Superficial Vascular Complex Research Articles

Analysis of Microvasculature in Nonhuman Primate Macula With Acute Elevated Intraocular Pressure Using Optical Coherence Tomography Angiography.

PurposeTo investigate responses of macular capillary vessel area density (VAD) of superficial and deep retinal vascular plexuses to elevations in intraocular pressure (IOP) in cynomolgus macaque monkeys using optical coherence tomography angiography (OCTA).MethodsIn five general anesthetized male cynomolgus monkeys, the IOP was increased incrementally by 10 mmHg from baseline (10 mmHg) to 70 mmHg and then decreased back to 10 mmHg (recovery state). Structural OCT (30° × 30°) and OCTA (20° × 15°) centered on the macula were obtained at each IOP and 3, 15, and 30 minutes after recovery. En face images of the superficial vascular complex (SVC) and deep vascular complex (DVC) were extracted, and VAD (%) compared with that at baseline was calculated.ResultsThe VADs in the SVC and DVC at baseline and at 30 mmHg IOP were 34.96%, 34.15%, 35.38%, and 30.12%, respectively. The VAD plateaued until 30 mmHg; however, the VAD was affected more in the DVC than in the SVC (P = 0.008) at 30 mmHg. It showed a significant reduction at 40 mmHg (16.52% SVC, P = 0.006; 18.59% DVC, P = 0.012). In the recovery state, the SVC showed full retention of baseline VAD, but the DVC maintained VAD approximately 70% of that at baseline. Structural OCT showed hyperreflectivity in the nuclear layer, retinal swelling, and an undifferentiated ellipsoid zone from 50 mmHg.ConclusionsDespite physiological autoregulation, perifoveal microcirculation was affected at high IOP ≥ 40 mmHg, especially in the DVC, which explains the pathological mechanism of macular vulnerability in ischemic diseases.

The Diagnostic Value of Pulsar Perimetry, Optical Coherence Tomography, and Optical Coherence Tomography Angiography in Pre-Perimetric and Perimetric Glaucoma.

The purpose of this article is to investigate the diagnostic value of Pulsar perimetry (PP), optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA) in pre-perimetric glaucoma (PPG) and perimetric glaucoma (PG). This retrospective cross-sectional study included 202 eyes (145 eyes in the control group, 40 eyes in the PPG group, and 17 eyes in the PG group) from 105 subjects. The results were analyzed by paired t-tests and Wilcoxon signed-rank test. The area under the curve (AUC), sensitivity, and specificity were used to evaluate the diagnostic accuracy. Pearson correlation was used to investigate the relationships of each parameter. The most sensitive parameters for differentiating the control group from the PPG group by using Pulsar, OCT, and OCTA were square loss variance of PP (AUC = 0.673, p < 0.001), superior ganglion cell complex thickness (AUC = 0.860, p < 0.001), and superior-hemi retina thickness (AUC = 0.817, p < 0.001). In the PG group, the most sensitive parameters were mean defect of PP (AUC = 0.885, p < 0.001), whole image of ganglion cell complex thickness (AUC = 0.847, p < 0.001), and perifoveal retina thickness (AUC = 0.833, p < 0.001). The mean defect of PP was significantly correlated with vascular parameters (radial peripapillary capillary (RPC), p = 0.008; vessel density of macular superficial vascular complex (VDms), p = 0.001; vessel density of macular deep vascular complex (VDmd), p = 0.002). In conclusion, structural measurements using OCT were more sensitive than vascular measurements of OCTA and functional measurements of PP for PPG, while PP was more sensitive than the structural and vascular measurements for PG. The mean defect of PP was also shown to be highly correlated with the reduction of vessel density.

Differences in cysts characteristics and related influence on the anatomical response after dexamethasone implant in diabetic macular oedema.

To assess the clinical significance of suspended scattering particles in motion (SSPiM) and different cystic phenotypes in diabetic macular oedema (DME) treated with dexamethasone implant (DEX-i). A retrospective review of type 2 diabetic patients with DME treated with a DEX-i was conducted. Swept-source optical coherence tomography angiography (OCTA, PLEX Elite 9000) with a 3-mm volume cube was performed. Regions of interest were delineated with Fiji software (version 2.1.0/1.53.c) in the superficial vascular complex (SVC) and deep capillary plexus (DCP) at baseline, 2- and 4-months after DEX-i. SSPiM was defined as regions of variable reflectivity with a decorrelation signal. Without a detectable decorrelation signal, its counterpart was addressed as 'corpuscular,' while hyporeflective cysts were optical empty without hyperreflective material enclosed. After treatment, the hyporeflective component demonstrated substantial reabsorption in the SVC (-95.4% at 2- and -84.4% at 4-months, p < 0.01 both) and DVC (-84.4%, 2-months), with a less critical decrease of the corpuscular component in the SVC (2-months: -41.9%, p = 0.001 and 4 months: -1.8%, p = 0.73), and not significant in the DVC. SSPiM did not significantly change in the SVC and DVC neither at 2- and 4-months (p > 0.05, all). After a single DEX-i, the clearance of different cystic phenotypes proceeds with resorption of hyporeflective, followed by corpuscular components. SSPiM demonstrated minimal response, indicating a severe BRB breakdown that may require repeated treatment to reach a satisfactory anatomical response.

Changes of macular vessel density and thickness in gas and silicone oil tamponades after vitrectomy for macula-on rhegmatogenous retinal detachment

PurposeTo investigate the macular vessel density and thickness in macular-on rhegmatogenous retinal detachment (RRD) after vitrectomy with gas and silicone oil (SO) tamponade.MethodsPatients with macular-on RRD eyes, treated with a single successful vitrectomy with gas or SO tamponade and a minimum 30 months follow-up, were reviewed. Best-corrected visual acuity (BCVA), macular vessel density and retinal thickness by using optical coherence tomography angiography, were compared to the contralateral eyes.ResultsSixteen eyes with gas tamponade and 17 eyes with SO tamponade were included in the study. LogMAR best-corrected visual acuity (BCVA) slightly improved from 0.25 ± 0.18 (Snellen 20/36) to 0.17 ± 0.23 (Snellen 20/30) in eyes with gas tamponade, and decreased from 0.30 ± 0.22 (Snellen 20/40) to 0.49 ± 0.28 (Snellen 20/62) in eyes with SO tamponade. The parafoveal vessel densities in superficial vascular complex (SVC) and the corresponding inner retinal thickness (IRT) were similar between the affected eyes and the contralateral eyes in gas tamponade group (P = 0.578, P = 0.943), while significantly reduced in the affected eyes, compared to the contralateral eyes in SO tamponade group (P < 0.001, P < 0.001).ConclusionEyes in SO tamponade group had worse BCVA, lower SVC vessel densities and thinner corresponding IRT after vitrectomy for macular-on RRD, than those in gas tamponade group.

Automated vessel centerline extraction and diameter measurement in OCT Angiography

Abstract Optical Coherence Tomography Angiography (OCTA) is a non-invasive imaging technique that enables the visualization of perfused vasculature in vivo. In ophthalmology, it allows the physician to monitor diseases affecting the vascular networks of the retina such as agerelated macular degeneration or diabetic retinopathy. Due to the complexity of the vasculature in the retina, it is of interest to automatically extract vascular parameters which describe the condition of the vessels. Suitable parameters could improve the diagnosis and the treatment during the course of therapy. We present an automated algorithm to compute the diameters of the vessels in en face OCTA images. After segmenting the images, the vessel centerline was computed using a thinning algorithm. The centerline was refined by detecting invalid pixels such as spurs and by continuing the centerline until the ends of the vessels. Lastly, the diameter was computed by dilating a discrete circle at the position of the centerline or by measuring the distance between both borders of the vessels. The developed algorithms were applied to in vivo images of human eyes. Certainly, no ground truth was available. Hence, a plausibility check was performed by comparing the measured diameters of two different layers of the retina (Superficial Vascular Complex (SVC) and Deep Vascular Complex (DVC)). Each layer exhibits a different characteristic vasculature. The algorithm clearly reflected the differences from both retinal layers. The measured diameters demonstrate that the DVC consists of more capillaries and considerably smaller vessels compared to the SVC. The presented method enables automated analysis of the retinal vasculature and forms thereby the basis for monitoring diseases influencing the vasculature of the retina. The validation of the method using an artificial ground truth is still needed.

Investigation on Non-Segmentation Based Algorithms for Microvasculature Quantification in OCTA Images

Abstract Optical Coherence Tomography Angiography (OCTA) is an imaging modality that provides threedimensional information of the retinal microvasculature and therefore promises early diagnosis and sufficient monitoring in ophthalmology. However, there is considerable variability between experts analysing this data. Measures for quantitative assessment of the vasculature need to be developed and established, such as fractal dimension. Fractal dimension can be used to assess the complexity of vessels and has been shown to be independently associated with neovascularization, a symptom of diseases such as diabetic retinopathy. This investigation assessed the performance of three fractal dimension algorithms: Box Counting Dimension (BCD), Information Dimension (ID), and Differential Box Counting (DBC). Two of those, BCD and ID, rely on previous vessel segmentation. Assessment of the added value or disturbance regarding the segmentation step is a second aim of this study. The investigation was performed on a data set composed of 9 in vivo human eyes. Since there is no ground truth available, the performance of the methods in differentiating the Superficial Vascular Complex (SVC) and Deep Vascular Complex (DVC) layers apart and the consistency of measurements of the same layer at different time-points were tested. The performance parameters were the ICC and the Mann- Whitney U tests. The three applied methods were suitable to tell the different layers apart and showed consistent values applied in the same slab. Within the consistency test, the non-segmentation-based method, DBC, was found to be less accurate, expressed in a lower ICC value, compared to its segmentation-based counterparts. This result is thought to be due to the DBC’s higher sensitivity when compared to the other methods. This higher sensitivity might help detect changes in the microvasculature, like neovascularization, but is also more likely prone to noise and artefacts.

Microvascular Breakdown Due to Retinal Neurodegeneration in Ataxias.

Neurodegenerative ataxias are devastating disorders of the cerebellum and spinal cord, accompanied by death of retinal ganglion cells, leading to relentlessly progressive decline of motor coordination and permanent disability. Retinal microvascular affection has not yet been determined. The aim of this study is to assess whether retinal microvascular alterations occur and, if so, whether they are concurrent with or follow cell death in the retina in neurodegenerative diseases. This study involves the cross-sectional observational study of 43 patients with ataxia and 43 controls enrolled from August 1, 2018, to September 30, 2020. The extent of ataxia was determined by the Scale for the Assessment and Rating of Ataxia. Changes in retinal vasculature were examined by optical coherence tomography angiography (OCT-A) and retinal cell and fiber density by OCT in ataxias concurrently. When comparing the ataxia cohort with healthy subjects, ataxia patients exhibited reduced vessel density in the radial peripapillary capillary (RPC) network (P=0.005), capillary density inside the optic nerve head (cdONH) (P < 0.001), nasal superficial vascular plexus (P=0.03) as well as reduced ganglion cell layer (GCL) volume (P=0.04), and temporal peripapillary retinal nerve fiber layer thickness (P=0.04). Mixed effect analysis modeling laterality confirmed these findings. These findings demonstrate a distinct pattern of concurrent changes in vessel density of the retinal superficial vascular complex, encompassing the superficial vascular plexus, RPC network and cdONH, and retinal GCL volume, providing new insights into the ongoing degeneration in ataxias. Our findings may have relevance for design of novel therapeutic approaches for ataxias and possibly other neurodegenerative diseases.

Deep learning-based signal-independent assessment of macular avascular area on 6×6 mm optical coherence tomography angiogram in diabetic retinopathy: a comparison to instrument-embedded software

SynopsisA deep-learning-based macular extrafoveal avascular area (EAA) on a 6×6 mm optical coherence tomography (OCT) angiogram is less dependent on the signal strength and shadow artefacts, providing better diagnostic accuracy...

Normative intercapillary distance and vessel density data in the temporal retina assessed by wide-field spectral-domain optical coherence tomography angiography.

A limitation of conventional optical coherence tomography angiography (OCTA) is the limited field of view normally used in data acquisition. As the technology improves, larger fields of view that capture information away from the macular are being explored in order to provide an enhanced ability to detect pathology. However, normative measurements for important OCTA metrics like vessel density and intercapillary distance are not currently well-characterized in the peripheral retina. In this prospective study, we measured vessel density and intercapillary distance of the superficial vascular complex, ganglion cell layer plexus, and deep capillary plexus in montaged macular/temporal scans from 53 (33 men) healthy volunteers. Vessel density and intercapillary distance were also compared across different regions of the retina, including along arcs at separate distance from the fovea. Compared to the central macular region, the temporal retina had significantly lower vessel density, decreased thickness, and greater intercapillary distance in the superficial vascular complex, GCLP ganglion cell layer plexus, and deep capillary plexus (Wilcoxon rank sum test P < 0.001), with each of the plexuses examined here showing a general decrease in vessel density and an increase in intercapillary distance towards the temporal region. No significant difference was noted comparing corresponding vessel density and intercapillary distance regions above and below the macula, and multiple linear regression showed that age and intraocular pressure were not associated with vessel density and intercapillary distance in most models. Repeatability analysis reported as intraclass correlation coefficients demonstrated moderate to excellent reliability of vessel density and intercapillary distance in all OCTA layers. These results should help provide an enhanced baseline to help identify vascular pathology in the peripheral retina.

Клиническая эффективность субпорогового лазерного лечения фокального диабетического макулярного отека с использованием навигационной системы (краткосрочные результаты)

Purpose. To evaluate the clinical efficacy of subthreshold laser treatment for focal DME with continuous and micropulse mode based on navigated technology. Methods. We observed 17 patients (17 eyes) with DME at the age from 25 to 71 years (on average 44±1.6 years). After the stage of diagnostic search for morphological changes in the retina and preoperative planning all patients underwent navigational laser treatment in and continuous and micropulse mode. The study evaluated the retinal thickness in the foveal avascular zone and outside it, the area of retinal ischemia, microaneurysms and edema zones at the level of the superficial vascular plexus and deep vascular complex. Follow-up periods were 1 and 3 months. Results. One month after laser treatment, all patients had positive dynamics, expressed in a decrease of edema height. BCVA increased on average to 0.8±0.06; mean central retinal sensitivity – up to 24.65±0.47 dB. After 3 months, a further decrease in the height of the edema was observed. BCVA increased on average for the group to 0.85±0.06, mean central retinal sensitivity – 25.5±0.3 dB. Сonclusion. Our preliminary results indicate the effectiveness of navigational subthreshold laser treatment for DME, based on targeted topographically oriented laser exposure according to OCT-angiography. Keywords: diabetic macular edema, navigational laser treatment, subthreshold laser therapy.

Optical coherence tomography angiography indicates subclinical retinal disease in neuromyelitis optica spectrum disorders

Background: Neuromyelitis optica spectrum disorders (NMOSD) are neuroinflammatory diseases of the central nervous system. Patients suffer from recurring relapses and it is unclear whether relapse-independent disease activity occurs and whether this is of clinical relevance. Objective: To detect disease-specific alterations of the retinal vasculature that reflect disease activity during NMOSD. Methods: Cross-sectional analysis of 16 patients with NMOSD, 21 patients with relapsing-remitting multiple sclerosis, and 21 healthy controls using retinal optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), measurement of glial fibrillary acidic protein (GFAP) serum levels, and assessment of visual acuity. Results: Patients with NMOSD but not multiple sclerosis revealed lower foveal thickness (FT) (p = 0.02) measures and an increase of the foveal avascular zone (FAZ) (p = 0.02) compared to healthy controls independent to optic neuritis. Reduced FT (p = 0.01), enlarged FAZ areas (p = 0.0001), and vessel loss of the superficial vascular complex (p = 0.01) were linked to higher serum GFAP levels and superficial vessel loss was associated with worse visual performance in patients with NMOSD irrespective of optic neuritis. Conclusion: Subclinical parafoveal retinal vessel loss might occur during NMOSD and might be linked to astrocyte damage and poor visual performance. OCT-A may be a tool to study subclinical disease activity during NMOSD.

Effect of algorithms and covariates in glaucoma diagnosis with optical coherence tomography angiography

PurposeTo assess the effects of algorithms and covariates in glaucoma diagnosis with optical coherence tomography angiography (OCTA).MethodsIn this prospective cross-sectional study, one eye each of 36 normal controls and 64...

Quantification of Nonperfusion Area in Montaged Widefield OCT Angiography Using Deep Learning in Diabetic Retinopathy.

PurposeTo examine the efficacy of a deep learning-based algorithm to quantify the nonperfusion area (NPA) on montaged widefield OCT angiography (OCTA) for assessment of diabetic retinopathy (DR) severity.DesignCross-sectional study.ParticipantsOne hundred thirty-seven participants with a full range of DR severity and 26 healthy participants.MethodsA deep learning-based algorithm was developed for detecting and quantifying NPA in the superficial vascular complex on widefield OCTA comprising 3 horizontally montaged 6 × 6-mm OCTA scans from the nasal, macular, and temporal regions. We trained the algorithm on 978 volumetric OCTA scans from all participants using 5-fold cross-validation. The algorithm can distinguish NPA from shadow artifacts. The F1 score evaluated segmentation accuracy. The area under the receiver operating characteristic curve and sensitivity with specificity fixed at 95% quantified network performance to distinguish patients with diabetes from healthy control participants, referable DR from nonreferable DR (nonproliferative DR [NPDR] less than moderate severity), and severe DR (severe NPDR, proliferative DR, or DR with edema) from nonsevere DR (mild to moderate NPDR).Main Outcome MeasuresWidefield OCTA NPA, visual acuity (VA), and DR severities.ResultsAutomatically segmented NPA showed high agreement with the manually delineated ground truth, with a mean ± standard deviation F1 score of 0.78 ± 0.05 in nasal, 0.82 ± 0.07 in macular, and 0.78 ± 0.05 in temporal scans. The extrafoveal avascular area (EAA) in the macular scan showed the best sensitivity at 54% for differentiating those with diabetes from healthy control participants, whereas montaged widefield OCTA scan showed significantly higher sensitivity than macular scans (P < 0.0001, McNemar’s test) for detecting eyes with DR at 66%, referable DR at 63%, and severe DR at 62%. Montaged widefield OCTA showed the highest correlation (Spearman ρ = 0.74; P < 0.0001) between EAA and DR severity. The macular scan showed the strongest negative correlation (Pearson ρ = –0.42; P < 0.0001) between EAA and best-corrected VA.ConclusionsA deep learning-based algorithm for montaged widefield OCTA can detect NPA accurately and can improve the detection of clinically important DR.

Radial Peripapillary Capillary Plexus Sparing and Underlying Retinal Vascular Impairment in Intermediate Age-Related Macular Degeneration

PurposeTo examine location-specific retinal vascular changes in intermediate age-related macular degeneration (iAMD) using age-matched, high-density en face optical coherence tomography angiography (OCTA) cluster analysis.MethodsEn face OCTA images of the 6 × 6 mm macular area were retrospectively acquired from 60 iAMD eyes and 60 age-matched normal eyes and then subdivided into 126 × 126 (47.62 × 47.62 µm) grids within the superficial and deep vascular complex. Grid-wise vessel perfusion (VP) were compared between iAMD and normal eyes from the corresponding 10-yearly age cohort, forming difference plots. Difference plots were further separated by normative topographical map spatial clusters (C1-6), derived from normaldatabase eyes (n = 236, 20–81 years old).ResultsOverall difference plots showed decreased VP in the superficial (−12.19%) and deep vascular complex (−6.44%) of iAMD compared to normal eyes (P < 0.0001 both comparisons). Cluster-based difference plots highlighted nonuniform changes in the superficial vascular complex, with sparing of VP at the nasal macula (corresponding to the radial peripapillary capillary plexus) versus decreased VP toward the temporal macula and foveal avascular zone (FAZ) (C1–6 all comparisons P < 0.0001, except C1 vs. C2 P > 0.99 and C4 vs. C5 P = 0.11). The deep vascular complex displayed diffusely decreased VP, greater at the FAZ (P < 0.0001).ConclusionsHigh-density en face OCTA cluster analysis suggests relative sparing of the radial peripapillary capillary plexus and impairment of underlying retinal vasculature, supporting potential anterograde transsynaptic degeneration in iAMD. These location-specific data may better guide future diagnostic and management protocol of iAMD.

The foveal avascular zone area in healthy eyes measured by ocular coherence tomography angiography using a full spectrum probabilistic algorithm.

Report the foveal avascular zone (FAZ) area imaged by OCT angiography (OCTA) using a full spectrum probabilistic algorithm in eyes of healthy individuals from Costa Rica without any ocular or systemic pathology. Retrospective chart review of consecutive healthy patients that were evaluated from January 2018 to October 2018 that underwent OCTA of the macular area. The OCTA consisted of a 10° × 10° cube of 512 A scans separated by 6µm each with an automated real time mode of 5. The FAZ area of the superficial vascular complex (SVC), the deep vascular complex (DVC), superficial vascular plexus (SVP), intermediate vascular plexus (IVP) and the deep vascular plexus (DVP) were measured manually by 2 different observers at 3 different times. A total of 234 eyes of 121 patients were included in this study. Mean age was 50years (range, 15-89), 85 patients (70%) were female. Inter- and intra-observer agreements were excellent. The mean FAZ areas in the different layers were 0.258 ± 0.0035 mm2 for the SVC, 0.205 ± 0.01 mm2 for the DVC, 0.415 ± 0.01 mm2 for the SVP, 0.305 ± 0.01 mm2 for the ICP and 0.420 ± 0.01 mm2 for the DCP. The mean FAZ areas in most of the measured layers increased with age and decreased with CMT. Gender and spherical equivalence were not correlated with FAZ area. Manual measurements of the FAZ imaged by OCT-A using a full spectrum probabilistic algorithm are widely reproducible both by the same observer and between observers. The FAZ increases with age and decreases with CMT in normal individuals.

Macular perfusion analysed by optical coherence tomography angiography after uncomplicated phacoemulsification: benefits beyond restoring vision

BackgroundThe purpose of the study is to investigate the changes of macular perfusion by OCT-angiography (OCT-A) after uncomplicated phacoemulsification.MethodsOCT-A was performed before cataract surgery, 1 week, 1 month, and 3 months after surgery recording superficial vascular complex (SVC), nerve fiber layer vascular plexus (NFLVP), superficial vascular plexus (SVP), deep vascular complex (DVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP), as well as large choroidal blood vessels and choriocapillaris (CC). Explant area (EA), vessels area (VA), vessels percentage area (VPA), total number of junctions (TNJ), junctions density (JD), total vessels length (TVL), average vessels length (AVL), total number of end points (TNEP), and mean lacunarity (ML) throughout all layers were analysed.ResultsSignificant changes of vascular parameters in 55 eyes of 55 patients mostly reached plateau one week after surgery and remained stable up to 3 m after surgery, occurring in all retinal layers but not in choroid and CC. The greatest increase in VPA (22.79%), TVL (16.71%), AVL (166.71%) and JD (29.49%) was in SVC. On the contrary, the greatest change of ML (− 53.41%) appeared in DVC.ConclusionsThis is the first OCT-A study demonstrating perfusion alterations in macula after phacoemulsification due to functional hyperaemia. We presume the effect is evoked by increased light intensity stimulation of retina after cataract removal. Accordingly, phacoemulsification in elderly population could have advantageous feature in addition to restoring visual acuity.

Near-infrared fundus autofluorescence alterations correlate with swept-source optical coherence tomography angiography findings in patients with retinitis pigmentosa

Thirty-eight patients from 37 families with retinitis pigmentosa (RP) underwent macular 6 × 6-mm swept-source optical coherence tomography angiography (SS-OCTA) and 30° near-infrared fundus autofluorescence (NIR-FAF) acquisitions in one eye. Superficial vascular complex (SVC), deep capillary complex (DCC) and choriocapillaris (CC) angiograms were registered with NIR-FAF acquisitions to comparatively assess subjects with and without central area of preserved NIR-FAF (APA). On the subset of patients showing an APA, the vessel densities for SVC and DCC and flow deficits for CC were assessed in three directions (superior, inferior and temporal) from the fovea and compared to healthy 1:1 age-matched controls. Nine patients with no APA had evidence of severe central OCTA alterations at all levels, especially in the DCC. In the other 29 subjects presenting APA, all OCTA parameters were similar to healthy eyes within the APA, where the retina preserves its structural integrity. Outside the APA, both the DCC and CC were significantly reduced in all directions. These alterations are probably related to the outer retinal atrophy outside the APA. Comparing OCTA to other imaging modalities is helpful to determine the potential interest of OCTA findings as an outcome measure for disease status and progression.

Correlation between macular perfusion and ganglion-cell complex thickness in primary open-angle glaucoma patients using optical coherence tomography angiography

Purpose The aim of this study was to correlate the macular perfusion and ganglion-cell complex (GCC) thickness in patients with primary open-angle glaucoma (POAG) using optical coherence tomography angiography (OCTA).Patients and methods This is a cross-sectional observational study that included 51 eyes of 51 patients with POAG. The vascular density (VD) in the superficial vascular complex and deep vascular complex (SVC and DVC) was assessed by OCTA and the GCC thickness was assessed by spectral-domain OCT. Patients were divided into three groups according to severity by visual field mean deviation into mild (less than −6.0 dB), moderate (between −6.0 and −12.0 dB), and severe (more than −12.0 dB).Results The mean VD measurements in the SVC were 46.0±5.8, 45.8±4.4, and 36.0±6.6 in the ‘mild,’ ‘moderate,’ and ‘severe’ groups, respectively, while in the DVC, the mean VD measurements were 49.8±8.0, 47.0±7.4, and 40.4±9.4, respectively. The differences in the VD between the three groups were more significant in the SVC (P<0.001) than in the DVC (P=0.004). The correlation between the GCC thickness and the VD was statistically significant in the SVC only in the whole image and in the perifoveal area (P<0.001).Conclusion In POAG patients, changes in VD in the macular area measured with OCTA can be correlated with GCC changes and visual-field changes and can be used as a diagnostic tool. POAG preferentially affects the SVC rather than the DVC.

Perfusion Findings in Surgically Resolved Myopic Foveoretinal Detachment

<i>Purpose</i>: Published data on long-term macular perfusional findings and qualitative vessel density (VD) evaluation of myopic foveoretinal detachment (FRD) are limited. This study aimed to evaluate the OCT angiographic findings after uncomplicated successful macular surgery in fully surgically resolved myopic FRD. <i>Methods:</i> Between October 2016 and April 2020, an interventional, single-surgeon case series was conducted involving three structurally fully resolved highly myopic eyes with FRD. Long-term postoperative spectral domain-optical coherence tomography (SD-OCT) and functional and follow-up perfusion evaluations with SD-OCT and OCT angiography were performed. The main outcome was long-term structural and macular perfusion status after successful surgical resolution of myopic FRD. <i>Results</i>: The mean evolution time of myopic FRD was 7.33 ± 3.68 months. The mean follow-up time was 59.3 ±12.20 months and the mean time for resolution of myopic FRD was 4.6 ± 1.98 weeks. Using a paired-samples permutation test, we observed that surgery was associated with a significant improvement in visual acuity: best-corrected visual acuity decreased from logMAR 0.88 ± 0.15 pre-surgery to 0.36 ± 0.20 post-surgery (P<0.0001). Qualitative VD evaluation patterns were lower in eyes post-surgery than in normal emmetropic and highly myopic eyes. The observed foveal avascular zone (FAZ) area was large and irregular in fully resolved myopic FRD. A lack of SD-OCT structural postoperative findings and better qualitative perfusion findings were associated with better final visual results. <i>Conclusion:</i> The results revealed postoperative microstructural abnormalities on SD-OCT with VD qualitative deficiencies in the superficial vascular complex of the macula with FAZ abnormalities in the three eyes.

Plexus-specific retinal capillary avascular area in exudative age-related macular degeneration with projection-resolved OCT angiography

ObjectiveTo detect the plexus-specific retinal capillary avascular area in exudative age-related macular degeneration (EAMD) with projection-resolved optical coherence tomography angiography (PR-OCTA).Methods and analysisIn this prospective cross-sectional single centre study, eyes...