Coherence Tomography Angiography In Eyes Research Articles

Longitudinal Assessment of Intraretinal Microvascular Abnormalities in Diabetic Retinopathy Using Swept-Source Optical Coherence Tomography Angiography.

To longitudinally investigate the changes in intraretinal microvascular abnormalities (IRMAs) over time, employing swept-source optical coherence tomography angiography in eyes with diabetic retinopathy. In this retrospective, longitudinal study, we evaluated 12 × 12-mm swept-source optical coherence tomography angiography centered on the macula at baseline and last available follow-up visit for (1) IRMA changes during follow-up, defined as (a) stable, (b) regressed, (c) obliterated, and (d) progressed; and the (2) development of new neovascularization (NV) and their origins. Competing-risk survival analysis was used to assess the factors associated with these changes. In total, 195 eyes from 131 participants with diabetic retinopathy were included. Stable, regressed, obliterated, and progressed IRMA were observed in 65.1%, 12.8%, 11.3%, and 19% of eyes with diabetic retinopathy, respectively. Anti-VEGF injections during the follow-up periods and a slower increase of foveal avascular zone were associated with IRMA regression (P < 0.001 and P = 0.039). Obliterated IRMA were correlated with previous panretinal photocoagulation (P < 0.001) and a lower deep capillary plexus vessel density at baseline (P = 0.007), as well as with follow-up anti-VEGF injections (P = 0.025). A higher baseline ischemia index (ISI) and panretinal photocoagulation during the follow-up periods were associated with IRMA progression (P = 0.049 and P < 0.001). A faster increase in ISI predicted the development of NV elsewhere (NVE) from veins (P < 0.001). No significant factors were found to be associated with NVE originating from IRMA. Changes in IRMA closely correlated with the severity of retinal ischemia and treatment. Notably, our study confirmed the potential, yet relatively rare, development of NVE from IRMA in a large cohort; however, the risk factors associated with this transformation require further exploration.

Comparative study of widefield swept-source optical coherence tomography angiography in eyes with concomitant age-related macular degeneration and diabetic retinopathy

Background/aimsWe sought to evaluate widefield swept-source optical coherence tomography angiography (WF SS-OCTA) among eyes with concomitant age-related macular degeneration (AMD) and diabetes mellitus or diabetic retinopathy (DM/DR).MethodsThis cross-sectional, comparative study...

CENTRAL AND PERIPHERAL INVOLVEMENT OF THE RETINA IN THE INITIAL STAGES OF DIABETIC RETINOPATHY.

To determine the degree of central microvascular closure using optical coherence tomography angiography in eyes of patients with type 2 diabetes with visible lesions only in the central retina or only in the periphery. Cross-sectional study. All 127 eyes underwent ultra-widefield fundus photography 200° examinations with OPTOS California (Optos, Dunfermline, United Kingdom) and Cirrus Angioplex optical coherence tomography angiography 3 × 3 mm acquisitions (ZEISS, Dublin, CA). Twenty-five eyes showed visible lesions only in the central retina, 57 only in the peripheral retina, and 45 presented visible lesions in entire retina. The group with visible lesions only in the periphery showed definite closure in the superficial capillary plexus in 49% of the eyes, whereas the group with visible lesions only in the central seven-early treatment diabetic retinopathy study fields area showed a definite closure in 64%. Central capillary closure is already present in the initial stages of diabetic retinopathy even when lesions are only visible in the peripheral retina. Capillary closure in the superficial capillary plexus is three times more frequent than in the deep capillary plexus, demonstrating earlier closure of the superficial capillary plexus. Eyes with visible lesions only in the periphery show a milder form of retinopathy.

Comparison of Retinochoroidal Vascular and Structural Changes after Half-Dose Photodynamic Therapy versus Half-Fluence Photodynamic Therapy Based on Optical Coherence Tomography Angiography in Eyes with Chronic Central Serous Chorioretinopathy

Purpose: The aim of this study is to compare the efficacy of half-fluence photodynamic therapy (PDT) and half-dose PDT on the choroidal structure via perfusion of the retinal plexus and choriocapillaris in eyes with chronic central serous chorioretinopathy (cCSCR). Materials and Methods: This retrospective study included 43 eyes in 43 patients with cCSCR. Patients in group 1 received half-fluence (verteporfin 6 mg m⁻²) PDT and those in group 2 received half-dose (verteporfin 3 mg m⁻²) PDT. Enhanced depth imaging optical coherence tomography and optical coherence tomography angiography (OCTA) images were recorded 1 day before and 3 months after PDT. Total choroidal area (TCA), luminal area (LA), and stromal area (SA) were calculated using Image J software. Results: From baseline to 3 months post PDT TCA decreased from 2.43 ± 0.47 mm² to 2.08 ± 0.59 mm² (p < 0.001), LA decreased from 1.78 ± 0.11 mm² to 1.54 ± 0.26 mm² (p < 0.001), and SA decreased from 0.76 ± 0.33 mm² to 0.53 ± 0.37 mm² (p < 0.001) in group 1. Choriocapillaris vascular density measured via OCTA increased from 37.82 ± 10.99 at the initial visit to 44.96 ± 15.34 at month 3 after half-fluence PDT administered to the fovea (p < 0.001). Deep capillary plexus vessel density was 32.49 ± 11.36 at baseline and increased to 43.27 ± 11.40 at month 3 after half-fluence PDT administered to the fovea (p < 0.001) in group 1. TCA decreased to 2.00 mm² ± 0.51 mm² from 2.39 mm² ± 0.43 mm² (p < 0.001), LA decreased to 1.53 ± 0.29 mm² from 1.74 ± 0.16 mm² (p = 0.019). Although SA decreased from 0.76 ± 0.33 mm² to 0.53 ± 0.37 mm² in group 2, the difference was not significant (p = 0.07). Based on OCTA, choriocapillaris vascular density increased from 43.68 ± 10.38 mm² at baseline to 47.46 ± 6.42 mm² at 3 months after half-dose PDT onto the fovea (p = 0.049). Deep capillary plexus vessel density increased from 34.37 ± 9.36 mm² at the initial visit to 38.17 ± 8.81 mm² 3 months after half-dose PDT onto the fovea (p = 0.046) in group 2. At 3 months, post-PDT subretinal fluid (SRF) was significantly higher resolution in group 1 than in group 2 (p = 0.021). Conclusions: OCTA shows there is a significant increase in deep capillary plexus and choriocapillaris perfusion 3 months after both half-fluence PDT and half-dose PDT. Although there was a significant decrease in LA in both groups, based on OCTA there was a significant decrease in SA, a significant increase in choriocapillaris and deep capillary perfusion in group 1; therefore, the level of SRF resolution at month 3 post PDT might explain its higher incidence in group 1.

CORRELATION OF PHOTORECEPTOR INTEGRITY WITH RETINAL VESSEL DENSITY AND CHORIOCAPILLARIS IN EYES WITH DIABETIC RETINOPATHY.

To investigate the correlation of foveal photoreceptor integrity with the vessel density (VD) of the retina and choriocapillaris using swept source optical coherence tomography angiography in eyes with diabetic retinopathy. We retrospectively reviewed subjects having eyes with diabetic retinopathy, who underwent optical coherence tomography angiography using swept source optical coherence tomography (DRI OCT Triton; Topcon). We analyzed the area of the foveal avascular zone and VDs of the superficial capillary plexus, deep capillary plexus, and choriocapillaris. The length of the lateral extent of ellipsoid zone disruption, central subfield thickness, and subfoveal choroidal thickness were measured. Furthermore, we analyzed factors that were closely associated with the length of ellipsoid zone disruption. A total of 159 eyes with diabetic retinopathy and 30 healthy control eyes were included in this study. In all eyes, the lengths of ellipsoid zone disruption were positively correlated with the foveal avascular zone area (P = 0.009). However, they were negatively correlated with the parafoveal VD of the superficial capillary plexus (P = 0.049), the foveal VD of deep capillary plexus (P = 0.003), and that of the choriocapillaris (P = 0.036). The size of the foveal avascular zone and ischemia at the deep capillary plexus may play an important role in maintaining foveal photoreceptor integrity in eyes with diabetic retinopathy. Considering optical coherence tomography angiography artifacts, such as projection and shadowing, future studies are required to reveal the correlation between ellipsoid zone disruption and the VD of the choriocapillaris.

Variations in Repeated Measurements of Retinal Vessel Density Using Optical Coherence Tomography Angiography in Eyes with Branch Retinal Vein Occlusion

Variations in Repeated Measurements of Retinal Vessel Density Using Optical Coherence Tomography Angiography in Eyes with Branch Retinal Vein Occlusion

Impact of image averaging on vessel detection using optical coherence tomography angiography in eyes with macular oedema and in healthy eyes.

To assess the repeatability of multiple automatic vessel density (VD) measurements and the effect of image averaging on vessel detection by optical coherence tomography angiography (OCTA). An observational study was conducted in a series of healthy volunteers and patients with macular oedema. Five sequential OCTA images were acquired for each eye using the OptoVue HD device. The effect of the averaging of the 5 acquisitions on vessel detection was analysed quantitatively using a pixel-by-pixel automated analysis. In addition, two independent retina experts qualitatively assessed the change in vessel detection in averaged images segmented in 9 boxes and compared to the first non-averaged image. The automatic VD measurement in OCTA images showed a good repeatability with an overall mean intra-class correlation coefficient (ICC) of 0.924. The mean ICC was higher in healthy eyes compared to eyes with macular oedema (0.877 versus 0.960; p < 0.001) and in the superficial vascular plexus versus the deep vascular complex (0.967 versus 0.888; p = 0.001). The quantitative analysis of the effect of the averaging showed that averaged images had a mean gain of 790.4 pixels/box, located around or completing interruptions in the vessel walls, and a mean loss of 727.2 pixels/box. The qualitative analysis of the averaged images showed that 99.6% of boxes in the averaged images had a gain in vessel detection (i.e., vessels detected in the averaged image but not in the non-averaged image). The loss of pixels was due to a reduction in background noise and motion artifacts in all cases and no case of loss of vessel detection was observed. The automatic VD measurement using the OptoVue HD device showed a good repeatability in 5 acquisitions in a row setting. Averaging images increased vessel detection, and in about a third of boxes, decreased the background noise, both in healthy eyes and, in a greater proportion, in eyes with macular oedema.

CHORIOCAPILLARIS FLOW IMPAIRMENT IN TYPE 3 MACULAR NEOVASCULARIZATION: A Quantitative Analysis Using Swept-Source Optical Coherence Tomography Angiography.

To quantitatively analyze choriocapillaris alterations using swept-source optical coherence tomography angiography in eyes presenting with Type 3 macular neovascularization (MNV) and to compare these alterations with eyes presenting with intermediate AMD (iAMD). Macular 3 × 3-mm swept-source optical coherence tomography angiography scans were retrospectively analyzed in eyes with Type 3 MNV and in eyes with iAMD. The choriocapillaris en face slabs were extracted from the swept-source optical coherence tomography angiography device after manual segmentation. En face choriocapillaris flow images were compensated with en face choriocapillaris structure images, followed by the Phansalkar local thresholding method using a window radius of 4 and 8 pixels. The percentage of flow deficits (FD%), the number, size, and total area of FDs were computed for comparison. A secondary analysis was performed in the four corners of the image to include equidistant regions in all eyes. Twenty-six Type 3 MNV eyes of 21 patients and 26 iAMD eyes of 17 patients were included. Compared with iAMD eyes, eyes with Type 3 MNV displayed a higher FD% (41.37% ± 14.74 vs. 19.80% ± 9.63 using radius 4 pixels [P < 0.001]; 45.24% ± 11.9 vs. 26.63% ± 8.96 using radius 8 pixels [P < 0.001]). The average size of FDs was significantly larger in Type 3 MNV eyes compared with iAMD eyes (P < 0.001), whereas the number of FDs was significantly lower in Type 3 MNV compared with iAMD eyes (P < 0.001). Type 3 MNV eyes present with increased choriocapillaris flow impairment compared with iAMD eyes. Reduced choriocapillaris perfusion may contribute to Type 3 MNV development and pathogenesis.

Prospective Cross-Sectional Study of Repeatability of Peripapillary Capillary Density Measurement Using Optical Coherence Tomography Angiography in Eyes With Optic Nerve and Retinal Vascular Pathology.

Optical coherence tomography angiography (OCTA) is a new noninvasive imaging modality that provides high resolution images of the optic nerve head and peripapillary retinal capillary vasculature which can be affected by optic nerve or retinal pathologies. High repeatability of peripapillary capillary density measurement using OCTA has been demonstrated in normal eyes and eyes with glaucoma. The purpose of our study was to quantify the repeatability of peripapillary capillary density measurement using OCTA in both normal eyes and eyes with optic atrophy, optic disc edema, and retinal vasculopathy. This prospective cross-sectional study enrolled 31 patients (59 eyes) including 16 eyes with optic nerve pathology (7 with disc edema from papilledema and 9 with optic atrophy), 35 eyes with retinal vascular disease, and 8 normal eyes. All eyes were imaged twice (30 minutes apart) with the Optovue AngioVue OCTA instrument to obtain 4.5 × 4.5 mm peripapillary scans. Scans were considered good quality if signal strength was 6 or greater. The OCTA parameters obtained include the radial peripapillary capillary (RPC) density of the whole disc, inside the disc, peripapillary region, and the 4 quadrants of the disc (superior, nasal, inferior, and temporal). A Student's t test was used to compare means. Intraclass correlation coefficient (ICC) was calculated to measure repeatability. Repeatability of RPC density measurements for all regions analyzed demonstrated good to excellent repeatability for the whole cohort {ICC for the whole image was 0.915 (95% confidence interval [CI] = 0.855-0.951)}; ICC for the peripapillary region was 0.945 (95% CI = 0.905-0.969). In the subset of eyes with good image quality (i.e., signal strength ≥ 6), ICC was slightly higher for all regions, with excellent repeatability of the peripapillary region (ICC was 0.971 [95% CI = 0.943-0.986]). Conversely, for eyes with poor image quality scans (i.e., signal strength < 6), ICC was lower, corresponding to moderate to good repeatability for most parameters. For the subset of eyes with optic atrophy, disc edema from papilledema or retinal vasculopathy, all had good to excellent repeatability of the vessel density of the entire disc (ICC values were 0.954 [95% CI = 0.804-0.990], 0.921 [95% CI = 0.711-0.982], and 0.895 [95% CI = 0.788-0.951, respectively]) and of the peripapillary region (ICC values were 0.980 [95% CI = 0.904-0.996], 0.966 [95% CI = 0.854-0.993], and 0.916 [95% CI = 0.827-0.961], respectively). The peripapillary capillary density measurement obtained using a commercial OCTA instrument is highly repeatable in eyes with optic nerve atrophy, disc edema from papilledema, or retinal vasculopathy.

Evaluation of The Foveal Avascular Zone Alterations Through Optical Coherence Tomography Angiography In Eyes With Retinal Vein Occlusion.

Background: To detect the effectiveness of OCT-A in evaluation of foveal avascular zone (FAZ) alterations in eyes with retinal vein occlusion . Objectives: To investigate the relationship between best-corrected visual acuity (BCVA) and the FAZ in patients with (RVO) evaluated with (OCT-A) in comparison to the unaffected fellow eyes. Patients and Methods: We retrospectively reviewed the medical records of 15 patients with (RVO); BRVO in 8 patients, CRVO in 7 patients) and we considered the unaffected fellow eyes of these patients as a control group, who were evaluated by OCT-A by a 6 mm × 6-mm region scan centered on the fovea and parafoveal area. The (FAZ), and foveal and parafoveal vascular density in superficial and deep vascular plexuses were analyzed. Result: The mean superficial FAZ area (SL FAZ area) measured 0.40mm in the study group and 0.30mm in the control group. The mean deep FAZ area(DL FAZ area) measured 0.46 mm in the study group and 0.35 mm in the control group. The SL FAZ and DL FAZ areas in eyes with RVO were larger than those in control eyes (P = 0.002, P = 0.033).We found a negative correlation between the BCVA and the superficial FAZ area in eyes with RVO (r = _0.42, P = 0.11).We found a negative correlation between the BCVA and deep FAZ area in the control group(r=_0.30, P 0.26). Conclusions: OCT-A allows detecting FAZ enlargement.Also, we found statistically significant negative correlation between FAZ enlargement and BCVA in patients with RVO.

IDIOPATHIC FOVEAL HYPOPLASIA: Quantitative Analysis Using Optical Coherence Tomography Angiography.

To evaluate vascular density (VD), fractal dimension, and skeletal density on optical coherence tomography angiography in eyes with idiopathic foveal hypoplasia (IFH). Patients presenting with IFH to Creteil University Eye Clinic between January 2015 and October 2018 and age-matched healthy controls were retrospectively evaluated. Vascular density, skeletal density, and fractal dimension analyses were computed on optical coherence tomography angiography superficial capillary plexa (SCP) and deep capillary plexa (DCP) images on the whole image using a custom algorithm. Vascular density on the central 1 mm and the peripheral 8 mm for the two groups was performed. Thirty-six eyes of 21 patients (18 eyes with IFH and 18 control eyes) were included. A decrease of VD at the level of the SCP and DCP was found in eyes with IFH compared with healthy control eyes (P = 0.005 for VD at the level of the SCP and P = 0.003 for VD at the level of the DCP, respectively). On the central 1 mm, VD was decreased in healthy eyes (32.3% ± 4.8) at the level of the SCP compared to IFH eyes (55.6% ± 46.3) (P < 0.001). Skeletal density was decreased in IFH eyes in both SCP and DCP (P =< 0.001). Fractal dimension was lower in IFH eyes in both SCP and DCP (P < 0.001). Vascular density, skeletal density, and fractal dimension are reduced at the level of SCP and DCP in patients with IFH compared with controls, reflecting a particular anatomical and vascular organization. Quantitative analysis using optical coherence tomography angiography could help to evaluate the severity of IFH.

Stepwise segmentation error correction in optical coherence tomography angiography images of patients with diabetic macular edema.

Aim:To determine the minimum number of optical coherence tomography B-scan corrections required to provide acceptable vessel density measurements on optical coherence tomography angiography images in eyes with diabetic macular edema.Methods:In this prospective, noninterventional case series, the optical coherence tomography angiography images of eyes with center-involving diabetic macular edema were assessed. Optical coherence tomography angiography imaging was performed using RTVue Avanti spectral-domain optical coherence tomography system with the AngioVue software (V.2017.1.0.151; Optovue, Fremont, CA, USA). Segmentation error was recorded and manually corrected in the inner retinal layers in the central foveal, 100th and 200th optical coherence tomography B-scans. The segmentation error correction was then continued until all optical coherence tomography B-scans in whole en face image were corrected. At each step, the manual correction of each optical coherence tomography B-scan was propagated to whole image. The vessel density and retinal thickness were recorded at baseline and after each optical coherence tomography B-scan correction.Results:A total of 36 eyes of 26 patients were included. To achieve full segmentation error correction in whole en face image, an average of 1.72 ± 1.81 and 5.57 ± 3.87 B-scans was corrected in inner plexiform layer and outer plexiform layer, respectively. The change in the vessel density measurements after complete segmentation error correction was statistically significant after inner plexiform layer correction. However, no statistically significant change in vessel density was found after manual correction of the outer plexiform layer. The vessel density measurements were statistically significantly different after single central foveal B-scan correction of inner plexiform layer compared with the baseline measurements (p = 0.03); however, it remained unchanged after further segmentation corrections of inner plexiform layer.Conclusion:Multiple optical coherence tomography B-scans should be manually corrected to address segmentation error in whole images of en face optical coherence tomography angiography in eyes with diabetic macular edema. Correction of central foveal B-scan provides the most significant change in vessel density measurements in eyes with diabetic macular edema.

Evaluation of change in the vascular density of choriocapillaris on optical coherence tomography angiography in eyes with serpiginous choroiditis.

Purpose:Serpiginous choroiditis (SC) is primarily an inflammation of choriocapillaris leading to nonperfusion. A quantitative assessment of choriocapillaris perfusion can be done by measuring the flow-density by OCT-Angiography (OCTA). This study measures a change in the flow-density of choriocapillaris with the resolution of inflammation.Methods:The OCTA images of a choriocapillaris slab of 30 eyes with active SC were subjected to binarization and vessel density was measured at baseline and final visits and compared.Results:Upon comparing the vessel density of the affected areas by OCTA of choriocapillaris-slab at baseline and final visits, there was statistically significant (P < 0.0001) improvement after the resolution of inflammation. The vessel density of a demarcated normal area was significantly higher when compared to that of lesions at baseline (P < 0.0001) and final visit (P < 0.0001).Conclusion:OCTA is a useful tool to assess reduction in the inflammatory activity on treatment in SC. This study shows that with treatment the perfusion of choriocapillaris improves; however, it remains lower than normal.

Circumpapillary and macular vessel density assessment by optical coherence tomography angiography in eyes with temporal hemianopia from chiasmal compression. Correlation with retinal neural and visual field loss.

To compare the circumpapillary and macular vessel density (cpVD/mVD) of eyes with temporal visual field (VF) defect and band atrophy (BA) of the optic nerve and normal controls using OCTA and to verify the association of VD parameters with circumpapillary retinal nerve fibre layer (cpRNFL) thickness, macular ganglion cell complex (mGCC) thickness and VF loss. Thirty-three eyes of 26 patients with BA and 42 eyes of 22 age-matched normal controls underwent OCT + OCTA scanning. cpVD and cpRNFL were expressed as average and sector measurements. mVD and mGCC were calculated as averages and in quadrants and hemiretinas. VF loss was estimated using the 24-2 and the 10-2 protocols. Generalized estimated equation models were used for comparisons and area under the receiver operating characteristics (AROC) were calculated. Compared with controls, BA eyes displayed smaller average cpVD and mVD values (p < 0.001 and AROC = 0.91 for both). Sectorial measurements were also reduced, especially the nasotemporal sector average cpVD (p < 0.001 and AROC = 0.96) and the nasal retina mVD measurements (p < 0.001 and AROC = 0.93). cpVD and mVD correlated strongly with corresponding cpRNFL and mGCC thickness measurements in affected regions (r range: 0.67-0.78 and 0.56-0.76, respectively). Similarly, cpVD and mVD parameters correlated significantly with corresponding VF loss (r range: 0.45-0.68). cpVD and mVD are significantly reduced in BA eyes compared with controls and are strongly correlated with retinal neural and VF loss. cpVD and mVD reduction on OCTA could serve as a surrogate for retinal neural loss in compressive optic neuropathy and might be useful in its management.

Textural Properties of Choriocapillaris on OCTA in Healed Inflammatory Choriocapillaropathies.

To evaluate the flow characteristics and textural properties of choriocapillaris (CC) on optical coherence tomography angiography in eyes with resolved inflammatory choriocapillaropathies and Vogt-Koyanagi-Harada (VKH) disease. A cohort of eyes with healed acute posterior multifocal placoid pigment epitheliopathy (APMPPE), serpiginous choroiditis (SC), and VKH disease were included. A 3 mm × 3 mm OCT angiogram of CC was acquired and graded for flow characteristics and textural properties. This study included 16 patients. Texture was heterogeneous in all eyes in the SC and VKH groups, and in four eyes (40%) in the APMPPE group. Most of the eyes with VKH disease had severe low flow, whereas most of the SC and APMPPE eyes demonstrated mild low flow. Heal duration had a strong negative correlation with severity of CC low flow and a weak, statistically nonsignificant correlation with texture heterogeneity. Despite the resolution of active inflammation, partial CC hypoperfusion and texture disruptions persist for longer durations and may resolve in a time dependent manner. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:566-572.].

Collateral vessels on optical coherence tomography angiography in eyes with branch retinal vein occlusion

AimsTo detect collateral vessels using optical coherence tomography angiography (OCTA) in eyes with branch retinal vein occlusion (BRVO) and to investigate the associations with visual outcomes and macular oedema.MethodsEyes with...

EVALUATION OF MACULAR ISCHEMIA IN EYES WITH CENTRAL RETINAL VEIN OCCLUSION: An Optical Coherence Tomography Angiography Study.

To quantitatively assess macular perfusion status using optical coherence tomography angiography in eyes with aflibercept-treated central retinal vein occlusion and resolved macular edema and to investigate the impact of macular morphology and perfusion status on visual function. This prospective consecutive case series included 23 patients with central retinal vein occlusion. All patients received intravitreal aflibercept injections before analysis. Visual acuity, macular sensitivity, and the macular nonperfusion area (NPA) were evaluated in eyes without macular edema. The macular NPA was evaluated by optical coherence tomography angiography using 3 mm × 3 mm images of the macula. Foveal ellipsoid zone disruption was also analyzed. The superficial macular NPA measured 4.15 mm ± 0.71 mm (95% confidence interval 3.85-4.46), and the deep macular NPA measured 4.23 mm ± 0.97 mm (95% confidence interval 3.82-4.56). The logarithm of the minimum angle of resolution visual acuity was significantly associated with foveal ellipsoid zone disruption (P = 0.001), the superficial macular NPA (P = 0.015), and the deep macular NPA (P = 0.018). Macular sensitivity correlated negatively with logarithm of the minimum angle of resolution visual acuity (P = 0.007), the superficial macular NPA (P = 0.029), and the deep macular NPA (P = 0.040), but not with the foveal ellipsoid zone disruption (P = 0.435). Optical coherence tomography angiography is a novel technique that enables segmented evaluation of the macular perfusion status in eyes with central retinal vein occlusion and provides visual prognostic information. Enlargement of the macular NPA in the superficial and deep layers was significantly correlated with impaired visual acuity and with decreased macular sensitivity in patients with aflibercept-treated central retinal vein occlusion and resolved macular edema.

Optical Coherence Tomography Angiography in Eyes with Indeterminate Choroidal Neovascularization: Results from the AVATAR Study

To evaluate the use of optical coherence tomography angiography (OCTA) to detect choroidal neovascularization (CNV) in eyes with indeterminate CNV features on conventional imaging. The AVATAR study is a prospective observational study of OCTA in patients undergoing routine spectral-domain optical coherence tomography (SD-OCT) for macular disease. Subjects enrolled in the AVATAR study for which CNV was considered as part of a differential diagnosis based on clinical exam and/or prior imaging, but in whom the presence of CNV was not definitive on SD-OCT and fluorescein angiography (FA) imaging. All patients were imaged with the Avanti RTVue XR HD (Optovue, Fremont, CA) and the Cirrus HD-OCT (Zeiss, Oberkochen, Germany) systems. OCTA scans were assessed for the presence or absence of CNV. SD-OCT scans were assessed for the presence of fluid, hyperreflective material, serous pigment epithelial detachment (PED), shallow irregular PED, vitreomacular adhesion, epiretinal membrane, retinal pigment epithelium atrophy and central subfield retinal thickness. Univariate and multivariate logistic regression analyses were performed to identify features on SD-OCT associated with the presence of CNV on OCTA. Twenty-nine eyes of 29 patients met the criteria for inclusion. A CNV lesion was detected on OCTA in 8 (28%) eyes; 21 (72%) eyes were negative for CNV. After adjusted for age, gender and central subfield retinal thickness, the presence of shallow irregular PED [odds ratio, 148; 95% confidence interval, 3.22-6830; p = 0.011], as well as the combinations of intraretinal fluid and sub-retinal pigment epithelium material [odds ratio, 16.8; 95% confidence interval, 1.43-198; p = 0.025] on SD-OCT were significantly associated with the presence of CNV on OCTA. OCTA enabled the identification of CNV that was otherwise indeterminate with prior imaging in select eyes. The presence of a shallow irregular PED as well as intraretinal fluid combined with sub-retinal pigment epithelium material were both associated with the presence of CNV. OCTA may be a valuable adjunct to conventional SD-OCT and FA imaging in the detection and surveillance of CNV, particularly in diagnostic dilemmas.

Automated Quantification of Nonperfusion Areas in 3 Vascular Plexuses With Optical Coherence Tomography Angiography in Eyes of Patients With Diabetes

Diabetic retinopathy (DR) is a leading cause of vision loss that is managed primarily through qualitative clinical examination of the retina. Optical coherence tomography angiography (OCTA) may offer an objective and quantitative method of evaluating DR. To quantify capillary nonperfusion in 3 vascular plexuses in the macula of eyes patients with diabetes of various retinopathy severity using projection-resolved OCTA (PR-OCTA). Cross-sectional study at a tertiary academic center comprising 1 eye each from healthy control individuals and patients with diabetes at different severity stages of retinopathy. Data were acquired and analyzed between January 2015 and December 2017. Foveal avascular zone area, extrafoveal avascular area (EAA), and the sensitivity of detecting levels of retinopathy. The study included 39 control individuals (20 women [51%]; mean [SD] age, 43.41 [19.37] years); 16 patients with diabetes without retinopathy (8 women [50%]; mean [SD] age, 56.50 [12.43] years); 23 patients with mild to moderate nonproliferative DR (18 women [78%] ; mean [SD] age, 62.48 [10.55] years); and 32 patients with severe nonproliferative DR or proliferative DR (12 women [38%]; mean age, 53.41 [14.05] years). Mean (SD) foveal avascular zone area was 0.203 (0.103) mm2 for control individuals, 0.192 (0.084) mm2 for patients with diabetes without retinopathy, 0.243 [0.079] mm2 for mild to moderate nonproliferative DR, and 0.359 (0.275) mm2 for severe nonproliferative DR or proliferative DR. Mean (SD) EAA in whole inner retinal slab in these groups, respectively, were 0.020 (0.031) mm2, 0.034 (0.047) mm2, 0.038 (0.040) mm2, and 0.237 (0.235) mm2. The mean (SD) sum of EAA from 3 segmented plexuses in each of the respective groups were 0.103 (0.169) mm2, 0.213 (0.242) mm2, 0.451 (0.243) mm2, and 1.325 (1.140) mm2. With specificity fixed at 95%, using EAA in inner retinal slab, the sensitivity of detecting patients with diabetes from healthy control individuals was 28% (95% CI, 18%-40%), 31% for patients with DR (95% CI, 19%-45%), and 47% for patients with severe DR (95% CI, 29%-65%) from whole inner retinal EAA. With the sum of EAA from 3 individual plexuses, the sensitivities were 69% (95% CI, 57%-80%), 82% (95% CI, 70%-91%), and 97% (95% CI, 85%-100%), respectively. Avascular areas were not associated with signal strength index. The commercial vessel density from the 2-plexus scheme distinguished the groups with lower sensitivity and were dependent on SSI. Automatically quantified avascular areas from a 3-layer segmentation scheme using PR-OCTA distinguished levels of retinopathy with a greater sensitivity than avascular areas from unsegmented inner retinal slab or measurements from a commercially available vessel density in 2-layer scheme. Additional studies are needed to investigate the applicability of nonperfusion parameters in clinical settings.

Evaluation of Shape of Foveal Avascular Zone by Optical Coherence Tomography Angiography in Eyes With Branch Retinal Vein Occlusion

Purpose: To determine the relationship between morphological parameters of the foveal avascular zone (FAZ) in the optical coherence tomography angiographic (OCTA) images and the best-corrected visual acuity (BCVA) in branch retinal vein occlusion (BRVO). Methods: This was a retrospective cross-sectional study. Eyes with BRVO without apparent macular edema were studied. The superficial FAZ in 3 × 3 mm OCTA images were delineated manually. The size and shape, the circularity and axial ratio, of the FAZ were determined, and the values were compared to that of the controls. The correlation of these parameters with the BCVA was analyzed. Results: The mean FAZ area was larger in BRVO eyes than in controls, but the larger size was not correlated with the BCVA (BRVO, 0.49 ± 0.12 mm2; control, 0.38 ± 0.12 mm2; P = .135). The axial ratio of the BRVO eyes was significantly larger than that of controls ( P &lt; .001). The axial ratio was significantly correlated with BCVA ( R = .382, P = .050). Although the circularity was significantly smaller in the BRVO eyes than that in controls ( P &lt; .001), it was not significantly correlated with the BCVA. Conclusion: The shape of the FAZ would be a more appropriate parameter than the size in determining BCVA in eyes with BRVO.