Relationship Between Foveal Threshold and Macular Structure/Function/Vessel Density in Glaucoma.

To compare choroidal neovascularization (CNV) area and vessel density (VD) measurements between two different swept-source optical coherence tomography angiography (SS-OCTA) devices. En face optical coherence tomography angiography (OCTA) images of patients affected by neovascular age-related macular degeneration were collected prospectively from two devices: Zeiss PLEX Elite 9000 (Carl Zeiss Meditec, Dublin, CA) and Topcon DRI OCT Triton SS-OCTA (Topcon, Tokyo, Japan). Choroidal neovascularization area and VD of images were measured and analyzed with ImageJ software by two readers to evaluate the agreement between two devices, with respect to different image size (3 × 3 and 6 × 6 mm) and different image segmentation (automatic vs. manual), and a Topcon equivalent Zeiss segmentation as control (i.e., the equivalent anatomical slab given by Topcon device on the Zeiss device). A total of 30 eyes (30 patients) were analyzed. There was an excellent agreement between the two readers in CNV area measurements intraclass correlation coefficient >0.9 in all analyses. We found excellent agreement in CNV area measurements (manual and automatic segmentations) when comparing 3 × 3-mm or 6 × 6-mm images both for each single device and between the two devices (overall intraclass correlation coefficient > 0.9). Vessel density measurements between manual to automatic segmentation within the same device and same image size had a high intraclass correlation coefficient value, but there was a poor agreement in VD between different image sizes (3 × 3 mm vs. 6 × 6 mm) in the same device and also comparing the two devices (3 × 3 Topcon vs. 3 × 3 Zeiss; 6 × 6 Topcon vs. 6 × 6 Zeiss). There was a poor agreement between the Topcon equivalent Zeiss segmentation and all other segmentations. There was an excellent agreement in CNV area measurements for both swept-source optical coherence tomography angiography devices in automatic and manual segmentations. However, the Topcon equivalent Zeiss segmentation was not comparable with any of the preset segmentations of Topcon and Zeiss devices. There was a poor agreement in CNV VD between different image size and different devices. For these reasons, it seems that, for accurate longitudinal analysis of VD, it is better to use the same device for each individual, even if both devices can be used interchangeably for CNV area measurements using automatic or manual segmentations.

Macular and Optic Nerve Head Vessel Density and Progressive Retinal Nerve Fiber Layer Loss in Glaucoma

PurposeTo evaluate the spatial relationship between macular superficial vessel density (SVD) and macular ganglion cell-inner plexiform layer (GCIPL) thickness in primary angle closure glaucoma (PACG), and to investigate diagnostic abilities of macular SVD and foveal avascular zone (FAZ) parameters.MethodsThis was a cross-sectional study on 38 PACG patients (38 eyes) and 25 healthy subjects (25 eyes). Macular region was imaged using a 1050-nm-wavelength swept-source optical coherence tomography (OCT) angiography (OCTA) system (DRI OCT Triton, TOPCON). Vessel density of the macular region was quantified by ImageJ software. The peripapillary retinal nerve fiber layer (pRNFL) thicknesses and macular GCIPL thickness were obtained by swept-source OCT. Pearson correlation analysis was used to evaluate the spatial positional relationship between macular SVD and macular GCIPL thickness. At the same time, the correlation between macular SVD and pRNFL thickness was evaluated. Areas under the receiver operating characteristics curves (AUCs) of OCT, OCTA and FAZ measurement metrics were calculated to assess the diagnostic ability for glaucoma.ResultsMacular GCIPL thickness had a moderate correlation with the macular SVD in the inferonasal sector (r = 0.426, P = 0.008). In addition, there was a strong correlation between inferonasal sector of macular vessel density and 5,6,7,8 clock-hour regions of the pRNFL thicknesses (all r > 0.5). Inferoinferior sector of macular SVD and 6,7 clock-hour regions of pRNFL thicknesses also had strong correlation (all r > 0.5). The AUCs of macular SVD ranged between 0.61 (superonasal sector) and 0.76 (inferoinferior sector). The FAZ circularity index showed the highest diagnostic power (AUC = 0.94;95% CI, 0.85–0.99), followed by superotemporal sector of macular GCIPL thicknesses (0.93;95% CI,0.83–0.98).ConclusionsSector of macular SVD not only had a spatial positional correlation with corresponding macular GCIPL thickness, but also with clock-hour regional pRNFL thicknesses in PACG eyes. FAZ circulation index might be a useful diagnostic parameter.

Reproducibilidad de la densidad vascular peripapilar, cabeza del nervio óptico y área macular por OCT-A de acuerdo con la severidad del glaucoma

Signal Strength Reduction Effects in OCT Angiography

To provide a normative vessel density (VD) database for the macula through swept-source optical coherence tomography angiography (OCTA) and to assess the main determinants of this measurement. In contrast with dye angiography, the recently introduced OCTA technique allows for the non-invasive measurement of retinal and choroidal VD metrics. Cross-sectional study. The right eyes of 346 healthy subjects were studied. In 105 subjects both eyes were imaged. Foveal and parafoveal macular VD measurements were obtained in the retinal superficial capillary plexus (SCP), deep capillary plexus (DCP), and in the choriocapillaris (CC) layer. Also recorded were age, sex, axial length (AL), foveal and choroidal thickness (CT). Normative database and determinants of macular VD measured by OCTA. Mean participant age was 38.3 ± 20.1 years (mean ± SD) (range 5-83). Foveal VDs in the different plexuses were: SCP 22.1% ± 5.0% (7.3-35.1), DCP 19.9% ± 6.3% (6.9-51.2) and CC: 52.8% ± 4.3% (40.2-62.1). Parafoveal VDs ranged from 45.4% ± 3.7% to 51.8% ± 4.6%. Positive correlation was observed between foveal VD and foveal thickness (R = .327), as well as between parafoveal DCP VD and CT (R = .250;P ≤ .006), while correlation with age was negative in the SCP and CC (R = -.283;P < .001). No associations were detected between macular VD and sex or AL (P ≥ .05). Macular VD showed wide individual variation, was positively correlated with foveal thickness and with CT, negatively correlated with age, and showed no correlation with AL or sex.

To investigate the relationship between the visual field (VF) deterioration and vessel density (VD) around the optic nerve head (ONH) in a sector-wise manner in eyes with retinitis pigmentosa (RP). The present study enrolled the RP patients who demonstrated VF constriction within central 10°. The VD around the ONH was measured with optical coherence tomography angiography (OCTA), using three binarization methods and the relationships between VD and the mean deviation (MD) value were investigated, respectively. Then, the VD in each quadrant (superior, temporal, inferior, nasal) around the ONH was calculated using Otsu method (OVDs: vessel density measured with Otsu method in the superior region, OVDt: vessel density measured with Otsu method in the temporal region, OVDi: vessel density measured with Otsu method in the inferior region, OVDn: vessel density measured with Otsu method in the nasal region). Considering the foveal position relative to the optic disc, angle-corrected binarized OCTA images were created and the VD was measured in each sector (AcOVDs: angle-corrected OVDs, AcOVDt: angle-corrected OVDt, AcOVDi: angle-corrected OVDi, and AcOVDn: angle-corrected OVDn). We investigated the relationship between the MD value and OVDs, OVDt, OVDi and OVDn. Furthermore, the correlation between the MD value and AcOVDs, AcOVDt, AcOVDi and AcOVDn was analyzed. Thirty-six eyes were examined in the current study. Among Niblack, Bernsen and Otsu methods, the VD measured with Otsu method was closely related to the MD value. Among OVDs, OVDt, OVDi and OVDn, the optimal model for the MD value included OVDt and OVDi. On the other hand, among AcOVDs, AcOVDt, AcOVDi and AcOVDn, the optimal model for the MD value included only AcOVDt. The sector-wise VD around the ONH reflects VF deficit severity and is a candidate for improving the assessment of VF deterioration in eyes with RP.

Background Glaucoma is a prevalent cause of visual impairment, and early detection is critical to prevent progressive vision loss. Optical coherence tomography angiography (OCT-A) enables visualization of retinal and optic nerve microvasculature and holds promise for early glaucoma detection. Aims This study aims to assess microvasculature density alterations in glaucoma using OCT-A. Methods An observational cross-sectional case–control study was conducted at Benghazi Eye Hospital in Libya from December 2022 to August 2023. It included 160 eyes of 126 patients diagnosed with primary open-angle glaucoma and 120 eyes of 96 control subjects. OCT-A was performed using the Swept-Source OCT DRI Triton. Vessel density measurements were obtained from OCT-A images using new built-in software within the device. The data presented as mean ± standard deviation and percentages were analyzed using SPSS. The statistical significance of the differences between different groups was determined using independent t-tests, and the level of significance was set at p-value less than 0.05. Results OCT-A demonstrated significantly reduced microvasculature density in glaucoma eyes across all optic nerve sectors including the inferior (29.0%), superior (25.2%), central (23.5%), nasal (9.9%), and temporal sectors (9.3%; p &lt; 0.02). Moreover, glaucoma patients exhibited a significant reduction in vessel density in the superior macula (17% reduction), the temporal (15.7%,), nasal (12.9%), and inferior sectors (12.6%) (p &lt; 0.002). No statistical difference was seen with vessel density of the central sector (0.49%, p &gt;0.05). Conclusion OCT-A demonstrated significant reductions in microvasculature density in glaucoma patients compared with healthy controls. These findings support the association between glaucoma and vascular changes. Additionally, the TOPCON Swept-Source OCT DRI Triton new software shows promise as a valuable tool for early detection and monitoring of glaucoma-related vascular changes.

BackgroundHigh myopia represents a health issue and leads to the development of complications that threaten vision. The study of macular changes in high myopia patients has undergone great advances with updated technology via new spectral optical coherence tomography (OCT) and Optical coherence tomography angiography (OCTA). Most of related studies have focused on the adults and additional studies need to investigate macular changes in children and adolescents. This study aimed to evaluate the changes in the macular structure by OCT and the macular vessel density in high myopia in children and adolescents by OCTA.MethodsA cross-sectional comparative study. The population was divided into two groups: group 1 (4–11 years) and group 2 (12–18 years). The results were comparable to those of control study of the same age group. The two high myopia groups and the control groups were examined by macular OCT and OCTA to evaluate macular thickness and vessel density in the superficial and deep capillary plexuses.ResultsOCT measurements of patients in group 1 revealed that central macular thickness was significantly lower in high myopia group than in the control group and measured 220.91 ± 27.87 μm and 258.23 ± 17.26 μm, respectively, (P < 0.0001). However, in group 2 the central macular thickness in the high myopia group and control group was 236.32 ± 27.76 μm and 247.09 ± 16.81 μm respectively, and the difference was not statistically significant (P = 0.09). The parafoveal macular thickness and the perifoveal macular quadrants thickness were significantly lower in high myopic children and high myopic adolescents (P < 0.0001) than age matched controls. The parafoveal and perifoveal vessel densities in the superficial and deep capillary plexuses were lower in the high myopia groups than in the age-matched controls in both groups with a few segment exceptions in group 1. The FAZ was significantly wider in group 1 than in the age-matched emmetropes (P = 0.02). The FAZ was wider in group 2 than controls, but the difference was not statistically significant, (P = 0.75).ConclusionHigh myopic children and adolescents have thinner macular thickness than comparable age-matched emmetropes and have less vessel density in superficial and deep capillary plexuses with a wider FAZ.

To assess the diagnostic ability of foveal avascular zone (FAZ) parameters to discriminate glaucomatous eyes with visual field defects (VFDs) in different locations (central vs. peripheral) from normal eyes. Totally, 125 participants were separated into 3 groups: normal (n=45), glaucoma with peripheral VFD (PVFD, n=45), and glaucoma with central VFD (CVFD, n=35). The FAZ area, perimeter, and circularity and parafoveal vessel density were calculated from optical coherence tomography angiography images. The diagnostic ability of the FAZ parameters and other structural parameters was determined according to glaucomatous VFD location. Associations between the FAZ parameters and central visual function were evaluated. A larger FAZ area and longer FAZ perimeter were observed in the CVFD group than in the PVFD and normal groups. The FAZ area, perimeter, and circularity were better in differentiating glaucomatous eyes with CVFDs from normal eyes [areas under the receiver operating characteristic curves (AUC), 0.78 to 0.88] than in differentiating PVFDs from normal eyes (AUC, 0.51 to 0.64). The FAZ perimeter had a similar AUC value to the circumpapillary retinal nerve fiber layer and macular ganglion cell-inner plexiform layer thickness for differentiating eyes with CVFDs from normal eyes (all P>0.05, the DeLong test). The FAZ area was significantly correlated with central visual function (β=-112.7, P=0.035, multivariate linear regression). The FAZ perimeter had good diagnostic capability in differentiating glaucomatous eyes with CVFDs from normal eyes, and may be a potential diagnostic biomarker for detecting glaucomatous patients with CVFDs.

Introduction: The aim of the study was to quantitatively characterize the longitudinal changes in macular vessel density (VD) in eyes with high myopia using swept source-optical coherence tomography angiography (SS-OCTA). Methods: A total of 108 high myopic subjects (axial length [AL] ≥26.0 mm) and 180 age-matched normal subjects were recruited and followed up for at least 1 year. Here, 6 × 6 mm SS-OCTA scans centered at the fovea were used to obtain measurements of macular VD in both the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Linear regression analyses were performed to determine the independent factors associated with the change rates of parafoveal VD over time. Results: High myopia group presented a great loss of VD in both SCP and DCP, whereas control group only showed a significant reduction of VD in the SCP (all p < 0.05). The decrease of VD in the parafoveal region of high myopia group was faster than that of control group (SCP, −2.81%/year vs. −1.05%/year, p = 0.002; DCP, −1.06%/year vs. −0.01%/year, p = 0.004), as well as in the inner and outer ring (all p < 0.05). Longer baseline AL was demonstrated to be significantly associated with faster reduction of parafoveal VD in both SCP (estimate, −0.49; 95% CI: −0.79 to −0.18; p = 0.002) and DCP (estimate, −0.22; 95% CI: −0.42 to −0.03; p = 0.025) in high myopia group. Conclusions: High myopes exhibited a faster reduction of VD in parafoveal region and in the inner and outer ring in comparison with healthy controls. Longer baseline AL was associated with greater loss of parafoveal VD in patients with high myopia.

To evaluate strength of associations between optical coherence tomography (OCT)-angiography vessel density (VD) measurements in the macula and peripapillary region of the optic nerve head (ONH) with standard structural OCT thickness measures. This cross-sectional study included 333 eyes of 219 primary open-angle glaucoma patients, 41 glaucoma suspects, and 73 healthy participants from the Diagnostic Innovations in Glaucoma Study (DIGS) with good quality OCT angiography images. The strength of associations between microvasculature measures in the ONH retinal nerve fiber layer (RNFL) and superficial macula layer was assessed using linear regression models. Associations between ONH and macula VD, and circumpapillary (cp) RNFL thickness and macular ganglion cell complex (mGCC) measures were also evaluated. The strength (r) of associations among VD and thickness measures of ONH and macula ranged from 14.1% to 69.4%; all were statistically significant (P<0.001). The association between ONH and macula whole-image VD (r=41.0%) was significantly weaker than the relationship between mGCC and cpRNFL thickness (r=69.4%, P<0.001). Although both cpRNFL and mGCC thicknesses tended to be more strongly associated with ONH VD (r=39.2% and 26.7%, respectively) than macula VD (r=27.5% and 17.7%, respectively), differences did not reach statistical significance (P=0.050 and P=0.113, respectively). The strength of the association of VD with cpRNFL and mGCC thicknesses varies by retinal layer. The weaker association of macula VD compared with ONH VD with tissue thickness may be due to differences in micorovasculature between the macula and ONH.

PurposeTo evaluate the effects of lowering intraocular pressure (IOP) on foveal avascular zone (FAZ), peripapillary and macular vessel density (VD) by optical coherence tomography angiography (OCTA) in patients with open angle glaucoma after trabeculectomy.Study designProspective studyMethodsTwenty eyes of 20 patients with primary open angle glaucoma (POAG) or exfoliation glaucoma (EG) who were followed up to six months and underwent trabeculectomy were included in our study. OCTA, AngioVue (Optovue Inc.) software was used to analyse the FAZ, peripapillary VD, macular superficial capillary plexus (SCP) and deep capillary plexus (DCP) VD. The parameters of the preoperative and postoperative controls were compared statistically.ResultsTwelve of the patients (60%) had POAG and eight (40%) had EG. Mean IOP measured was 22.4±2.4 mmHg preoperatively and 14.9±2.4 mmHg in the postoperative sixth month (p <0.001). There were no significant changes in OCTA optic disc and macular SCP VD values at the end of the sixth month. In macular DCP parameters; whole image VD (WI-VD), foveal VD (F-VD), parafoveal VD (PAF-VD) and perifoveal VD (PEF-VD) values increased statistically (p=0.003; p=0.026; p=0.006; p=0.004). There was a statistically significant decrease in FAZ area (FAZ-A) and FAZ perimeter (FAZ-P); and a significant increase was found in foveal density values (FD) (p=0.026; p=0.049; p=0.005).ConclusionsWe found that reducing IOP by trabeculectomy did not affect the microcirculation of the peripapillary region and macular SCP, while there was a significant increase in the DCP parameters of the macular region.

Pseudoexfoliation glaucoma eyes had a similar level of peripapillary and superficial macular vessel densities compared with primary open-angle glaucoma eyes matched for age and glaucoma severity when assessed by optical coherence tomography angiography (OCT-A). To compare vessel density (VD) measured by OCT-A between primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG) in the peripapillary and macular areas. The circumpapillary (cpVD), parafoveal (pfVD), and perifoveal vessel densities (perifVD) were obtained using OCT-A (AngioVue/RTVue-XR) in 98 eyes from 98 subjects [age, visual acuity, visual field (VF) mean deviation (MD) matched 49 POAG and 49 PXG eyes]. Global and 8 sectoral VDs in the peripapillary capillary layer were compared. In the macula, the superficial and deep layers of the pfVD and perifVD were analyzed globally and in 4 quadrants. Univariate and multivariate linear regression models were built using cpVD, pfVD, and perifVD as dependent variables and covariates [age, intraocular pressure (IOP), axial length, signal strength index (SSI), and retinal nerve fiber layer (RNFL) thickness] were considered independent variables. In the peripapillary region, none of the VDs differed between groups both before and after adjustment. When we adjusted superficial and deep layer macular VDs for age, IOP, SSI, axial length, and RNFL thickness, all of which could affect measurements, the 2 groups did not differ in any sector. The cpVD in POAG eyes significantly correlated with VF MD and RNFL thickness, whereas IOP, VF MD, and RNFL thickness affected cpVD in PXG. The macular VD in the deep layer was associated with only SSI in both groups. Age-matched and glaucoma severity-matched PXG and POAG did not significantly differ in cpVD or in most of the superficial macular VD parameters.

Optical coherence tomography angiography features of optic nerve head drusen and nonarteritic anterior ischemic optic neuropathy