD (49.24% vs. 52.51%, p < 0.05). The WT (311.03 micrometers (μm) vs. 323.55 μm, p < 0.05), FT (244.57 μm vs. 256.98 μm, p < 0.05), and PFT (320.63 μm vs. 332.02 μm, p < 0.05). No significant differences in DP retinal VD were found between the two groups. No statistically significant differences in the FAZ were found. The fsVD and FT were correlated with biometry and the age of the study participants. There was a correlation between FAZ and FT (p < 0.001). There were no correlations between retinal VD in both plexuses and refractive error, sex, NT-proBNP, and LVEF. (4) Conclusions: In children with CHF in the course of DCM as compared to the control group, significantly decreased retinal VD in SP was observed. The results of our study indicate that measurements of the OCTA may be a useful diagnostic method in children with chronic heart failure, but it is necessary to conduct further studies in larger groups of participants and long-term observation of these patients.

Evaluation of optical coherence tomography angiography parameters in patients treated with Hydroxychloroquine

BackgroundOne of the major side effects of Hydroxychloroquine (HCQ) is retinopathy. The aim of this study was to evaluate the Optical coherence tomography angiography (OCTA) parameters in a group of patients who have Hydroxychloroquine-induced retinopathy based on Multifocal electroretinography (mfERG) with a group who do not have retinopathy.MethodThis is a Cross-Sectional Study. In this study, patients with Rheumatoid arthritis (RA) or Systemic lupus erythematosus (SLE) who had been taking Hydroxychloroquine for at least 7 years were included. MfERG and OCTA imaging were performed for all patients. Patients were divided into Normal mfERG and Abnormal mfERG groups based on mfERG results. OCTA parameters were studied in these two groups.ResultSixty-one patients (61 eyes) were included. Forty-one patients had SLE and 20 patients had RA. Forty patients (66.7%) had Abnormal mfERG. The mean vascular density (VD) in Superficial capillary plexus (SCP) layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). Mean VD in SCP layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). In RA subgroup, mean VD in SCP layer in PeriFovea region in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). Mean VD in deep capillary plexus (DCP) layer in Whole Image, Superior Hemi, Inferior Hemi, PeriFovea area in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). This discrepancy was also observed in the RA subgroup but not in the SLE subgroup. The mean of none of the parameters of foveal avascular zone (FAZ) (mm2), Flow Area of Outer Retina (mm2) and Flow Area of Choriocapillaris (mm2) were not statistically significant between the groups Abnormal mfERG and Normal mfERG. (p-value> 0.05).ConclusionVD in the DCP layer decreased in abnormal mfERG patients compared to patients with normal mfERG. But it seems that VD in SCP layer, FAZ Area and Flow Area are similar in both groups. OCTA may be used as a non-invasive tool in the diagnosis of early stages of HCQ-induced retinopathy, especially in RA patients, but further studies are needed.

Superficial and Deep Macula Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes.

Macular superficial capillary plexus (SCP) vessel density is more informative than deep capillary plexus (DCP) vessel density for the detection of glaucoma. The purpose of this study was to characterize optical coherence tomography angiography macular SCP and projection-resolved DCP vessel densities and compare their diagnostic accuracies with ganglion cell complex (GCC) thickness in healthy, glaucoma suspect, and glaucoma eyes. Sixty-eight eyes of 44 healthy subjects, 26 eyes of 16 preperimetric glaucoma suspects, and 161 eyes of 124 glaucoma patients from the Diagnostics Innovations in Glaucoma Study with good quality high-density 6×6 mm2 macula optical coherence tomography angiography images were included. The diagnostic accuracy of SCP vessel density, projection-resolved DCP vessel density and GCC thickness were compared among groups. Mean whole image vessel density (wiVD; % of area occupied by vessels containing flowing blood) in the SCP layer was highest in healthy eyes (49.7%), followed by glaucoma suspect eyes (46.0%), and glaucoma eyes (40.9%) (P<0.001). Mean wiVD in the DCP layer was similar in healthy (50.6%), glaucoma suspect (47.3%), and glaucoma eyes (45.7%) (P=0.925). Diagnostic accuracy of both GCC thickness and SCP wiVD was significantly higher than DCP wiVD for classifying healthy and glaucoma eyes [adjusted area under the receiver operating characteristic curve (95% confidence interval): GCC=0.86 (0.72, 0.94), SCP=0.80 (0.66, 0.91) and DCP=0.44 (0.30, 0.57)] (P<0.001). SCP vessel densities have better diagnostic accuracy for detecting glaucoma than DCP vessel densities. Although the diagnostic accuracy of the macula SCP is relatively modest, it is more informative than the DCP.

Repeatability of Optical Coherence Tomography Angiography Measurements in Patients with Retinal Vein Occlusion.

PurposeTo analyze the repeatability of vessel density (VD) measurements and manual foveal avascular zone (FAZ) measurements using optical coherence tomography angiography (OCTA) in patients with retinal vein occlusion (RVO) without macular edema.MethodsThe study population consisted of patients with RVO and central macular thickness <300 μm. For each subject, measurements were performed twice with a 5-minute interval. The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were calculated to analyze the repeatability of results obtained with the OCTA device. To identify factors related to repeatability, we performed Pearson correlation analyses based on the CV of potential factors.ResultsA total of 48 eyes were included in the study. The ICCs of the VDs in superficial capillary plexus (SCP) and the deep capillary plexus (DCP) were 0.748 and 0.665, respectively, and the CVs of the VDs in SCP and DCP were 9.1% and 12.6%, respectively. The ICCs associated with the FAZ of the superficial layer (SFAZ) and that of the deep layer (DFAZ) were 0.965 and 0.956, respectively, and the CV of the SFAZ and DFAZ were 8.8% and 9.7%, respectively. From Pearson correlation analyses, OCTA quality was significantly correlated with the CV of the VDs of SCP and DCP. However, there were no variables that were significantly correlated with the CV of SFAZ and DFAZ, including OCTA quality.ConclusionsVD measurements in the SCP layer using OCTA exhibited good repeatability, and VD measurements in the DCP layer exhibited relatively low repeatability compared to that of SCP layer measurements in patients with RVO without macular edema after treatment with bevacizumab. Manual measurement of the FAZ area in both SCP and DCP layers resulted in good repeatability. In addition, the repeatability of VD measurements in SCP and DCP layers was correlated with OCTA image quality.

Enhanced Visualization of Retinal Microvasculature in Optical Coherence Tomography Angiography Imaging via Deep Learning.

Background: To investigate the effects of deep learning denoising on quantitative vascular measurements and the quality of optical coherence tomography angiography (OCTA) images. Methods: U-Net-based deep learning denoising with an averaged OCTA data set as teacher data was used in this study. One hundred and thirteen patients with various retinal diseases were examined. An OCT HS-100 (Canon inc., Tokyo, Japan) performed a 3 × 3 mm2 superficial capillary plexus layer slab scan centered on the fovea 10 times. A single-shot image was defined as the original image and the 10-frame averaged image and denoised image generated from the original image using deep learning denoising for the analyses were obtained. The main parameters measured were the OCTA image acquisition time, contrast-to-noise ratio (CNR), peak signal-to-noise ratio (PSNR), vessel density (VD), vessel length density (VLD), vessel diameter index (VDI), and fractal dimension (FD) of the original, averaged, and denoised images. Results: One hundred and twelve eyes of 108 patients were studied. Deep learning denoising removed the background noise and smoothed the rough vessel surface. The image acquisition times for the original, averaged, and denoised images were 16.6 ± 2.4, 285 ± 38, and 22.1 ± 2.4 s, respectively (P < 0.0001). The CNR and PSNR of the denoised image were significantly higher than those of the original image (P < 0.0001). There were significant differences in the VLD, VDI, and FD (P < 0.0001) after deep learning denoising. Conclusions: The deep learning denoising method achieved high speed and high quality OCTA imaging. This method may be a viable alternative to the multiple image averaging technique.

INTRAOCULAR AND INTEROCULAR DIFFERENCES IN PARAFOVEAL VASCULAR DENSITY IN DIABETIC PATIENTS WITHOUT DIABETIC RETINOPATHY.

To evaluate the associations among optical coherence tomography angiography-measured vascular density (VD), intraocular and interocular VD differences, and clinical factors in diabetic patients without diabetic retinopathy. We retrospectively reviewed 94 Type 2 diabetic patients without diabetic retinopathy who had undergone optical coherence tomography angiography. Vascular density and vessel skeleton density were measured in a 3-mm central zone in the total capillary plexus, superficial capillary plexus, deep capillary plexus (DCP), and choriocapillaris layers. Intraocular VD difference was determined between the superior and inferior zones, while interocular VD difference was determined between both eyes of the patient. Associations between optical coherence tomography angiography parameters and clinical factors were evaluated. Vascular density and intraocular and interocular VD differences were significantly associated with signal strength of the image, which was related with age and lens opacity. In multivariate analysis, diabetes duration was negatively associated with skeleton density in total capillary plexus and superficial capillary plexus layers, and positively associated with intraocular VD difference in superficial capillary plexus layer. Estimated glomerular filtration rate was negatively associated with intraocular skeleton density difference in total capillary plexus layer, interocular VD, and skeleton density differences in total capillary plexus layer. Intraocular and interocular VD difference may be an easy and sensitive way to detect subtle early microvascular changes in diabetic patients.

Relationship between Size of the Foveal Avascular Zone and Carbohydrate Metabolic Disorders during Pregnancy.

Aim To determine whether the area of the foveal avascular zone (FAZ), as a morphological indicator of the microcirculation of the perifoveal capillary network, changes in the carbohydrate metabolism disorders during pregnancy (the gestational age of patients with gestational diabetes mellitus (GDM) and preexisting diabetes (PexD)). Methods Ten normal individuals and 41 eyes of 41 patients, 28 with GDM and 13 with PexD, were studied. A 3 × 3 mm area of the FAZ of the superficial capillary plexus layer (SCP) and the deep capillary plexus layer (DCP) was determined by optical coherence tomography angiography (OCTA; RS-3000 Advance, NIDEK). The significance of the correlation between the size of the FAZ and the weeks of pregnancy was determined. Results The area of the FAZ of the SCP was 0.38 ± 0.11 mm2 (normal eyes), 0.41 ± 0.16 mm2 (GDM), and 0.43 ± 0.10 mm2 (PexD). The area of the FAZ of the DCP was 0.78 ± 0.23 mm2 (normal eyes), 0.69 ± 0.16 mm2 (GDM), and 0.79 ± 0.25 mm2 (PexD). No significant difference in the FAZ sizes was observed between the groups. The average number of weeks of pregnancy was 24.1 ± 8.2 weeks in the eyes with GDM and 23.3 ± 11.4 weeks in the eyes with PexD (P > 0.05). Significant correlations were found between the size of the FAZ of the SCP and the number of weeks (r = 0.37, P=0.04 for GDM, and r = 0.49, P=0.04 for PexD, Spearman's rank-order correlation coefficient). Conclusions For GDM and PexD under established glycemic control, the area of the FAZ is not affected, but vascular changes occurred at the early phase of pregnancy.

Grading of macular perfusion in retinal vein occlusion using en-face swept-source optical coherence tomography angiography: a retrospective observational case series

BackgroundTo evaluate the efficacy of swept –source optical coherence tomography angiography (SS-OCTA) in grading macular perfusion in retinal vein occlusion.MethodsRetrospective observational case series including patients with different types of retinal vein occlusion (RVO). SS-OCTA utilizes OCTARA algorithm to examine the retinal vascular plexuses for the presence of morphological signs of ischemia according to a predetermined grading scheme. The findings were compared with fundus fluorescein angiography (FFA), and swept-source optical coherence tomography (SS-OCT) features. Bivariate correlation, coefficient of determination, and crosstabs procedures were used to calculate inter-variable linear correlation, relative contribution of the tested variables, and multivariate association, respectively.ResultsThe study included 144 eyes of 138 patients. The most common type of RVO was branch retinal vein occlusion (BRVO) (53%). The superficial capillary plexus (SCP) and the deep capillary plexus (DCP) did not correlate with each other in all parameters tested. Increased central macular thickness (CMT) and disrupted retinal outer layers (DROL) were associated with increased severity of ischemia in DCP. Disorganized retinal inner layers (DRIL) correlated significantly with the presence of perifoveal capillary ischemia in the SCP and the DCP. Macular ischemia on FFA correlated with ischemia in the SCP layer only. Increased CMT, DROL and DRIL on SS-OCT, and SCP and DCP ischemia on SS-OCTA contributed significantly to diminished best-corrected visual acuity (BCVA).ConclusionSS-OCTA is more precise in defining the extent and location of maximum ischemic insult following RVO compared to FFA, hence represents a more efficient grader for ischemic damage in the posterior pole. Increased CMT, DRIL, and DROL on SS-OCT, and SCP and DCP ischemia on SS-OCTA are significant predictors of poor visual outcome.

Retinal flow density by optical coherence tomography angiography is useful for detection of nonperfused areas in diabetic retinopathy.

Fluorescein angiography (FA) has been conventionally used for detection of retinal nonperfused area (NPA) in diabetic retinopathy (DR) in spite of its qualitative evaluation. Optical coherence tomography angiography (OCTA) has been recently reported to be useful for the quantification of retinal vascular disorder in DR. In this study, we examined whether retinal flow density (FD) measurement in OCTA was useful for NPA detection in DR. The study included 41 eyes from 29 patients with DR who underwent FA and OCTA. Regions surrounded by arteries or veins were extracted in the OCTA image, and the FDs in each region were measured by Image J. Furthermore, each region was classified as NPA or perfused area (PA) in FA. The receiver operating characteristic (ROC) curve was prepared by logistic regression analysis of the FD. The AUC (area under the ROC curve) and cutoff value of FD were also calculated. Two hundred fifty-two regions were analyzed and classified into 38 NPA regions and 214 PA regions using FA. FD of each capillary plexus in NPA was significantly smaller than in PA (p< 0.0001). The AUC of total capillary plexus layers (TCP), superficial capillary plexus layer (SCP), and deep capillary plexus layer (DCP) was 0.975, 0.974, and 0.971, respectively. All areas, where the FD was more than the cutoff value (0.07 in TCP), were diagnosed with PA. Three areas with intraretinal microvascular abnormalities (IRMA) were diagnosed as PA despite being below the cutoff value. FD measurement in OCTA is useful for NPA detection in DR.

Wide-field optical coherence tomography angiography using extended field imaging technique to evaluate the nonperfusion area in retinal vein occlusion

PurposeOptical coherence tomography angiography (OCTA) is a newly developed technology which allows us to reconstruct the three-dimensional chorioretinal vasculature without dye injection. OCTA is a noninvasive, rapid, and reproducible method to assess retinal ischemia. However, one of its limitations is the size of scanning area. A novel yet simple technique to expand the scan length on optical coherence tomography has been reported as an extended field imaging (EFI) technique. It involves imaging the posterior pole through trial frames fitted with a +20 diopter lens. We applied this technique to OCTA to evaluate retinal vein occlusion.Materials and methodsTen eyes of nine patients with retinal vein occlusion were studied. The average age was 69.0 years (range: 49–93 years). We obtained OCTA images by using RTVue XR Avanti OCT with AngioVue®. The images of OCTA with scan size of 8×8 mm were obtained with and without EFI, and then they were compared.ResultsOCTA with EFI technique was performed successfully in all eyes. The nonperfusion area was well defined in superficial capillary plexus layer. The images with EFI were able to capture the larger area of the fundus by an average of 188.5% than those without EFI. The posterior pole inside the vascular arcade was well covered with this technique. The area of the fundus imaged by OCTA with EFI technique was even larger than that of fluorescein angiography using Heidelberg Retina Angiograph 2, which captured a 30° field.ConclusionOur results suggested that OCTA with EFI technique is very useful to evaluate the retinal ischemia in retinal vein occlusion.