Macular Optical Coherence Tomography Angiography Research Articles

Associations between macular retinal vasculature and severity of idiopathic epiretinal membrane

BackgroundTo demonstrate the associations between the morphology of macular retinal vasculature and disease severity of idiopathic epiretinal membrane (ERM).MethodsMacular structures were assessed using optical coherence tomography (OCT), and were classified as “with pseudohole” or “without pseudohole”. The 3 × 3 mm macular OCT angiography images were analyzed using the Fiji software to obtain the vessel density, skeleton density, average vessel diameter, vessel tortuosity, fractal dimension, and foveal avascular zone (FAZ)-related parameters. The correlations between these parameters and ERM grading as well as visual acuity were analyzed.ResultsFor ERM with or without a pseudohole, increased average vessel diameter, decreased skeleton density, and decreased vessel tortuosity were all associated with inner retinal folding and thickened inner nuclear layer, indicating more severe ERM. In 191 eyes without a pseudohole, the average vessel diameter increased, fractal dimension decreased and vessel tortuosity decreased with increasing ERM severity. The FAZ was not associated with ERM severity. Decreased skeleton density (r = -0.37), vessel tortuosity (r = -0.35), and increased average vessel diameter (r = 0.42) were correlated with worse visual acuity (All P < 0.001). In 58 eyes with pseudoholes, a larger FAZ was associated with a smaller average vessel diameter (r = -0.43, P = 0.015), higher skeleton density (r = 0.49, P < 0.001), and vessel tortuosity (r = 0.32, P = 0.015). However, none of the retinal vasculature parameters correlated with visual acuity and central foveal thickness.ConclusionIncreased average vessel diameter, decreased skeleton density, decreased fractal dimension and decreased vessel tortuosity were good indicators of ERM severity and associated visual impairment.

Optical Coherence Tomography Angiography Assessment in Congenital Aniridia

This study aims to characterize foveal vasculature assessed by optical coherence tomography angiography (OCT-A) in congenital aniridia which is hallmarked by foveal hypoplasia (FH). Cross-sectional case-control analysis. At the National Referral Center for congenital aniridia, patients with confirmed PAX6-related aniridia and FH diagnosed on spectral-domain OCT (SD-OCT) with available OCT-A and matched control subjects were included. OCT-A was performed in patients with aniridia and control subjects. Foveal avascular zone (FAZ) and vessel density (VD) were collected. VD in the foveal and parafoveal areas at the level of the superficial and deep capillary plexi (SCP and DCP, respectively) were compared between the 2 groups. In patients with congenital aniridia, correlation between VD and the grading of FH was assessed. Among 230 patients with confirmed PAX6-related aniridia, high-quality macular B-scans and OCT-A were available in 10 patients. On the foveal area, mean VD was higher in aniridia patients (41.10%, n=10) than in control subjects (22.65%, n=10) at the level of the SCP and the DCP (P=.0020 and P=.0273, respectively). On the parafoveal area, mean VD was lower in patients with aniridia (42.34%, n=10) than in healthy subjects (49.24%, n=10) at the level of both plexi (P=.0098 and P=.0371, respectively). In patients with congenital aniridia, a positive correlation was found between the grading of FH and the foveal VD at the SCP (r=0.77, P=.0106). Vasculature is altered in PAX6-related congenital aniridia, higher in foveal and lower in parafoveal areas, especially when FH is severe, which is consistent with the concept that the absence of retinal blood vessels is essential for foveal pit development.

Comparison of the vessel density measurements of the macula, optical disc, and peri-papillary region between ocular hypertension patients and healthy controls

ObjectiveTo evaluate Optical Coherence Tomography Angiography (OCT-A) findings in patients with Ocular Hypertension (OHT) and compare them with healthy individuals. MethodsThirty-four patients with ocular hypertension (OHT) and 22 healthy individuals were included in the study. Foveal thickness, retinal vascular density in superficial and deep capillary plexus and choriocapillaris, foveal avascular zone (FAZ), acircularity index (AI), foveal vessel density (FD), non-flow area, capillary and all vessel densities in the peripapillary area and the disc were automatically measured using the Angiovue software of OCT-A and compared between groups. ResultsThe comparison of the macular OCT-A findings did not reveal a significant difference between the two groups in terms of central macular thickness, superficial and deep capillary plexus vessel density (p>0.05). The foveal avascular zone width was significantly higher in OHT subjects compared to the control group (0.30±0.08 µ and 0.25±0.11 µ, respectively; p = 0.04). The comparison of optic nerve OCT-A findings revealed that the whole-field vessel density (wVD) (p = 0.007), peripapillary vessel density (pVD) (p = 0.001), inferior, superior and temporal radial peripapillary capillary plexus vessel density (p = 0.006, p = 0.008, p = 0.02) and the mean retinal nerve fiber layer thickness (p = 0.02) were significantly lower in the OHT group. ConclusionsOur findings suggest that the decrement in the optic disc vascular density and foveal avascular zone width was significantly higher in OHT subjects. The possible effect or role of these microvascular changes in terms of glaucoma development should be examined through further studies.

Macular optical coherence tomography angiography analysis in diabetes mellitus patients with a history of Covid-19

PurposeThere is evidence of decreased vessel density in optical coherence tomography angiography (OCTA) after Covid-19. We aimed to investigate whether the outcome of retinal vasculopathy would be worse if patients with diabetes mellitus (DM) were infected with coronavirus using OCTA to assess retinal vessels. MethodsOne eye of each subject was included in the study. Diabetic patients without retinopathy and non-diabetic controls were divided into four groups according to their Covid-19 history: group 1=DM(-)Covid-19(-); group 2=DM(+)Covid-19(-); group 3=DM(-)Covid-19(+); and group 4=DM(+)Covid-19(+). All Covid-19 patients were not hospitalised. Macular OCTA scans were performed in a 6 × 6 mm area. ResultsDiabetes had no effect on the area of the foveal avascular zone (FAZ), but Covid-19 caused an increase in FAZ area. Diabetes and Covid-19 had an effect on both the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) in the fovea. Eta squared (ƞ2) is a measure of effect size. The effect size of Covid-19 (ƞ2=0.180) was found to be greater than that of diabetes (ƞ2=0.158) on the SCP, whereas the effect size of diabetes (ƞ2=0.159) was found to be greater than that of Covid-19 (ƞ2=0.091) on the DCP. ConclusionsThe percentage of vessel density was lower in the fovea and the FAZ area was enlarged in the diabetic patients who recovered from Covid-19. In diabetic patients Covid-19 may lead to deterioration of vascular metrics.

Diurnal changes in choroidal optical coherence tomography angiography indices over 24 hours in healthy young adults

This prospective study investigated the magnitude and pattern of variation in choroidal optical coherence tomography angiography (OCT-A) indices every 4 h over 24 h in healthy young myopic (n = 24) and non-myopic (n = 20) adults. Choriocapillaris and deep choroid en-face images from macular OCT-A scans were analysed from each session to extract magnification-corrected vascular indices including choriocapillaris flow deficit number, size and density and deep choroid perfusion density in the sub-foveal, sub-parafoveal, and sub-perifoveal regions. Choroidal thickness was also obtained from structural OCT scans. Significant variations over 24 h (P < 0.05) were observed in most of the choroidal OCT-A indices excluding sub-perifoveal flow deficit number, with peaks observed between 2 to 6 AM. For myopes, peaks occurred significantly earlier (3–5 h), and the diurnal amplitude was significantly greater for sub-foveal flow deficit density (P = 0.02) and deep choroidal perfusion density (P = 0.03) compared with non-myopes. Choroidal thickness also showed significant diurnal changes (P < 0.05) with peaks between 2 to 4 AM. Significant correlations were found between diurnal amplitudes or acrophases of choroidal OCT-A indices and choroidal thickness, intraocular pressure, and systemic blood pressure. This provides the first comprehensive diurnal assessment of choroidal OCT-A indices over 24 h.

CHORIOCAPILLARIS STRUCTURE IN THE FELLOW EYES OF PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

Histological choriocapillaris abnormalities have been reported in age-related macular degeneration (AMD). Averaging multiple en face optical coherence tomography angiography improves the quality of imaging of the choriocapillaris. This study used multiple en face swept source optical coherence tomography angiography image averaging to examine the structural changes in the choriocapillaris in the fellow eyes of patients with neovascular AMD. All patients underwent macular optical coherence tomography angiography imaging. One eye per subject was repeatedly imaged, and nine raster scan sets were obtained. Registered en face images were averaged, and area of flow voids and number of flow voids were measured using ImageJ software. Forty-eight patients with neovascular AMD were recruited for analysis. Twenty-seven patients had polypoidal choroidal vasculopathy, and 22 eyes had soft drusen. Twenty-six eyes of 26 healthy individuals were included as age-matched normal controls. The choriocapillaris had a meshwork appearance in all eyes. The mean flow void area of the choriocapillaris was larger in patients with AMD than normal controls (1.14 ± 0.16 mm2 vs. 1.01 ± 0.12 mm2, P = 0.002). The mean size of each flow void was greater in patients with AMD than normal controls (729 ± 210 µm2 vs. 583 ± 120 µm2, P = 0.003). The mean flow void area of the choriocapillaris was larger in eyes with soft drusen than without soft drusen (1.2 ± 0.2 mm2 vs. 1.1 ± 0.1 mm2, P = 0.024). Multiple en face image averaging revealed precise choriocapillaris structures in the fellow eyes of patients with neovascular AMD.

Multimodal Retinal Imaging in Patients with Diabetes Mellitus and Association with Cerebrovascular Disease

Introduction: This study aimed to evaluate the association between macular optical coherence tomography angiography (OCT-A) metrics, characteristics of ultrawide field (UWF) imaging, and cerebrovascular disease in patients with diabetes mellitus (DM) with different stages of diabetic retinopathy (DR). Methods: 516 eyes of 258 DM patients were enrolled in two centers (Milan and Belfast). UWF color fundus photos (CFPs) were obtained with Optos California (Optos, PLC) and graded for both DR severity and predominantly peripheral lesions presence (>50% of CFP lesions) by two independent graders. OCT-A (3 × 3 mm), available in 252 eyes of 136 patients, was used to determine perimeter, area, and circularity index of the foveal avascular zone and vessel density (VD); perfusion density (PD); fractal dimension on superficial, intermediate (ICP), and deep capillary plexuses; flow voids (FVs) in the choriocapillaris. Results: Out of 516 eyes, 108 eyes (20.9%) had no DR, and 6 eyes were not gradable. The remaining 402 eyes were as follows: 10.3% (53) had mild nonproliferative DR (NPDR), 38.2% (197) had moderate NPDR, 11.8% (61) had severe NPDR, and 17.6% (91) had proliferative DR. A worse DR stage was associated with a history of stroke (p = 0.044). Logistic regression analysis after taking into account sex, type of DM, age, DM duration, and OCT-A variables found that PD and VD on ICP were significantly associated with presence of stroke and DR severity. Conclusion: OCT-A metrics show an association with the presence of cerebrovascular complications, providing potentially useful parameters to estimate vascular risk in patients with DM.

Post COVID-19 Retinal Evaluation Using Optical Coherence Tomography Angiography: A Case Control Study

ABSTRACT Purpose To study the effect of coronavirus disease of 2019 (COVID-19) on retinal vasculature by Optical Coherence Tomography Angiography (OCTA). Methods Macular OCTA images of patients recovered from COVID-19 infections were studied including foveal avascular zone (FAZ), capillary vascular densities (CVD) of the superficial and deep capillary network (SCP, DCP), and central foveal thickness (CFT). Results The FAZ area was significantly larger in post COVID-19 cases compared to the healthy controls (p=0.032). Post COVID-19 cases had significant lower CVDs in perifoveal quadrants of the SCP. They also had lower CVD in the whole area, parafoveal, temporal and inferior perifoveal areas in the DCP. The parafoveal DCP area showed a positive correlation with disease duration (r=0.249, p-value=0.018). The whole SCP was significantly larger in cases with lymphopenia (p-value=0.004). Conclusion This study found asymptomatic retinal vascular affection in post COVID-19 eyes showing a relation with disease clinical and laboratory features.

Temporal macular thinning and vessel density correlation in children and young adults with sickle cell disease.

Optical coherence tomography angiography (OCTA) is a recent noninvasive imaging technology that has proved to provide a comprehensive evaluation of retinal vascular abnormalities in adult patients with sickle cell disease (SCD). However, the pediatric population remains less studied. The purpose of this study is to evaluate the correlation between temporal vessel density (VD) in OCTA and temporal macular thinning in optical coherence tomography (OCT) in children and young adults with SCD. We reviewed medical records, OCT and OCTA (Spectralis®) scans from a sample of 32 eyes from 16 patients (7 female + 9 male) under 25 years old. The OCT macular thickness data and OCTA image data were processed using Python 3.9 programming language, and statistical analysis was performed. Pearson Correlation Coefficient between macular thickness and VD for inner and outer temporal areas was 0.47 (p-value = 0.006) and 0.74 (p-value < 0.001), respectively. A t-test was also performed to prove that there is a statistically significant VD difference in patients with higher and lower macular thickness (p < 0.001). These results show that children with outer temporal macular thinning on OCT have lower outer temporal VD on OCTA suggesting that microvascular insults may lead to chronic ischemic changes in the inner retinal layers.

Association of macular vessel density and ganglion cell complex thickness with central visual field progression in glaucoma

Background/aimsTo evaluate the association of macular vessel density (VD) and ganglion cell complex (GCC) thickness with 10–2 central visual field (CVF) progression in glaucoma.MethodsIn this retrospective cohort study, patients with...

Comparative study on retinal microvasculature changes between acute and chronic central serous chorioretinopathy.

Central serous chorioretinopathy (CSC) is generally a common fundus disease in young and middle-aged Asian men. Acute and chronic CSC can lead to different degrees of injury to the retinal blood flow. This study aims to observe and compare the blood flow density in different retinal capillary layers in patients with acute and chronic CSC using optical coherence tomography angiography (OCTA) technology. Twelve patients with acute CSC and 8 patients with chronic CSC including 12 eyes with acute CSC (acute CSC eye group), 11 eyes with chronic CSC (chronic CSC eye group), and 17 normal eyes (normal eye group) were enrolled in this study. All patients underwent 3 mm×3 mm, 6 mm×6 mm macular OCTA scanning. The retinal microvascu-lature was divided into superficial vascular complexes (SVC), intermediate capillary plexuses (ICP), and deep capillary plexuses (DCP) using the projection resolved-OCTA algorithm. Inner retina includes SVC, ICP, and DCP. The vessel density in each retinal layer and the inner retina were calculated and compared. Macular OCTA scanning of 3 mm×3 mm showed that there was no significant difference in blood flow density of SVC and ICP among the 3 groups (both P>0.05); blood flow density of DCP and inner retina in the chronic CSC eye group was significantly lower than that in the acute CSC eye group and the normal eye group (all P<0.05); there was no significant difference in retinal blood flow density of different layer between the acute CSC eye group and the normal eye group (all P>0.05). Macular OCTA scanning of 6 mm×6 mm showed that inner retinal blood flow density of the chronic CSC eye group was significantly lower than that of the acute CSC eye group and the normal eye group (both P<0.05); there was no significant difference in blood flow density of SVC among the 3 groups (P>0.05). The vessel density of DCP and inner retina in the eyes with chronic CSC are significantly reduced, which may result in impaired visual function. Therefore, we recommend that patients with acute CSC should be properly treated to avoid progressing into chronic CSC.

Pentosan Polysulfate Sodium-Associated Maculopathy: Early Detection Using OCT Angiography and Choriocapillaris Flow Deficit Analysis

To compare choriocapillaris flow deficit (CC-FD) analysis using optical coherence tomography angiography (OCTA) in eyes of patients treated with high cumulative dosages of pentosan polysulfate sodium (PPS) but no signs of retinal toxicity versus healthy age-matched controls. Retrospective clinical cohort study. Patients treated with PPS for interstitial cystitis with a cumulative dose of > 1000 g underwent multimodal imaging screening to exclude evidence of PPS maculopathy or other retinal findings. All study patients and age-matched healthy controls completed a 3×3 mm macular volume scan OCTA using the SOLIX full-range OCT. En face OCTA images at the level of the CC were exported and CC-FDs were computed and compared between groups. Fifteen patients treated with PPS and 15 age-matched controls were included. The mean PPS cumulative dose was 1974 ± 666 g over a mean of 17.6 ± 6.8 treatment years. All patients registered a visual acuity of 20/25 or better and normal fundus autofluorescence (FAF), OCT, multicolor, near-infrared reflectance (NIR), and ultra-widefield fundus color and autofluorescence images. The CC-FD was 32.7 ± 3.6% in the PPS group compared with 28.6 ± 4.3% in the control group (P=.023). Patients treated with PPS long enough to accumulate dosages > 1000 g showed significant CC flow impairment before the development of macular toxicity signs with OCT, NIR, and FAF compared with age-matched normal controls. Thus, the choroid may be the earliest manifestation of ocular toxicity, predating the development of clinically evident retinal pigment epithelium (RPE) injury. The subsequent RPE disruption may be the result of choriocapillaris impairment or primary PPS toxicity. Assessment of the CC on OCTA may be a useful tool for early detection of toxicity, although further longitudinal studies are required.

Association of Resolved Paracentral Acute Middle Maculopathy Lesions with Diabetic Retinopathy.

To evaluate the association between paracentral acute middle maculopathy (PAMM) lesions and diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA). Thirteen diabetic patients without DR, 13 patients with mild nonproliferative DR (NPDR), 18 patients with moderate-to-severe NPDR, and 20 patients with proliferative DR (PDR) were included in this retrospective study. For each patient, 6 mm × 6 mm macular OCTA scans of both eyes were reviewed for the presence of acute and resolved PAMM lesions. Among diabetic patients with and without DR, 49 (94.9%) and 7 (53.8%) patients demonstrated small resolved PAMM lesions, respectively. The odds ratio for the presence of resolved PAMM lesions in the eye with DR compared to the eye of diabetic patient without DR was 21.8 (P < 0.001, 95% confidence interval 7.0-67.8). In the mild NPDR group, moderate-to-severe NPDR group, and the PDR group, 11 (84.6%), 18 (100.0%), and 20 (100.0%) patients demonstrated resolved PAMM lesions, respectively. There was a statistically significant increasing prevalence of PAMM lesions as the severity of DR increased (P < 0.001). Small resolved PAMM lesions are a common form of ischemic retinal lesions in DR.

Decreased Visual Acuity Accompanied with Central Scotomas in Normal Tension Glaucoma: Macular Optical Coherence Tomography Angiography Cases

Purpose: To report two cases of decreased visual acuity (VA) accompanied with central scotomas in normal tension glaucoma (NTG) patients investigated with macular optical coherence tomography (OCT) angiography between the eye with decreased VA and the fellow eye.Case summary: A 64-year-old male visited with decreased VA in the right eye as best corrected VA of (0.5). On OCT Angiography, macular vessel density (VD) from superficial layer was smaller in the right eye than the fellow eye as 56.03 and 88.15 (optical density), respectively. Macular VD from deep layer was similar between the two eyes as 116.33 and 113.35 (optical density), respectively. A 52-year-old male presented with decreased VA in the left eye as best corrected VA of (0.5). Macular VD from superficial layer was smaller in the left eye than the fellow eye as 115.55 (optical density) and 131.28 (optical density). VD from deep layer did not show much difference, which was 118.16 and 125.17 (optical density), respectively. On both cases no specific finding was observed at macula on funduscopy or macular OCT. Central scotomas on visual fields and findings of NTG were observed.Conclusions: In these two patients with decreased VA accompanied with NTG and central scotomas, macular VD from superficial layer was reduced compared to the fellow eye. Macular OCT angiography may reflect the macular structural changes caused by reduced vision.

Computerized Texture Analysis of Optical Coherence Tomography Angiography of Choriocapillaris in Normal Eyes of Young and Healthy Subjects.

Computerized texture analysis uses higher-order mathematics to identify patterns beyond what the naked eye can recognize. We tested its feasibility in optical coherence tomography angiography imaging of choriocapillaris. Our objective was to determine sets of parameters that provide coherent and consistent output when applied to a homogeneous, healthy group of patients. This observational cross-sectional study involved 19 eyes of 10 young and healthy Caucasian subjects. En-face macular optical coherence tomography angiography of superficial choriocapillaris was obtained by the RTVue-XR Avanti system. Various algorithms were used to extract texture features. The mean and standard deviation were used to assess the distribution and dispersion of data points in each metric among eyes, which included: average gray level, gray level yielding 70% threshold and 30% threshold, balance, skewness, energy, entropy, contrast, edge mean gradient, root-mean-square variation, and first moment of power spectrum, which was compared between images, showing a highly concordant homology between all eyes of participants. We conclude that computerized texture analysis for en-face optical coherence tomography angiography images of choriocapillaris is feasible and provides values that are coherent and tightly distributed around the mean in a homogenous, healthy group of patients. Homology of blob size among subjects may represent a “repeat pattern” in signal density and thus a perfusion in the superficial choriocapillaris of healthy young individuals of the same ethnic background.

The Association Between Regional Macula Vessel Density and Central Visual Field Damage in Advanced Glaucoma Eyes.

Both macular superficial vessel density and ganglion cell complex (GCC) thickness measurement are significantly associated with regional and global 10-degree central visual field (VF) sensitivity in advanced glaucoma. The purpose of this study was to evaluate the regional and global structure-function relationships between macular vessel density (MVD) assessed by optical coherence tomography angiography (OCTA) and 10-2 VF sensitivity in advanced open angle glaucoma eyes. Macular OCTA and 10-2 VF sensitivity of 44 patients [mean deviation (MD) <-10 dB] were evaluated. Regional and global VF mean sensitivity (MS) was calculated from total deviation plots. Superficial and deep MVD were obtained from 3 × 3 and 6×6 mm 2 OCTA scans using 2 sectoral definitions. Spectral-domain optical coherence tomography macular GCC thickness was obtained simultaneously from the same scan as the MVD measurements. Linear regression models were used to assess the associations ( R2 ). Lower MS was significantly associated with a reduction in superficial MVD and GCC in each region of both scan sizes for both maps. Associations were weaker in the individual sectors of the whole image grid than the Early Treatment Diabetic Retinopathy Study map. Deep-layer MVD was not associated with central MS. Although 6×6 mm 2 and perifoveal vessel density had better associations with central 10-degree MS compared with GCC thickness (eg, R2 from 25.7 to 48.1 µm and 7.8% to 32.5%, respectively), GCC associations were stronger than MVD associations in the central 5-degree MS. Given a stronger MVD-central 10-degree VF association compared with GCC, as well as stronger GCC-central 5-degree VF association compared with MVD, MVD and GCC are complementary measurements in eyes with advanced glaucoma. A longitudinal analysis is needed to determine the relative utility of the GCC and MVD measurements.

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.

Quantitative Evaluation of Retinal Microvascular Abnormalities in Patients With Type 2 Diabetes Mellitus Without Clinical Sign of Diabetic Retinopathy.

PurposeTo evaluate microvascular abnormalities in the macula and peripapillary area in diabetic patients without clinical signs of diabetic retinopathy (DR) and compare them with healthy control eyes, using optical coherence tomography angiography (OCTA).MethodsA prospective study was performed of 49 eyes from 49 diabetic patients without clinical signs of DR and a control group of 52 eyes from 52 healthy normal individuals. The 3 × 3 mm macular scans and 4.5 × 4.5 mm optic disc scans were obtained with the OCTA RTVue-XR Avanti system. Angiograms from the superficial capillary plexus, the deep capillary plexus of the macula scans, and radial peripapillary capillary plexus of the optic disc scans were analyzed with MATLAB. Multivariate binary logistic regression and the least absolute shrinkage and selection operator (LASSO) regression were used to select ideal parameters that distinguish diabetic eyes without DR from normal eyes. A receiver operating characteristic (ROC) curve was generated, and sensitivity and specificity were calculated.ResultsOur final model identified FD-300 (foveal vessel density in a 300-µm-wide region around foveal avascular zone) as the only parameter selected by both the LASSO regression and the final multivariate logistic regression model that significantly differentiates diabetic eyes without clinical signs of DR from healthy normal eyes. The area under the ROC curve of FD-300 was 0.685, and sensitivity and specificity were 65.3% and 71.2%, respectively.ConclusionsQuantitative evaluation of retinal microvascular abnormalities using OCTA identified FD-300 as a useful biomarker versus the other macular and peripapillary OCTA metrics in the early detection of preclinical diabetic retinal abnormalities.Translational RelevanceOCTA may be useful in detecting early retinal microvascular abnormalities in diabetic patients before the clinical findings of DR become visible.

Analysis of Macular Microvasculature in Human Immunodeficiency Virus Infection

ABSTRACT Purpose To evaluate the retinal and choroidal microvascular blood flow in patients with human immunodeficiency virus (HIV) infection using optical coherence tomography angiography (OCTA). Methods Macular OCTA parameters including vessel density (VD) of parafoveal superficial capillary plexus (SCP-VD) and deep capillary plexus (DCP-VD), foveal vessel density (FD), foveal avascular zone area, and flow area of choriocapillaris were analyzed in 42 HIV-positive patients, and compared with 42 healthy controls. Results The mean SCP-VD, DCP-VD and FD were significantly lower in HIV-positive group compared with controls (p < .001, p = .014, p = .026; respectively). Reduced SCP-VD was associated with higher HIV RNA plasma level (r = −0.400, p = .021) and lower CD4 + T cell count (r = 0.314, p = .046) in HIV-positive patients. Conclusions Macular microvascular blood flow is affected by HIV infection. OCTA can detect microvascular flow abnormalities in retinal capillary plexus in HIV-positive patients.

Intrasession Repeatability and Intersession Reproducibility of Macular Vessel Parameters on Optical Coherence Tomography Angiography in Glaucomatous and Non-Glaucomatous Eyes

Purpose Using optical coherence tomography angiography (OCTA), this study compared intrasession repeatability versus intersession reproducibility of macular vessel parameters in glaucoma and non-glaucoma subjects. Methods 6 × 6 mm2 macular OCTA scans (Cirrus HD-OCT 5000) were acquired from glaucomatous and non-glaucomatous subjects as part of an observational, longitudinal study. Vessel area density (VAD) and vessel skeleton density (VSD) were calculated using research-based quantification software while perfusion density (PDZ) and vessel density (VDZ) were calculated using commercially developed software (Cirrus 11.0, Carl Zeiss Meditec). Intrasession repeatability and intersession reproducibility were determined using within-eye standard deviation (SW), within-eye coefficient of repeatability (CRW), within-eye coefficient of variation (CVW), and intraclass correlation coefficients (ICC). Results The intrasession repeatability and intersession reproducibility for macular OCTA parameters were similar to one another for both non-glaucomatous and glaucomatous eyes. Intrasession CVW from the non-glaucoma group (n = 73) was 1.097% for VAD, 1.007% for VSD, 2.980% for PDZ, and 2.714% for VDZ. Intersession CVW from the non-glaucoma group (n = 55) was 1.389% for VAD, 1.279% for VSD, 2.935% for PDZ, and 2.695% for VDZ. Intrasession CVW from the glaucoma group (n = 59) was 1.189% for VAD, 0.970% for VSD, 3.827% for PDZ, and 3.542% for VDZ. Intersession CVW from the glaucoma group (n = 45) was 1.412% for VAD, 1.132% for VSD, 3.915% for PDZ, and 3.654% for VDZ. Non-glaucomatous intrasession ICC ranged from 0.711 to 0.824, non-glaucomatous intersession ICC ranged from 0.649 to 0.762, glaucomatous intrasession ICC ranged from 0.710 to 0.853, and glaucomatous intersession ICC ranged from 0.661 to 0.827. Conclusions Macular OCTA scans can be a useful tool in monitoring the longitudinal progression of glaucoma due to their high repeatability and reproducibility.