Superficial Retinal Capillary Plexus Research Articles

Parafoveal and peripapillary vessel density in pediatric and juvenile craniopharyngioma patients

We assessed the retinal microvascular alterations detected by optical coherence tomography angiography (OCT-A) in pediatric and juvenile craniopharyngioma (CP) patients with chiasmal compression. We included 15 eyes of 15 pediatric or juvenile CP patients and 18 eyes of 18 healthy subjects. The evaluation of vessel density from the superficial retinal capillary plexus (SRCP), the deep retinal capillary plexus, and the radial peripapillary capillary (RPC) segments was obtained by OCT-A. The association between vessel density measures and functional and structural measurements was also analyzed. There were significant reductions in the nasal sector of the SRCP (p < 0.0001) and all sectors of the RPC segment vessel density (nasal, temporal, and superior; p < 0.0001, inferior; p = 0.0015) in CP patients postoperatively compared to the healthy subjects. The peripapillary retinal nerve fiber layer (r = 0.6602, p = 0.0074) and ganglion cell-inner plexiform layer thicknesses (r = 0.7532, p = 0.0030) were associated with RPC segment vessel density. Visual acuity (r = − 0.5517, p = 0.0330) and temporal visual field sensitivity loss (r = 0.5394, p = 0.0465) showed an association with SRCP vessel density. In pediatric and juvenile patients with CP, parafoveal and peripapillary vascular changes following chiasmal compression were observed. The changes in vascular structures were closely related to structural and functional outcomes.

Distribution characteristics of retinal nerve fiber layer thickness in macular area and its relationship with vessel density in highly myopic eyes

AIM: To investigate the distribution characteristics of retinal nerve fiber layer thickness and vessel density in macular area of eyes with high myopia, using optical coherence tomography angiography (OCTA). METHODS: Forty eyes in 20 patients diagnosed with high myopia, age 29.90±7.92 years old, with a spherical equivalent of -8.95±2.01 D, were recruited. The retinal nerve fiber layer (RNFL) thickness and the vessel density of the superficial retinal capillary plexus, deep retinal capillary plexus, and choroidal capillary were measured by OCTA. Macular regions within a 6-mm diameter circle were divided into 9 subfields: the central subfield, and the pericentral and peripheral regions of superior, inferior, nasal, and temporal quadrants. The retinal nerve fiber layer thicknesses of different subfields were compared, and their relationships with spherical equivalent, axial length, and vessel density were analyzed. RESULTS: In the pericentral region, the retinal nerve fiber layer thickness of the superior quadrant was the lowest, whereas thickness was highest in the inferior quadrant (all P&lt;0.05). In the peripheral region, the retinal nerve fiber layer thickness of the temporal quadrant was the lowest (all P&lt;0.05). A negative correlation was found between the retinal nerve fiber layer thickness and spherical equivalent (r=-0.356, P=0.024) in the peripheral superior subfield. The vessel density of superficial retinal capillary plexus was positively correlated with retinal nerve fiber layer thickness in the nasal and inferior quadrants of the pericentral region and in the superior, nasal, and inferior quadrants of the peripheral region (r=0.314, 0.408, 0.467, 0.655, and 0.737 respectively; and all P&lt;0.05), whereas the vessel density of choroidal capillary was negatively correlated with retinal nerve fiber layer thickness in the peripheral superior subfield (r= -0.356, P=0.024). CONCLUSION: The RNFL of macular areas is not uniformly distributed in high myopia (HM). As the spherical equivalent (SE) increases, the RNFL thickness decreases in certain areas, which correlates with the vessel density(VD) of superficial retinal capillary plexus (SCP) and choroidal capillary (CC) layers.

Microvascular Changes After Conbercept Intravitreal Injection of PDR With or Without Center-Involved Diabetic Macular Edema Analyzed by OCTA.

PurposeTo investigate the intravitreal injection of conbercept as a treatment strategy for proliferative diabetic retinopathy (PDR) with or without center-involved diabetic macular edema (CI-DME) and evaluate its effect on the microvascular changes in the eyes.MethodsIn this prospective study, 43 patients including 29 cases (56 eyes) in CI-DME with PDR patients, and 14 cases (26 eyes) in the non-center involving diabetic macular edema (NCI-DME) with PDR patients were involved in this study. The best corrected visual acuity (BCVA), central retinal thickness (CRT), foveolar avascular zone (FAZ), and macular capillary vessel density (VD) of the superficial retinal capillary plexus (SCP) and deep retinal capillary plexus (DCP) were assessed before and after conbercept treatments for 1, 3, or 6 months.ResultsThe BCVA was significantly increased after conbercept treatment in the eyes of CI-DME patients. After 6 months of treatment with the conbercept, microvascular density of the inferior area in SCP and the central fovea area in DCP increased significantly, regardless of the central fovea involvement. The effect of the conbercept treatment on the VD of NCI-DME was higher than that of CI-DME. Then, after 6 months of treatment, the CRT of patients with CI-DME and NCI-DME were decreased significantly.ConclusionsIn this study, an intravitreal injection of conbercept significantly improved vision, alleviated macular edema in patients with DME. Conbercept treatment also altered the microvascular density in the retina.

Evaluation of macular vessel density changes after strabismus surgery using optical coherence tomography angiography

To compare retinal vessel density before and after strabismus surgery using swept-source optical coherence tomography angiography (SS-OCTA). In this longitudinal, single-arm pilot study, vascular density in the deep capillary plexus (DCP), superficial retinal capillary plexus (SCP) and choriocapillaris layer (CCL) in consecutive subjects undergoing strabismus surgery was assessed using SS-OCTA preoperatively (T0), on the first day postoperatively (POD1), and 30 days postoperatively (POD30). A total of 92 eyes of 56 patients (54% males) were included. Mean patient age was 41.1 ± 22.7. OCT vascular density of the DCP was 50.20 ± 5.57 at T0, 52.74 ± 4.77 at POD1, and 50.92 ± 4.58 at POD30. The differences were statistically significant for T0 versus POD1 (P < 0.05). Vascular density of the CCL was 50.72 ± 4.80 at T0, 53.59 ± 3.65 at POD1, and 51.39 ± 4.64 at POD30. The differences were statistically significant for T0 versus POD1 (P < 0.05). No significant differences were found in SCP (P > 0.05). Transitory hemodynamic changes can occur in the DCP and in the CCL following muscle recession procedures.

Evaluation of Capillary and Other Vessel Contribution to Macular Perfusion Density Measured with Optical Coherence Tomography Angiography.

Parafoveal circulation of the superficial retinal capillary plexus is usually measured with vessel density, which determines the length of capillaries with circulation, and perfusion density, which calculates the percentage of the evaluated area that has circulation. Perfusion density also considers the circulation of vessels larger than capillaries, although the contribution of these vessels to the first is not usually evaluated. As both measurements are automatically generated by optical coherence tomography angiography devices, this paper proposes a method for estimating the contribution of vessels larger than capillaries by using a coefficient of determination between vessel and perfusion densities. This method can reveal a change in the proportion of perfusion density from vessels larger than capillaries, even when mean values do not differ. This change could reflect compensatory arterial vasodilatation as a response to capillary dropout in the initial stages of retinal vascular diseases before clinical retinopathy appears. The proposed method would allow the estimation of the changes in the composition of perfusion density without the need for other devices.

Retinal Microvascular Density Was Associated With the Clinical Progression of Parkinson's Disease.

BackgroundRetinal microvascular density has been studied in neurodegenerative diseases, whereas patients with Parkinson’s disease (PD) at different clinical stages have been rarely investigated. The present study aimed to evaluate the microvascular variations in superficial retinal capillary plexus (SCP) in patients with PD on different Hoehn-Yahr (H-Y) stages by optical coherence tomography angiography (OCTA), as well as determine their relationships with clinical parameters.MethodsIn total, 115 patients with PD and 67 healthy controls (HCs) were recruited. The PD group was divided into three groups based on the H-Y stage. The OCTA examination was performed in all participants, and the macular vessel density (m-VD), peripapillary vessel density (p-VD), and foveal avascular zone (FAZ) area were measured.ResultsThe m-VD in all regions, p-VD in center [6.1 (4.8, 6.95) mm–1 in healthy eyes vs. 5.1 (3.7, 6.4) mm–1 in patients], nasal inner (NI) [18.5 (17.8, 19.3) mm–1 in healthy eyes vs. 17.9 (17.1, 18.7) mm–1 in patients], temporal outer (TO) [19.6 (18.9, 20.2) mm–1 in healthy eyes vs. 19.3 (18.5, 19.7) mm–1 in patients] regions and FAZ area [0.36 (0.32, 0.39) mm2 in healthy eyes vs. 0.29 (0.26, 0.33) mm2 in patients] noticeably decreased in PD groups compared with HC (p < 0.05). Moreover, the FAZ area was suggested to decline significantly in patients with PD with H-Y I stage (p < 0.05), while it was more serious in the H-Y III stage in patients. Furthermore, we found that m-VD exhibited a significant negative correlation with age, disease duration, UPDRS scores, NMSS scores, and H-Y stage.ConclusionOCTA has the potential to non-invasively detect the microvascular changes in patients with PD with different clinical stages in vivo, and it may be a valuable tool to monitor the PD progression.

Investigation of Retinal Microcirculation in Diabetic Patients Using Adaptive Optics Ophthalmoscopy and Optical Coherence Angiography.

The current research approaches the retinal microvasculature of healthy volunteers (17 subjects), patients with diabetes mellitus without retinopathy (19 subjects), and of diabetic patients with nonproliferative (17 subjects) and proliferative (21 subjects) diabetic retinopathy, by using adaptive optics ophthalmoscopy and optical coherence ophthalmoscopy angiography. For each imaging technique, several vascular parameters have been calculated in order to achieve a comparative analysis of these imaging biomarkers between the four studied groups. The results suggest that diabetic patients with or without diabetic retinopathy prove signs of retinal arteriole structural alterations, mainly showed by altered values of wall to lumen ratio, calculated for the superior or inferior temporal branch of the central retinal artery, near the optic nerve head, and significant changes of the vascular density in the retinal superficial capillary plexus. Both adaptive optics ophthalmoscopy and optical coherence ophthalmoscopy angiography are providing useful information about the retinal microvasculature from early onset of diabetic disease, having a promising diagnostic and prognostic role in the future.

Analysis of Macular Retinal Thickness and Microvascular System Changes in Children with Monocular Hyperopic Anisometropia and Severe Amblyopia.

Objective To study the changes of macular retinal thickness and microvascular system in children with monocular hyperopic anisometropia and severe amblyopia using optical coherence tomography angiography (OCTA) and to explore the value of OCTA in the diagnosis and treatment of amblyopia. Methods Thirty-two children with monocular hyperopic anisometropia and severe amblyopia who were treated in the Department of Ophthalmology of the First Affiliated Hospital of Gannan Medical College from January 2020 to December 2020 were included in the study. Eyes with amblyopia (n = 32) served as the experimental group, and the contralateral healthy eyes (n = 32 eyes) served as the control group. All children underwent comprehensive ophthalmological examination including slit lamp, eye position, visual acuity, optometry, eye movement, intraocular pressure, ocular axis, and fundus examination to rule out organic lesions. Macular 6 mm × 6 mm scans were performed on both eyes of all subjects by the same experienced clinician using an OCTA instrument. After ImageJ processing, the vessel density, inner layer, and full-layer retinal thickness (RT) of superficial retinal capillary plexus (SCP) were obtained. All data were analyzed by SPSS21.0 software, and a paired t-test was used for comparison between groups. P < 0.05 was considered to indicate statistical significance. Results The vessel densities of macular SCP in the amblyopia and control groups were 47.66 ± 2.36% and 50.37 ± 2.24% in the outer superior, 49.19 ± 2.64% and 51.44 ± 2.44% in the inner inferior, 49.63 ± 2.51% and 51.41 ± 3.03% in the outer inferior, and 45.56 ± 3.44% and 50.44 ± 3.52% in the outer temporal regions, respectively. The vessel density of macular SCP in the amblyopia group was significantly lower than that in contralateral healthy eyes in the outer superior, inner inferior, outer inferior, outer temporal, and central regions. There was no significant difference between the two groups in the inner superior, inner nasal, outer nasal, and inner temporal regions. The macular RT in the amblyopia group and the control group is 90.38 ± 6.09 μm and 87.56 ± 5.55 μm in the outer temporal, respectively. The RT in the macular inner layer in the outer temporal region of the amblyopia group was thicker than that of the control group (P < 0.05). There was no significant difference in the other eight regions between the two groups. The whole macular RT in the amblyopia group was thicker than that in the control group in nine regions, and the central area of macular RT in the amblyopia and control groups was 229.06 ± 6.70 μm and 214.50 ± 10.36 μm, respectively. Conclusion The OCTA results showed the overall RT of macula in 9 areas in the amblyopia group was thicker than that in the control group, which could show that the macular retinal thickness can be a potential way to distinguish the children with monocular hyperopic anisometropia and severe amblyopia.

The role of optical coherence tomography angiography in the assessment of retinal microcirculation in thrombotic microangiopathy associated with malignant arterial hypertension

To evaluate retinal microcirculation using OCT-A imaging data in the group of patients with TMA associated with MAH. The study consisted of a qualitative and quantitative analysis of OCT-A data from 7 patients (14 eyes) with TMA associated with MAH and verified by renal biopsy. The control group included 7 healthy individuals (14 eyes). The following parameters were analyzed: area size of the foveal avascular zone FAZ, mm, vessel density (VD, %) and vessel skeleton density (VSD, %). The indicators were measured separately in the deep and superficial vascular plexuses and divided by localization into: the total density of the entire measured area, central density, density by quadrants (superior, inferior, nasal and temporal). All quadrants were subdivided into inner (corresponding to parafovea) and outer (corresponding to perifovea). Local foci of vascular attenuation of the deep retinal capillary plexus, pathological tortuosity of blood vessels in the deep and superficial retinal capillary plexuses were found in 100% of study group patients. Per-quadrant analysis of OCT-A finding in the macular zone revealed a statistically significant decrease in VD of the deep retinal capillary plexus (p<0.05). A direct correlation was found between glomerular filtration rate and the VD index in the outer inferior (r=0.567; p=0.034) and inner temporal quadrants (r=0.613; p=0.020) of the deep retinal capillary plexus, as well as the level of hemoglobin in blood serum and VD in inner temporal quadrant of the deep vascular plexus (r=0.596; p=0.025). Changes revealed with OCT-A are the symptoms of TMA in MAH patients spreading to the retinal microvasculature, mainly at the level of the deep retinal capillary plexus.

Evaluation of Retinal Vessel Density and Foveal Avascular Zone in Unilateral Exudative Choroidal Neovascularization by Optical Coherence Tomography Angiography.

Objectives:To evaluate treatment-naïve patients with neovascular-exudative age-related macular degeneration (eARMD) in one eye and early-/intermediate-stage nonexudative ARMD (neARMD) in the fellow eye by optical coherence tomography-angiography (OCTA).Methods:A total of 70 eyes of 35 patients (17 females) with first diagnosis of eARMD in one eye and early/intermediate-stage neARMD in the fellow eye were included in this study. The eARMD diagnosis was confirmed by fluorescein angiography. Each subject underwent OCTA imaging by RTVue XR Avanti OCT device. Capillary vessel density (VD) of superficial (SCP) and deep (DCP) retinal capillary plexuses and foveal avascular zone (FAZ) parameters were measured.Results:The mean age was 72.0±8.9 years (range 59–87). The mean visual acuity was 0.7±0.5 logMar for the eARMD eyes and 0.4±0.3 logMar for the fellow eyes (p=0.012). Nineteen patients (54.3%) had occult choroidal neovascularization (CNV), and 16 patients (45.7%) had classical CNV. The mean FAZ area was measured 0.30 ± 0.11 mm2 in the eARMD eyes and 0.27±0.11 mm2 in the fellow eyes (p=0.387). The FAZ circularity index measurement was 1.15±0.03 in eARMD eyes and 1.11±0.05 in the fellow eyes (p=0.014). There was no statistically significant difference in any measure of the macular SCP and DCP’s VD between eARMD eyes and their fellow eyes.Conclusion:Potential retinal vascular alterations will be important in ARMD pathogenesis.

Effects of Hydroxychloroquine on Retinal Vessel Density in Patients with Rheumatoid Arthritis over One-Year Follow-Up: A Pilot Study

Background: To employ optical coherence tomography angiography (OCTA) to evaluate the effects of hydroxychloroquine (HCQ) on the superficial capillary plexus (SCP) and deep retinal capillary plexus (DCP) in patients affected by rheumatoid arthritis (RA). Methods: Patients with recent diagnosis of “definite RA”, based on 2010 Rheumatoid Arthritis Classification Criteria, were included in a prospective, observational imaging study carried out by the G.B. Bietti Foundation between March 2019 and January 2020. Vessel density (VD) of SCP and DCP, central foveal thickness (CFT) and foveal avascular zone (FAZ) values were collected by OCTA. The primary outcome measure was the VD alteration of SCP and DCP in RA-patients after one year of HCQ treatment. Results: OCTA data analysis showed no statistically significant reduction in the mean VD of SCP and DCP, including the mean global area, central subfield, inner ring and temporal, superior, nasal, and inferior sectors, as well as in the mean CFT and FAZ areas. Conclusions: OCTA demonstrated no early change in the VD in the SCP and DCP, in RA-patients after one year of HCQ treatment. A longer monitoring period would more precisely establish the treatment’s effect on the VD and its correlation with HCQ toxicity.

Evaluation of macular perfusion in patients with treatment-naive overt hypothyroidism using optical coherence tomography angiography

Background/Aim: Thyroid hormones play an essential role in retinal development and physiological functions. Although the effects of hyperthyroidism on ocular circulation are well-defined, no studies report the effects of clinical hypothyroidism on retinal and choroidal circulation. We aimed to compare the macular vessel density and flow indexes of patients with treatment-naive hypothyroidism and healthy controls using optical coherence tomography angiography (OCTA). Methods: This case-control study included 104 eyes of 52 participants. Group 1 (n=24) consisted of patients with treatment-naive overt hypothyroidism, while Group 2 (n=28) consisted of age and sex-matched healthy controls. Images were obtained using AngioVue software 2.0 of the OCTA device in a 6 × 6 mm area centered on the macula. Foveal avascular zone (FAZ) area, macular retinal thickness, FAZ perimeter (PERIM), choroidal flow index (CF), outer retinal flow index (ORF) and macular vessel density (VD) in the superficial (SCP) and deep retinal capillary plexus (DCP) were recorded for all patients. Results: The whole [Group 1: 49.9 (7.0)%; Group 2: 54.6 (5.9)%], parafoveal [Group 1: 54.7 (4.8)%; Group 2: 58.6 (3.9)%] and perifoveal [Group 1: 51.5 (7.2)%; Group 2: 55.9 (6.8)% ] VD in DCP were significantly lower in Group 1 compared to Group 2 (P=0.012; P=0.002 and P=0.028 respectively). However, parafoveal VD in SCP was significantly higher in Group 1 [52.4 (2.26)] than in Group 2 [49.9 (6.87)] (P=0.032). The mean VD in DCP was significantly positively correlated with the choroidal (P=0.021) and outer retinal flow indexes (P=0.033). The mean foveal VD in DCP was significantly positively correlated with the mean foveal (P<0.001), parafoveal (P=0.001) and perifoveal retinal thicknesses (P<0.001). Conclusion: Our study has provided, for the first time, a quantitative assessment of macular perfusion in patients with overt hypothyroidism using OCTA. The reduction in VD in the DCP might be attributed to the lack of angiogenic effects of T4 or neural hypometabolism secondary to hypothyroidism.

Evaluation of macular microvasculature and foveal avascular zone in patients with retinal vein occlusion using optical coherence tomography angiography.

To quantitatively evaluate the vessel density of macular microvasculature, choriocapillary, and foveal avascular zone (FAZ) in both eyes of patients with unilateral retinal vein occlusion (RVO) using the optical coherence tomography angiography (OCTA) compared with the normal controls. A retrospective review was conducted on 72 patients with unilateral RVO (72 eyes with RVO and 72 RVO fellow eyes) and 72 healthy individuals (72 normal control eyes). The 3 × 3 mm macular angiogram was acquired using the OCTA. The vessel densities of the retinal superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillary plexus (CCP) were measured, and FAZ was quantified. The RVO eyes compared to their fellow eyes, and the fellow eyes compared to the normal controls, showed a significantly lower vessel density in both the SCP and DCP in the whole image and parafovea (P < 0.05) and the CCP (P < 0.05), except for the foveal region (P > 0.05). No significant differences between the RVO eyes and the fellow eyes in the FAZ area and perimeter (P > 0.05) were observed, while the acircularity index in the RVO eyes was significantly higher than the fellow eyes (P < 0.05). Additionally, the FD-300 in the RVO eyes was significantly lower than their fellow eyes (P < 0.05). The OCTA reveals that the macular microvasculature of the RVO fellow eyes can be impaired in both the superficial and deep retinal layer as well as the choriocapillary, suggesting the influence of systemic factors in the development of RVO.

A comparative study of type 1 neovascularization: Neovascular age-related macular degeneration versus pachychoroid neovasculopathy.

This study aimed to compare type 1 choroidal neovascularization (CNV) characteristics in eyes with pachychoroid neovasculopathy (PNV) and neovascular age-related macular degeneration (nAMD) using optical coherence tomography angiography (OCTA). Treatment naive 23 eyes of 23 patients with PNV and 24 eyes of 24 patients with nAMD were evaluated. The height of pigment epithelial detachment (PED) and the central macular thickness were determined. OCTA sensitivity, CNV area, morphological patterns, and retinal superficial capillary plexus vessel density (SCP-VD) values were compared. The frequency of quiescent CNV, subretinal hyperreflective exudation (SHE), subretinal/intraretinal fluid, serous PED, double-layer sign (DLS), and pachyvessels were noted. CNV was detected on OCTA in 83.3% of nAMD eyes and 91.3% of PNV eyes (p = 0.66). Indistinct pattern was more common (74% vs 50%) and the CNV area (mm2) was smaller in PNV (0.77 ± 0.54 vs 1.57 ± 1.43) but did not reach significant levels (p = 0.27 and 0.33 respectively). SCP-VD was similar between the groups (p = 0.38). Statistically significant differences were found between groups in age and subfoveal choroidal thickness (p < 0.05). DLS and pachyvessels were found to be more frequently in PNV (p < 0.05). However, both groups had similar rates of quiescent CNV, SHE, subretinal/intraretinal fluid, and serous PED (p > 0.05). Morphological features, area, and activation findings of type 1 CNV may play a limited role in differentiating nAMD and PNV cases.

Analysis of the retinal capillary plexus layers in a murine model with diabetic retinopathy: effect of intravitreal injection of human CD34+ bone marrow stem cells.

BackgroundDiabetic retinopathy is a retinal vasculopathy involving all three retinal capillary plexus layers. Since human CD34+ bone marrow stem cells (BMSCs) have the potential to promote revascularization of ischemic tissue, this study tests the hypothesis that intravitreal injection of human CD34+ BMSCs can have protective effects on all layers of the retinal vasculature in eyes with diabetic retinopathy.MethodsStreptozotocin (STZ)-induced diabetic mice were injected intravitreally with 50,000 human CD34+ BMSCs or phosphate-buffered saline (PBS) into the right eye. Systemic immunosuppression with rapamycin and tacrolimus was started 5 days before the injection and maintained for study duration to prevent rejection of human cells. All mice were euthanized 4 weeks after intravitreal injection; both eyes were enucleated for retinal flat mount immunohistochemistry. The retinal vasculature was stained with Isolectin-GS-IB4. Confocal microscopy was used to image four circular areas of interest of retina, 1-mm diameter around the optic disc. Images of superficial, intermediate, and deep retinal capillary plexus layers within the areas of interest were obtained and analyzed using ImageJ software with the Vessel Analysis plugin to quantitate the retinal vascular density and vascular length density in the three plexus layers.ResultsThree distinct retinal capillary plexus layers were visualized and imaged using confocal microscopy. Eyes that received intravitreal injection of CD34+ BMSCs (N=9) had significantly higher vascular density and vascular length density in the superficial retinal capillary plexus when compared to the untreated contralateral eyes (N=9) or PBS treated control eyes (N=12; P values <0.05 using ANOVA followed by post-hoc tests). For the intermediate and deep plexus layers, the difference was not statistically significant.ConclusionsThe protective effect of intravitreal injection of the human CD34+ BMSCs on the superficial retinal capillary plexus layers is demonstrated using confocal microscopy in this murine model of diabetic retinopathy.

OCT retinal angiography features in patients with rheumatoid arthritis: A pilot study.

To evaluate the superficial (SCP) and deep retinal capillary plexus (DCP) by mean of optical coherence tomography angiography (OCTA) in treatment-naïve patients affected by rheumatoid arthritis (RA). Between March 2019 and January 2020, patients with recent diagnosis of "definite RA" based on 2010 Rheumatoid Arthritis Classification Criteria were included in a Prospective, observational single center case-control study carried out at G.B. Bietti Foundation. Data were compared with those of 16 healthy age- and sex-matched subjects. Values of the vessel density (VD) of SCP and DCP, central foveal thickness (CFT), foveal avascular zone (FAZ) were collected by mean of OCTA. Main outcome measure was the VD alteration of SCP and DCP in treatment-naïve RA-patients. No difference in age, sex-distribution, best-corrected visual acuity, CFT was registered between the two groups. OCTA data analysis showed in RA-patients a statistically significant reduction in the VD in the mean global area, inner ring, especially in the superior quadrant of the SCP. A trend of VD reduction was also registered in temporal, nasal, and inferior quadrants, respectively, although it did not reach a statistically significant value. Assessment of VD of DCP and FAZ area did not evidence any difference among the groups. OCTA allows to highlight the vascular remodeling of the retinal microcirculation in RA-patients, even in early stages of the disease, demonstrating a reduction of VD. Outcomes of the current investigation can provide new insight in the pathogenetic mechanism of RA and extend the potential applications of this diagnostic tool.

Evaluation of the effect of the severity of diabetic retinopathy on microvascular abnormalities and vascular density using optical coherence tomography angiography.

To quantify and to study the relationship between retinal microvascular changes and different stages of diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA). This prospective observational study included the eyes of patients with different stages of DR. OCTA was performed in all eyes using a 9 × 9mm protocol. We analyzed the superficial and deep retinal capillary plexuses, for the following OCTA parameters: number of microaneurysms (MA), number of intraretinal microvascular abnormalities (IRMA), the total surface of capillary non-perfusion (CNP) areas, and vascular density (VD). The association between those parameters and the severity of DR was studied. A total of 70 eyes of 45 patients were included. The number of MA in the superficial capillary plexus (SCP) showed a significant association with DR severity (p = 0.03). The number of IRMA and the total surface of CNP areas were associated with the severity of DR in both plexuses (p = 0.019 in the SCP and p = 0.044 in the DCP for IRMA; p < 0.001 in the SCP and p = 0.001 in the DCP for CNP areas). The VD decreased significantly with the severity of DRin the DCP (p = 0.04). The number of vascular abnormalities andthe surface of CNP areas were significantly associated with the severity of DR. The decrease in vascular density in the DCP with increasing disease severity suggests that the DCP is more vulnerable to vascular changes than the SCP. Those parameters might be tools for a future DR severity scale based on OCTA. In addition to its capability of detecting vascular changes in DR non-invasively, OCTA may also serve as a valuable tool to graduate DR.

Retinal Vascular Changes during the Menstrual Cycle Detected with Optical Coherence Tomography Angiography.

Purpose To evaluate the effects of the menstrual cycle on the retinal vascular status of healthy women by optical coherence tomography angiography (OCTA). Materials and Methods Healthy women with regular natural menstrual cycles of 28 to 30 days were recruited for this prospective study. The women's retinal vascular status was measured by OCTA at 3 time points: the early follicular, ovulatory, and midluteal phases of the menstrual cycle. The main outcome measures were foveal avascular zone (FAZ) parameters, perfusion density (PD) percentage in the superficial retinal capillary plexus (SCP), and PD percentage in the deep retinal capillary plexus (DCP). The mean arterial pressure (MAP), spherical equivalent (SE), best-corrected visual acuity (BCVA), intraocular pressure (IOP), and axial (AL) were also measured in a same menstrual cycle. Results In total, 62 right eyes of 62 women were included in the study. The mean age was 27.0 ± 1.73 (range, 24 to 31) years, and the mean menstrual cycle was 28.90 ± 0.84 (range, 28 to 30) days. The mean values of the DCP-PD parameters were significantly decreased in the nasal and inferior ETDRS subfields during the ovulatory phase. The mean DCP-PD in the nasal ETDRS subfield in the early follicular, ovulatory, and luteal phases was 54.11 ± 2.85, 56.39 ± 3.03, and 55.70 ± 3.27, respectively. The mean DCP-PD in the inferior ETDRS subfield in the early follicular, ovulatory, and midluteal phases was 52.90 ± 3.30, 54.86 ± 2.51, and 55.21 ± 2.64, respectively. No significant differences were found in MAP, SE, AL, IOP, FAZ area, or other quadrants of PD parameters, and no significant correlation was found between parameters by OCTA and age, MAP,SE, axial length, or IOP. Conclusions The DCP-PD decreased in the nasal and inferior ETDRS subfields during the ovulatory phase in our study. This may indicate the need to consider the menstrual phase when interpreting DCP-PD parameters by OCTA in healthy women.

Changes in Macular Microvascular Structure in Macular Edema Secondary to Branch Retinal Vein Occlusion Treated with Antivascular Endothelial Growth Factor for One Year.

Purpose To observe the changes in macular microvascular structure and the correlation between anatomy and visual function in patients with macular edema secondary to branch retinal vein occlusion (BRVO) treated with antivascular endothelial growth factor for one year. Methods This prospective study enrolled 39 patients (one eye per patient) who received intravitreal injections of ranibizumab for macular edema secondary to BRVO. All patients received a minimum of 3 initial monthly ranibizumab injections and criteria-driven pro re nata (PRN) dosing thereafter for visual acuity (VA) and central retinal thickness (CRT) stabilization. The follow-up period of this study was one year. The vascular density (VD) of the superficial retinal capillary plexus (SCP) and deep retinal capillary plexus (DCP), the foveal avascular zone (FAZ) area, the FAZ perimeter, the VD within a 300 μm wide ring surrounding the FAZ (FD-300), and the acircularity index (AI) were measured automatically by optical coherence tomography angiography (OCTA) at baseline, month 6, and month 12. Results Compared with those before treatment, the VD of the SCP significantly decreased 6 months after treatment (P < 0.05), while the area and perimeter of the FAZ increased significantly (P < 0.01). After 12 months of treatment, the area and perimeter of the FAZ increased significantly (P < 0.01). There was no significant difference in any parameters between 12 months and 6 months after treatment (P > 0.05). The change in BCVA was negatively correlated with the VD of the SCP at 12 months (P=0.0447, r = −0.3233). There was a relationship between the DBP and AI, and CRT was related to VD of DCP at baseline (P=0.028, 0.0209; r = 0.383, −0.384). The PERIM and AI at 12 months were significantly associated with the recurrence of macular edema, and the changes in vascular density in the SCP and PERIM were significantly associated with the number of injections within 12 months (P < 0.05). Conclusions One year after ranibizumab treatment, the area and perimeter of the FAZ were enlarged, while the VD of the SCP and DCP remained stable, which indicated that ranibizumab treatment did not improve macular blood supply and macular ischemia in BRVO patients.

Early effects of viper envenomation on retina and optic nerve blood flow: An optical coherence tomography angiography study

In this study, the early retinal and optic nerve blood flows of patients exposed to Viper bite were evaluated with non-invasive optical coherence tomography angiography (OCTA) and compared with healthy controls. The retinal and optic disc OCTA data of 31 victims of viper bite (group S) without systemic envenomation clinical symptoms and 31 healthy controls (group C) were compared. Only patients with early signs of envenomation were included in the study. Optical coherence tomography angiographies were performed with RTVue XR Avanti with AngioVue software. Vascular densities in the whole image, foveal, parafoveal regions at the superficial and the deep capillary plexus segments were acquired and statistically analyzed. The flow area parameters were measured in the superficial retinal capillary plexus, deep retinal capillary plexus, outer retinal capillary plexus, and choriocapillaris layers of the macula in 1-mm and 3-mm diameter areas. The peripapillary flow areas were measured for the optic nerve head, vitreous, radial peripapillary capillary (RPC), and choroid in a 4.50-mm diameter area. Foveal and parafoveal thicknesses were also measured and compared. The average hospital admission time of the patients in group S was 1.24 ± 0.75 (0.50–3.00) hours. Age (p = 0.103) and gender (p = 0.714) were similar in both groups. Superficial (p = 0.010), deep flow areas (p = 0.034), and superficial parafoveal vascular density (p = 0.001) were significantly reduced in group S compared to group C. The outer retinal flow area (p < 0.001) increased significantly in group S. Nerve head flow area (p = 0.035), one of the optic disc flow areas, was found to be decreased in group S. Notably, foveal (p < 0.001) and parafoveal (p = 0.003) thicknesses and superficial (p = 0.001) and deep (p < 0.001) foveal vascular densities were greater in group S. Compared to group C, the superficial (p = 0.009) and deep (p = 0.009) foveal flow areas in the central foveal area with a diameter of 1 mm increased significantly in group S. Viper venom may cause blood flow changes in the retina and optic disc and an increase in retinal thickness in the early period although there are no signs of systemic envenomation.