Optical Coherence Tomography Angiography Measurements Research Articles

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

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

OCT angiography metrics predict intradialytic hypotension episodes in chronic hemodialysis patients: a pilot, prospective study

In chronic hemodialysis (HD) patients, intradialytic hypotension (IDH) is a complication that increases mortality risk. We run a pilot study to analyzing possible relationships between optical coherence tomography angiography (OCT-A) metrics and IDH with the aim of evaluating if OCT-A could represent a useful tool to stratify the hypotensive risk in dialysis patients. A total of 35 eyes (35 patients) were analyzed. OCT-A was performed before and after a single dialysis session. We performed OCT-A 3 × 3 mm and 6 × 6 mm scanning area focused on the fovea centralis. Patients were then followed up to 30 days (10 HD sessions) and a total of 73 IDHs were recorded, with 12 patients (60%) experiencing at least one IDH. Different OCT-A parameters were reduced after dialysis: central choroid thickness (CCT), 6 × 6 mm foveal whole vessel density (VD) of superficial capillary plexus (SPC) and 6 × 6 mm foveal VD of deep capillary plexus (DCP). At logistic regression analysis, IDH was positively associated with baseline foveal VD of SCP and DCP, while an inverse association was found with the choroid. In Kaplan–Meier analyses of patients categorized according to the ROC-derived optimal thresholds, CCT, the 3 × 3 foveal VD of SCP, the 3 × 3 mm and 6 × 6 mm foveal VD of DCP and the 6 × 6 mm foveal VD of SCP were strongly associated with a higher risk of IDH over the 30-days follow-up. In HD patients, a single OCT-A measurement may represent a non-invasive, rapid tool to evaluate the compliance of vascular bed to HD stress and to stratify the risk of IDH in the short term.

Quantitative assessment of retinal thickness and vessel density using optical coherence tomography angiography in patients with Alzheimer's disease and glaucoma.

PurposeAssessment and a direct comparison of retinal vessel density with the thickness of inner retinal layer (IRL) and outer retinal layer (ORL) in the same regions of the macula in subjects with Alzheimer’s disease (AD) and primary open-angle glaucoma (POAG).MethodsWe analyzed data from 48 eyes of healthy control (HC) participants, 71 eyes with POAG, and 49 eyes of AD patients. Ophthalmic examination included optical coherence tomography (OCT) imaging to measure IRL and ORL thickness and OCT angiography (OCTA) in the same region for the imaging of vessel density in the superficial vascular plexus (SVP) and deep vascular plexus (DVP) of the retina. A direct comparison of vessel density and retinal layers thickness, which different dynamic ranges, was obtained by normalizing values as percentage losses.ResultsPatients with AD presented significantly greater losses of vascular density in the DVP and ORL thickness compared to POAG (p <0.001), but percentage losses of vessel density in SVP and IRL thickness were considerable in POAG compared to AD eyes (p<0.001). Positive associations among presence of AD were observed primarily in outer retina where a 1% decrease of ORL thickness was associated with about 24–29% increase in odds of the presence of AD. According to OCTA measurements, a 1% decrease of vessel density in DVP was positively associated with a 4–9% increase in odds of the presence of AD. In POAG positive associations among presence of disease were observed only in inner retina where 1% loss of IRL thickness and a 1% loss of vessel density in the SVP were positively associated with a 13–23% increase in risk of presence of the disease.ConclusionsAnalysis of ORL thickness and vessel density in DVP could potentially improve diagnostic capabilities and may provide a valuable approach for predicting of AD.

Reduction of Foveal Avascular Zone After Vitrectomy Demonstrated by Optical Coherence Tomography Angiography.

Purpose: To investigate the effect of pars plana vitrectomy on foveal circulation, and in particular the foveal avascular zone (FAZ), using optical coherence tomography angiography (OCTA).Methods: This was a prospective, non-randomized, comparative case series of patients that underwent vitrectomy. Twenty-six eyes of 26 patients that underwent vitrectomy were studied postoperatively by OCTA. Our patients underwent 23 or 25G pars plana vitrectomy (PPV) for any posterior segment pathology. Three-dimensional OCTAs (DRI Triton Swept Source OCT; Topcon) of the capillary plexus were obtained three months post-operatively. The FAZ measurements of the fellow eyes were used as controls.Main outcome measures: Change in FAZ area between vitrectomized eyes and controls.Results: From a total of 26 patients, 17 underwent vitrectomy due to retinal detachment (RD). Almost all patients demonstrated a statistically significant reduction in FAZ size based on the OCTA measurements. Τhe mean difference in FAZ size for the superficial capillary plexus (SCP) was -93.77 ± 71.73 μm and for the deep capillary plexus (DCP) -88.87 ± 75.41 μm, both statistically significant (p=0.000), while the amount of reduction in μm was the same for both SCP and DCP.Conclusion: The foveal avascular zone seems to be reduced following vitrectomy as shown by optical coherence tomography angiography. It is postulated that this may be the result of changes in the physiology of the vitrectomized eye, and that this change should be attributed to the removal of the vitreous itself rather than other structures such as the internal limiting membrane.

Quantitative Optical Coherence Tomography Angiography (OCTA) Parameters in a Black Diabetic Population and Correlations with Systemic Diseases.

This is a cross-sectional, prospective study of a population of black diabetic participants without diabetic retinopathy aimed to investigate optical coherence tomography angiography (OCTA) characteristics and correlations with systemic diseases in this population. These parameters could serve as novel biomarkers for microvascular complications; especially in black populations which are more vulnerable to diabetic microvascular complications. Linear mixed models were used to obtain OCTA mean values ± standard deviation and analyze statistical correlations to systemic diseases. Variables showing significance on univariate mixed model analysis were further analyzed with multivariate mixed models. 92 eyes of 52 black adult subjects were included. After multivariate analysis; signal strength intensity (SSI) and heart disease had statistical correlations to superficial capillary plexus vessel density in our population. SSI and smoking status had statistical correlations to deep capillary plexus vessel density in a univariate analysis that persisted in part of the imaging subset in a multivariate analysis. Hyperlipidemia; hypertension; smoking status and pack-years; diabetes duration; creatinine; glomerular filtration rate; total cholesterol; hemoglobin A1C; and albumin-to-creatinine ratio were not significantly associated with any OCTA measurement in multivariate analysis. Our findings suggest that OCTA measures may serve as valuable biomarkers to track systemic vascular functioning in diabetes mellitus in black patients.

Superficial macular vessel density in eyes with mild, moderate, and severe primary open-angle glaucoma.

The aim of this study is to report changes in and associations of macular vessel density (VD) and perfusion density (PD) using optical coherence tomography angiography (OCTA) in mild, moderate, and severe open-angle glaucoma. One hundred thirty-three patients with open-angle glaucoma (133 eyes: 47 mild, 33 moderate, and 53 severe glaucoma) and 73 normal subjects (right eyes) were included in this cross-sectional study. All subjects underwent Cirrus OCTA measurements. One-way analysis of variance (ANOVA) was used to compare macular VD and PD between the controls and mild, moderate, and severe glaucoma groups. Multiple linear regression was performed with OCTA parameters as the predicted variable and age, gender, spherical equivalent (SE), intraocular pressure (IOP), mean deviation (MD), signal strength (SS), and mean macular ganglion cell-inner plexiform layer (mGCIPL) thickness as the predictor variables. The total area of VD showed significant differences between the controls vs. mild (p < 0.001) and moderate vs. severe glaucoma (p = 0.003); no significant difference was found between mild and moderate glaucoma (p = 1.000). Macular VD was associated with age (β = -0.02, p = 0.003), MD (β = 0.04, p = 0.001), SS (β = 1.43, p < 0.001), and mGCIPL thickness (β = 0.04, p = 0.002) but not with gender, SE, and IOP (all p > 0.05). Macular microcirculation declined significantly in mild and severe glaucoma. No significant difference was found between mild and moderate glaucoma. Decrease macular VD was independently associated with age, severe MD, lower SS, and thinner mGCIPL thickness.

Macular vessel density, branching complexity and foveal avascular zone size in normal tension glaucoma

The aim of this study was to investigate the relationship between glaucoma severity and perifoveal vessel density (pfVD), branching complexity, and foveal avascular zone (FAZ) size in normal tension glaucoma (NTG). 31 patients with NTG washed out of glaucoma medications were subjected to tests including; intraocular pressure measurement; standard automated perimetry; optical coherence tomography (OCT) measurement of macular ganglion cell complex (mGCC), inner macular thickness (IMT) and circumpapillary retinal nerve fibre layer (cpRNFL); and OCT angiography measurement of pfVD, FAZ perimeter and multispectral fractal dimensions (MSFD). Eyes with more severe glaucoma had significantly thinner mGCC and cpRNFL and lower pfVD. MD decreased by 0.4 dB (95% CI 0.1 to 0.6 dB, P = 0.007) for every 1% decrease in pfVD. Lower MSFD was observed in eyes with lower pfVD and in patients with systemic hypertension. Multivariable analysis, accounting for age and OCTA quality, found lower pfVD remained significantly associated with thinner IMT, thinner mGCC and worse MD but not with MSFD. pfVD was reduced in NTG and was diminished in eyes with worse MD. Macular vessel branching complexity was not related to severity of visual field loss but was lower in patients with systemic hypertension.

Comparison of Optical Coherence Angiography Measurements in Patients with Neovascular and Non-Neovascular Age-Related Macular Degeneration.

Objectives:The purpose of the study was to determine the differences of optical coherence tomography angiography (OCTA) measurements between the patients with neovascular age-related macular degeneration (AMD) and non-neovascular early AMD.Methods:This retrospectively designed study included patients with neovascular AMD (N-AMD group) and non-neovascular early AMD (NN-AMD group). The patients had a completed ocular examination including best-corrected visual acuity (BCVA, in decimal), intraocular pressure (IOP, mmHg), and OCTA measurements such as choroidal blood flow (au) and retinal vessel density (VD, %).Results:The N-AMD group (1.46±0.28 au) showed a lower mean choroidal flow measurement than the NN-AMD group (1.73±0.32 au), (p<0.001). The patients in the N-AMD group had reduced VD measurements in all superficial and deep retinal layers compared with the NN-AMD group. However, significant differences in VD measurements were observed only in total superficial parafovea and in the superior and inferior quadrants of superficial parafovea while comparing the N-AMD and NN-AMD groups (p<0.05 for all). Almost all deep retinal VD measurements (p<0.05 for them) were significantly different in the N-AMD group except the overall and foveal zones (p=0.144 and p=0.433, respectively).Conclusion:Retinal VD is reduced in patients with N-AMD when compared to NN-AMD. This outcome offered a retinal vessel contribution to AMD pathogenesis.

The Influence of Topical Cyclopentolate Instillation on Peripapillary and Macular Microvasculature Measured by Optical Coherence Tomography Angiography in Healthy Individuals.

Purpose:To investigate the influence of topical cyclopentolate 1%, as an anti-muscarinic mydriatic agent, on the peripapillary and macular microvasculature by optical coherence tomography angiography (OCT-A) in healthy adults.Methods:A total of 41 healthy adults without any systemic or ocular disease were enrolled for this prospective consecutive study. All patients underwent OCT-A measurements (OptoVue Inc., Freemont, CA, USA) to assess optic disc status for radial peripapillary capillary network (whole image, inside disc, and peripapillary capillary densities), and superficial and deep capillary plexus whole, foveal, parafoveal and perifoveal densities, and foveal avascular zone (FAZ) densities. Foveal retinal thicknesses and all quadrant retinal fiber layer thicknesses were also assessed. The 4.5 mm × 4.5 mm peripapillary and 6 mm × 6 mm macular OCT-A images were undertaken before and 30 min after instillation of topical cyclopentolate 1% to the right eyes.Results:The mean age of subjects was 38.14 ± 14.10 years. All macular, optic disc, and FAZ densities, foveal retinal thicknesses, average, and all quadrant retinal fiber layer thicknesses were statistically similar between baseline and after administration of topical cyclopentolate 1% (P > 0.05).Conclusion:The current study demonstrated that pupillary dilation with topical cyclopentolate 1% seems to have no statistical effect on macular and peripapillary OCT-A measurements of healthy adults.

Assessment of optical coherence tomography angiography and multifocal electroretinography in eyes with and without nonproliferative diabetic retinopathy.

Purpose:To examine (i) the retinal structure and function using optical coherence tomography angiography (OCTA) and multifocal electroretinography (mfERG), respectively, in eyes with and without nonproliferative diabetic retinopathy (NPDR), (ii) and their interrelationship between retinal structure (OCTA) and function (mfERG) in the two groups independently.Methods:This was a prospective observational study. One hundred twenty-one eligible participants with type 2 diabetes with No DR (n = 89), or with mild or moderate NPDR (n = 32) underwent ophthalmic examination, ultrawide field-view fundus photography, OCTA, and mfERG. Group differences were assessed using a Mann–Whitney U test. Correlations were assessed using Spearman's rho.Results:There were no significant differences in OCTA measures between the two groups. The mfERG P1 implicit times (rings 1–6) were significantly delayed and P1 response densities in rings 5 and 6 were significantly lower in participants with NPDR compared to those with No DR. In those with No DR, P1 implicit times in almost all rings were delayed in relation to lower vessel density and perfusion (maximum variance noted was 13%). In individuals with NPDR, the P1 response density in rings 2 and 3 showed a positive nonsignificant correlation with macular perfusion.Conclusion:In those with diabetes with No DR, retinal neuronal function is influenced by lower macular vessel density and perfusion. The retinal neuronal function is abnormal in individuals with NPDR compared to those with No DR and is not correlated with OCT angiometric measures, suggesting the likelihood of a different retinal structural correlate.

Analysis of optical coherence tomography angiography measurements following retinal detachment surgery

Analysis of optical coherence tomography angiography measurements following retinal detachment surgery

Early Visual Functional Outcomes and Morphological Responses to Anti-Vascular Growth Factor Therapy in Diabetic Macular Oedema Using Optical Coherence Tomography Angiography

PurposeDiabetic macular oedema (DME) is a vision-threatening complication of diabetic retinopathy. Spectral domain optical coherence tomography angiography (OCTA) is useful for assessing DME. We performed serial OCTA measurements before and after 3 monthly intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections to understand its relationship with best corrected visual acuity (BCVA), central macular thickness (CMT) and vascular indices.MethodsOCTA assessment consisting of 6 × 6 mm scans centred on fovea and en-face retinal angiograms were obtained. Scans were done at baseline and at 1 month following each of the 3 intravitreal injections of anti-VEGF (ranibizumab, Lucentis®).ResultsOur prospective study included 24 eyes of 24 subjects, aged 63.0 ± 5.0 years. There was a mean gain of 0.07 LogMAR (3 letters) and reduction of CMT, vessel density (VD) and perfusion density (PD) by end of 3rd month. CMT was independently associated with improvement in BCVA. There were significant reductions in FAZ area, VD and PD over 3 months from baseline.ConclusionAt three months, intravitreal anti-VEGF therapy is associated with visual function recovery in DME, with reduction in CMT being the most reliable predictor of response. OCTA shows a reduction in VD and PD respectively suggestive of reduced macular perfusion in the short term. Simultaneous reduction in FAZ size can be due to reversal of manual displacement of the retinal capillaries resulting from resolution of intraretinal oedema.

Focal Structure–Function Relationships in Primary Open-Angle Glaucoma Using OCT and OCT-A Measurements

PurposeTo evaluate the focal structure–function associations among visual field (VF) loss, optical coherence tomography angiography (OCT-A) vascular measurements, and optical coherence tomography (OCT) structural measurements in glaucoma.MethodsIn this cross-sectional study, subjects underwent standard automated perimetry, OCT-based nerve fiber thickness measurements, and OCT-A imaging. Mappings of focal VF test locations with OCT and OCT-A measurements were defined using anatomically adjusted nerve fiber trajectories and were studied using multivariate mixed-effects analysis. Segmented regression analysis was used to determine the presence of breakpoints in the structure–function associations.ResultsThe study included 119 eyes from 86 Chinese subjects with primary open-angle glaucoma (POAG). VF mean deviation was significantly associated with global capillary perfusion density (β = 0.13 ± 0.08) and global retinal nerve fiber layer thickness (β = 0.09 ± 0.02). Focal capillary density (FCD) was significantly associated with VF losses at 34 VF test locations (66.7% of 24-2 VF), with 24 of the 34 locations being within 20° of retinal eccentricity. Focal nerve layer (FNL) thickness was significantly associated with 16 VF test locations (31.4% of 24-2 VF; eight locations within 20° eccentricity). For VF test locations in the central 10° VF, VF losses below the breakpoint were significantly associated with FCD (slope, 0.89 ± 0.12, P < 0.001), but not with FNL thickness (slope, 0.57 ± 0.39, P = 0.15).ConclusionsFocal capillary densities were significantly associated with a wider range of visual field losses and in a larger proportion of the visual field compared to nerve fiber thickness.

Influences of Hypomagnesemia on Optic Nerve and Retinal Vascular Structure Determined Using Optical Coherence Tomography (OCT) Angiography.

ABSTRACT Purpose: To evaluate the effects of low blood magnesium levels on the optic nerve, retina, and retinal vascular structure. Methods: This observational and cross-sectional study was conducted between June 2019 and May 2020 with participants aged 20–39 years, who had a visual acuity of ≥20/20, the axial length of 22–24.5 mm, refractive defect spherical equivalent of ≤±3D, and intraocular pressure of ≤21 mm Hg. All participants had a complaint of twitching in their eyes. The participants with normal serum magnesium levels constituted the control group, and patients with hypomagnesemia constituted the patient group. Updated AngioScan software (Navis ver. 1.8.0.) of Nidek’s RS-3000 Advance system was used to analyze the spectral domain-optical coherence tomography (SD-OCT) and optical coherence tomography-angiography (OCT-A) images. Results: A total of 100 right eyes of 100 individuals was included in the study. The mean retinal nerve fiber layer (RNFL) thickness was 108.52 ± 12.46 μm in the control group, and 97.3 ± 9.7 μm in the hypomagnesemia group (P < .001). In the control group, the global superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel densities (VDs) were 41.92 ± 2.29, and 37.54 ± 3.83, respectively. In the patient group, the global SCP and DCP VDs were 37.66 ± 3.14, and 32.95 ± 5.57, respectively. The SCP and DCP VD percentages were significantly lower in the patient group. The mean foveal avascular zone (FAZ) area, perimeter and circularity index (CI) were 0.32 ± 0.13 mm2, 2.89 ± 0.59 mm, and 0.52 ± 0.09, respectively, for the control group and 0.38 ± 0.11 mm2, 2.99 ± 0.64 mm, and 0.38 ± 0.1, respectively, for the patient group. The FAZ area and perimeter were significantly higher (P = .013 and P = .001) and FAZ CI was significantly lower (P < .001) in the patients with hypomagnesemia. Conclusion: Our study revealed that OCT and OCT-A measurements may be used in the determination of the optic nerve and retinal vascular structure changes in hypomagnesemia.

Association of childhood obesity with retinal microvasculature and corneal endothelial cell morphology.

To investigate the optical coherence tomography angiography (OCTA) and specular microscopy (SM) findings in obese children and compare them with healthy ones. In this prospective study, 50 eyes of 25 obese children [body mass index (BMI)≥95th percentile], 36 eyes of 18 control age- and sex- matched healthy subjects (BMI <85th percentile) were included. Demographic features and ophthalmological examination including OCTA measurements as well as SM findings were assessed. Cellular morphology was observed by noncontact SM and results for corneal endothelial cell density (cells/mm2), coefficient of variation of cell size and percentage of hexagonal cells were obtained. The OCTA was performed with 6 × 6mm sections for macula and 4.5 × 4.5mm sections for optic disc in all eyes. Foveal retinal thickness (FRT), retinal nerve fiber layer (RNFL) thickness, vessel density in different sections of retina and optic nerve head were analyzed. All SM parameters, RNFL thickness for average, and all quadrants and optic disc radial peripapillary capillary densities were similar between groups. However, FRT, flow area for choriocapillaris, superficial and deep foveal capillary densities were significantly higher in obese group when compared to controls (242.4±18.2µm vs. 232.1±16.5µm, p=0.024, 2.2±0.1mm2 vs, 2.2±0.0mm2, p=0.042, 22.4±6.9% vs. 15.6±5.5%, p=0.001, and 38.9±7.5% vs. 31.1±8.6 %, p=0.001, respectively). Obese children seem to have higher values of FRT, flow area for choriocapillaris, superficial and deep foveal capillary densities. These results may have significant implications for understanding of how childhood obesity could affect retinal microvasculature.

The effect of electronic cigarette smoking on retinal microcirculation: Enlargement of the foveal avascular zone.

To evaluate retinal microcirculation in electronic cigarette (e-cigarette) smokers using optical coherence tomography angiography (OCTA). OCTA measurements were performed on the left eyes of 21 e-cigarette smokers and 21 healthy controls. Superficial and deep foveal, perifoveal and parafoveal vessel densities, outer retina and choriocapillaris flow area, foveal avascular zone (FAZ), and central macular thickness were evaluated in both groups. The FAZ area was larger in e-cigarette smokers than the control group, and the difference was statistically significant (p = 0.003). The superficial foveal, superficial total, deep foveal and deep total vascular densities were significantly lower in the e-cigarette group compared to the control group (p = 0.011, p = 0.012, p = 0.022, and p = 0.041, respectively). Central macular thickness was lower in the e-cigarette smokers but the difference was not statistically significant (p = 0.678). E-cigarette smoking causes enlargement of the FAZ area and decreases vascular densities.

Quantification of the Peripapillary Microvasculature in Eyes with Glaucomatous Paracentral Visual Field Loss

To quantify abnormalities in the peripapillary microvasculature in eyes with primary open-angle glaucoma (POAG) and paracentral visual field (VF) loss. Prospective, cross-sectional study. Thirty-three POAG patients, including 15 with paracentral VF loss and 18 with peripheral VF loss, and 31 control participants underwent swept-source OCT angiography (OCTA) of the peripapillary region. The POAG groups were matched by VF mean deviation (MD). The peripapillary microvasculature from the internal limiting membrane to the retinal nerve fiber layer (RNFL) interface was quantified within a 0.70-mm annulus around Bruch's membrane opening after removal of large vessels. Both vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS) suggestive of flow were measured. Regional VD and IOS were measured from the affected hemisphere corresponding to the VF hemifield of more severe loss, which was used to calculate the paracentral total deviation (PaTD), or total deviation within the central 10°. One eye per participant was included. Difference in peripapillary OCTA measurements between paracentral and peripheral VF loss groups and correlation of peripapillary VD and IOS with PaTD. The POAG groups had matched VF MD (-3.1 ± 2.5 dB paracentral vs. -2.3 ± 2.0 dB peripheral; P= 0.31), did not differ in average RNFL thickness (71.1 ± 14.7 μm vs. 78.1 ± 15.0 μm; P= 0.55), but differed in age (59.2 ± 9.6 years paracentral vs. 67.4 ± 6.6 years peripheral; P= 0.02). Compared with control participants, both paracentral and peripheral VF loss groups showed reduced VD (P < 0.001 and P= 0.009, respectively) and IOS (P < 0.001 and P= 0.01, respectively) in the affected hemisphere. Compared with POAG eyes with peripheral VF loss, the paracentral group showed reduced peripapillary VD (38.0 ± 2.0%, 35.0 ± 2.2%, respectively; P= 0.001) and IOS (44.3 ± 3.1%, 40.4 ± 4.0%, respectively; P= 0.02) in the affected hemisphere. Among all POAG eyes, peripapillary VD and IOS of the affected hemisphere correlated significantly with functional measurement of paracentral loss (PaTD, r= 0.40, P= 0.02; r= 0.45, P= 0.008; respectively). These correlations remained significant after adjusting for age (r= 0.41, P= 0.02; r= 0.47, P= 0.01; respectively). Regional peripapillary microvasculature showed decreased VD and flow in POAG with paracentral loss, supporting its importance in this glaucoma subtype.

Optical Coherence Tomography Angiography in Macular Neovascularization: A Comparison Between Different OCTA Devices.

PurposeThe purpose of this study is to compare the ability of 3 optical coherence tomography angiography (OCTA) devices to measure lesion area in patients with macular neovascularization (MNV) with type 1, 2 and mixed neovascularization (NV).MethodsOCTA, fluorescein angiography (FA), indocyanine green angiography (ICGA), and structural optical coherence tomography (OCT) were performed. NV lesion area measurements were performed by two graders.ResultsTwenty-eight eyes were included: 20 with NV were classified as type 1, 6 as type 2, and 2 as mixed type. AngioVue and Spectralis detected the NV in 26 out of 28 eyes (92.8%). The intraclass correlation coefficient (ICC) between readers for the three different OCTA with the different slabs was high. The NV area was larger in the outer retina to choriocapillaris (ORCC) and choriocapillaris (CC) images for the AngioVue device and the PLEX Elite device compared to avascular images (P < 0.05). The mean values of the NV area were not significantly different among the three instruments (Friedman test, P > 0.05) for the avascular zone (AV), ORCC, and CC images. Median (interquartile range [IQR]) NV were significantly different among avascular images, ORCC images, and CC images of the AngioVue device (P = 0.046), of the Spectralis device (P = 0.015), and the PLEX Elite device (P < 0.001).ConclusionsThe ORCC slabs showed the highest detection rate for NV detection independently to the device used, and swept source (SS)-OCTA measurements of ORCC slabs showed the highest detection rate of NVs compared to the spectral domain (SD)-OCTA.Translational RelevanceIt is pivotal to realize how much we can rely on OCTA to make a diagnosis of NV.

Optical Coherence Tomography Angiography in Type 1 Diabetes Mellitus. Report 1: Diabetic Retinopathy.

PurposeThe purpose of this study was to evaluate specifically in type 1 diabetes mellitus (DM) individuals the relationship between perifoveal superficial capillary plexus (SCP) parameters assessed by optical coherence tomography angiography (OCTA) and diabetic retinopathy (DR) grade.MethodsCross-sectional analysis of a large scale prospective OCTA trial cohort (ClinicalTrials.gov NCT03422965). A total of 1186 eyes (593 individuals), 956 type 1 DM eyes (478 patients), and 230 control eyes (115 healthy volunteers) were included in this study. DR stage was graded according to the International Classification. OCTA imaging was performed with a commercially available device (Cirrus HD-OCT). Vessel density (VD), perfusion density (PD), and foveal avascular zone (FAZ) area, perimeter and circularity measurements were quantified in the SCP and receiver operating characteristic (ROC) curves were constructed for each OCTA parameter.ResultsVD and PD (in both 3 × 3 and 6 × 6 mm captures) were inversely associated with DR stage (P < 0.001 in all cases) in a multiple regression analysis after controlling by age, gender, signal strength index, axial length, and DM duration. Greater FAZ area and perimeter and conversely lower circularity measurements were observed as DR severity increased in both scanning protocols (P < 0.05 in all cases).ConclusionsIn type 1 DM individuals, OCTA provides an objective, continuous, and reliable method for accurate quantification of VD, PD, and FAZ parameters in the SCP, which ultimately correlate with DR stages.Translational RelevanceObjective OCTA measurements of the retinal microvasculature could substitute the clinical DR classification in patients with type 1 DM, identify patients at risk of DR progression, and inform treatment decisions to modify the evolution of the disease.

Referenced scans improve the repeatability of optical coherence tomography angiography measurements in normal and glaucoma eyes

AimTo compare the repeatability of peripapillary perfusion density and flux index measurements on referenced and non-referenced optical microangiography (OMAG) scans in normal, glaucoma suspect and glaucoma eyes.MethodsIn a cross-sectional study,...