Search Results (121)

Background: Retinal microvascular changes may serve as biomarkers for disease activity in multiple sclerosis (MS). This study evaluated macular and peripapillary vascular plexus densities using optical coherence tomography angiography (OCTA) in patients with relapsing MS (RMS) and healthy controls (HCs), exploring their association with disease activity based on the NEDA-3 concept. Methods: In a cross-sectional study, 117 RMS patients and 37 HCs underwent OCTA imaging. Parameters analyzed included superficial vascular plexus (SVP), deep vascular plexus (DVP), foveal avascular zone (FAZ), and radial peripapillary capillary (RPC) density. Images with artifacts were excluded. Associations between OCTA metrics and demographic, clinical, and MRI volumetrics, as well as NEDA-3 status, were evaluated using multivariate generalized estimating equations. Receiver operating characteristic (ROC) curves assessed predictive capacity. Results: Compared to HCs, MS eyes with prior optic neuritis showed significantly lower SVP density (p < 0.05). DVP and FAZ parameters did not differ between groups. SVP and DVP densities correlated with age, disease duration, relapse history, and MRI volumetrics, including gray matter and whole brain volume. SVP density predicted NEDA-3 status (AUC = 0.82), while DVP also showed predictive value (AUC = 0.64). FAZ FD (Foveal density) was associated with gray matter and whole brain atrophy (AUC = 0.62–0.61). Conclusions: Retinal vascular alterations correlate with clinical and MRI measures in MS. Reduced SVP and DVP densities may serve as markers of recent disease activity, and FAZ metrics reflect neurodegeneration. OCTA may be a valuable non-invasive tool for monitoring MS progression. Full article

Post-COVID-19 syndrome (PCS) is a multifactorial disorder comprising different subgroups. Our study aimed to investigate the longitudinal changes in retinal microcirculation in PCS patients. Eighty PCS patients were recruited at the Department of Ophthalmology at the Friedrich-Alexander University of Erlangen-Nürnberg. Retinal microcirculation was measured twice using optical coherence tomography angiography (OCT-A) within the superficial vascular plexus (SVP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), and peripapillary region. Vessel density (VD) was calculated using the Erlangen Angio Tool with an APSified and Bruch’s membrane opening-based analyses. The least-squares means (LS-Means) of VD were 30.4 (SE = 0.168) vs. 30.3 (SE = 0.166) (SVP), 22.4 (SE = 0.143) vs. 22.2 (SE = 0.141) (ICP), 23.9 (SE = 0.186) vs. 23.8 (SE = 0.185) (DCP), and 27.4 (SE = 0.226) vs. 27.0 (SE = 0.224) (peripapillary) in patients with PCS at visits 1 and 2, respectively. The study cohort showed physically stable PCS symptoms with PEM/fatigue and concentration disorders as major symptoms and only a slight, clinically irrelevant improvement of the Bell Score. The multivariate longitudinal model confirmed the clinical observations by showing that VD did not change significantly during follow-up (p = 0.46). Strong interdependencies between the macular layers (p < 0.001) were observed. The data of the present study suggests that while overall APSified macular VD and BMO-based APSified peripapillary VD were stable within a PCS cohort of physically stable PCS symptoms, individual patients may experience coordinated microvascular changes, particularly within the macular plexuses. Together, the results support a model of heterogeneous yet biologically consistent microvascular response in PCS pathophysiology. Full article

Background and Objectives: Circadian fluctuations in blood pressure, particularly the non-dipping pattern characterized by the absence of a nocturnal decline, are associated with an increased risk of microvascular complications. The retina, as a highly sensitive microvascular tissue, offers a valuable window into systemic hemodynamic alterations. However, the literature lacks detailed structural analyses that evaluate all retinal regions by segmenting nighttime into specific time intervals. Notably, the early morning period (04:00–08:00), during which stress hormones such as cortisol and catecholamines rise physiologically, leads to increased blood pressure that may significantly affect retinal microcirculation. This prospective study aims to assess retinal microvascular structures in dipper and non-dipper individuals using structural optical coherence tomography and to investigate their relationship with blood pressure parameters by dividing nighttime into distinct time segments. Materials and Methods: A total of 60 participants were classified as dipper (n = 26) or non-dipper (n = 34) based on 24 h ambulatory blood pressure monitoring results. Structural optical coherence tomography was used to evaluate superficial and deep capillary plexus densities in the foveal, parafoveal, and perifoveal regions, along with the area and perimeter of the foveal avascular zone (FAZ) and flow density (FD). Blood pressure values, including systolic, diastolic, mean arterial, and pulse pressure, were recorded during two nighttime intervals (00:00–04:00 and 04:00–08:00), and correlations with retinal parameters were analyzed. Results: No significant differences were observed in retinal microvascular parameters between the dipper and non-dipper groups. Deep capillary densities, particularly in the parafoveal and perifoveal regions, showed significant positive correlations with serum total protein, albumin, and very low-density lipoprotein (VLDL) levels. Furthermore, systolic and mean arterial pressures measured during the 04:00–08:00 interval demonstrated significant positive correlations with deep retinal vascular densities. The FAZ perimeter was negatively correlated with pulse pressure variability, while FD showed a negative correlation with mean arterial pressure variability. Conclusions: This prospective study is among the first to investigate the effects of circadian blood pressure patterns on retinal microvascular structures by segmenting nighttime into specific intervals and employing comprehensive structural optical coherence tomography across the entire retina. The findings suggest that retinal microvascular structure may be associated with fluctuations in blood pressure. Analyses of blood pressure measurements between 04:00 and 08:00 may offer supplementary insights into the evaluation of retinal microvascular structure. Full article

Retinal vasculature is essential for maintaining visual function by supporting metabolically active neurons. However, the retina lacks redundant blood supply, rendering it highly susceptible to vascular dysfunction. Understanding mechanisms of retinal vascular abnormalities is critical for therapies that preserve vascular and neuronal integrity, yet progress has been hindered by limited models and genetic diversity. To address this gap, we examined the retinal vasculature in multiple aged strains from the BXD recombinant inbred mouse panel, a genetically diverse, tractable, and physiologically relevant platform for uncovering novel genetic drivers and disease mechanisms. We identified BXD32 as a striking outlier with dramatically reduced vessel density. Using optical coherence tomography, optical coherence tomography angiography, and histological analyses, we comprehensively characterized retinal vasculature and structural integrity of BXD32 mice during aging. We found progressive, age-dependent vascular dysfunction and degeneration, beginning in the deep capillary plexus and advancing to the intermediate and superficial layers. These changes were accompanied by neuronal degeneration, including photoreceptor loss and thinning of the ganglion cell complex. Our findings establish BXD32 as a spontaneous and genetically tractable model of inherited retinal neurovascular degeneration and provide a foundation for future studies to identify causative genetic loci and underlying molecular mechanisms. Full article

Background: Rhegmatogenous retinal detachment (RRD), the most common type of retinal detachment, requires prompt surgery to reattach the retina and avoid permanent vision loss. While surgical treatment is adapted to each individual case, one frequent option is pars plana vitrectomy (PPV) with silicone oil (SO) tamponade. Despite achieving anatomical success (complete retinal attachment), concerns persist regarding potential microvascular alterations in the retina and choroid, with a negative impact on visual function. Optical coherence tomography angiography (OCTA) allows detailed, in-depth imaging of retinal and choroidal circulation, whereas microperimetry makes it possible to accurately assess macular function. This review aims to strengthen the existing evidence on vascular and functional alterations at the macular level after SO tamponade in cases of RRD. Methods: A narrative review was conducted using a structured approach, utilizing a PubMed search from January 2000 up to April 2025. Twenty-three studies on OCTA and microperimetry after SO tamponade for RRD were included. Data on vessel densities, choroidal vascular index (CVI), foveal avascular zone (FAZ) size, and retinal sensitivity were extracted and qualitatively analyzed. Results: Studies consistently reported a reduction in the vessel density within the superficial capillary plexus (SCP) under SO tamponade, with partial but incomplete reperfusion post-removal. Choroidal perfusion and CVI were also decreased, exhibiting a negative correlation with the duration of SO tamponade. Microperimetry demonstrated significant reductions in retinal sensitivity (~5–10 dB) during SO tamponade, which modestly improved (~1–2 dB) following removal but generally remaining below normal levels. Conclusions: SO tamponade causes substantial retinal and choroidal vascular impairment and measurable macular dysfunction, even after anatomical reattachment of the retina. It is recommended to perform early SO removal (~3–4 months) and implement routine monitoring by OCTA and microperimetry with the aim of optimizing patient outcomes. Future research should focus on investigating protective strategies and enhancing visual rehabilitation following RRD repair. Full article

Introduction: This pilot study aimed to test the feasibility of a novel vectorial image analysis method to quantify coronal microvascular displacement in different retinal plexuses in intermediate age-related macular degeneration (iAMD) over 6 months. Material and methods: A retrospective series of iAMD patients with at least 6-month follow-up was included if they had complete medical records, best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and OCT angiography (OCTA). En-face (coronal) vascular displacement between baseline and 6 months was assessed in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) using the Farneback motion tracking algorithm applied to consecutive OCTA scans. Results: Eighteen eyes of 18 iAMD patients met the inclusion criteria. Average coronal vascular displacement (T₀–T₆) was 13.7 ± 7.72 µm for the SCP, 15.11 ± 10.06 µm for the DCP, and 19.02 ± 12.25 µm for the CC slab. Reticular pseudodrusen (RPD) was associated with greater displacement in the DCP (p = 0.047), but not in the SCP (p = 0.980) or CC (p = 0.473). Quantitative analysis confirmed the highest DCP displacement in RPD eyes (66.7%, p = 0.02), while drusenoid pigment epithelial detachment showed the greatest reorganization in the CC (100%, p = 0.02). Discussion: Retinal vessels undergo significant tangential displacement in iAMD, suggesting a structural reorganization of the microvasculature. Such remodeling may constitute a compensatory response to ultrastructural alterations resulting in ischemia. Full article

Purpose: To systematically review the evidence regarding the characteristics of Optical Coherence Tomography Angiography (OCTA) in acute retinal arterial occlusion (RAO), with a particular focus on vascular alterations across the superficial and deep capillary plexuses, choroid, and peripapillary regions. Methods: A comprehensive literature search was performed across PubMed, Web of Science, Scopus, EMBASE, Google Scholar, and the Cochrane Database up to April 2025. The search terms included “Optical coherence tomography angiography,” “OCTA,” “Retinal arterial occlusion,” “Central retinal artery occlusion,” and “Branch retinal artery occlusion.” Studies were included if they evaluated the role of OCTA in diagnosing or assessing acute RAO. Case reports, conference abstracts, and non-English articles were excluded. Two reviewers independently conducted the study selection and data extraction. The methodological quality of the included studies was assessed using the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. Results: The initial search yielded 457 articles, from which 10 studies were ultimately included in the final analysis after a rigorous screening process excluding duplicates, non-English publications, and ineligible articles based on title, abstract, or full-text review. The included studies consistently demonstrated that OCTA is a valuable, noninvasive modality for evaluating microvascular changes in RAO. Key OCTA findings in acute RAO include significant perfusion deficits and reduced vessel density in both the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Several studies noted more pronounced involvement of the SCP compared to the DCP. OCTA parameters, such as vessel density in the macular region, have been found to correlate with visual acuity, suggesting a prognostic value. While findings regarding the foveal avascular zone (FAZ) were mixed, the peripapillary area frequently showed reduced vessel density. Conclusion: Acute RAO is an ocular emergency that causes microvascular ischemic changes detectable by OCTA. This review establishes OCTA as a significant noninvasive tool for diagnosing, monitoring, and prognosticating RAO. It effectively visualizes perfusion deficits that correlate with clinical outcomes. However, limitations such as susceptibility to motion artifacts, segmentation errors, and the lack of standardized normative data must be considered. Future standardization of OCTA protocols and analysis is essential to enhance its clinical application in managing RAO. Full article

Background: This study aimed to evaluate retinal arteriole parameters using adaptive optics (AO) rtx1™ (Imagine Eyes, Orsay, France) and peripapillary and macular vessel densities with optical coherence tomography angiography (OCTA) in eyes with different stages of primary open-angle glaucoma (POAG) compared to healthy eyes. It also investigated the associations between vascular parameters and glaucoma severity, as defined by structural (OCT) and functional (visual field) changes. Methods: Fifty-seven eyes from 31 POAG patients and fifty from 25 healthy volunteers were examined. Retinal arteriole morphology was assessed using the AO rtx1™-fundus camera, which measured lumen diameter, wall thickness, total diameter, wall-to-lumen ratio (WLR), and wall cross-sectional area. OCTA was used to measure vessel densities in superficial (SCP) and deep (DCP) capillary plexuses of the macula and radial peripapillary capillary plexus (RPCP) and FAZ area. Structural OCT parameters (RNFL, GCC, rim area) and visual field tests (MD, PSD) were also performed. Results: Glaucoma eyes showed significantly thicker arteriole walls (12.8 ± 1.4 vs. 12.2 ± 1.3 µm; p = 0.030), narrower lumens (85.5 ± 10.4 vs. 100.6 ± 11.1 µm; p < 0.001), smaller total diameters (111.0 ± 10.4 vs. 124.1 ± 12.4 µm; p < 0.001), and higher WLRs (0.301 ± 0.04 vs. 0.238 ± 0.002; p < 0.001) than healthy eyes. In glaucoma patients, OCTA revealed significantly reduced vessel densities in SCP (36.39 ± 3.60 vs. 38.46 ± 1.41; p < 0.001), DCP (36.39 ± 3.60 vs. 38.46 ± 1.41; p < 0.001), and RPCP plexuses (35.42 ± 4.97 vs. 39.27 ± 1.48; p < 0.001). The FAZ area was enlarged in eyes with glaucoma (0.546 ± 0.299 vs. 0.295 ± 0.125 mm²); p < 0.001). Positive correlations were found between vessel densities and OCT parameters (RNFL, r = 0.621; GCC, r = 0.536; rim area, r = 0.489), while negative correlations were observed with visual field deficits (r = −0.517). Conclusions: Vascular deterioration, assessed by AO rtx1™ and OCTA, correlates closely with structural and functional damage in glaucoma. Retinal microcirculation changes may precede structural abnormalities in the optic nerve head. Both imaging methods enable the earlier detection, staging, and monitoring of glaucoma compared to conventional tests. Full article

Background/Objectives: To investigate the role of multimodal imaging, specifically optical coherence tomography angiography (OCTA) and adaptive optics (AO), in the diagnosis and monitoring of diabetic retinopathy. Methods: Our study represents an observational, cross-sectional analysis including sixty-nine patients from four distinct groups: a control group (17 patients), diabetic patients without diabetic retinopathy (no DR) (14 patients), diabetic patients with non-proliferative diabetic retinopathy (NPDR) (18 patients), and diabetic patients with proliferative diabetic retinopathy (PDR patients). A comprehensive ophthalmological evaluation, along with high-resolution imaging using OCTA and AO, was performed. OCTA images of the superficial capillary plexus, acquired with the OCT Angio Topcon, were analyzed using a custom-developed MATLAB algorithm, while AO retinal vascular images were evaluated with the manufacturer’s software of the Adaptive Optics Retinal Camera rtx1™. Results: Our findings demonstrated statistically significant reductions in foveal avascular zone circularity, superficial capillary plexus density, vessel length density, and fractal dimension, correlating with the severity of diabetic retinopathy, particularly in the PDR. Additionally, mean wall thickness and wall-to-lumen ratio were significantly increased in patients with diabetic retinopathy, notably in PDR. Conclusions: In conclusion, our findings demonstrate that the combined use of OCTA and AO imaging offers complementary insights into the microvascular alterations associated with diabetic retinopathy progression and severity. These high-resolution modalities together reveal both perfusion deficits and structural vascular changes, underscoring their utility as essential tools for early detection, staging, monitoring, and informed management of DR. Full article

Background/Objectives: This study aims to investigate the progression of retinal microvascular changes using OCTA in young T1DM patients without clinical signs of DR over a period of 3 years. Methods: This prospective, longitudinal study analyzed OCT angiograms of T1DM patients without clinical signs of DR. It included 40 T1DM patients aged between 7 and 20 years old who formed the T1DM study group and 40 healthy subjects with similar demographic characteristics to the control group. The patients underwent comprehensive ophthalmic examination and OCT imaging using a Retina Wide protocol (6 × 6 mm). We analyzed the following microvascular retinal parameters: FAZ area, perimeter and circularity and superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density. Results: Statistically significant differences between the two groups were identified for the following parameters: the mean FAZ area at follow-up (0.38 ± 0.13) was larger than the mean FAZ area at baseline (0.31 ±0.11), the mean FAZ perimeter at follow-up (3.22 ± 0.75) was larger than the mean FAZ perimeter at baseline (2.61 ± 00.52) and the men FAZ circularity index at follow-up (0.47 ± 0.13) was decreased compared to the FAZ circularity index at baseline (0.56 ± 0.12). A statistically significant difference were also registered for the following parameter: the total SCP and DCP vessel density was decreased at follow-up (37.47 ± 1.57) compared to baseline (38.79 ± 1.00). Conclusions: OCTA long-term monitoring of T1DM patients represents an effective method for tracking progressive changes in FAZ parameters and capillary plexus vascular density. Full article

Background/Objectives: This study investigates the macular microvasculature in a large cohort of primary Sjögren’s disease (SjD) patients using optical coherence tomography angiography (OCTA), focusing on how disease duration, activity, and hydroxychloroquine (HCQ) treatment influence retinal microcirculation. Methods: A total of 106 eyes (53 SjD patients) and 70 eyes (35 age- and gender-matched healthy controls (HCs)) were examined. The vessel area density (VAD, %) and foveal avascular zone (FAZ, mm2) were measured in three retinal layers: Superficial Vascular Plexus (SVP), Intermediate Capillary Plexus (ICP), and Deep Capillary Plexus (DCP), respectively, in three peri-macular circular sectors (c1, c2, c3) each. Results: The VAD was significantly lower in c1 of the DCP in SjD compared to HCs (29.14 ± 7.07 vs. 31.78 ± 9.55, p = 0.038). The FAZ was significantly larger in SjD in both SVP (0.41 ± 0.13 vs. 0.34, 0.11, p < 0.001; Cohen’s |d| = 0.55) and DCP (0.45 ± 0.15 vs. 0.4 ± 0.14, p = 0.014; Cohen’s |d| ± 0.38). Significant correlations were observed between the FAZ size and reductions in the VAD in the SVP and DCP (p = 0.010, Cohen’s |d| = 0.2; p < 0.001, Cohen’s |d| ± 0.26) and across all layers combined (p = 0.019, Cohen’s |d| = −0.18). Conclusions: There was a negative correlation between the VAD in the DCP and disease duration (ρ = −0.28, p = 0.040). No significant correlation was identified between the duration of HCQ intake and the VAD or FAZ. Our findings indicate microvascular alterations in the DCP of SjD, characterized by a reduced VAD and an enlarged FAZ, which may be attributable to inflammatory or arteriosclerotic factors. OCTA may prove to be a valuable tool for the stratification of vascular risk in SjD. Full article

Purpose: Varicella zoster virus (VZV) vasculopathy can occur in patients with herpes zoster (HZ). Our aim was to evaluate the retinal microvascular vessel density (VD) in patients with trigeminal HZ measured by optical coherence tomography angiography (OCTA). Methods: 48 eyes of 24 patients with HZ and 48 eyes of 24 healthy age- and gender-matched controls were included in this study. All participants underwent an OCTA examination using RTVue XR Avanti with AngioVue. The VD data of the macular 3 × 3 mm OCT angiogram of the superficial capillary plexus (SCP), the deep capillary plexus (DCP), and the choriocapillaris (CC) as well as the VD data of the optic nerve head (ONH) were extracted and analyzed. Results: The VD in the SCP, DCP, and CC of patients with HZ was significantly lower compared with healthy controls (p < 0.05). Equally, there was a noticeable reduction in the inside disk area of the ONH. There was no statistically noticeable reduction in the FAZ area and central retinal thickness. Conclusions: In this study, HZ patients demonstrated a decrease in the retinal VD of the SCP, DCP, ONH, and the CC. Quantitative analysis of retinal perfusion using OCTA may therefore help in the diagnosis and monitoring of HZ. Further studies must show to what extent this may be an indication of VZV-related vasculopathy and whether OCTA data can be used as a biomarker in these patients in the future. Full article

Our study aimed to assess the anatomical changes in the retina, including the assessment of the reduction of diabetic macular edema (DME) on optical coherence tomography (OCT) and the improvement of retinal microvascular parameters, defined by the reduction of nonperfusion areas on OCT angiography (OCTA) after intravitreal injections of 6 mg faricimab, an anti-VEGF drug used in the treatment of DME. The study included twenty-two patients aged between 61 and 74 years, each of whom received four loading doses of 6 mg faricimab at 1-month intervals, as described in the summary of product characteristics. Hemodynamic parameters were analyzed by OCT angiography before the first intravitreal injection of faricimab and one month after each subsequent injection. The following parameters were analyzed: non-perfusion area (NPA), superficial capillary plexus (SCP) and deep capillary plexus (DCP), outer retinal flow area (ORFA), choriocapillaris flow area (CCFA) and foveal avascular zone (FAZ). Despite differences in the magnitude of improvement and time to improvement from the start of treatment with intravitreal injections of 6 mg faricimab, reductions in DME and improvements in OCTA parameters resulted in increased retinal blood flow and better visual acuity. Full article

Objectives: To evaluate the short- and long-term effects of subthreshold micropulse laser (SMPL) treatment on the microvascular network in diabetic macular edema (DME). Methods: This 12-month prospective study included 67 eyes (67 patients) with mild DME and good best-corrected visual acuity (BCVA), randomized into SMPL (33 eyes) or sham (34 eyes) groups. Assessments were performed at baseline (T1), 3 months (T2), and 12 months (T3). Optical coherence tomography (OCT) and OCT angiography (OCTA) were used to measure central retinal thickness (CRT), macular thickness (MT), macular volume (MV), foveal avascular zone (FAZ) area, microaneurysm (MA) count, and vessel parameters in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Results: The SMPL group showed a greater relative reduction in FAZ area in the SCP at 3 months (3.21 ± 13.03% vs. −5.73 ± 13.3%; p = 0.032) with a trend toward significance at 12 months (2.37 ± 12.47% vs. −3.3 ± 7.92%; p = 0.086) compared to the sham group. No changes in FAZ size, MA count, and other microvascular parameters were observed in either group. In the SMPL group, BCVA improved at 3 months (T2 > T1, p = 0.003); CRT decreased at 12 months (T2 > T3, p = 0.023); MT decreased at 12 months (T2 > T3, p = 0.006) and MV decreased at 12 months (T2 > T3, p = 0.007). No changes were detected in the sham group. No treatment-related complications occurred. Conclusions: SMPL may improve the macular microvasculature in mild DME by reducing FAZ size in the SCP. It provides visual and functional benefits while maintaining a favorable safety profile. Full article

Background: The aim of the study was to assess retinal circulation in military pilots, as well as to determine the relationship between the type of aircraft, flight altitude, total hours of flight time and parameters of retinal circulation, using OCT angiography (OCT-A). Methods: This cross-sectional study enrolled 44 military pilots and 44 controls. The inclusion criteria encompassed healthy adult men. Due to the fact that military pilots cannot suffer from any vision defects or any other eye disease, the exclusion criteria concerned the control group and included refractive error exceeding −3 diopters (D) and +3 D and concomitant eye diseases, such as any retinal or choroidal pathologies, glaucoma, uveitis. The exclusion criteria for both groups were low-quality OCT-A images. Subsequently, the results of the measurements obtained for 176 eyes were included in further descriptive and multivariate analyses, of which 88 were in the pilot group versus 88 in the comparison group. Results: The total vessel density in superficial and deep capillary plexuses was significantly decreased (p = 0.0176, p < 0.0001, resp.) the longer the flight experience, particularly in the parafoveal region (p = 0.0299 and p < 0.0001, resp.). Moreover, the foveal avascular zone area was significantly increased proportionally to the total hours of flight (p = 0.0083). Also, the total vessel density was increased with a higher flight altitude in the deep capillary plexus (p = 0.0042), especially in the parafoveal region (p = 0.0110). Conclusions: Gravitational forces manifesting in the unique conditions of the flight of military pilots seem to induce microvascular changes in the retina. Full article