Quantification of foveal avascular zone area and macular vascular density changes in papilledema by swept-source optical coherence tomography angiography

This work provide objective measures of foveal avascular zone area and macular vascular density by swept-source optical coherence tomography angiography during the follow-up of a patient with papilledema due to secondary intracranial hypertension.

Intravoxel incoherent motion as a surrogate marker of perfused vascular density in rat brain

Intravoxel incoherent motion (IVIM) MRI has emerged as a valuable technique for the assessment of tissue characteristics and perfusion. However, there is limited knowledge about the relationship between IVIM-derived measures and changes at the level of the vascular network. In this study, we investigated the potential use of IVIM MRI as a noninvasive tool for measuring changes in cerebral vascular density. Variations in quantitative immunohistochemical measurements of the vascular density across different regions in the rat brain (cortex, corpus callosum, hippocampus, thalamus, and hypothalamus) were related to the pseudo-diffusion coefficient D* and the flowing blood fraction f in healthy Wistar rats. We assessed whether region-wise differences in the vascular density are reflected by variations in the IVIM measurements and found a significant positive relationship with the pseudo-diffusion coefficient (p < 0.05, β = 0.24). The effect of cerebrovascular alterations, such as blood-brain barrier (BBB) disruption on the perfusion-related IVIM parameters, is not well understood. Therefore, we investigated the effect of BBB disruption on the IVIM measures in a rat model of metabolic and vascular comorbidities (ZSF1 obese rat) and assessed whether this affects the relationship between the cerebral vascular density and the noninvasive IVIM measurements. We observed increased vascular permeability without detecting any differences in diffusivity, suggesting that BBB leakage is present before changes in the tissue integrity. We observed no significant difference in the relationship between cerebral vascular density and the IVIM measurements in our model of comorbidities compared with healthy normotensive rats.

Investigation of Gastrointestinal Toxicities Associated with Concurrent Abdominal Radiation Therapy and the Tyrosine Kinase Inhibitor Sunitinib in a Mouse Model

Tyrosine kinase inhibitors (TKIs) may be combined with radiation therapy (RT) to enhance tumor control; however, increased incidences of gastrointestinal (GI) toxicity have been reported with this combination. We hypothesize that toxicity is due to compromised intestinal healing caused by inhibition of vascular repair and proliferation pathways. This study explores underlying tissue toxicity associated with abdominal RT and concurrent sunitinib in a mouse model. Four groups of CD-1 mice were treated with 12 Gy abdominal RT, oral sunitinib, abdominal RT + sunitinib, or sham treatment. Mice received oral sunitinib or the vehicle via gavage for 14 days. On day 7, mice were irradiated with 12 Gy abdominal RT or sham treated. Mice were euthanized on day 14 and intestinal tract was harvested for semiquantitative histopathologic evaluation and immunohistochemical quantification of proliferation (Ki67) and vascular density (CD31). Non-irradiated groups had stable weights while abdominal irradiation resulted in weight loss, with mice receiving RT + SUN having greater weight loss than mice receiving RT alone. Semiquantitative analysis showed significant increases in inflammation in irradiated groups. The difference in the density of CD31+ cells was significantly increased in RT alone compared to SUN alone. Ki67+ density was not significant. In summary, we identify a lack of angiogenic response in irradiated GI tissues when abdominal RT is combined with a TKI, which may correlate with clinical toxicities seen in canine and human patients receiving combined treatment.

Does SarsCoV-2 infection really cause damage to retinal microcirculation in mild cases of COVID-19?

Aim To evaluate changes of retinal microcirculation in mild cases of recovered COVID-19 patients at least three months after the infection by optical coherence tomography angiography (OCTA) non-invasive method. Methods In this prospective cross-sectional study, 50 right eyes of 50 recovered COVID-19 patients were compared with 50 right eyes of age and gender-matched healthy controls. After the complete ophthalmological examination, all participants underwent OCTA measurements (RTVue XR Avanti, Optovue, Fremont, CA, USA). Results The time between the initial onset of symptoms, and ophthalmologic examination was 479.20 ±197.10 (126-754) days. Findings of ophthalmic examination of all eyes of the recovered COVID-19 patients were within normal range. Significantly reduced superficial (p=0.046) and deep (p=0.044) macular vessel density (VD) in foveal region in the eyes of the recovered COVID-19 patients was found compared with healthy controls. Significantly enlarged foveal avascular zone (FAZ) area and perimeter in the eyes of the recovered COVID-19 patients (p<0.001) were found too. Conclusion Recovered COVID-19 patients have impaired retinal microcirculation, which can be a cause of the development of retinal vascular diseases.

Changes in retinal and choroidal thickness and vascular density in patients with systemic lupus erythematosus: Assessed by optical coherence tomography angiography

OBJECTIVE

The aim was to investigate the changes in retinal and choroidal thickness and vascular density in patients with systemic lupus erythematosus (SLE) using optical coherence tomography angiography (OCTA).

METHODS

Twenty-nine patients with SLE (29 eyes) and 25 control subjects (25 eyes) were enrolled. SLE activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Retinal thickness (RT), inner retinal thickness (IRT), outer retinal thickness (ORT), choroidal thickness (ChT), retinal superficial vascular density (SVD), retinal deep vascular density (DVD), choriocapillary vascular density (CCVD), foveal avascular zone (FAZ), superficial FAZ (sFAZ), and deep FAZ (dFAZ) were measured using OCTA. The retinal and choroidal thickness and vascular density between the control group and SLE group were compared. The relationships between SLEDAI scores and the retinal and choroidal thickness and vascular density in SLE group were analyzed.

RESULTS

The SVD was significantly increased, and the DVD and CCVD were significantly decreased in the SLE group compared to the control group (p < .05). The results of receiver operating characteristic (ROC) showed that the area under the curve (AUC) values of SVD, DVD, and CCVD were 0.873, 0.729, and 0.727, indicating a high accuracy in discriminating patients with SLE from controls. Correlation analysis showed that the SLEDAI scores were positively correlated with dFAZ (r = 0.589, p = .001) and FAZ (r = 0.451, p = .018), and negatively correlated with DVD (r = -0.491, p = .009) and CCVD (r = -0.521, p = .005).

CONCLUSIONS

DVD and CCVD were decreased in the SLE and might be related to the disease activity. SVD, DVD, and CCVD may hold promise in the discovery of biomarkers for diagnosing SLE.

Does Placental Efficiency and Vascularization Affect Puppy Health? A Study in Boxer and Dobermann Dogs

BACKGROUND

The anatomical and functional characteristics of the placenta influence the adaptive ability of the fetus to the extrauterine environment. Placental efficiency, measured as the gram of neonate produced by each gram of placenta, summarizes these characteristics. In the present study, placental efficiency and its impact on the 7-day postpartum life of the puppies were studied in canine large breeds.

METHODS

Placental efficiency (PE) was computed using chorioallantois weight (WPE) and surface (SPE) efficiency for puppies born from natural delivery or elective cesarean section. Capillary density was also histologically determined. Neonate viability was estimated by the APGAR score and the daily weight gain (DWG) was recorded on day 7 after delivery.

RESULTS

from 15 large-breed bitches, 69 live puppies were born by natural delivery (24 puppies) and elective cesarean section (45 puppies). Cluster analysis detected a group of neonates for which reduced placental efficiency (8 for the WPE, 9 for the SPE) was identified, despite a placental weight and surface within the mean and no difference in capillary density. In this group, the DWG was lower and the mortality within 7 days was higher.

CONCLUSIONS

the results suggest that placental efficiency could be an additional tool for the evaluation of a puppy in the first 7 days after delivery.

Evaluation of macular choroidal and microvascular network changes by activity scores and serum antibodies in thyroid eye patients and healthy subjects

AIM

To investigate the choroidal thickness and the microvascular network changes around the macula in thyroid eye disease (TED) patients at different stages and the relationship of those changes with risk factors, serum antibodies and the severity of TED.

METHODS

A total of 85 participants were enrolled. All participants underwent ophthalmology and endocrinology examinations. Subfoveal choroidal thickness (SFCT), superficial (s) and deep (d) foveal avascular zone (FAZ) area, mean (m) and central (c) superficial vascular density (SVD), deep vascular density (DVD) measurements of the enrolled cases were performed with Topcon swept source optical coherence tomography (OCT)/OCT angiography (OCTA) DRI OCT Triton. Multiple linear regression analysis was used to explore the associations between SFCT, FAZ area, SVD, DVD and the relevant factors of TED.

RESULTS

Those with active TED patients had higher c-DVD and m-DVD levels (P<0.05), however there is no statistically significant difference in SFCT between active and stable TED patients. Among the serum antibodies, it was observed that s-FAZ and d-FAZ increased, c-SVD and m-SVD decreased in patients with high thyroid stimulating hormone-receptor autoantibodies (TRAB) level, whereas SFCT thickened in patients with high levels of both TRAB and human thyroglobulin (hTG). There was no significant difference in SFCT, FAZ, SVD and DVD measurement at gender, between hyperthyroid and euthyroid patients and among those with or without thyroid papillary carcinoma.

CONCLUSION

The results show that both disease activation and serum antibodies differentially affect both superficial and deep retinal vascular density. It has also been shown that high serum antibody levels affect choroidal thickness independent of clinical activity.

Peripapillary and macular vascular densities in healthy, ocular hypertensive, and different stages of glaucomatous eyes

AIM

To investigate vascular changes in different stages of glaucoma and to evaluate the role of optical coherence tomography angiography (OCTA) in the early diagnosis of glaucoma.

METHODS

Glaucoma patients and healthy controls (n=29 eyes) were investigated in this cross-sectional comparative study. Glaucoma patients were grouped as ocular hypertension (n=44 eyes), preperimetric glaucoma (PPG; n=32 eyes), early glaucoma (EG; n=35 eyes), moderate stage glaucoma (MG; n=36 eyes), and advanced glaucoma (AG; n=35 eyes). Peripapillary and macular vascular densities (VDs) of all participants were compared and correlations of VDs and retinal nerve fiber layer thickness (RNFLT), ganglion cell analysis (GCA), and visual field (VF) tests were evaluated. Area under the receiver operation characteristic curves (AUC) of the peripapillary and macular VD parameters were obtained.

RESULTS

VD values decreased with the progression of glaucoma. Most peripapillary and macular VD parameters of PPG and EG groups were lower than healthy controls (P<0.001). There was no significant difference in RNFLT between the PPG and EG groups, but most peripapillary and macular VDs were found to be lower in EG group than in PPG group (P<0.05). In most disease group, VDs were significantly correlated with OCT parameters (P<0.001) and VF index (P<0.05). There were no significant correlations between VF and RNFLT indices in the AG group, but significant correlations were found between VF and VD values (P<0.05). AUC for discriminating between healthy and glaucomatous eyes were highest in whole image peripapillary VD (AUC: 0.865, 0.929, and 0.986, respectively in EG, MG, and AG groups).

CONCLUSION

OCTA can be used in the early diagnosis of glaucoma and can be useful in follow-up of the advanced disease. In cases where limitations or suspicions in structural and functional tests are present, OCTA can be used as a supportive diagnostic test, both in EG and AG.

The use of optical coherence tomography angiography to measure changes in iris vasculature after strabismus surgery

INTRODUCTION

Anterior segment ischemia (ASI) is a rare but potentially sight-threatening complication of strabismus surgery. Preoperative imaging of the iris vasculature may be appropriate in patients at high risk of ASI. In clinical practice, this is currently done through invasive fluoresceine or indocyanine green (ICG) angiography and in study context through laser speckle contrast imaging. The purpose of this study is to investigate the use of noninvasive optical coherence tomography angiography (OCTA) as a screening tool for ASI in strabismus surgery.

METHODS

A prospective interventional trial was conducted from September until November 2021 at the Leuven University Hospitals. Patients scheduled for strabismus surgery to one or more rectus muscles underwent OCTA preoperatively and at day two postoperatively. The vascular density was calculated for all images with sufficient quality. Information on risk factors for ASI was collected. A two-sided t-test was used for pairwise comparison pre- and postoperatively. Filling defects were qualitatively assessed.

RESULTS

Eighteen patients were included. In only seven muscles of five patients, images of sufficient quality on both image acquisition moments were suitable for statistical analysis. The mean age of these patients was 45.2 years and 40% were women. A mean vascular density of 53,099% preoperatively and a mean density of 50,782% postoperatively with a mean decrease of 2.316% (p = .318, 95% confidence interval [-2.886; 7.516]) was found. No filling defects were identified.

DISCUSSION

The small final number of images contributing to statistical analysis shows that current application of the OCTA technique is hampered by poor image quality and poor repeatability. We identified difficulties in the image acquisition process and variable pupil size due to iris muscle contractions as the two main reasons. We believe that adjustments in the OCTA software such as pupil tracking and tracking of iris vasculature can largely overcome these limitations. Furthermore, there is a need for a normative database to allow good quantitative comparison and risk stratification. We conclude that OCTA could be suitable for screening in prevention of ASI with both qualitative and quantitative analysis if adjustments are made.

Macular changes following cataract surgery in eyes with early diabetic retinopathy: an OCT and OCT angiography study

Background

To evaluate changes in macular status and choroidal thickness (CT) following phacoemulsification in patients with mild to moderate nonproliferative diabetic retinopathy (NPDR) using optical coherence tomography.

Methods

In this prospective study, all of the patients underwent uncomplicated phacoemulsification. Retinal superficial capillary plexus vascular density (SCP-VD), macular thickness (MT), and CT were measured pre- and postoperatively.

Results

Twenty-two eyes of 22 cataract patients with mild to moderate NPDR without diabetic macular edema (DME) and 22 controls were enrolled. BCVA increased in two groups at 3 months postoperatively. At 1 and 3 months postoperatively, SCP-VD in the diabetic retinopathy (DR) group significantly increased; changes in SCP-VD in parafovea were significantly greater in the DR group than in the control group. MT and CT in the DR group significantly increased at all visits postoperatively in the fovea and perifovea. Changes in parafoveal MT were significantly greater in the DR group than in the control group at all visits postoperatively. Changes in CT and MT in the fovea were significantly greater in patients with DR than in the controls 1 and 3 months postoperatively.

Conclusion

Uncomplicated phacoemulsification resulted in greater increases in SCP-VD, MT and CT in patients with early DR without preoperative DME than in controls.

Investigation of altered retinal microvasculature in female patients with rheumatoid arthritis: optical coherence tomography angiography detection

BACKGROUND

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disorder that primarily causes symmetrical polyarthritis and bone deformity. In RA patients, sight-threatening inflammatory eye complications would be expected.

OBJECTIVE

The objective of the study is to ascertain the macular retinal vessel density changes in RA patients and controls using optical coherence tomography angiography (OCTA), and to investigate the association between disease and microvascular density alterations.

METHODS

A total of 12 RA patients (24 eyes) and 12 age- and gender-matched control participants (24 eyes) were recruited to the study. We used the Early Treatment Diabetic Retinopathy Study partitioning, hemispheric quadrants and annular partitioning to segment each image into different subregions. The vascular density of superficial retina layer, deep retina layer and conjunctival capillary plexus was quantitatively measured by OCTA and compared with the control group. Correlation analysis was used to explore the relationship between STMI and conjunctival capillaries densities.

RESULTS

In the superficial retinal layer, the vascular density of S, I, L, SL, SR, IL and C1-C5 were significantly decreased in the RA group compared with the control group (P<0.05). For the deep retinal layer, the vascular density of S, SL, SR, IL, C1, C2 and C4 also decreased in RA group. A significant positive correlation was indicated between conjunctival vascular and STMI densities (r = 0.713, P<0.05).

CONCLUSION

OCTA results suggest that RA patients present with a reduced macular retinal vascular density. These subtle alterations of ocular microcirculation may precede severe eye involvements and may be a potential biomarker for early distinguishing abnormal eyes from healthy eyes.

Optical Coherence Tomography Angiography Parameters in Indian Patients With Central Serous Chorioretinopathy

Background In this study, we aimed to evaluate optical coherence tomography angiography (OCTA) parameters among Indian patients affected with central serous chorioretinopathy (CSCR). Methodology A cross-sectional study on Indian patients having unilateral or bilateral affection with CSCR was conducted at the Department of Ophthalmology, Guru Nanak Eye Centre, and Maulana Azad Medical College, New Delhi. A history of ocular symptoms such as a diminution of vision, metamorphopsia, decreased contrast sensitivity (CS), and defective color vision (CV) and their duration were obtained. A detailed ocular examination for best-corrected visual acuity (BCVA), intraocular pressure (IOP), CV, and CS was done. Following this, fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed. OCT was done for central foveal thickness (CFT), subfoveal choroidal thickness (SFCT), neurosensory detachment (NSD), pigment epithelial detachment (PED), and choroidal neovascular membranes (CNVMs). The OCTA imaging was done to examine the foveal avascular zone (FAZ) size, perimeter and circularity, vessel density (VD), and features such as enlarged/distorted FAZ, dark areas, dark spots, abnormal vessels, and choriocapillaris island (CCI) in the retino-choroidal layers. We compared the OCTA features of affected eyes with those of fellow eyes. Results The study involved 52 eyes of 40 CSCR patients, including 32 (80%) males and eight (20%) females with a mean age of 39.3 ± 6.1 (24-49) years. Of the 40 patients, 12 (30%) had a bilateral involvement. The mean CFT was 300.3 ± 158.4 µ, and the SFCT was 258.5 ± 60.4 µ. The mean distance BCVA was the logarithm of the minimum angle of resolution (logMAR) 0.58 ± 0.32. The OCTA showed features such as enlarged/distorted FAZ (36.53% eyes), dark areas (NSD/PED) (84.61% eyes), dark spots (PED) (5.76% eyes), abnormal vessels (dilated vessels/CNVM) (96.15% eyes), and CCI (17.30% eyes). The mean FAZ area, perimeter, and circularity were 0.40 ± 0.71 mm2, 41.8 ± 280.0 mm, and 0.48 ± 0.12, respectively. The VD in the superficial capillary plexus (SCP) was 25.4 ± 14.1, deep capillary plexus (DCP) 15.0 ± 11.5, outer retina (OR) 5.9 ± 6.8, outer retinal choriocapillaris (ORCC) 33.7 ± 16.9, choriocapillaris 29.7 ± 17.5, and choroid 29.9 ± 17.5. The fellow eyes showed a mean FAZ area, perimeter, and circularity of 0.34 ± 0.23 mm2, 76.8 ± 391.2 mm, and 0.47 ± 0.11, respectively, while VD of SCP was 25.9 ± 13.6, DCP 16.5 ± 11.7, OR 14.3 ± 14.9, ORCC 38.0 ± 16.5, choriocapillaris 36.3 ± 17.7, and choroid 35.5 ± 19.2. Conclusions The CSCR eyes had a thicker fovea and sub-foveal choroid (SFC). The FAZ area of affected eyes was larger, while the perimeter was smaller than that in the fellow eye. In the affected eye, the VD in all the retino-choroidal layers was lower, although it was significantly reduced in OR whole (p = 0.006) and foveal choroid (p = 0.022).

Effect of adipose-derived stem cells seeding and surgical prefabrication on composite scaffold vascularization

The study aimed to evaluate an angiogenic effect of adipose-derived stem cells (ASCs) seeding and surgical prefabrication (placing a vascular pedicle inside the scaffold) on developed composite scaffolds made of poly-ε-caprolactone (PCL), β-tricalcium phosphate (β-TCP), and poly (lactic-co-glycolic acid) (PLGA) (PCL+β-TCP+PLGA). Moreover, we aimed to compare our data with previously tested PCL scaffolds to assess whether the new material has better angiogenic properties. The study included 18 inbred male WAG rats. There were three scaffold groups (six animals each): with non-seeded PCL+β-TCP+PLGA scaffolds, with PCL+β-TCP+PLGA scaffolds seeded with ASCs and with PCL+β-TCP+PLGA scaffolds seeded with ASCs and osteogenic-induced. Each rat was implanted with two scaffolds in the inguinal region (one prefabricated and one non-prefabricated). After 2 months from implantation, the scaffolds were explanted, and vessel density was determined by histopathological examination. Prefabricated ASC-seeded PCL+β-TCP+PLGA scaffolds promoted greater vessel formation than non-seeded scaffolds (19.73 ± 5.46 vs 12.54 ± 0.81; p = .006) and those seeded with osteogenic-induced ASCs (19.73 ± 5.46 vs 11.87±2.21; p = .004). The developed composite scaffold promotes vessel formation more effectively than the previously described PCL scaffold.

Retinal microvasculature features in patients with migraine: a systematic review and meta-analysis

Background

Migraine is a central nervous system disorder involving neuronal and vascular factors. The brain has a close anatomical relationship with retinal vessels and similar regulatory processes, and the retinal vascular system is the only in vivo vessel that can be directly visualized, while optical coherence tomography angiography (OCTA) is an advanced retinal vascular imaging technique. In this study, OCTA was used to study the retinal vascular density (VD) and foveal avascular zone (FAZ) in migraine patients, which provided a theoretical basis for its use as a candidate for rapid and non-invasive diagnosis of migraine.

Methods

Published studies comparing retinal microvascular profiles between migraine patients and healthy controls were obtained by a comprehensive search of electronic databases. Nine studies were finally included, including 775 eyes (migraine group: 444 eyes, control group: 331 eyes). Pooled effect sizes were presented as standardized mean differences (SMDs) and 95% confidence intervals (CIs). Statistical analysis was performed using Review Manager software (version 5.30).

Results

The combined results revealed that the superficial and deep macular whole enface VD (MWEVD) (superficial VD: SMD = -0.30, P = 0.0001; deep VD: SMD = -0.61, P = 0.02), superficial foveal VD (FVD) (SMD = -0.42, P = 0.03), deep parafoveal VD (PFVD) (SMD = -0.31, P = 0.002), and peripapillary VD (PVD) (SMD = -0.49, P = 0.002) were significantly reduced in migraine patients compared with healthy people. However, there was a significant increase in the area of the FAZ in migraine patients (SMD = 0.56, P < 0.0001).

Conclusion

Migraine patients are prone to retinal microcirculation disorders, such as decreased blood vessel density and increased avascular area in the fovea. This provides a theoretical basis for OCTA as a candidate for rapid, non-invasive diagnosis of migraine.

Retinal Vascular Density Using Optical Coherence Tomography-Angiography in Optic Neuritis

The aim of this study is to access the perifoveolar and peripapillary vascular density (VD) using optical coherence tomography-angiography (OCT-A) in eyes with optic neuritis (ON) and in fellow eyes, then compare that to healthy controls.

METHOD

This is a cross-sectional study including 22 patients with unilateral ON and 20 control eyes of healthy subjects. A complete clinical examination and OCT-A were performed at least 6 months after the acute episode of optic neuritis. Vascular plexuses of the peripapillary and perifoveolar images obtained from OCT-A were used to calculate the VD in each plexus: superficial, deep, and peripapillary capillaries for each group (ON eyes, fellow eyes, healthy eyes).

RESULTS

Compared to healthy control eyes, in the peripapillary area, we found a significant decrease in VD not only in ON eyes but also in fellow eyes in average (p ≤ 0.05) and in the temporal sector (p < 0.001). In the perifoveolar area, the VD of the superficial capillary plexus is decreased in all sectors (p < 0.001) in ON eyes and only in the upper sector (p = 0.037) of fellow eyes compared to control eyes. VD correlates with ganglion cell layer (GCL) thickness in ON and in fellow eyes.

CONCLUSION

Peripapillary vascular density is decreased in both affected eyes and fellow eyes after a unilateral episode of optic neuritis, suggesting a subclinical involvement of the disease. Further studies are needed to clarify the mechanism and clinical implications of these data.

Macular and Peripapillary Vascular Densities in Non-Glaucomatous Eyes of Patients with Unilateral Glaucoma

Objectives

Our purpose was to investigate vascular alterations in the non-glaucomatous eyes of patients with unilateral primary open angle glaucoma using optical coherence tomography angiography and to evaluate the role of vascular damage in glaucoma pathogenesis.

Materials and Methods

This cross-sectional study included 60 eyes of 30 patients with unilateral glaucoma (63.4±8.8 years) and 30 eyes of 30 healthy subjects (65.6±9.1 years). Three groups were formed: group A, affected eyes of unilateral glaucoma patients; Group B, non-glaucomatous eyes of unilateral glaucoma patients; and group C, healthy controls.

Results

When group A was compared with groups B and C, significant differences were detected in rim area, cup volume, mean cup/disc ratio, and retinal nerve fiber layer thickness parameters (p<0.001 for all). No significant difference was detected between groups B and C (p>0.05 for all). In peripapillary and macular vessel density (VD) comparisons, all parameters except intradisc VD were found to be lower in group A (p<0.0167 for all). No statistically significant difference was detected between groups B and C (p>0.05 for all).

Conclusion

The VD values in eyes with glaucoma were found to be lower than in the other two groups. However, no difference was observed between the non-glaucomatous eyes of glaucoma patients and those of healthy individuals. Thus, the results did not support our hypothesis that VD alterations would be observed in the fellow eyes of patients with unilateral glaucoma if the vascular pathway were responsible in the pathogenesis of glaucoma.

Inter-examiner and intra-examiner reliability of optical coherence tomography angiography in vascular density measurement of retinal and choriocapillaris plexuses in healthy children aged 6-15 years

Objective

This study aimed to test the inter-examiner and intra-examiner reliability of macular vascular density (VD) measurement of retinal and choriocapillaris plexuses in healthy children using optical coherence tomography angiography (OCTA).

Materials and methods

Ninety-two school children were prospectively recruited. Macular OCTA images (6 × 6 mm²) were obtained thrice by two examiners using the RTVue-XR Avanti OCT system. The coefficient of variation (COV), intraclass correlation coefficient (ICC), and Bland-Altman plots were used to evaluate the repeatability and reproducibility.

Results

Ninety participants aged 6-15 years were enrolled; two participants were excluded because of low-quality images. In the retina, the reproducibility and repeatability of VD became poorer from superficial to deep retinal capillary plexus (superficial: COV = 4.61-11.11%; intermediate: COV = 7.73-14.15%; deep: COV = 14.60-32.28%). For both reproducibility and repeatability, the ICC ranged from moderate to high (superficial plexus: ICC = 0.570-0.976; intermediate plexus: ICC = 0.720-0.968; deep plexus: ICC = 0.628-0.954). In the choroid, the inter-examiner reproducibility and intra-examiner repeatability of the VD measurement of choriocapillaris were excellent in the macula, fovea, parafovea, and perifovea (COV = 1.00-6.10%; ICC = 0.856-0.950). The parameters of the foveal avascular zone (FAZ) also showed significant reproducibility and repeatability (COV = 0.01-0.21%; ICC = 0.743-0.994).

Conclusion

The VD measurements of the choriocapillaris and FAZ parameters using OCTA showed excellent inter-examiner and intra-examiner reliability in school children. The reproducibility and repeatability of the VD of three retinal capillary plexuses depended on the depth of the retinal capillary plexus.

The Association of Neovascularization With Optical Coherence Tomography Angiography Parameters in Proliferative Diabetic Retinopathy

AIM

We aim to find an association between neovascularization (NVn) and optical coherence tomography angiography (OCTA) parameters in proliferative diabetic retinopathy (PDR).

METHODS

In a prospective study, 41 subjects including 28 (68%) males and 13 (32%) females having PDR were examined for neovascularization disc (NVD) and neovascularization elsewhere (NVE) clinically and with fundus fluorescein angiography (FFA). A total of 79 eyes were found to be involved. We examined OCTA parameters including foveal avascular zone (FAZ) size, perimeter and circularity, and vessel density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina (OR), outer retinal chorio-capillaries (ORCC), chorio-capillaries (CC), and choroid (C) in these subjects.

RESULTS

 In eyes with NVD, the central foveal thickness (CFT) (p=0.83) and sub-foveal choroidal thickness (SFCT) (p=0.08) were higher, the FAZ area was significantly larger (p=0.005), and the VD was lower in all retino-choroidal layers. However, it was significantly lower in SCP foveal (p=0.005) and ORCC foveal (p=0.05) than in eyes not having NVD. For NVE, the CFT (p=0.03) and SFCT (p=0.01) were more in affected eyes. The eyes without NVE had a better circularity index (p=0.07) and the highest VD in OR slab (p=0.02) than those eyes that had NVE < ½ disc area (DA) and NVE > ½ DA. On comparing eyes without NVE, NVE < ½ DA, and NVE > ½ DA, the latest had the highest VD in SCP (p=0.59) and lowest VD in DCP (p=0.43) and OR (p=0.02). The VD in ORCC, CC, and choroid was highest in the no NVE group, followed by the NVE > ½ DA and NVE < ½ DA groups in that order. The subjects having vitreous hemorrhage (VH) and intra-retinal microvascular abnormalities (IRMA) had higher values for CFT and SFCT than eyes without these.

CONCLUSIONS

 An increased CFT and SFCT are associated with the appearance of NVD, NVE, VH, and IRMA. The presence of NVD, VH, and IRMA is associated with a larger FAZ area, while that of IRMA and NVE is associated with reduced FAZ circularity. Eyes with NVD, VH, and IRMA had lesser VD in all the retino-choroidal layers. Eyes with NVE > ½ DA had the highest VD in SCP and lowest in DCP and OR; this pattern of VD foretells severer affection in NVE. IRMA was associated with a larger FAZ area, larger FAZ perimeter, and lesser circularity, indicating the presence of central ischemia.

Swept Source Optical Coherence Tomography Angiography Findings in Birdshot Chorioretinitis: A Cross Sectional Study of 21 Patients

PURPOSE

Birdshot chorioretinitis (BSCR) is a form of posterior uveitis that is classically characterized by hypopigmented choroidal lesions outside of the major arcades. However, little is known about the extent of choroidal involvement in the macula. We aim to describe the vascular abnormalities observed at the level of the choriocapillaris (CC) in the maculae of BSCR patients, using swept source optical coherence tomography angiography (SS-OCTA).

METHODS

A cross-sectional, observational study was conducted. Eligible patients underwent clinical examination and SS-OCTA imaging. The main outcome measures were the frequency of vascular abnormalities observed at the level of the CC on SS-OCTA and foveal choriocapillaris vascular density (CVD).

RESULTS

Twenty-one patients were included, with a median age of 61.5 years. All patients had bilateral disease with a median disease duration of 6 years. All but one patient received systemic immunosuppressive drug therapy, and 19 patients had suppressed inflammation on treatment at the time of the SS-OCTA assessment. Of the 42 affected eyes, 39 (92.9%) had gradable SS-OCTA images, with a mean LogMAR visual acuity of 0.18 (Snellen equivalent 20/30). In total, 34 of 39 (87.2%) eyes had some degree of pathologic flow loss, and after controlling for patient age and disease activity, both worse VA and longer disease duration remained statistically significantly associated with reduced foveal CVD.

CONCLUSIONS

Our findings suggest that pathologic CC flow loss in the macula is frequently encountered and may contribute to visual function decline in patients with BSCR. Further studies with longitudinal follow-up are needed to characterize the evolution of these areas of pathologic CC flow loss over time.

Distribution of the Retinal Microcirculation Based on the Morphology of the Optic Nerve Head in High Myopia

PURPOSE

To explore the retinal microvasculature of the optic nerve head and macula and their associations with the optic nerve head deformation in high myopia.

METHODS

One hundred sixty-seven eyes from patients with high myopia (HM) were enrolled in a cross-sectional study. We have evaluated and measured characteristics like the tilt ratio of the optic disc, interpupillary vascular density (IVD), peripapillary vascular density (PVD), macular vascular density (MVD), subfoveal choroidal thickness (SFCT) and foveal avascular zone (FAZ). The subjects were classified as a non-tilt group (control group) and a tilt group based on the tilt index. The above parameters were utilized to compare the two groups. In addition, we collected the data from the subjects' right eyes to analyze variance, the Kruskal-Wallis test, and the least significant difference.

RESULTS

The patients were divided into the non-tilt group of ninety-one eyes and the tilt group of seventy-six eyes. We found that the IVD in the tilt group was more significant than in the non-tilt group (t = -2.794, P = .006). On the other hand, the PVD was less in the tilt group than in the non-tilt, especially in the NS, NI and IN directions (t_NS = 3.782; t_NI = 3.07; t_IN = 2.086; P < .05). Interestingly, the values of PVD were the highest in temporal, second in superior and inferior and lowest in nasal. Concerning the fovea-DMVD (including fovea, parafovea and perifovea), we characterized them as more minor in the tilt group when compared to those in the non-tilt group (P < .05).

CONCLUSION

Herein, we discovered that the retinal microvasculature differed significantly in patients with HM according to the ONH morphology. In this population, lower PVD and thinner SFCT were associated with higher odds of the tilted optic disc. In addition, the other two characteristics, the IVD and DMVD, were affected by the ONH deformation. Finally, we showed that PVD demonstrated better predictability of rapid myopic progression than MVD.

Changes of optic nerve head microcirculation in high myopia

AIM

To analyze the correlation of age, spherical equivalent (SE), and axial length (AL) with the microcirculation of optic nerve head (ONH) in high myopia (HM).

METHODS

In this cross-sectional clinical study, 164 right eyes were included. Optical coherence tomography angiography (OCTA) was used to detect ONH vessel density. Eyes were classified based on age, SE, and AL. Groups of Age1, Age2, and Age3 were denoted for age classification (Age1<20y, 20y≤Age2<30y, Age3≥30y); Groups SE1, SE2, and SE3 for the SE classification (-9≤SE1<-6 D, -12≤SE2<-9 D, SE3<-12 D); Groups AL1, AL2, AL3, and AL4 for the AL classification (AL1<26 mm, 26≤AL2<27 mm, 27≤AL3<28 mm, AL4≥28 mm).

RESULTS

No significant difference was observed in vessel density among the Age1, Age2, and Age3 groups (all P>0.05) and the SE1, SE2, and SE3 groups (all P>0.05). No significant difference was observed in the intrapapillary vascular density (IVD) among AL1, AL2, AL3, and AL4 groups (P>0.05). However, a significant decrease was found in the peripapillary vascular density (PVD) in the AL1, AL2, AL3, and AL4 groups (F=3.605, P=0.015), especially in the inferotemporal (IT; F=6.25, P<0.001), temporoinferior (TI; F=2.865, P=0.038), and temporosuperior (TS; F=6.812, P<0.001) sectors. The IVD was correlated with age (r=-0.190, P<0.05) but not with SE or AL (P>0.05). The PVD was correlated with AL (r=-0.236, P<0.01) but not with age or SE (P>0.05).

CONCLUSION

With the increase of AL, the IVD remains stable while the PVD decreases, especially in the three directions of temporal (IT, TI, and TS). The main cause of microcirculation reduction may be related to AL elongation rather than an increase in age or SE.

The correlation of retinal neurodegeneration and brain degeneration in patients with Alzheimer's disease using optical coherence tomography angiography and MRI

Introduction

Pathological changes in Alzheimer's disease can cause retina and optic nerve degeneration. The retinal changes are correlated with cognitive function. This study aimed to explore the relationship of retinal differences with neuroimaging in patients with Alzheimer's disease, analyze the association of cognitive function with retinal structure and vascular density, and identify potential additional biomarkers for early diagnosis of Alzheimer's disease.

Method

We performed magnetic resonance imaging (MRI) scans and neuropsychological assessments in 28 patients with mild Alzheimer's disease and 28 healthy controls. Retinal structure and vascular density were evaluated by optical coherence tomography angiography (OCTA). Furthermore, we analyzed the correlation between neuroimaging and OCTA parameters in patients with mild Alzheimer's disease with adjustment for age, gender, years of education, and hypertension.

Results

In patients with mild Alzheimer's disease, OCTA-detected retinal parameters were not significantly correlated with MRI-detected neuroimaging parameters after Bonferroni correction for multiple testing. Under multivariable analysis controlled for age, gender, years of education, and hypertension, the S-Hemi (0-3) sector of macular thickness was significantly associated with Mini-cog (β = 0.583, P = 0.002) with Bonferroni-corrected threshold at P < 0.003.

Conclusion

Our findings suggested decreased macular thickness might be associated with cognitive function in mild AD patients. However, the differences in retinal parameters didn't correspond to MRI-detected parameters in this study. Whether OCTA can be used as a new detection method mirroring MRI for evaluating the effect of neuronal degeneration in patients with mild Alzheimer's disease still needs to be investigated by more rigorous and larger studies in the future.

Macular vessel densities by optical coherence tomography angiography in patients with intermediate uveitis

Purpose

To evaluate the macular microvascular changes in patients with intermediate uveitis (IU) using optical coherence tomography angiography (OCT-A) and to determine the relationship of OCT-A measurements with disease duration and activity.

Methods

This cross-sectional study was performed at the uvea department of a tertiary hospital. Patients with IU (8 women, 8 men; mean age: 28.80 ± 12.80 years) were included in the study. The macular thickness measurements obtained by optical coherence tomography (OCT) (Heidelberg Spectralis, Heidelberg Engineering, Heidelberg, Germany) and macular superficial and deep vessel density (VD) parameters obtained by OCT-A (Avanti RTVue-XR; Optovue, Fremont, CA, USA) were compared with healthy subjects (12 men, 22 women; mean age: 28.40 ± 8.32 years). Eyes with pathology including marked obvious edema in the macula were not included in the study.

Results

The macular thickness was found to be higher in the patient group (p < 0.001). The deep and superficial VD measurements in almost all quadrants in both superficial and deep layers were significantly lower in the IU patient group (p < 0.05). Macular thickness was increased in the active state of IU (p = 0.03), however, none of the OCT-A parameters showed a significant difference between active and inactive IU patients (p > 0.05). No correlation was observed between OCT-A parameters and total IU disease duration.

Conclusion

Quantitative analyses of macular vascular structures demonstrate significantly reduced VD in both superficial and deep retinal layers in IU patients. Considering the importance of the macula in visual prognosis, OCT-A can provide crucial data for the monitoring and follow-up of IU patients.

Quantitative study of peripapillary retinal nerve fiber layer thickness and peripapillary vessel density in patients with different stages of Parkinson's disease

AIM

To observe the changes in the thickness of peripapillary retinal nerve fiber layer (pRNFL) and peripapillary vessel density (pVD) in patients with different stages of Parkinson's disease (PD).

METHODS

Totally 47 patients (47 eyes) with primary PD were divided into the mild group and the moderate-to-severe group according to Hoehn & Yahr (H&Y) stage. Among them, there were 27 cases (27 eyes) in mild group and 20 cases (20 eyes) in moderate-to-severe group. And 20 cases (20 eyes) who were included in the control group were healthy people who came to our hospital for health screening at the same time. All participants underwent optical coherence tomography angiography (OCTA) examinations. The pRNFL thickness, total vessel density (tVD) and capillary vessel density (cVD) of the optic disc in average, superior half, inferior half, superior nasal (SN), nasal superior (NS), nasal inferior (NI), inferior nasal (IN), inferior temporal (IT), temporal inferior (TI), temporal superior (TS), and superior temporal (ST) were measured. One-way ANOVA was used to compare the differences of optic disc parameters among the three groups, and Pearson and Spearman correlations were used to analyze the correlation between pRNFL, pVD and the disease duration, H&Y stage and UPDRS-III score in patients with PD, respectively.

RESULTS

There were significant differences in pRNFL thickness in average, superior half, inferior half, SN, NS, IN, IT and ST quadrants among the three groups (P<0.05). In PD group, the pRNFL thickness in average, superior half, inferior half, NS and IT quadrants were negatively correlated with H&Y stage and UPDRS-III score, respectively (P<0.05). There were statistically significant differences in the cVD of whole image, inferior half, NI and TS quadrants, the tVD of the whole image, inferior half, and peripapillary among the three groups (P<0.05). In PD group, the tVD of whole image and the cVD of NI and TS quadrants were negatively correlated with the H&Y stage, respectively (P<0.05); the cVD of TS quadrant was negatively correlated with UPDRS-III score (P<0.05).

CONCLUSION

The thickness of pRNFL in PD patients is significantly decreased, and it is negatively correlated with H&Y stage and UPDRS-III score. With the increase of the severity of the disease, the pVD parameters in PD patients increase at first in the mild group, and then decrease in the moderate-to-severe group, and negatively correlate with H&Y stage and UPDRS-III score.

Precision (repeatability and reproducibility) of papillary and peripapillary vascular density measurements using optical coherence tomography angiography in children

Importance

Optical coherence tomography angiography (OCTA) has been widely applied into children, however, few studies have assessed the repeatability and reproducibility of papillary and peripapillary VD in healthy children.

Objective

To assess the precision of papillary and peripapillary vascular density (VD) measurements using optical coherence tomography angiography (OCTA) and analyze the effects of the signal strength index (SSI) and axial length (AL) on precision estimates.

Design setting and participants

This was a prospective observational study. Seventy-eight children aged 6-16 years underwent 4.5 × 4.5 mm OCTA (RTVue XR Avanti) disc scans: two scans by one examiner (repeatability) and two additional scans by another examiner (reproducibility). Within-subject standard deviation (Sw), test-retest reproducibility (TRT), within-subject coefficient of variation (CoV), intraclass correlation coefficient (ICC), and Bland-Altman analysis were performed.

Main outcomes and measures

In repeatability measurement, the fluctuation ranges (minimum to maximum) of VD between intraexaminer A/B in Sw, TRT, CoV, and ICC were (1.05-2.17)% / (1.16-2.32)%, (2.9-6)% / (3.21-6.44)%, (1.9-4.47)% / (2.08-5)%, and (0.588-0.783)% / (0.633-0.803)%, respectively. In reproducibility measurement, the fluctuation ranges of VD in Sw, TRT, CoV, and ICC were 1.11-2.13%, 3.07-5.91%, 1.99-4.41%, and 0.644-0.777%, respectively. VD was negatively correlated with SSI in most sectors of the peripapillary (e.g., inferior nasal, temporal inferior, temporal superior, superior temporal, and superior nasal). AL was positively correlated with inferior temporal VD and negatively correlated with superior nasal VD.

Conclusion and relevance

Optical coherence tomography angiography showed moderate-to-good repeatability and reproducibility for papillary and peripapillary perfusion measurements in healthy children. The SSI value affects most of the peripapillary VD, while AL affects only the temporal inferior and nasal superior peripapillary VD.

Retinal ganglion cell and microvascular density loss in hereditary spastic paraplegia

Background

Hereditary spastic paraplegia (HSP) is characterized by progressive degeneration of distal axons in the long corticospinal tracts. Loss of retinal cells and microvascular networks has neither been suspected nor investigated. We concurrently examined the retinal microvasculature and retinal layer morphology in patients with HSP to assess whether retinal features may portray disease and its progression.

Methods

Fifteen patients with HSP and 30 healthy controls were included in this cross-sectional case-control study. Disease severity was assessed with the Spastic Paraplegia Rating Scale (SPRS). Severity of ataxia was determined by the Scale for the Assessment and Rating of Ataxia (SARA). Retinal microvasculature was measured by means of optical coherence tomography angiography (OCT-A) and morphology of retinal layers using structural OCT. Mixed-effects models were applied for data analysis.

Results

HSP patients showed significantly reduced vessel density of the superficial vascular plexus (SVP), reduced ganglion cell layer (GCL) volume, reduced inner plexiform layer (IPL) volume and reduced temporal-inferior peripapillary retinal nerve fiber layer (pRNFL) thickness versus healthy controls. GCL volume reduction correlated significantly with the worsening of visual acuity and higher SARA scores.

Conclusions

These findings demonstrate that, in HSP both cells and vascular networks of the retina are compromised. Assessment of the retinal GCL, IPL and SVP may aid in diagnosis and monitoring of disease progression as well as provide novel structural outcome measures for clinical trials.

Evaluation of Retinal Microvascular Perfusion Changes in Patients with Celiac Disease

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.

Long-Term Variations in Retinal Parameters after Uncomplicated Cataract Surgery

Background: Cataract phacoemulsification surgery provides excellent refractive results; however, it also elicits changes in the posterior segment of the eye. This study aimed to determine changes in retinal parameters measured by spectral-domain optical coherence tomography (SD-OCT) and OCT angiography (OCTA) after an uncomplicated cataract surgery, including the impact of effective phacoemulsification time (EPT). Methods: The study included 44 patients without retinal abnormalities, followed up after unilateral uncomplicated cataract phacoemulsification in a single ophthalmological unit. Patients were evaluated for the following parameters at baseline and at 2 weeks, 3 months, and 12 months after the surgery: best corrected visual acuity, central retinal thickness (CRT), average central retinal thickness (CRTA), central retinal volume (cube volume (CV)), vessel density central (VDC), vessel density full (VDF), vessel perfusion central (VPC), and vessel perfusion full (VPF). The EPT recorded at each procedure was used as a covariant for the evaluation of changes in retinal parameters after the surgery. Analysis included 44 eyes for SD-OCT and 17 for OCTA evaluation, according to adopted scan quality thresholds. Results: A significant increase in CRT, CRTA, and CV was noted at each follow-up point compared with baseline. The rising tendency was observed in the first 3 months after the surgery, with a decline over the subsequent months. The VPF parameter showed a stable improvement after the surgery. The analysis of covariance did not confirm any significant effect of the EPT on variations in CRT, CV, CRTA, VDC, and VPF and there was a weak effect on the VDF parameter. Conclusions: Uncomplicated cataract surgery results in an increase in retinal thickness and volume in the first few months after the surgery, followed by a spontaneous decline in these parameters in the subsequent months. A long-standing improvement is noted in the VPF parameter.

Evaluation of Radial Peripapillary Capillary Density in G6PD Deficiency: An OCT Angiography Pilot Study

Glucose-6-phosphate-dehydrogenase (G6PD) deficiency is an inherited enzymatic disorder causing hemolytic anemia. The purpose of this pilot study was to compare vascular density (VD) values of the radial peripapillary capillary (RPC) plexus in G6PD-deficient and G6PD-normal men, using optical coherence tomography angiography (OCTA).

METHODS

46 G6PD-deficient men and 23 age-matched male controls were included. A complete ophthalmological evaluation, consisting of slit-lamp biomicroscopy, best-corrected visual acuity, intra-ocular pressure measurement, structural optical coherence tomography, and OCTA scanning of the optic nerve head, was performed. The en-face angioflow images were carefully analyzed and the VD values of the RPC plexus were measured using the AngioAnalytics™ software embedded in the OCTA device. Medical conditions, including systemic hypertension, hypercholesterolemia, and diabetes mellitus, were also investigated.

RESULTS

G6PD-deficient eyes showed higher values of VD in all peripapillary sectors, but a statistical significance (p = 0.03) was reached only in the infero-temporal sector. There were no significant differences in terms of hypercholesterolemia, systemic arterial hypertension, and diabetes mellitus between the two study groups.

CONCLUSION

Results show that VD values of the RPC plexus are higher in G6PD-deficient men than in G6PD-normal subjects, but a statistically significant difference was found only in the inferior temporal sector. Overall, our preliminary findings support the hypothesis that the RPC layer of G6PD-deficient men consists of a denser vascular network, which may contribute to offering protection against ocular atherosclerotic vasculopathies.

Assessment of the Retinal Vessels in Keratoconus: An OCT Angiography Study

This study investigated vascular density and foveal avascular zone (FAZ) parameters using optical coherence tomography angiography (OCT-A) in patients with keratoconus (KC). Participants with KC and healthy controls were included and underwent best-corrected visual acuity (BCVA), keratometry, anterior segment OCT, and macular OCT-A examinations. Of the 70 subjects (mean age 42.9 ± 15.31 years), 79 KC and 47 healthy eyes were included. Significant reductions in the KC group were recorded for the FAZ area, with a mean (±SD) of 0.19 ± 0.12 vs. 0.25 ± 0.09 mm2 p < 0.001. Central vascular density in KC patients was lower compared with the controls: 6.78 ± 4.74 vs. 8.44 ± 3.33 mm−1 p = 0.049; the inner density was also decreased in the study group (13.64 ± 5.13 vs. 16.54 ± 2.89 mm−1, p = 0.002), along with the outer density (14.71 ± 4.12 vs. 16.88 ± 2.42 mm−1, p = 0.004) and full density (14.25 ± 4.30 vs. 16.57 ± 2.48) p = 0.003. Furthermore, BCVA was positively correlated with central vascular density (R = 0.42 p = 0.004, total R = 0.40, p = 0.006) and inner density (R = 0.44, p = 0.002) in patients with KC but not in controls. Additionally, we found a correlation between K2 and inner vascular density (R = −0.30, p = 0.043) and central epithelium thickness and outer density (R = 0.03, p = 0.046). KC patients had lower macular vascular density and a smaller FAZ than healthy participants. The BCVA in KC patients was correlated with the vascular density.

Optical Coherence Tomography Angiography for the Evaluation of Retinal and Choroidal Vasculature in Retinitis Pigmentosa: A Monocentric Experience

Purpose: We investigated the chorioretinal microvascular changes in patients with retinitis pigmentosa (RP) by optical coherence tomography angiography (OCTA). Methods: Twenty-six patients (52 eyes) affected by RP were compared with 19 healthy controls (38 eyes). OCTA 3 mm × 3 mm macular scans were performed in all subjects. We evaluated the vessel density (VD) of the superficial capillary plexus (VD SCP), deep capillary plexus (VD DCP), choriocapillaris (VD CC), and choroid (VD choroid). We also evaluated the foveal avascular zone (FAZ) area, and the correlation between clinical and OCTA parameters. We also measured central retinal thickness (CRT) and subfoveal choroidal thickness (CT). Results: RP patients compared to healthy controls showed significantly lower VD SCP values (27.56% ± 15.37 vs. 49.39% ± 1.55; p-value < 0.0001), lower VD DCP values (38.43% ± 15.23 vs. 3.34% ± 0.26; p-value < 0.0001), lower VD CC values (46.02% ± 1.293 vs. 50.63% ± 0.4274; p-value = 0.0040), and lower VD choroid values (38.48% ± 15.23 vs. 3.34% ± 0.26; p-value < 0.0001). Even the FAZ area was significantly lower in RP patients (0.45 mm2 ± 0.35 vs. 0.26 mm2 ± 0.13; p-value < 0.0001). The FAZ area was larger with increasing age, both in control (r = 0.42; p = 0.012) and RP group (r = 0.46; p-value = 0.009). In RP patients, there was a statistically significant correlation between best-corrected visual acuity and VD SCP (r = 0.24, p-value = 0.04) and VD DCP (r = 0.52; p-value = 0.0004) and between subfoveal choroidal thickness and VD SCP (r = 0.43, p-value < 0.001) and VD DCP (r = 0.35, p-value < 0.001). Conclusions: In our study, OCTA reported relevant vascular alterations in RP patients in comparison with the healthy controls, in agreement with the published literature. These abnormalities were associated with choroidal atrophy and related to visual acuity loss. OCTA provided clinically significant information and may represent a reliable tool for the management of RP patients.

Retinal Optical Coherence Tomography Angiography Parameters Between Patients With Different Causes of Chronic Kidney Disease

Background

Chronic kidney disease (CKD) is a major public health issue because of the rising number of patients with the risk of progression to end-stage renal disease. The retinal micro-vasculatures provide a unique window to assess systemic microcirculation. Optical Coherence Tomography Angiography (OCTA) parameters may provide a non-invasive method for systemic correlation. This research aims to compare the association of OCTA parameters in different causes of CKD.

Methods

This is a single-center cross-sectional study on patients with CKD at the Universiti Kebangsaan Malaysia Medical Centre over 2 years. Patients with CKD were divided into three groups: DM group (diabetic CKD), HPT group (hypertensive CKD), and AG group (autoimmune-related glomerulonephritis CKD). The OCTA parameters, namely, the foveal avascular zone (FAZ), vascular density (VD), perfusion density (PD), and macular volume (MV), were measured and recorded using OCTA. Blood and urine analyses were taken as the patient's CKD profile. The demographic data, the OCTA parameters and the CKD profiles, were analyzed using SPSS version 23.

Results

The right eyes of 232 patients were included. The median age of the control and CKD subjects were 36 and 61 years old respectively. The proportion of the subjects under the control, diabetes mellitus (DM), HPT, and AG group were 30.6, 53.4, 5.6, and 10.4% respectively. There was no significant difference in FAZ, but there is a significant difference in the VD, PD, and MV between the control and CKD groups. There was a statistically significant difference between the three different causes of CKD in VD and PD (p < 0.001, p = 0.001, respectively). When compared with the control group for VD and PD, there were significant differences between the DM-control group (p < 0.001, p < 0.001) even when the age variable was considered, but no significant difference when comparing the HPT-control and the AG-control. There was a significant correlation between age, FBS, and HbA1c with VD and PD. There was no significant association between CKD profile and FAZ.

Conclusion

Our study showed the meaningful reduction of VD and PD in patients with diabetes and CKD. However, the use of OCTA to screen or predict CKD in patients living with diabetes mellitus, hypertension, or autoimmune nephritis was not shown to be useful.

The alterations of retinal vasculature detected on optical coherence tomography angiography associated with chronic obstructive pulmonary disease

OBJECTIVES

This study aimed to evaluate the retinal vasculature of the macula and optic disc in patients with chronic obstructive pulmonary disease (COPD) by optical coherence tomography angiography (OCTA).

METHODS

The right eyes of 70 COPD patients and 71 healthy individuals were evaluated. These patients had moderate airflow limitation and mean PO2 of 60 mmHg, and their average age was less than 60 years. Superficial and deep capillary plexus vascular densities, foveal avascular zone (FAZ) width, and optic disc parameters were measured with OCTA. In addition, the correlation between the PO2 level in COPD patients and superficial, deep, and peripapillary vascular densities and FAZ was examined in the study.

RESULTS

The COPD group had a significant decrease in the vascular density in the superficial (fovea [p = 0.019]; parafovea [p = 0.013]; and perifovea [p = 0.001]) and deep capillary plexus (fovea [p = 0.028]; parafovea [p = 0.005]; and perifovea [p = 0.002]). Also, the enlargement of the FAZ (p = 0.002) and a decrease in the peripapillary vascular density (p = 0.006) were observed in the COPD group. There was a positive correlation between PO2 level and superficial, deep, and peripapillary vascular densities in COPD patients and a negative correlation with FAZ (r = 0.559-0.900).

CONCLUSION

Hypercapnia, respiratory acidosis, and chronic hypoxia associated with COPD may affect the macula and optic nerve, resulting in a serious decrease in vascular density, and OCTA can be a very important tool in the follow-up and treatment of these patients.

Macular and Optic Nerve Microvascular Alteration in Relation to Axial Length, by Optical Coherence Tomography Angiography (OCTA)

Aim

To study the effect of axial length (AL) on quantitative characterization of macular and optic nerve microvasculature using optical coherence tomography angiography (OCTA) in healthy individuals.

Methods

A cross-sectional study where participants were divided into 3 groups according to AL; A: ≤22.5 mm, B: 22.6–24.5 mm, C: >24.5 mm. Superficial vascular density (SVD), deep vascular density (DVD), foveal avascular zone (FAZ), and radial peripapillary capillary density (RPCD) were calculated using OCTA. Pearson correlation was run to identify the relation between AL and study parameters.

Results

One hundred and twelve eyes of 56 participants (20 males, 36 females) were included. Mean FAZ was 0.33 ± 0.15 mm², 0.27 ± 0.1 mm² and 0.28 ± 0.2 mm² in Groups A, B, and C, respectively (p value 0.073). No significant difference was found between 3 groups, as regards superficial foveal density and vessel density inside the disc. Deep foveal density was significantly lower in Group A in comparison to Groups B and C (p value 0.021 and 0.005, respectively). As for other parameters of SVD, DVD and RPCD, no significant difference was observed between Groups A and B; however, the same parameters were significantly lower in Group C when compared to Group A and B. AL was found to be negatively correlated to FAZ (r −0.191, p value 0.043) and most of parameters of SVD, DVD, and RPCD (p value < 0.0001).

Conclusion

Most of optic nerve and macular microvascular parameters were significantly lower in eyes with longer axial lengths when compared to those with shorter axial lengths. Moreover, most of these parameters were negatively correlated with AL.

Retinal Microvascular Changes in Patients with Multiple Myeloma: A Study Based on Optical Coherence Tomography Angiography

PURPOSE

Ocular microvascular networks and variables were analyzed using optical coherence tomography angiography (OCTA) in patients with multiple myeloma (MM) who had no pathological findings in their routine ophthalmologic examinations.

MATERIALS AND METHODS

The study included 31 patients with a diagnosis of MM and 30 healthy controls. The ophthalmologic examination findings and OCTA measurements of the participants were prospectively analyzed. We evaluated the superficial capillary plexus (SCP) vessel density (VD) and deep capillary plexus (DCP) VD in macular region, radial peripapillary capillary (RPC) VD, optic nerve head (ONH) VD and the foveal avascular zone (FAZ) area.

RESULTS

The samples were gender-balanced, and there were no significant differences in age or gender between the MM and control groups. From the OCTA, all the ONH-VD measurements, except for the peripapillary and superotemporal parameters, were found to be significantly lower in MM patients than in the control group; the same was found for the whole image, inferonasal, superonasal, and superotemporal RPC-VD values; for all the SCP-VD values, except for the inferior hemi and temporal; and for all the DCP-VD values. It was also observed that the deep FAZ area was wider in the MM group than in the control group.

CONCLUSIONS

We detected decreased VD in deep and superficial macular retinal areas, papillary, peripapillary regions, suggesting decreased blood flow and possible ischemia in MM patients. Therefore, obtaining information on ischemia by using a noninvasive and easily measurable method such as OCTA, may be beneficial in terms of follow-up and treatment but this needs to be supported by further, larger studies.

Retinal thickness and microvascular alterations in the diagnosis of systemic lupus erythematosus: a new approach

BACKGROUND

To investigate the differences of retinal thickness (RT) and superficial vascular density (SVD) between patients with systemic lupus erythematosus (SLE) and healthy controls using optical coherence tomography angiography (OCTA).

METHODS

Individuals with SLE (n=12; 24 eyes) and healthy controls (n=12; 24 eyes) were recruited to this study. The study protocol was in accordance with the tenets of the Declaration of Helsinki (as revised in 2013). The monocular best-corrected visual acuity (BCVA) was determined using a Snellen eye chart. Each image was segmented into 9 early treatment diabetic retinopathy study subregions, within which the macular RT and SVD were measured by OCTA. The vascular perfusion area as a percentage of the measured area was considered to be the vascular density.

RESULTS

The mean age of the SLE group was 33.80±9.49 years, and the mean age of the control group was 33.20±9.41 years. The mean duration of SLE was 4.33±2.67 years. The BCVA was significantly different between the SLE and control groups (0.17±0.20 vs. 0.05±0.07, respectively; P=0.021). In the SLE group, inner RT was reduced in the outer superior and temporal regions and full RT was reduced in the outer temporal region, compared with the control group (P<0.05). In the outer temporal region, the area under the receiver operating characteristic curve (AUC) for the inner RT was 0.805 [95% confidence interval (CI): 0.674 to 0.935], and the full RT was 0.828 (95% CI: 0.701 to 0.955). Thinning of RT was negatively correlated with erythrocyte sedimentation rate (ESR) in the inner retina at the outer temporal and outer superior regions and the full retina at the outer temporal region (P<0.05). The SVD was significantly lower in SLE participants than in controls in the central region, all 4 inner quadrants, and 4 outer quadrants (P<0.05). In the SLE group, SVD was positively correlated with inner RT in the outer superior region, inner RT, and full RT in the outer temporal region (P<0.05).

CONCLUSIONS

Variations in RT within the macular area may affect visual acuity. The OCTA measurement of RT may be a potential marker for diagnosis of SLE and an indicator of its inflammatory activity.

[Choroidal microvascular dropout as a biomarker of glaucoma progression in patients with diabetes mellitus]

PURPOSE

To study the occurrence, features of the development of choroidal microvascular dropout (CMvD) as a possible marker of the severity of the glaucoma process and to assess the impact of diabetes mellitus (DM) on the progression of these changes.

MATERIAL AND METHODS

The study included 258 eyes (258 patients), which were divided into groups: 1st - 58 patients (58 eyes) with stage I POAG and DM; 2nd - 50 patients (50 eyes) with stage I POAG; 3rd - 50 patients (50 eyes) with stage III POAG and DM; 4th - 50 patients (50 eyes) with stage III POAG; 5th - 50 patients (50 eyes) with DM. The observation period lasted 24 months. The occurrence and dynamics of the development of CMvD, their relationship with structural and functional indicators of the optic disc in the course of observation were evaluated in patients with POAG and DM.

RESULTS

CMvD was detected in stage I POAG in 17 eyes (34%), in patients with DM - in 27 eyes (54%), in the combined course of stage I POAG and DM - in 46 eyes (79.31%), in patients with stage III glaucoma - in 100% of cases. In patients with stage III glaucoma, the CMvD area indicators exceeded the values in other groups and practically did not differ regardless the presence of DM (0.59±0.13 mm², p=0.005) and its absence (0.57±0.14 mm², p=0.005). In the first year of follow-up, the increase in the area size of microvascular disorders in patients with POAG I was 5.88%, in comorbid patients - 3.84%, but by the end of the follow-up it increased by 19.23%, and in the group of patients with a high rate of progression - by 31.25%. Strong reliable correlations of CMvD with mean deviation (r=0.89) were revealed, as well as moderate correlations - with structural indicators of the optic disc (r=0.59) and with hemodynamic indicators (r=0.54 and r=0.52).

CONCLUSION

Development of CMvD is both a result of glaucomatous damage to the optic nerve and a consequence of a disruption of its hemodynamics at the level of the deep capillary plexus. The results of the study demonstrate the adverse effect of DM on the course of glaucoma, which determines the initiation of microvascular disorders that aggravate the severity of the glaucoma process and the rate of its progression.

Analysis of the relationship between placental histopathological aspects of preterm and term birth

OBJECTIVES

This study aims to establish a correlation between placental histopathological and immunohistochemical (IHC) changes and preterm birth with fetal growth restriction (FGR, formerly called intrauterine growth restriction - IUGR).

PATIENTS, MATERIALS, AND METHODS

This prospective study was performed on a group of 30 parturients, with singleton gestation, of which 15 patients gave birth at term, and the other 15 patients gave birth prematurely. After the statistical correlation of the clinical and demographic data with premature birth (PB) and term birth (TB), we performed histological and IHC research on the respective placentae. To observe normal and pathological microscopic placental structures, we used the Hematoxylin-Eosin (HE) and Periodic Acid Schiff-Hematoxylin (PAS-H) classical stainings, but also special immunostaining with anti-cluster of differentiation 34 (CD34) and anti-vascular endothelial growth factor (VEGF) antibodies.

RESULTS

We found a statistically significant difference between the TB∕PB categories and the age of the patients, their antepartum weight, the weight of the newborns, and the placenta according to the sex of the newborn. Histological analysis revealed in the case of TB, small areas of perivillous amyloid deposition, with the significant extension of these areas both intravillous and perivillous in the case of PB. Massive intravillous calcifications, syncytial knots, and intravillous vascular thrombosis were also frequently present in PB. With PAS-H staining were highlighted the intra∕extravillous vascular basement membranes, but especially the massive fibrin deposits rich in glycosaminoglycans. By the IHC technique with the anti-CD34 antibody, we noticed the numerical vascular density, higher in the case of TB, but in the case of PB, there were large areas of placental infarction, with a lack of immunostaining in these areas. Through the anti-VEGF antibody, we observed the presence of signal proteins that determined and stimulated the formation of neoformation vessels in the areas affected by the lack of post-infarction placental vascularization. We observed a highly significant difference between placental vascular density between TB∕PB and newborn weight, sex, or placental weight.

CONCLUSIONS

Any direct proportional link between the clinical maternal-fetal and histological elements yet studied must be considered. Thus, establishing an antepartum risk group can prevent a poor pregnancy outcome.

[Structural and microvascular changes in the retina and choroid in patients with chronic kidney disease]

PURPOSE

To study the main structural and microvascular changes in the retina and choroid in patients with diabetic retinopathy (DR) and chronic kidney disease (CKD), and their relationship with impaired renal function.

MATERIAL AND METHODS

The study included 158 patients (304 eyes). The 1^st group consisted of 50 patients with CKD (97 eyes); group 2 - 65 patients with DR (119 eyes), group 3 - 43 patients with CKD and DR (86 eyes). All study patients underwent complete ophthalmological examination, including optical coherence tomography (OCT) and OCT angiography (OCTA) of the macular region.

RESULTS

The analysis of structural parameters in groups of patients showed a decrease in the thickness of the ganglion cell layer and the inner plexiform layer of the retina in patients with DR (70.85±14.49 μm), with the lowest value in the CKD+DR group (65.84±15.34 μm) in comparison with the CKD group (75.64±10.32 μm). In the groups of patients with CKD, the thickness of the choroid (207.3±40.36 μm) was significantly reduced in comparison with the group of patients with DR (258.8±26.63 μm) and correlated with the stage of the disease. Patients in the CKD+DR group had the lowest perfusion and vascular density in the macular region (31.23±10.91% and 13.15±2.73 mm), an increase in the area and perimeter of the foveal avascular zone (0.55±0.26 mm², 3.30±0.84 mm). Pronounced correlations of decrease in choroidal thickness, vascular density, and perfusion volume with low glomerular filtration rate and CKD stage, as well as urea and creatinine levels were determined. An increase in the area of the foveal avascular zone correlated with lower retinal capillary density, decreased perfusion volume, and the stage of both DR and CKD.

CONCLUSION

Structural and hemodynamic disorders of the retina and choroid can be recognized as significant biomarkers for non-invasive diagnosis of microvascular complications of diabetes mellitus and impaired renal function.

Evaluation of Peripapillary Microcirculation in Patients with Acromegaly

OBJECTIVES

The aim of this study was to evaluate the radial peripapillary capillary (RPC) and the optic nerve head (ONH) perfusion of patients with acromegaly using optical coherence tomography angiography (OCTA).

METHODS

Twenty-four eyes of 24 acromegaly patients comprised the study group and 24 eyes of 24 healthy individuals were used as a control group. The ONH and RPC vascular density (VD) was measured for each patient using OCTA. The insulin-like growth factor 1 (IGF-1) levels were also recorded and compared.

RESULTS

The VD of the inferior nasal ONH and nasal RPC was significantly lower in the acromegaly group than in the control group (p=0.047 and p=0.001, respectively). There was a significant negative correlation between the VD of the superior nasal ONH and the IGF-1 level (r=-0.283, p=0.038).

CONCLUSION

The ONH and RPC VD values measured using OCTA were segmentally different in the acromegaly group compared with those of the control group. This method of non-invasive quantitative analysis of retinal perfusion using OCTA may be useful for future studies involving patients with acromegaly.

Mapping of choriocapillaris vascular density in young and aged healthy subjects

PURPOSE

To compare macular vascular density (VD) of the choriocapillaris (CC) between young and aged healthy individuals.

METHODS

A cross-sectional study was performed enrolling young and senior healthy individuals of Caucasian race and an axial length (AL) lower than 26 mm, and without systemic or ophthalmological diseases. CC VD was imaged with DRI Triton OCTA using a 6 × 6 mm macular analysis. Internal software delimited CC boundaries and gave colour pictures, which were analysed and codified into numbers, and a grid of 30 × 30 VD values was obtained. Two-dimension (2D) and three-dimension (3D) representations were created.

RESULTS

53 eyes of 53 young healthy individuals and 30 eyes of 30 senior healthy individuals were enrolled. Mean age was 27.17 ± 3.90 years, and 67.00 ± 7.41 years, respectively (p < 0.001). There were no differences in intraocular pressure (IOP) or AL (23.73 ± 0.79 mm, 23.18 ± 0.80 mm, respectively, p = 0.24). There were differences in foveal VD and in temporal perifoveal macula, but not in nasal perifoveal macula. Foveal VD was the highest in both groups.

CONCLUSIONS

Foveal CC VD has been found to be considerably high with this method, and it is the area which most decreases with age. Nasal perifoveal VD is not reduced in older individuals. These outcomes are opposite to other studies using different methods but they are in line with previous histological findings.

Magnetic Resonance Imaging Assessment of Pulmonary Vascularity in Infants with Congenital Diaphragmatic Hernia: A Novel Tool for Direct Assessment of Severity of Pulmonary Hypertension and Hypoplasia

OBJECTIVES

To assess the feasibility of magnetic resonance imaging (MRI) for postnatal assessment of pulmonary vascularity in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Infants with prenatally diagnosed CDH (n = 24) received postnatal pulmonary MRI. Infants with nonpulmonary birth defects served as controls (n = 5). Semiautomatic segmentation was performed to obtain total vascular volume using time of flight images to assess vascularity.

RESULTS

Average vascular density (vascular volume/lung volume) in control infants was 0.23 ± 0.06 mm³/mm³ compared with 0.18 ± 0.06 mm³/mm³ in infants with CDH is (P = .09). When stratified further based on CDH severity, the difference between control infants and moderate CDH group was statistically significant. (0.23 mm³/mm³ vs 0.15 mm³/mm³, P = .01). Ipsilateral vascular density on MRI in infants with CDH significantly correlated with the prenatal pulmonary hypertensive index (P = .0004, Spearman R = +0.87) and with number of days on mechanical ventilation (P = .04, Spearman R = -0.44), total days on inhaled nitric oxide (P = .02, Spearman R = -0.47), use of epoprostenol for acute pulmonary hypertension (PH) (0.14 mm³/mm³ vs 0.20 mm³/mm³, P = .005), and use of sildenafil for chronic PH (0.15 mm³/mm³ vs 0.19 mm³/mm³, P = .03).

CONCLUSIONS

Our results suggest that postnatal pulmonary vascularity assessed by MRI strongly correlates with prenatal and postnatal markers of PH severity and that pulmonary vascularity may serve as a direct measure of pulmonary vascular hypoplasia in infants with CDH.

Microvascular and Structural Alterations of the Macula in Early to Moderate Glaucoma: An Optical Coherence Tomography-Angiography Study

In glaucoma, macular optical coherence tomography (OCT) typically shows a thinning of the three inner segments and OCT-angiography (OCTA) a reduction of the vascular density (VD). It is still unclear if glaucoma directly affects macular VD. This retrospective study included 31 glaucoma patients of early and moderate stage (GS1, GS2, Mills et al.) and 39 healthy individuals. Macular segments' thickness and superficial and deep plexus vascular density (VD) were obtained using spectral-domain OCT and OCTA, respectively. One-way analysis of variance (ANOVA) was used to compare healthy controls and glaucoma patients according to their glaucoma stage. Using correlation analyses, the association between glaucoma and either OCT or OCTA parameters was evaluated. A glaucoma stage-stratified linear regression analysis was then performed. Inner macular segment and whole retinal thickness were reduced in GS1 and GS2 patients compared to healthy controls (e.g., ganglion cell layer GCL: controls: 47.9 ± 7.4, GS1: 45.8 ± 5.1, GS2: 30.6 ± 9.4, ANOVA: p < 0.0001). Regarding OCTA-parameters, the VD of both segmentation levels was reduced in glaucoma patients, particularly when comparing GS2 patients with controls (superficial plexus: p = 0.004) and GS2 with GS1 (p = 0.0008). Linear regression revealed an association between these parameters and the presence of glaucoma (for superior plexus: R2 = 0.059, p = 0.043). Finally, a correlation between macular segment thickness and VD was observed, but with a strength increasing with glaucoma severity (GCL and superior plexus VD: controls: R2 = 0.23, GS1 R2 = 0.40, GS2 R2 = 0.76). Despite the glaucoma-independent correlation between macular segment thickness and VD, disease severity strengthens this correlation. This consideration suggests that glaucoma directly influences OCT and OCTA parameters individually.

Evaluation of the effect of high-intensity interval training on macular microcirculation via swept-source optical coherence tomography angiography in young football players

Purpose:

This study was conducted to evaluate the effect of high intensity interval training (HIIT) on macular microcirculation, measured by swept source optical coherence tomography angiography (ss OCTA) in young football players.

Methods:

Football players between 18–20 years old were included. After a detailed ophthalmological examination, physiological parameters, including height, body weight, body fat, systemic blood pressure, hematocrit values, oxygen saturation, and heart rate, were recorded. Intraocular pressure and ss OCTA parameters were measured one day before and the day after the high intensity interval training program using DRI OCT Triton (Topcon, Tokyo, Japan) between 11:00 am and 1:00 pm.

Results:

Fifteen participants completed the study. All were males with a mean age of 18.1 ± 0.4 years. Systolic and diastolic blood pressure and oxygen saturation did not change significantly (P > 0.05), while hematocrit levels increased remarkably (P = 0.049) after the HIIT program. Heart rates and intraocular pressure decreased (P = 0.003, P = 0.017, respectively). There was a significant increase in the central vessel density in deep capillary plexus (before: 18.7 ± 3.8%, after: 21.1 ± 4.5%) and central vessel density in choriocapillaris (before: 54.5 ± 2.8%, after 56.9 ± 2.2%) (P = 0.02, P = 0.02, respectively), although no changes were observed in other ss OCTA or in the central macular thickness and subfoveal choroidal thickness.

Conclusion:

A 6 week, high intensity interval training program with three exercise sessions per week seems not to alter mean superficial vascular densities, deep foveal avascular zone, and superficial foveal avascular zones, central macular thickness, or subfoveal choroidal thickness, while the central deep vascular density and central choriocapillaris vascular density increased remarkably among ss OCTA parameters.

Analysis of optic disc and macular vascular density in patients with non-proliferative diabetic retinopathy

OBJECTIVE

To analyze the vascular density of optic disc and macular area in patients with non-proliferative diabetic retinopathy (NPDR).

METHODS

The medical records of 97 patients with NPDR who were hospitalized in our hospital from April 2019 to April 2020 were collected, and the patients were divided into mild/moderate group (n=44) and severe group (n=53). In addition, 38 cases of age- and gender-matched healthy individuals after the physical examination during the same period were included in the healthy control group. The general data were collected and the ocular basic and optical coherence tomography angiography were performed.

RESULTS

Compared with the healthy control group, the best corrected visual acuity of patients with NPDR was decreased, the radial capillary density of the whole optic disc and its surrounding areas, all areas except the upper nasal side, and the shallow and deep capillary density of different macular areas witnessed an evident drop (P<0.05). There was a negative correlation between the vascular density of the optic disc and macular area and the severity of the disease, and it had a high evaluation value for the disease (P<0.05).

CONCLUSION

The vascular density of the optic disc and macular area decreases in NPDR patients, which is closely related to the severity of the disease.

The Immune Microenvironment of Chordomas: An Immunohistochemical Analysis

Simple Summary

Chordoma patients may be amenable to immunotherapy; however, the immune microenvironment of chordomas needs further investigation. We performed the immunohistochemical analysis of a chordoma series, showing that these tumors have a unique microenvironment characterized by the absence of PD-L1 tumor cell expression, but feature PD-L1+ immune cells playing a negative prognostic role.

Abstract

Chordomas are rare sarcomas that are usually treated by surgery and/or radiotherapy since these are chemo-resistant tumors, but immunotherapy could be a possible option for chordoma patients. However, few reports investigating the composition of the chordoma immune microenvironment exist. We immunohistochemically studied 81 chordomas regarding their immune microenvironment factors and compared them with clinicopathological data. Macrophages and CD4 cells were the most prominent inflammatory cell populations, followed by CD8 T cells, while CD20 B cells and high endothelial venules (MECA-79+) were less frequently found. PD-L1 (22C3) expression by inflammatory cells was found in 21 (26%) tumors and was associated with a larger tumor size. None of the cases showed the expression of PD-L1 by tumor cells. Survival analysis showed that younger patients had a better overall survival. Considering the immunohistochemical factors studied, higher CD8, the presence of PD-L1+ immune cells, and higher vascular density were adverse prognostic factors, but in multivariate analysis, only PD-L1+ immune cells retained prognostic significance. To conclude, chordoma tumor cells do not express PD-L1, but PD-L1+ immune cells seem to play a negative prognostic role, supporting the need for further studies in this field and the possible beneficial role of immunotherapy in these patients.

Altered vascular permeability but not angiogenesis may play a role in the epileptogenesis of human hippocampal sclerosis

OBJECTIVE

We investigated the role of angiogenesis and vascular permeability in the pathogenesis of human drug-resistant epilepsy due to hippocampal sclerosis.

METHODS

Resected hippocampi from 30 histologically confirmed cases of hippocampal sclerosis and 30 age-matched post-mortem controls were examined by immunohistochemical quantitation of vascular endothelial markers, CD31 and CD105 (markers of newly formed vessels), and data were analysed relative to MR volumetry. The blood-brain barrier was evaluated based on immunohistochemistry for IgG, albumin, VEGF and AQP4.

RESULTS

Mean vascular density in the hippocampus was 8.71/mm² in hippocampal sclerosis samples compared to 7.94/mm² in age-matched controls. No statistically significant increase in vascular density was found in hippocampal sclerosis samples. Although no neoangiogenesis was found in hippocampal sclerosis samples based on CD105, breakdown of the blood-brain barrier, enhanced neuronal expression of VEGF, and perivascular seepage of IgG and albumin with uptake within neurons and astrocytes were found. Redistribution of the water channel protein, AQP4, reflected by change from normal punctate labelling to intense diffuse staining in hippocampal sclerosis samples, indicated an altered glia-vascular interface, disrupting blood-brain barrier permeability.

SIGNIFICANCE

Our data show no objective histological evidence of angiogenesis in hippocampal sclerosis samples. When controlled for the confounding variable of hippocampal area, there was no difference in vascular density between cases and controls. A leaky blood-brain barrier and redistribution of AQP4 were identified which may contribute to epileptogenesis. This constitutes the largest study in the published literature evaluating a role of vascular permeability and angiogenesis in human hippocampal sclerosis.

Does exogenous androgen use affect the retinal blood flow: An OCTA study in transgender men

PURPOSE

This study aims to investigate the effect of using exogenous androgen on retinal microvascular structures in transgender men.

METHODS

Retinal microvascular structures of transgender men and healthy women in the control group were visualized with optical coherence tomography angiography (OCTA). Foveal avascular zone (FAZ), superficial capillary vascular density (sCVD), deep capillary vascular density (dCVD), and radial peripapillary capillary (RPC) vascular density were evaluated.

RESULTS

Thirty transgender men and 30 healthy women were included in the study. There were no significant differences between transgender men and the control group in terms of FAZ, central macular thickness, parafoveal, and perifoveal retinal thicknesses (p = 0.859, 0.288, 0.561, and 0.719; respectively). sCVD were found to be low in transgender men in the whole image, parafoveal, and perifoveal zones (p = 0.006, 0.025, and 0.005; respectively). Although there were low values of dCVD of the whole image, parafoveal, and perifoveal zones in transgender men, the difference was not statistically significant (p = 0.295, 0.085, and 0.270; respectively). RPC vessel densities in the whole image, peripapillary zone, and the inferior of the optic disc were found to be significantly low in transgender men (p = 0.003, 0.005, and 0.003; respectively).

CONCLUSION

In this study, a decrease in vessel density in the superficial retinal layers and around the optic disc was detected in transgender men. These findings suggest that routine ophthalmological examination may be important in individuals who use exogenous androgens.

Senescence, immune microenvironment, and vascularization in cardiac myxomas

AIMS

Cardiac myxomas are rare tumors of incompletely elucidated pathogenesis. The aim of this study is to explore the possible presence of a senescence phenotype in cardiac myxomas, associated with an inflammatory and vasculogenic tumor microenvironment.

METHODS AND RESULTS

This is a retrospective study of 29 cardiac myxomas with immunohistochemical detection of various inflammatory, vascular, and senescence markers. We show that all myxomas contain tumor cells in senescence overexpressing p16, and a fraction of senescent endothelial cells. Macrophages are the principal inflammatory cell population, followed by cytotoxic T cells, with fewer plasma cells, mastocytes, and B lymphocytes. These populations are found in different intratumoral localizations. Larger tumor volume is associated with a lower percentage of myxoid matrix, higher cellularity, higher macrophage, and lower number of mast cells as well as higher PD-L1 expression by inflammatory cells. Higher vascular density is associated with higher percentage of B cells, a lower number of macrophages and higher number of mastocytes, and lower PD-L1 expression by inflammatory cells. Tumors with higher vascular density and higher cellularity show higher amounts of p16 senescent endothelial cells.

CONCLUSIONS

Myxoma tumor cells are in senescence and reside inside a tumor microenvironment with a distinct inflammatory profile rich in macrophages and cytotoxic T cells, and a rich vasculature, probably attributed to a senescence-associated secretory phenotype.

Optical Coherence Tomography Angiography for the Evaluation of Retinal Vasculature in Fabry Disease: Our Experience and Review of Current Knowledge

Purpose: Optical coherence tomography angiography (OCTA) is a non-invasive and objective tool for the evaluation of the retinal microvascular changes in Fabry disease (FD). We investigated changes in retinal vasculature in FD patients, and the possible correlation with systemic parameters, by using OCTA, and reviewed the current status of literature.

Methods: Thirteen FD patients (eight females, five males, mean age 49.85 ± 14.7 years) were compared with 13 age- and sex-matched healthy controls. OCTA 3 × 3 mm macular scans were performed in all subjects. We evaluated the vessel density and vessel perfusion in distinct macular areas (whole, inner, and outer) of both the superficial capillary plexus (SCP VD and SCP VP) and of the deep capillary plexus (DCP VD and DCP VP). We also evaluated the foveal avascular zone (FAZ) metrics (area, perimeter, and circularity), and correlation between systemic and OCTA parameters. A literature review on the current understanding of OCTA in FD is then presented.

Results: FD patients showed significantly lower SCP VD values in the whole area (17.37 ± 2.08 mm⁻¹ vs. 18.54 ± 1.21 mm⁻¹; p-value 0.022), as well as in the outer area (17.46 ± 2.10 mm⁻¹ vs. 19.08 ± 1.14 mm⁻¹; p-value 0.002), but not in the inner. Even the DCP VD was significantly lower in all the imaged areas: whole (17.75 ± 3.93 mm⁻¹ vs. 19.71 ± 1.20 mm⁻¹; p-value 0.024), outer (18.25 ± 4.17 mm⁻¹ vs. 20.33 ± 1.20 mm⁻¹; p-value 0.023), and inner (19.54 ± 4.17 mm⁻¹ vs. 21.96 ± 1.55 mm⁻¹; p-value 0.011). There were no significant differences in vessel perfusion parameters (both SCP VP and DCP VP ones) and FAZ. No significant correlations were found between the OCTA parameters and systemic parameters (maximal left ventricular wall thickness and glomerular filtration rate) in FD patients.

Conclusions: OCTA can be considered as a promising non-invasive tool, which enables a quantitative evaluation of retinal vascular involvement in FD, despite the varying data reported in literature. Our results support the use of OCTA as an objective tool to evaluate retinal vascular abnormalities in FD. The utility of OCTA in FD needs to be validated by longitudinal studies taking into account the overall progression of the disease.