Choroidal Vascular Network Research Articles

Spectral Domain and Angiography Optical Coherence Tomography in Parkinson’s Disease: Structural And Vascular Changes in the Retina Correlate with Disease Severity and Progression

Background. Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by bradykinesia, resting tremor, and muscle rigidity. Visual disturbances have been also described among non-motor features. Objective. We aimed to investigate the structural and vascular changes in the retinal and choroidal vascular networks, and to assess any relationship with motor and non-motor symptoms (NMS) in PD patients. Methods. Ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), and subfoveal choroidal thickness (SFCT) were examined using spectral domain-optical coherence tomography (SD-OCT). The vessel density (VD) of retinal and choriocapillary vascular networks in macular area and the foveal avascular zone (FAZ) area were evaluated by OCT angiography (OCTA). All patients underwent clinical evaluation using motor section of the Unified PD Rating Scale (UPDRS-III) and the Hoehn and Yahr (HY) scale. Results. A total of 48 eyes from 24 PD patients and 50 eyes from 25 controls were assessed. At SD-OCT, GCC and RNFL were more significantly thin in patients compared to controls. At OCTA exam, PD subjects showed lower values in VD of superficial capillary plexus (SCP) and radial peripapillary capillary plexus in comparison to controls, whereas FAZ area resulted in a significant increase in the patient group. We found a negative correlation between the age at onset and VD of SCP, and between HY score and RNFL thickness and FAZ. UPDRS-III score was negatively correlated with VD of deep capillary plexus. Discussion. The impairment of retinal structure and microvasculature seems to correlate with disease severity and progression in PD. Retinal anomalies can be considered as non-motor manifestations that could occur already in the early stage of the disease.

Oxidative stress and optical coherence tomography angiography evaluation of choriocapillaris and retinal vessel density in children with obstructive sleep apnea.

To investigate the vascular networks of the retina and choroid using optical coherence tomography angiography (OCTA) to identify early biomarkers of obstructive sleep apnea (OSA) severity and to evaluate correlations with blood levels of oxidative stress. Patients with OSA were diagnosed based on video-polysomnography (PSG) and blood samples were collected to evaluate oxidative stress markers: total antioxidant status (TAS), biological antioxidant potential (BAP) test, Diacron reactive oxygen metabolites (d-ROMs) test. The eyes of children with OSA were evaluated and compared with eyes of healthy age-matched children. OCTA imaging was carried out to evaluate the choroidal and retinal vascular network density indices. A total of 31 children with OSA were recruited and compared with 10 healthy children. Choriocapillaris flow area decreased (p = 0.006) and superficial capillary plexus vessel density increased (p=0.01) with increasing severity of OSA. Children with OSA showed significant differences in TAS and d-ROMs test when compared to normal pediatric values (p<0.05). In calculating the correlations between PSG, oxidative stress, and OCTA variables, there was a negative correlation between choriocapillaris flow area and apnea hypopnea index (AHI) (p = 0.02, r2 -0.5) and between choriocapillaris flow area and the d-ROMs test (p 0.03; r2 0.5). The severity of OSA was associated with the choroidal and retinal capillary vascular networks. The correlation of the choriocapillaris flow area with AHI and the d-ROMs test indicates the connection of the choroidal microvasculature with the number of obstructive apnea and hypopnea events and oxidative stress.

Clinical Applications of Optical Coherence Tomography Angiography in Inherited Retinal Diseases: An Up-to-Date Review of the Literature.

Optical coherence tomography angiography (OCT-A) is a valuable imaging technique, allowing non-invasive, depth-resolved, motion-contrast, high-resolution images of both retinal and choroidal vascular networks. The imaging capabilities of OCT-A have enhanced our understanding of the retinal and choroidal alterations that occur in inherited retinal diseases (IRDs), a group of clinically and genetically heterogeneous disorders that may be complicated by several vascular conditions requiring a prompt diagnosis. In this review, we aimed to comprehensively summarize all clinical applications of OCT-A in the diagnosis and management of IRDs, highlighting significant vascular findings on retinitis pigmentosa, Stargardt disease, choroideremia, Best disease and other less common forms of retinal dystrophies. All advantages and limitations of this novel imaging modality will be also discussed.

Microvascular Alterations of Peripapillary Choriocapillaris in Young Adult High Myopia Detected by Optical Coherence Tomography Angiography

(1) Background: The microstructural alterations of the peripapillary choriocapillaris in high myopes remain elusive. Here, we used optical coherence tomography angiography (OCTA) to explore factors involved in these alterations. (2) Methods: This cross-sectional control study included 205 young adults' eyes (95 with high myopia and 110 with mild to moderate myopia). The choroidal vascular network was imaged using OCTA, and the images underwent manual adjustments to determine the peripapillary atrophy (PPA)-β zone and microvascular dropout (MvD). The area of MvD and the PPA-β zone, spherical equivalent (SE), and axial length (AL) were collected and compared across groups. (3) Results: The MvD was identified in 195 eyes (95.1%). Highly myopic eyes exhibited a significantly greater area for the PPA-β zone (1.221 ± 0.073 vs. 0.562 ± 0.383 mm2, p = 0.001) and MvD (0.248 ± 0.191 vs. 0.089 ± 0.082 mm2, p < 0.001) compared with mildly to moderately myopic eyes, and a lower average density in the choriocapillaris. Linear regression analysis showed that the MvD area correlated with age, SE, AL, and the PPA-β area (all p < 0.05). (4) Conclusions: This study found that MvDs represent choroidal microvascular alterations in young-adult high myopes, which were correlated with age, SE, AL, and the PPA-β zone. In this disorder, OCTA is important for characterizing the underlying pathophysiological adaptations.

The status of the choroid in patients with optic disc drusen.

To investigate the subfoveal and peripapillary choroidal thickness (CT) and the choroidal vascularity index (CVI) in patients with optic disc drusen (ODD). This cross-sectional study examined the eyes of 17 patients with ODD and 18 healthy control subjects. The CT values were calculated manually from the images captured by enhanced depth imaging-optical coherence tomography (EDI-OCT). The CVI was defined as the proportion of the vascular area to the total choroidal area at the subfoveal and peripapillary areas after binarization of the EDI-OCT images. It was found that the mean subfoveal CVI value in the ODD group was significantly lower than that in the control group (p = 0.006). The mean peripapillary CVI values were significantly lower in all of the quadrants in the ODD group when compared with the control group (p = 0.008 for the temporal quadrant, p = 0.014 for the nasal quadrant, p = 0.024 for the superior quadrant, and p = 0.038 for the inferior quadrant). Regarding the CT, there were no significant differences in the subfoveal and peripapillary CT values between the ODD group and the control group (p > 0.05 for all values). The findings of this study indicate ODD to be associated with decreased subfoveal and peripapillary CVI, even though the subfoveal and peripapillary CT values were within the normal range. This result may prove important in relation to identifying a choroidal vascular network that appears to be morphologically normal but microstructurally impaired due to ODD. Further studies are required to verify the significance of CVI in the pathogenesis and complications of ODD.

Changes in the peripapillary and subfoveal choroidal vascularity index after transsphenoidal surgery for pituitary macroadenoma.

To investigate the changes in peripapillary and subfoveal choroidal vascular indexes (CVI) before and after pituitary macroadenoma surgery by using a binarization method. In this cross-sectional study, we examined 17 eyes in 9 patients with pituitary macroadenomas who had undergone transsphenoidal pituitary surgery due to chiasmal compression. We also compiled data from 17of in 17 healthy subjects. ImageJ 1.51 software processing (National Institutes of Health, Bethesda, Maryland, USA) was used for binarization of optical coherence tomography scans. The CVI was computed as the ratio of luminal area to total choroidal areal. The CVI, OCT and VF parameters were analyzed in One-Way Repeated Measures ANOVA to determine significant changes in measurements during the postoperative course. The mean peripapillaryinferior and temporal quadrant CVIs weresignificantly lower in the eyes of patients with pituitary macroadenoma compared to controls (46.0 ± 0.03 versus. 42.8 ± 0.04, p = 0.02; 45.8 ± 0.03 Versus. 42.3 ± 0.04, p = 0.02). In repeated measure analysis, there was a significant effect of transsphenoidal microscobic pituitary surgery on peripapillary inferior quadrant CVI and BCVA, F(1.3, 21.5) = 6.62, p = 0.01 and F (1.8, 29.7) = 7.8, p < 0.005, respectively. This study suggests that PMa with chiasmal compression may lead to significant changes in the peripapillary CVI. Pituitary surgery had a favorable significant effect on peripapillary choroidal vascular network and BCVA. Furthermore, optical coherence tomography is a helpful technique for quantifying the alterations of peripapillary CVI during the preoperative and postoperative course.

Evaluation of macular and choroidal thickness in healthy residents living at high altitude.

Purpose:Assessment of long-term effects of high altitude on choroidal thickness.Methods:This prospective cross-sectional study included 88 and 79 age- and sex-matched healthy individuals who were living at sea-level (SL group) and high-altitude (HA group), respectively. Participants were required to have resided in the same place for at least 10 years. Spectral-domain optical coherence tomography (SD-OCT) scans were conducted in two different and were performed within the same time (08:00 am to 10:00 am). Central macular thickness (CMT) and choroidal thickness were measured at five different points (i.e., at the central fovea and 1 mm and 2 mm temporal and nasal of the fovea). Blood hemoglobin (Hb), red blood cell (RBC), hematocrit (Htc) levels, blood oxygen saturation, heart rate, and body mass index (BMI) were compared between groups statistically.Results:The HA group had a mean age of 47.5 ± 13.3 years, whereas the SL group was 48.7 ± 13.4 years (P = 0.57). There was no significant difference between the groups in terms of CMT. Subfoveal choroidal thickness (SCFT) was 282.73 ± 87.82 mm in the HA group and 310.49 ± 74.73 in the SL group (P = 0.02). The choroid was found to be thinner at all the measured locations in the HA group except the 2 mm nasal point of the fovea. However, only the difference at an SFCT was statistically significant. Furthermore compared with the SL group statistically significant higher Hb, RBC, Htc levels were determined in the HA group. In the multiple linear regression model analysis, age was found an only effective confounder factor for SCFT (P = 0.001, 95% CI 4.132–2.476).Conclusion:The systemic adaptive changes due to chronic high altitude exposure may cause structural changes in the choroidal vascular network. The current study results revealed significant thinning only at SFCT. Large-scale longitudinal studies are needed to obtain more definitive data on this subject.

In-Vivo Imaging of Ocular Microvasculature Using Swept-Source Optical Coherence Tomography Angiography in Seven Types of Lab Animals

The purpose of this study is to characterize the retinal and choroidal vascular networks in some of the most common animal species using swept-source optical coherence tomography angiography (SS-OCTA). Retinal angiographic images were acquired from healthy, anesthetized animals of seven species (mouse, rat, pig, rabbit, guinea pig, chicken, and non-human primate). We generated the enface angiograms to visualize the different retinal vascular plexuses and the choroidal vascular plexus. Quantitative OCTA metrics, including perfusion density, vessel density, and fractal dimension, were compared amongst the different species. There was a noticeable difference in the OCTA enface maps of the distinct vascular layers amongst the various species. Specifically, the non-human primate retina has the highest level of perfusion density and vessel density, whereas the rabbit retina exhibited the lowest level of vessel density. The mouse and the rat retina shared similar vascular patterns, and there was no difference in the OCTA metrics. Using one specific SS-OCTA system for all experiments eliminated multiple instrument-dependent factors, but the lateral resolution was still affected by eye size. Effects of varying lateral resolution on vascular metrics were investigated via a simulation. Overall, we achieved a large field of view of the distinct retinal and choroidal vascular plexuses and quantified the vascular metrics in multiple species, which could serve as protocol guidance and atlas to study the retinal and choroidal vascular abnormalities and their roles in ocular diseases resembling in-vivo histology.

Diagnosis of Alzheimer's disease by analyzing the roughness of the retinal layers

AbstractPurposeAlzheimer’s Disease (AD) is the most common cause of dementia. Retinal thickness changes had been reported in different stages of the disease, being these changes a biomarker of AD progression. There is increasing evidence that thinned and thickened regions are interspersed throughout the retinal layers of AD patients, resulting in the roughness of their bounding surfaces and thickness maps. The aim of this work is to prove the roughness of retinal layers, as assessed by the fractal dimension (FD) of their thickness maps, is an early biomarker of AD.MethodsA complete ophthalmological exam and cognitive test (Mini Mental State Examination) was carried out in 24 healthy volunteers and 19 patients with mild AD. Total retinal thickness and retinal layers thickness were studied by optical coherence tomography (OCT) and thickness retinal maps were obtained. From the whole retinal area scanned on each subject only a central square region available from all sample subjects was kept for roughness analysis. In this square, the FD of the thickness map of each retinal layer was calculated as an index of its roughness.ResultsThe FD of retinal layers is significantly higher (p &lt; 0.05) in the AD group, compared to the healthy group. The correlation of FD with cognitive score, visual acuity and age reaches statistical significance in 7 layers. Nearly all (44 out of 45) FD correlations among layers are positive and half of them (23) reached statistical significance (p &lt; 0.05). Factor analysis revealed two groups of retinal layers whose roughness evolves independently: the first includes two layers related to the outer segments and may be influenced by dysregulation of the choroidal vascular network; and the second includes the remaining layers, and may be associated with the inflammatory process of the retina.ConclusionsRoughness is a holistic feature of retinal layers that can be assessed by FD of their thickness maps and is an early biomarker of AD.

Imaging of iris vasculature: current limitations and future perspective.

Fluorescein and indocyanine green angiography have been the traditional ways to image the vasculature of the iris in the last few decades. Because of the invasive nature of these procedures, they are performed in rare situations, and thus, our understanding about iris vasculature is very limited. Optical coherence tomography angiography (OCTA) is a noninvasive imaging method that enables the detailed visualization of the retinal and choroidal vascular networks. More recently, it has been also used for the examination of the iris vasculature in healthy and disease eyes. However, there is a lack of uniformity in the image acquisition protocols and interpretations in both healthy and pathological conditions. Artifacts of iris OCTA include shadowing, motion, segmentations errors, mirror effects. OCTA devices have an eye-tracking system designed for the posterior segment and the applications of these systems on the anterior segment can determine motion lines, vessel duplication, and vessel discontinuity. OCTA of the iris should always be performed under ambient room lighting to create miosis and reduce iris vasculature changes during the examination. In the near future, eye-tracking systems specifically designed for the iris vessels could permit the follow-up function, and the development of new OCTA metrics could reveal interesting applications of this new imaging technique.

Roughness of retinal layers in Alzheimer\u2019s disease

There is growing evidence that thinned retinal regions are interspersed with thickened regions in all retinal layers of patients with Alzheimer’s disease (AD), causing roughness to appear on layer thickness maps. The hypothesis is that roughness of retinal layers, assessed by the fractal dimension (FD) of their thickness maps, is an early biomarker of AD. Ten retinal layers have been studied in macular volumes of optical coherence tomography from 24 healthy volunteers and 19 patients with mild AD (Mini-Mental State Examination 23.42 ± 3.11). Results show that FD of retinal layers is greater in the AD group, the differences being statistically significant (p < 0.05). Correlation of layer FD with cognitive score, visual acuity and age reach statistical significance at 7 layers. Nearly all (44 out of 45) FD correlations among layers are positive and half of them reached statistical significance (p < 0.05). Factor analysis unveiled two independent factors identified as the dysregulation of the choroidal vascular network and the retinal inflammatory process. Conclusions: surface roughness is a holistic feature of retinal layers that can be assessed by the FD of their thickness maps and it is an early biomarker of AD.

Choroidal changes in mild Alzheimer's disease patients as a biomarker of cerebral amyloid angiopathy

PurposeAlzheimer's disease (AD) is a progressive neurodegeneration in which vascular changes occur that constitute cerebral amyloid angiopathy. Recently, alterations and deposits have been discovered in the retinas and choroids of patients with AD that correlate with the evolution of the disease. The development of new techniques for the study of ocular vascularization, Laguna ONhE and Angio‐optical coherence tomography (OCTA), non‐invasive and non‐contrast tests, allow us to study ocular vascular alterations caused by AD.MethodsSeventeen patients with mild AD (mAD) and 49 healthy controls, all without ophthalmological diseases after a complete eye examination, were studied for haemoglobin (Hb) coefficient in the optic nerve head by Laguna ONhE, as well as choroid thickness and foveal avascular zone (FAZ) of the retina by OCTA. For statistical analysis, the Mann‐Whitney test was applied with the SPSS 22.00 program.ResultsThe Mini Mental State Examination of the mAD patients was 24.00 ± 5.32, while the control group was 29.40 ± 1.83, being the difference significant (p &lt; 0.001) between them. Comparing both group, no significant difference was found in the Hb coefficient of the optic nerve head, although in the papillomacular bundle, there was a slight increase of Hb coefficient in mAD patients. A significant (p &lt; 0.05) thinning of the choroid was found in the mAD patients, while the FAZ was unchanged in comparison to control.ConclusionsIn patients with mAD, a significant decrease in the choroidal vascular network was observed, while the retinal network and the Hb of the optic nerve head did not yet show any changes in mild stages of AD. These results show the choroidal changes as an early biomarker of amyloid angiopathy that could be used for the diagnosis and follow‐up of AD.

The application and progress of optical coherence topography angiography in polypoidal choroidal vasculopathy

Optical coherence tomography angiography (OCTA) is a novel, non-invasive imaging technology, which could acquire volumetric angiographic information. Numerous studies have reported the potential clinical use of OCTA in a variety of common retinal disorders. Polypoidal choroidal vasculopathy (PCV) is characterized by the formation of branching choroidal vascular networks (BVN) with terminal dilatations (polyps). Indocyanine green angiography (ICGA) remains the golden diagnostic standard for PCV. The clinical application of OCTA in PCV is also widely investigated recent years. But the results are controversially interpreted. In addition to various diagnostic accuracy of PCV from different studies, the clinical application of OCTA in PCV is limited. With the constant innovation of fundus imaging techniques, OCTA is reaching greater investigation depth and become more accurate at picking up blood flow signals, which also improves the diagnostic accuracy of PCV. In this paper, we reviewed the clinical application and research progress of OCTA in PCV, in order to provide some assistant for clinical practice and correct interpretation of the reports. (Chin J Ophthalmol, 2020, 56:950-955).

Choroidal vascularization and adrenergic innervation qualitative findings obtained with induced fluorescence preparations and optical coherence tomography angiography: possible correlations and perspectives

BackgroundRecent advances in optical coherence tomography (OCT) technology allow a more accurate choroidal visualization. The aim of this study is to provide histochemical analysis with induced fluorescence images of the choroidal stromal, vascular and nerve network, highlighting possible correspondences with OCT and OCT angiography (OCT-A) analysis.MethodsThe material examined with a histochemical process of induced fluorescence through condensation of biologically active monoamines with glyoxylic acid was obtained from 6 eyes enucleated for malignant melanoma and ciliary body neoplasia. The resulting images have been qualitatively compared with OCT and OCT-A choroidal images obtained from 10 volunteers, in order to identify possible relationships. Choriocapillary segmentation was performed automatically through the embedded analysis software, while segmentation of Sattler’s and Haller’s layers was performed through a manual method.ResultsHistochemical analysis provided accurate visualization of choroidal adrenergic innervation across all layers and its relationships with blood vessels and melanocytes. The above structures were not visualized at OCT and OCT-A which provided good visualization of blood vessels in Sattler’s and Haller’s layers as well-delimited hyporeflective areas. Decorrelation signal was not detected in OCT-A analysis due to low blood flow velocity in external choroidal layers.ConclusionsThe choroid is an extremely dynamic structure which deserves to be analyzed in vivo since it is involved in the pathogenesis of several ocular conditions. Direct evaluation of the activity of choroidal nerves and melanocytes is still not possible with OCT and OCT-A, even if they are capable of providing a satisfactory representation of choroidal vascularization.

Optical Coherence Tomography Angiography Analysis of Retinal and Choroidal Vascular Networks during Acute, Relapsing, and Quiescent Stages of Macular Toxoplasma Retinochoroiditis

Purpose To highlight the advantages of optical coherence tomography angiography (OCTA) in delineating the morphological features of the retinal and choroidal vascular network during acute, relapsing, and quiescent stages of macular toxoplasma retinochoroiditis. Methods This prospective study included patients presenting with both active and quiescent ocular toxoplasmoses. OCTA was obtained to diagnose and follow the subsequent vascular network changes at diagnosis and six months after acute presentation. Results Twenty-three eyes of 23 patients were included. In active lesions, OCTA showed extensive, well-delineated areas of intense hyposignal and perifoveal capillary arcade disruption in the parafoveal superficial capillary plexus (pSCP) and less extensive hyposignal in the parafoveal deep capillary plexus (pDCP). Signals of decreased deep capillary density and disorganization were also seen in the choroid. In nonactive lesions, OCTA demonstrated a homogenous and equally attenuated grayish hyposignal of the pSCP and pDCP and a partial restoration of the nonperfused choroidal areas. Conclusion OCTA is a useful technique for vascular network analysis in toxoplasma retinochoroiditis. It allows the visualization of the different network changes and behaviors during the different stages of the infection.

Optical coherence tomography angiography findings in Huntington's disease.

To evaluate the retinal and choriocapillaris vascular networks in macular region and the central choroidal thickness (CCT) in patients affected by Huntington disease (HD), using optical coherence tomography angiography (OCTA) and enhanced depth imaging spectral-domain OCT (EDI SD-OCT). We assessed the vessel density (VD) in superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) using OCTA, while CCT was measured by EDI SD-OCT. Sixteen HD patients (32 eyes) and thirteen healthy controls (26 eyes) were enrolled in this prospective study. No significant difference in retinal and choriocapillaris VD was found between HD patients and controls while CCT turned to be thinner in patients respect to controls. There were no significant relationships between OCTA findings and neurological parameters. The changes in choroidal structure provide useful information regarding the possible neurovascular involvement in the physiopathology of HD. Choroidal vascular network could be a useful parameter to evaluate the vascular impairment that occurs in this neurodegenerative disease.

Vascular Density and Retinal Function in Patients with Retinitis Pigmentosa Evaluated by Swept-Source OCT Angiography and Microperimetry

Purpose: To determine the retinal and choroidal vessel density in the macular area with swept-source optical coherence tomography (OCT) angiography (SS-OCTA) in patients affected by retinitis pigmentosa (RP), to compare their data with those on healthy subjects, and to study a possible morphofunctional correlation by microperimetry (MP-1). Methods: A total of 40 eyes of 40 patients affected by RP and 24 eyes of 24 healthy subjects were included in the study. Manually moving down the segmentation line of the SS-OCTA, we have evaluated the vessel density for the superficial retinal plexus, deep retinal plexus, choriocapillaris, and three levels of the choroid. Results: Linear regression analyses were performed of the retinal structure and function. No significant correlation was detected in any case (R² = 0, p > 0.05). A comparison between RP and healthy controls revealed a significant reduction in SS-OCTA mean capillary density in the RP group (p = 0.0011). This relationship was consistent across vascular layers (p = 0.2413). A significant association between the capillary density of the various vascular complexes was detected within individual eyes (p < 0.0001). Conclusions: This study represents the first comparing MP-1 and SS-OCTA data in the largest cohort of patients. RP patients showed a reduction in both the retinal and the choroidal vascular network in the macular area compared to healthy subjects.

Functional correlation between choroidal and retinal vascularity in low-grade diabetic retinopathy.

To perform an automated functional assessment of retinal and choroidal microvasculature in eyes with low-grade diabetic retinopathy (DR) using optical coherence tomography angiography (OCT-A) and to identify potential perfusion changes in case of early vascular damage. This is an observational, case-control study of consecutive diabetic patients with level 20 DR severity scale score and age-matched healthy subjects. A prototypal OCT-angiography was used to obtain the OCT-angiograms of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) layer. A validated automated microstructural analysis provided data on SCP, DCP and CC vascular perfusion density (VPD). A comparative assessment between different vascular layers and different groups was performed. Twenty-nine diabetic patients (7 females, 24%) and 20 healthy controls were enrolled. VPD values were significantly lower in the DCP (25.1% vs. 26.5%; p = 0.04) and CC (71.2% vs. 86.6%; p = 0.0001) of diabetic patients compared with controls. A statistically significant negative linear correlation was reported between CC VPD and DCP VPD in diabetic patients; at the reverse, a positive linear correlation between the same parameters was noticed in controls. Retinal and choroidal vascular networks, although distinct entities, seem functionally interconnected: varying the degree of perfusion may be a mutual compensatory mechanism in response to an ischemic injury.

Choroidal vasculature imaging with laser Doppler holography.

The choroid is a highly vascularized tissue supplying the retinal pigment epithelium and photoreceptors. Its implication in retinal diseases is gaining increasing interest. However, investigating the anatomy and flow of the choroid remains challenging. Here we show that laser Doppler holography provides high-contrast imaging of choroidal vessels in humans, with a spatial resolution comparable to state-of-the-art indocyanine green angiography and optical coherence tomography. Additionally, laser Doppler holography contributes to sort out choroidal arteries and veins by using a power Doppler spectral analysis. We thus demonstrate the potential of laser Doppler holography to improve our understanding of the anatomy and flow of the choroidal vascular network.

Research progress of nucleotide-binding oligomerzation domain like receptors 3 inflammasome in age-related macular degeneration

Polypoidal choroidal vasculopathy (PCV) is a kind of fundus disease characterized by choroidal anomalous branch vascular network and terminal polypoidal dilatation.The pathological basis of idiopathic choroidal neovascularization is similar to age-related macular degeneration (AMD). It is controversial that whether PCV and AMD is the same disease.Optical coherence tomography angiography (OCTA) is a new, noninvasive imaging technique that plays an important role in clinical practice.OCTA not only provides B-scans of the retina, but also offers rapid, high-resolution, repeated and accurate visualization of blood flow, which provides representation of the vascular morphology of the retina and choroid.OCTA is a noninvasive imaging modality capable of evaluating and assessing the morphology of PCV and their associated vascular patterns.The vascular endothelial growth factor (VEGF) participates in the pathophysiology of PCV, so anti-VEGF therapy has become the first-line treatment for PCV.Intravitreal injection of bevacizumab, ranibizumab, and aflibercept improves and stabilizes the vision of patients with PCV.In this article, we summarized the new progress of diagnosis and treatment associated with PCV. Key words: Polypoidal choroidal vasculopathy; Optical coherence tomography angiography imaging; Clinical feature; Diagnose; Therapy