Superficial Retinal Vessel Density Research Articles

Contribution of systemic factors on macular vessel density: a sex-specific population-based study.

To evaluate the influence of systemic factors on macular vessel density in quantitative Optical Coherence Tomography Angiography (OCTA) by sex. A cross-sectional study. A total of 2018 adults were recruited in this study. Participants were excluded (n=964) due to missing data, eye-related problems, or low OCTA scan quality. Macular vessel densities were measured with OCTA using split-spectrum amplitude decorrelation angiography algorithm. Only the data from the right eyes were selected for analysis. Multivariable linear regression analysis was performed to determine the associations between macular vessel density and obesity-related systemic factors in each gender group. The right eyes of 1054 participants (59.6% women) were enrolled. Men had significantly higher obesity parameters and associated risk factors. In multivariable linear regression analysis in men, older age and type 2 diabetes mellitus were independently associated with lower superficial retinal vessel density (β = -0.37, p = 0.002; β = -1.22, p = 0.03) and deep retinal vessel density, respectively (β = -0.66, p < 0.001; β = -1.76, p = 0.02); positive association was also observed between body mass index (BMI) and superficial retinal vessel density (β = 0.56, p = 0.02). In women, only higher systolic blood pressure was independently associated with a lower deep retinal vessel density (β = -0.50, p = 0.003). This large cross-sectional study shows that older age and type 2 diabetes mellitus are associated with lower superficial and deep retinal capillary vessel density in men. This may help clinicians better understand how systemic factors influence retinal vessel density in different genders and future studies can ascertain more potential sex differences.

Changes in Macular Thickness and Microvasculature in Koreans with Early Parkinson’s Disease

Purpose: To investigate the thickness of the nerve fiber layer-ganglion cell inner plexiform layer (NFL-GCIPL) complex and microvascular macular changes in Korean patients with early Parkinson’s disease using optical coherence tomography (OCT) and OCT angiography (OCTA).Methods: Forty-three eyes of 22 patients with early Parkinson’s disease were included. A control group of 20 patients (40 eyes) was also recruited. The thickness of the NFL-GCIPL macular complex was measured using OCT, and the densities of the superficial and deep macular retinal vessels were evaluated via OCTA in all subjects.Results: The NFL-GCIPL thicknesses of the superior, inferior, temporal, and nasal sectors were 94.70 ± 9.35, 93.32 ± 9.16, 90.18 ± 6.32, and 93.11 ± 8.75 μm in the control group and 92.05 ± 4.96, 91.32 ± 7.48, 84.74 ± 6.82, and 91.32 ± 7.47 μm in the Parkinson’s disease group, respectively; all thicknesses were significantly greater in the control group. The superficial and deep retinal vessel densities did not differ between the two groups.Conclusions: Neurodegenerative macular changes are more obvious than microvascular changes in patients with early Parkinson’s disease. Such neurodegenerative changes should be further evaluated in future cohort studies.

Evaluation of Retinal Blood Flow in Patients with Monoclonal Gammopathy Using OCT Angiography.

Monoclonal gammopathy (MG) is characterized by monoclonal protein overproduction, potentially leading to the development of hyperviscosity syndrome. To assess retinal circulation using optical coherence tomography angiography (OCTA) parameters in patients with monoclonal gammopathy. OCTA measurements were performed using the Optovue AngioVue system by examining 44 eyes of 27 patients with MG and 62 eyes of 36 control subjects. Superficial and deep retinal capillary vessel density (VD SVP and DVP) in the whole 3 × 3 mm macular and parafoveal area, foveal avascular zone (FAZ) area, and central retinal thickness (CRT) were measured using the AngioAnalytics software. The OCTA parameters were evaluated in both groups using a multivariate regression model, after controlling for the effect of imaging quality (SQ). There was no significant difference in age between the subjects with monoclonal gammopathy and the controls (63.59 ± 9.33 vs. 58.01 ± 11.46 years; p > 0.05). Taking into account the effect of image quality, the VD SVP was significantly lower in the MG group compared to the control group (44.54 ± 3.22% vs. 46.62 ± 2.84%; p < 0.05). No significant differences were found between the two groups regarding the other OCTA parameters (p > 0.05). A decreased superficial retinal capillary vessel density measured using OCTA in patients with MG suggests a slow blood flow, reduced capillary circulation, and consequent tissue hypoperfusion. An evaluation of retinal circulation using OCTA in cases of monoclonal gammopathy may be a sensitive method for the non-invasive detection and follow-up of early microcirculatory dysfunction caused by increased viscosity.

Evaluation of the Retinal Vessel Density and Subfoveal Choroidal Thickness in Central Cerous Chorioretinopathy Using Optical Coherence Tomography.

The purpose of this study was to quantitatively assess changes in the subfoveal choroidal thickness (SFCT) and superficial retinal vessel density (SRVD) in acute and chronic central serous chorioretinopathy (CSCR) patients, and estimate the correlation of SFCT and SRVD with best-corrected visual acuity (BCVA), respectively, using spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). This was a cross-sectional, case-control study. The study included CSCR patients treated at the Ho Chi Minh City Eye Hospital from May 2022 to October 2022. A total of 91 subjects (182 eyes) were included in this study, with 74 eyes in the unilateral acute CSCR group and 17 eyes in the unilateral chronic CSCR group; 91 eyes in the control groupwere patients' unaffectedother eyes.The mean age was 40.78 ± 1.26years (ranging from 31 to 45 years). The proportions of male and female patients were 78.0% and 22.0%, respectively. The major symptom was reduced vision, and the mean BCVA was0.36 ± 0.05 logMAR. The mean SFCT of CSCR eyes was 357.2 ± 11.8 μm, which was290.4 ± 8.5 μm in the control group (p < 0.05). The mean SRVD of chronic CSCR (24.2 ± 4.94%) and acute CSCR (28 ± 2.33%) eyes was lower compared with the control group(21.7 ± 1.87%).SFCT had a correlation with BCVA (r = -0.490, p < 0.05) in chronic CSCR; the center region of SRVD was likewise correlated with BCVA (r = -0.384, p < 0.05)and the parafoveal region of SRVD was also correlated with BCVA (r = -0.271, p < 0.05). Both altered SFCT and SRVD were identified in CSCR patients bySD-OCT and 6 x 6 mm OCT angiographyscans, and both were found to be correlated with BCVA. SD-OCT along with OCTA could be a good technique for quantitatively evaluating different CSCR courses.

A cross-sectional study of retinal vessel changes based on optical coherence tomography angiography in Alzheimer's disease and mild cognitive impairment.

The involvement of retina and its vasculature has been recently described in Alzheimer's disease (AD). Optical coherence tomography angiography (OCTA) is noninvasively used to assess the retinal blood flow. This study was to compare vessel density (VD) and blood perfusion density (PD) of the macular in AD patients, mild cognitive impairment (MCI) patients and healthy controls by OCTA, which may provide new ideas for diagnosis of AD or MCI. AD patients, MCI patients and healthy controls underwent a comprehensive ophthalmic and neurological evaluations, including cognitive function assessments as well as visual acuity, intraocular pressure (IOP), slit lamp examinations, and OCTA. General demographic data, cognitive function, retinal VD and PD were compared among three groups. The correlations among retinal VD, PD and cognitive function, amyloid-beta (Aβ) protein and phosphorylated Tau (p-Tau) protein were further evaluated. The correlations between retinal superficial capillary plexus and cognitive function, Aβ protein and p-Tau protein were also explored. A total of 139 participants were recruited into this study, including 43 AD patients, 62 MCI patients, and 34 healthy controls. After adjusting for sex, age, history of smoking, history of alcohol intake, hypertension, hyperlipidemia, best corrected visual acuity, and IOP, VD and PD in the nasal and inferior regions of the inner ring, superior and inferior regions of outer ring in the AD group were significantly lower than in the control group (p < 0.05). PD in nasal region of outer ring also significantly decreased in the AD group. VD and PD in superior and inferior regions of inner ring, superior and temporal regions of outer ring in the MCI group were markedly lower than in the control group (p < 0.05). After adjusting for sex and age, VD and PD were correlated with Montreal Cognitive Assessment Basic score, Mini-mental State Examination score, visuospatial function and executive function (p < 0.05), while Aβ protein and p-Tau protein had no relationship with VD and PD. Our findings suggest that superficial retinal VD and PD in macula may be potential non-invasive biomarkers for AD and MCI, and these vascular parameters correlate with cognitive function.

Choriocapillary Flow Correlation with Axial Length in High Myopia - An Angiography Study with Optical Coherence Tomography.

To investigate parameters of retinal and choroidal microcirculation quantitatively with optical coherence tomography angiography (OCTA) in high myopic children, and to explore potential correlations with age, axial length (AL), spherical equivalent (SE), and central retinal thickness (CRT). En face angiograms were generated with an OCTA device and evaluated with automated density and flow analyzer algorithms. Perfusion parameters were correlated with age, AL, SE, and CRT using Spearman's rank correlation analysis. Repeatability and reproducibility of perfusion parameter measurements were calculated in a high myopic cohort. Repeatability and reproducibility of OCTA measurements were good, ranging from 3.6 - 6.5%. Strong positive correlation was identified between age and CRT (rho = 0.673, p = 0.00) as well as between AL and SE (rho = 0.844, p = 0.00). There was a strong negative correlation between AL and choriocapillary flow density (CCFD) (rho = - 0.612, p = 0.00), and a moderate negative correlation between age and superficial parafoveal retinal vessel density (SPRVD) as well as CCFD (rho = - 0.497, p = 0.013 and rho = - 0.483, p = 0.023, respectively). OCTA appears to be a reliable tool for the quantitative investigation of retinal and choroidal microcirculation in a high myopic pediatric cohort. CCFD reduction was associated with increasing AL in this cohort.

Changes in and the association of retinal blood perfusion and retinal nerves in diabetic patients without retinopathy.

To explore intraretinal blood flow perfusion and nerve changes, as well as the correlation between them, in diabetic patients without diabetic retinopathy (NDR). Eighty-six NDR patients (86 eyes) who attended the ophthalmology clinic between December 2019 and December 2021 were included. Sixty-four eyes of 64 healthy examined controls in the same period were selected as the control group. The patients underwent routine ophthalmological examination, optical coherence tomography (OCT) and OCT angiography. The average thickness, minimum thickness and thickness of each quadrant except for the superior temporal quadrant of the ganglion cell-inner plexiform layer (GCIPL) in the macular area of the affected eyes in the NDR group were lower than that of the tested eyes in the control group (P < 0.05). The average retinal nerve fibre layer (RNFL) thickness of the NDR group and the superior, inferior and nasal quadrants around the optic disc of the affected eyes in the NDR group were lower compared with the tested eyes in the control group (P < 0.001, P = 0.003, P = 0.001, P = 0.009). The mean vessel length density in the parafoveal and perifoveal areas in the NDR group was positively associated with the mean GCIPL thickness in the macular area (ρ = 0.265, ρ = 0.257 and P < 0.001). No blood flow perfusion parameters in the NDR group were correlated with the RNFL thickness of the corresponding quadrant around the optic disc (P > 0.05). In diabetic patients without diabetic retinopathy, the superficial retinal vessel density in the macular area positively correlated with GCIPL thickness, and the superficial retinal vessel density around the optic disc was not correlated with RNFL thickness.

Analysis of macular blood flow changes in thyroid associated ophthalmopathy

BackgroundTo evaluate the changes in macular superficial retinal vessel density and their relation with visual acuity in thyroid-associated ophthalmopathy (TAO) patients with different severity.MethodsThis cross-sectional observational study included 70 TAO patients and 70 healthy controls. Only data from the right eyes were analyzed. TAO patients were divided into 7 subgroups according to the NOSPECS score. Foveal avascular zone (FAZ), vascular density (VD), and perfusion density (PD) of macular 1 mm diameter and 6 mm diameter areas were measured by optical coherence tomography angiography (OCTA).ResultsIn TAO patients, significant increases were found in macular and foveal vascular densities (FVD) and perfusion densities (FPD) while a significant decrease was found in the FAZ area when compared with the control group (p < 0.05). Spearman correlation analysis and multiple linear regression analysis showed that TAO severity grade was negatively correlated with FVD (β = -1.150, p = 0.032), FPD (β = -0.024, p = 0.042), MVD (β = -0.583, p = 0.020) and MPD (β = -0.011, p = 0.010). Clinical activity score (CAS) score showed positive correlation with FVD (β = 0.794, p = 0.035) and FPD(β = 0.017, p = 0.041). FVD (β = -0.009, p = 0.033), MVD(β = -0.034, p < 0.001), FPD(β = -0.416, p = 0.039) and MPD(β = -2.428, p < 0.001) all showed negative correlation with best corrected visual acuity (BCVA).ConclusionsThere was an overall increase in superficial macular blood flow in TAO patients compared with healthy controls and the blood flow decreased as TAO got worse. Superficial macular flow density was negatively correlated with BCVA.

Investigation of retinal microvasculature and choriocapillaris in adolescent myopic patients with astigmatism undergoing orthokeratology

BackgroundTo observe alterations of fundus microcirculation and retinal thickness in adolescent myopic patients with astigmatism after toric and spherical orthokeratology using optical coherence tomography angiography (OCTA), to explore the effects of orthokeratology on the retinal thickness and choroidal blood flow.MethodsA total of 48 patients were enrolled and divided into two group (toric orthokeratology (T) group and spherical orthokeratology (S) group) according to the type of lens design. OCTA was used to measure the superficial and deep retinal vessel densities at the macular region, radial peripapillary capillary (RPC) density, foveal avascular zone (FAZ) area, and choriocapillaris (ChC) perfusion area before and after orthokeratology for 3 months. The data were statistically analyzed by SPSS 19.0 software.ResultsCompared with before orthokeratology, the superficial vessel density in the fovea and parafovea in the T group significantly increased, and the deep vessel density in the whole area and fovea were significantly elevated after 3 months (P < 0.05). The superficial vessel density was significantly higher only in the parafovea in the S group after 3 months than that before orthokeratology (P < 0.05), deep vessel density in the whole area and parafovea after 3 months was significantly higher than that before orthokeratology (P < 0.05). RPC density in the two groups increased after 3 months of orthokeratology in the whole area and inside the disc area (P < 0.05).Three months after toric orthokeratology, FAZ area in the T group was significantly reduced by 0.05 (− 0.41 to + 0.08) mm2, while ChC perfusion area was enlarged by 0.06 ± 0.12 mm2. FAZ area in the S group significantly decreased by 0.01 (− 0.19 to + 0.01) mm2, whereas ChC perfusion area increased by 0.06 (− 0.07 to + 0.50) mm2. Retinal thickness in the two groups increased after 3 months of orthokeratology in the whole area and parafoveal area (P < 0.05).ConclusionOrthokeratology improved retinal blood flow in macular area and RPC while controlling myopia. The changes in FAZ and ChC perfusion areas did not significantly differ between toric and spherical orthokeratology.

Superficial Retinal Vessel Density and Foveal Avascular Zone in Myopic Anisometropia: An OCTA-Based Study in Young Chinese Children.

This retrospective study investigated superficial retinal vessel density (SRVLD) and foveal avascular zone (FAZ) area using optical coherence tomography angiography (OCTA) in children with myopic anisometropia. We included 84 eyes of 42 individuals with myopic anisometropia and no posterior segment abnormalities. All eyes underwent OCTA. Individual SRVLD and FAZ area were measured on OCTA. Using a paired t-test, we compared the interocular difference between the fellow eyes for all the measurements. SRVLD was significantly higher in the relatively more myopic eyes than in the fellow eyes in the whole population and in patients with an interocular difference of >1.5 D (p = 003 and 0.01, respectively). In patients with an interocular difference of ≤1.5 D in spherical equivalent refraction, only the nasal sector showed higher SRVLD in the less myopic eyes. SRVLD in the whole image and parafoveal sector was significantly lower in the dominant eye (paired t-test, p = 003 and 0.03, respectively), while other locations showed no difference. The area, perimeter, and circularity index in FAZ parameters showed no difference. SRVLD showed no significant differences between the two types of eyes, with an interocular difference of ≤1.5 D but increased in the relatively more myopic eyes than in the fellow eyes in children with myopic anisometropia, with an interocular difference of >1.5 D. Increasing SRVLD may show a compensatory increase to maintain retinal function and thus maintain normal visual function in the relatively more myopic fellow eyes. As the study to use patients as self-control with OCTA analysis in both eyes, this study provides some reference value for further interpretation of the pathogenesis of anisometropia.

POS0134 RELATIONSHIP BETWEEN RETINAL VASCULAR DENSITY DETECTED THROUGH OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AND INTIMAL MEDIAL THICKNESS: A NEW POTENTIAL MARKER OF CARDIOVASCULAR INVOLVEMENT IN SYSTEMIC LUPUS ERYTHEMATOSUS

BackgroundSystemic Lupus Erythematosus (SLE) patients have a 3- fold risk of CV events compared to the general population, mainly due to accelerated atherosclerosis that is not completely explained by the presence of traditional CV risk factors. Individuals with increased Intimal medial thickness (IMT) carry a higher risk to develop carotid atherosclerosis. Accordingly, IMT acts as a marker of subclinical atherosclerosis. In recent studies, SLE patients showed a significant higher IMT compared to healthy subjects. On the other side, SLE retinal involvement can be detected in 7-29% of cases, it is characterized mainly by retinal vasculopathy and it can be a marker of systemic vascular involvement. Optical Coherence Tomography Angiography (OCTA), a new diagnostic technique that can visualize retinal blood flow and evaluate the Fovea Avascular Zone (FAZ), has been investigated as an instrument for early detection of subclinical retinal vascular impairment in SLE.ObjectivesAim of this study is to examine a possible correlation between IMT and retinal vascular impairment assessed through OCTA in SLE.MethodsWe recruited SLE patients fulfilling 2019 EULAR/ACR classification criteria. Patients with other rheumatic, ophthalmological diseases, diabetes or history of CV diseases were excluded. We also collected patients’ demographic and clinical data, including sex, age, smoking habit, BMI, systolic and diastolic blood pressure (BP), C-Reactive Protein (CRP), total cholesterol, LDL, HDL, triglycerides. All patients underwent an ophthalmological evaluation, including OCTA estimation of superficial and deep retinal vessel density (VD), considering both the whole image and the foveal region, and FAZ area. Carotid ultrasound (US) comprising IMT assessment was also performed. Statistical analysis was accomplished using unpaired t-test or Mann Whitney U test, Pearson or Spearman rank correlation when appropriate.ResultsWe enrolled 37 SLE patients; demographic, clinical and US data are displayed in Table 1. Nine patients (24.3%) had uncontrolled arterial hypertension. According to US evaluation, carotid plaques were detected in six patients (16.2%). OCTA data were correlated with IMT values showing a negative correlation between IMT and both superficial and deep fovea VD (p=0.003, r=-0.4 and p=0.004, r=-0.4), while a positive correlation was found with FAZ area (p=0.02, r=0.4).Table 1.Demographic, clinical and US data of the study populationFemale sex n(%)28 (75.6)Age, yrs49.2±14.7Smokers n(%)12 (32.4)BMI25.1±5.2SBP, mmHg118.5±15.7DBP, mmHg73.3±11.6IMT, μM549.6±124IMT positively correlated with traditional CV risk factors, particularly age (p&lt;0.0001, r=0.7), BMI (p=0.007, r=0.3) and systolic BP (p=0.001, r=0.4). Patients with high BP levels showed not only a significant higher IMT compared to the group with normal BP values (p=0.04), but also a significant increased FAZ area (p=0.02). FAZ area correlated positively with CRP levels (p=0.0001, r=0.5). Triglycerides showed a positive correlation with IMT values (p=0.001, r=0.4) and FAZ area (p=0.04, r=0.3) while correlated negatively with deep fovea VD (p=0.04, R=-0.4). A reduction in deep whole retinal VD was detected among patients with carotid plaques compared to the group without (p=0.02), together with higher IMT values (p=0.04).ConclusionRetinal vascular impairment in SLE has been associated with IMT, atherosclerotic plaques and some CV risk factors as hypertension, hypertriglyceridemia and CRP levels. Search for new markers of preclinical CV damage in SLE is currently ongoing and OCTA might be an additional instrument to assess preclinical cardiovascular involvement in SLE.Disclosure of InterestsNone declared

Macular Changes Observed on Optical Coherence Tomography Angiography in Patients Infected With Human Immunodeficiency Virus Without Infectious Retinopathy.

PurposeAs the human immunodeficiency virus (HIV) pandemic is far from over, whether there are subclinical macular changes in HIV-positive patients is something that should not be overlooked. We aimed to apply optical coherence tomography angiography (OCTA) to assess the macular structure and microvasculature changes in patients with HIV without infectious retinopathy.MethodsHIV-positive and -negative participants were included and classified into three groups: HIV-negative, HIV-positive, and HIV-positive with microvasculopathy. OCTA parameters regarding macular structure and microvasculature were analyzed.ResultsCompared with the HIV-negative group, the superficial retinal vessel density (VD) in the parafovea sectors and the whole Early Treatment of Diabetic Retinopathy Study (ETDRS) grid and the choroidal vascularity index (CVI) in the whole ETDRS grid were significantly decreased in the HIV-positive and HIV-positive with microvasculopathy groups (p < 0.05). No differences were found in OCTA parameters between the HIV-positive and HIV-positive with microvasculopathy groups. Retinal, retinal nerve fiber layer-ganglion cell layer-inner plexiform layer (RNFL-GCL-IPL), RNFL, GCL-IPL, and INL thickness showed a negative association with the duration of HIV diagnosis or antiretroviral therapy (ART) (all p < 0.05). All OCTA microvasculature parameters showed no association with HIV-related clinical variables (all p > 0.05).ConclusionsSubclinical macular changes existed in HIV-infected patients without clinical infectious retinopathy. Substructures from inner retinal layers might be associated with HIV infection or ART duration.

Association between retinal vessel density and postoperative time after primary repair of rhegmatogenous retinal detachment.

The study aimed at a quantitative evaluation of macular vasculature after primary repair of rhegmatogenous retinal detachment (RRD) in correlation with the elapsed postoperative time. Optical coherence tomography angiography (OCT-A) was performed in 66 eyes of 33 patients in a retrospective case-control study: superficial and deep retinal vessel density (VD) of the whole image, fovea, parafovea, non-flow area, and foveal avascular zone (FAZ) were measured. Data of eyes with RRD were compared to the healthy fellow eyes in 3 groups according to the elapsed time after surgery: RD1: 6–12 months (n = 10), RD2: 1–2 years (n = 10), and RD3: 2–10 years (n = 13). In RD1 VD was significantly lower in the superficial parafoveal, deep parafoveal, and deep whole area compared to the fellow eyes. In RD3 VD was significantly lower in the superficial fovea, parafovea, whole image, and deep fovea, the non-flow area was significantly enlarged. OCT-A demonstrated a significant reduction in the superficial and deep regions of the macular vasculature after the repair of RRD. The deep area is more affected in the early postoperative period and the superficial region and the extent of the non-flow area are more involved after a longer postoperative time.

Retinal and choriocapillaris perfusion are associated with ankle-brachial-pressure-index and Fontaine stage in peripheral arterial disease

The purpose of this prospective case–control study was to assess whether parameters of retinal and choriocapillaris perfusion are altered in patients with peripheral arterial disease (PAD). Patients with PAD and healthy controls were imaged with swept-source optical coherence tomography angiography (OCT-A). Macula centered 3 × 3 mm OCT-A scans were acquired, binarized and perfusion was evaluated for vessel density (VD) and choriocapillaris non-perfused area. Clinical examination and non-invasive assessment included Fontaine staging, ankle-brachial-pressure-index (ABI) and vascular color-coded Doppler sonography. Fifty-two patients with PAD and 23 healthy controls were included. Superficial retinal VD was reduced in patients compared to controls (difference = − 0.013, p = 0.02), decreased with higher Fontaine stage (p = 0.01) and correlated with ABI (r = 0.42, p < 0.0001, 95% confidence interval [CI] 0.23–0.58). Choriocapillaris non-perfused area was larger in patients compared to controls (difference = 3.64%, p = 0.002, 95% CI 1.38–5.90%) and significantly correlated with ABI (r = − 0.22, p = 0.03, 95% CI − 0.40– − 0.03). Multivariate multiple regression analysis revealed a significant association of all OCT-A parameters with ABI and of deep retinal vessel density and choriocapillaris non-perfused area with Fontaine stage. In this first study of retinal and choroidal perfusion in patients with PAD we found both retinal and choroidal perfusion to be significantly impaired. OCT-A parameters could aid as indirect imaging biomarkers for non-invasive PAD staging and monitoring.

Effects of physical exercise on macular vessel density and choroidal thickness in children

We used swept-source (SS) optical coherence tomography (OCT) and OCT angiography (OCTA) to investigate the effects of moderate physical exercise on retinal and choroidal vessel densities (VDs) and thicknesses in children. One eye in each of 40 myopic children (mean age, 11.70 years) and 18 emmetropic children (mean age, 11.06 years) were included. SS-OCT 6 × 6-mm radial scans and SS-OCTA 3 × 3-mm images were centered on the macula. Heart rate (HR), systolic and diastolic blood pressure, and intraocular pressure (IOP) were recorded before and immediately after a 20-min stationary cycling exercise and after a 30-min rest. The subfoveal choroidal thickness (SFCT), choroidal thickness (CT), and VD at the superficial and deep retinal layers, choriocapillaris, and deeper choroidal vessels were determined. SFCT and CT were significantly lower at all locations immediately after exercise (p < 0.001) and did not fully recover after rest (p < 0.05). VD was lower in the deep retinal layer after exercise (p = 0.02) and higher in the superficial layer after rest (p = 0.03) in myopic eyes while it was higher in the superficial (p < 0.01) and deep layer (p < 0.01) after rest in emmetropic eyes. No significant exercise-related changes in the superficial retinal VD, choroidal VD, or IOP were observed. ΔCT% and ΔSFCT% were significantly correlated with increases in HR in myopic group (p = 0.04 and p = 0.03, respectively). Exercise increased retinal VD after rest in emmetropic eyes, and caused significant CT thinning that lasted for at least 30 min in both emmetropic and myopic eyes.

Evaluation of retinal vessel density and foveal avascular zone measurements in patients with obstructive sleep apnea syndrome.

To compare retinal capillary plexus vessel densities, choroidal thickness, optic disc vessel densities and foveal avascular zone measurements between normal subjects and subjects with obstructive sleep apnea syndrome (OSAS) using spectral-domain OCT angiography (OCTA). Forty eyes of patients with overall OSAS, 20 eyes of patients with mild-moderate OSAS, 20 eyes of patients with severe OSAS on polysomnography and 21 controls were evaluated with the RTVue-XR Avanti OCTA (Optovue, Inc., Fremont, CA). Superficial and deep retinal capillary plexus vessel densities, choroidal thickness and foveal avascular zone (FAZ) parameters (area, diameter, acircularity index of the FAZ, foveal density-300) were measured for all subjects. Superficial capillary plexus vessel densities of the groups were similar. Deep capillary plexus (DCP) vessel densities of all three OSAS groups decreased in the parafoveal region (< 0.001). In the perifoveal region, DCP vessel densities were decreased in the Overall OSAS group (p = 0.023) and in the Severe OSAS group (p = 0.021), whereas it was similar in the Mild-moderate OSAS group. Choroidal thickness decreased in all three OSAS groups (p < 0.001). All FAZ measurements and foveal density-300 measurements were similar compared to the control group. Our findings indicate that in severe OSAS patients, deep parafoveal, perifoveal vascular densities decrease and the choroid layer becomes thinner. When evaluating a patient with OSAS, it should be kept in mind that there may be eye involvement due to the disease.

Automated Evaluation of Parapapillary Choroidal Microvasculature in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

To determine whether parapapillary choroidal microvasculature (PPCMv) density as measured by optical coherence tomography angiography differs between pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG). Cross-sectional study. One hundred ninety-two eyes of 120 subjects from 2 academic referral institutions were enrolled. Automated PPCMv density was calculated using custom Matlab software in inner and outer annuli around the optic nerve region in addition to peripapillary superficial vasculature. Linear modeling was used to compare vessel densities among groups. Data from 64 eyes with PXS, 84 eyes with PXG, and 44 eyes healthy control subjects were analyzed. The differences of visual field mean deviation and peripapillary retinal nerve fiber layer thickness among study groups were statistically significant with lower values in PXG eyes compared with the PXS and control groups. Peripapillary superficial retinal vessel densities were significantly reduced in patients with PXG compared with patients with PXS and normal control subjects (all P < .001) without a difference between PXS and control eyes. Customized outer annular PPCMv density in the PXG group with a value of 11.1% (SD 5.1%) was lower than that in PXS with a value of 13.2% (SD 5.3%; P= .001). Similarly, PXS values were lower than those of control eyes with a value of 18.6% (SD 5.1%; P < .001). A progressive decrease in outer PPCMv from the control group to those with PXS without glaucoma to those with PXS and glaucoma (PXG) showed deep peripapillary vasculopathy in pseudoexfoliation syndrome. Choroidal vessel density may be affected early in the course of pseudoexfoliation before glaucoma develops.

Longitudinal changes in superficial microvasculature in glaucomatous retinal nerve fiber layer defects after disc hemorrhage

Glaucoma is a multifactorial optic neuropathy, possibly involving vascular dysfunction, leading to the death of retinal ganglion cells and their axons. Disc hemorrhage (DH) is known to be closely associated with the widening of retinal nerve fiber layer defect (NFLD); however, it has not been well elucidated how DH affects retinal microvasculature. We aimed to investigate the association between DH history and longitudinal changes in superficial retinal microvasculature in NFLD. We enrolled 15 glaucoma patients with DH history (32 glaucomatous NFLD locations, with or without DH history). NFLD-angle, superficial retinal vessel density (VD), and decreased superficial retinal microvasculature (deMv)-angle were assessed using optical coherence tomography angiography for at least three times over time. The mean follow-up period and OCT/OCTA scan interval were 21.3 ± 5.4 months (range, 12–28) and 6.8 ± 0.4 months (range, 2–18), respectively. Linear mixed-effects models showed that the presence of DH history was significantly associated with an additional NFLD-angle widening of 2.19 degree/year (P = 0.030), VD decrease of 1.88%/year (P = 0.015), and deMv-angle widening of 3.78 degree/year (P < 0.001). These changes were significantly correlated with each other (P < 0.001). Thus, the widening of NFLD was closely associated with deMv, and DH was associated with a subsequent decrease in superficial retinal microvasculature in NFLD.

Optical coherence tomography angiography in glaucoma.

Assessment of the vasculature within the optic nerve, peripapillary superficial retina, macula, and peripapillary choroid can be determined in glaucoma using optical coherence tomography angiography (OCTA). Decreased perfusion within the pre-laminar layer of the optic nerve has been correlated with glaucoma severity. The peripapillary superficial retinal vessel density allows diagnosis and detection of glaucoma progression in a manner similar to the peripapillary retinal nerve fiber layer (RNFL) thickness. Furthermore, decreased peripapillary vessel density of the intact hemiretina or unaffected eye of glaucomatous eyes suggests that vascular changes can occur prior to detectable visual field damage. The accuracy for glaucoma detection of the macular ganglion cell (MGC) thickness compared to macular vessel density has differed among studies. Several studies have reported reduction of macular vessel density as well as its ganglion cell thickness. Results of studies evaluating the parapapillary choroid have shown a greater prevalence of choroidal microvasculature dropout in glaucomatous eyes with a parapapillary gamma zone, which is associated with central visual field defects or glaucoma progression. It remains unclear whether the reduced vessel density in glaucoma is a primary event or secondary to glaucomatous damage. Further studies are warranted to elucidate this question.

Peripapillary Retinal and Choroidal Perfusion in Nonarteritic Ischemic Optic Neuropathy Using Optical Coherence Tomography Angiography.

Nonarteritic ischemic optic neuropathy (NAION) has been linked with vascular insufficiency, although the pathophysiology remains elusive. Optical coherence tomography angiography (OCTA) is a promising technology that noninvasively evaluates optic disc perfusion and that may help to characterize peripapillary vascular changes in NAION. This study aimed to evaluate peripapillary vascularity in NAION eyes and to compare it with fellow unaffected eyes and healthy control eyes using OCTA. In this cross-sectional study, OCTA of the optic nerve head was obtained in 10 nonacute unilateral NAION and 12 healthy age-matched controls using ZEISS Angioplex. Quantitative analysis of peripapillary retinal and choroidal vascularity of NAION eyes was done using the instrument's inbuilt algorithm and ImageJ software and compared with fellow and control eyes. Mean total peripapillary superficial retinal vessel and perfusion density as calculated by the instrument was significantly reduced in NAION eyes compared with fellow eyes (13.93 ± 4.27 mm/0.36 ± 0.07 for NAION eyes; 17.77 ± 1.26 mm/0.43 ± 0.08 for fellow eyes; P = .01/P = .05). Using the ImageJ software technique, the mean superficial retinal perfusion was found to be significantly reduced in NAION eyes (0.17 ± 0.07) compared with fellow eyes (0.25 ± 0.06; P < .01) and control eyes (0.25 ± 0.04; P < .01). At the level of choriocapillaris, it was not significantly affected in NAION eyes (0.37 ± 0.13) versus fellow (0.34 ± 0.14; P = .1) and control eyes (0.31 ± 0.34; P = .83). Analysis with the two techniques yielded differing results: the ImageJ analysis technique found a 32% reduction in superficial retinal perfusion in NAION eyes, whereas the instrument's inbuilt algorithm found a 16% reduction compared with fellow and control eyes (P ≤.01). Peripapillary vascularity can be estimated both at the retinal and choroidal levels using ImageJ software to analyze OCTA images. Retinal peripapillary vascularity is compromised in NAION eyes, but vascularity is not significantly affected at the choroidal level.