Search Results (192)

Background/Objectives: To evaluate interocular retinal and choroidal microvascular alterations associated with compensatory head tilt in unilateral congenital superior oblique palsy (SOP) and to investigate their relationship with head tilt degree using optical coherence tomography angiography (OCTA). Methods: This retrospective cross-sectional study included 34 patients with congenital SOP and head tilt–dominant abnormal head posture. A paired-eye design compared the tilt-side eye with the opposite-side eye. Superficial and deep capillary plexus (SCP, DCP) vessel density, foveal avascular zone (FAZ) parameters, choroidal vascularity index (CVI), and subfoveal choroidal thickness (SFCT) were assessed. Interocular differences were defined as Δ = opposite-side eye − tilt-side eye. Correlation and multivariable regression analyses were performed to assess associations with head tilt degree. The interocular difference in CVI (ΔCVI) and its association with head tilt degree were defined as the primary outcomes, whereas retinal OCTA parameters, FAZ metrics, and SFCT were considered exploratory secondary outcomes. Results: CVI showed the most prominent interocular difference, being higher in the opposite-side eye than in the tilt-side eye (0.71 ± 0.04 vs. 0.68 ± 0.04; p < 0.001), whereas SFCT did not differ significantly (p = 0.395). SCP foveal vessel density and DCP inferior vessel density showed nominal differences in the unadjusted analyses but did not remain statistically significant after Benjamini–Hochberg false discovery rate correction. ΔCVI correlated positively with head tilt degree (ρ = +0.533, p = 0.001) and remained independently associated in multivariable analysis (p = 0.001). Conclusions: Compensatory head tilt in congenital SOP is associated with measurable interocular microvascular asymmetry, predominantly at the choroidal level. CVI demonstrated the strongest association with head tilt severity, whereas retinal OCTA findings were exploratory, suggesting that OCTA may provide objective insight into posture-related choroidal microvascular alterations. Full article

Objective: This study aimed to evaluate the predictability of baseline optical coherence tomography angiography (OCTA) metrics utilizing a specialized capillary–large vessel segmentation analysis framework in patients with diabetic macular edema (DME) undergoing anti-vascular endothelial growth factor (anti-VEGF) therapy. Methods: Forty-two treatment-naïve eyes with DME receiving three monthly loading anti-VEGF injections were included. Superficial capillary plexus (SCP) images from 3 × 3 mm OCTA scans were processed to isolate the capillary network from the large vessels via image processing. Vessel density and skeleton density were extracted for the total, large-vessel, and capillary components. Multiple linear and logistic regression models were used to identify independent predictors of post-treatment best-corrected visual acuity (BCVA) and “good visual outcome” (≥3-line improvement or final BCVA of 20/40 or better). Results: Following three monthly anti-VEGF injections, the mean BCVA significantly improved from 0.57 ± 0.36 to 0.37 ± 0.30 LogMAR (p < 0.0001), and the mean central retinal thickness decreased from 424.3 ± 117.7 μm to 316.9 ± 84.7 μm (p < 0.0001). The proportion of patients who achieved a good visual outcome was 73.8%. Baseline central retinal thickness was associated with baseline BCVA (p = 0.049) but not predictive of post-treatment BCVA (p = 0.38) or good visual outcomes (p = 0.79). Baseline capillary vessel density was identified as a significant independent predictor of post-treatment BCVA (p = 0.024), whereas total and large-vessel metrics were not. Capillary vessel density was also the only significant predictor of good visual outcomes (p = 0.044). Conclusions: Baseline capillary vessel density is a robust predictor of visual prognosis after anti-VEGF therapy in patients with DME, underscoring the importance of capillary network integrity in functional recovery. Full article

Background/Objectives: The objective of this study was to evaluate macular perfusion changes after intracameral injection (ICI) of cefuroxime at the end of phacoemulsification. Methods: Patients who underwent routine phacoemulsification were enrolled. Subjects in the case group had ICI 1 mg/0.1 mL cefuroxime at the end of surgery. Using optical coherence tomography angiography (OCT-A), macular perfusions were assessed at T0 (before surgery), T1, T10, T30, and T90 (days after surgery). Perfusion parameters were calculated in the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). Independent t-tests were used to compare the changes from baseline in each parameter between groups. Results: A total of 33 eyes in the case group and 27 eyes in the control group were enrolled. After surgery, the case group showed a less pronounced reduction in the foveal avascular zone (FAZ) in the DCP at T10 (−0.06 ± 0.23 vs. −0.18 ± 0.18 mm², p = 0.041) and T30 (−0.04 ± 0.20 vs. −0.16 ± 0.24 mm², p = 0.050). At T90, there was no statistically significant difference in the FAZ change in the DCP between the groups. The postoperative changes in the vessel density, skeleton density, and acircularity index of the FAZ in the SCP and DCP, central retinal thickness, and best-corrected visual acuity were similar between the groups in all 3 months. Conclusions: Our findings indicate that intraoperative ICI low-dose cefuroxime is associated with a temporary deceleration in FAZ reduction in the DCP during the first postoperative month. From a personalized medicine perspective, these layer-specific microanatomic variations suggest that, while prophylactic cefuroxime is globally safe—demonstrating no evidence of inducing capillary dropout, aggravating macular thickening, or compromising visual outcomes within this cohort—preoperative and postoperative OCT-A monitoring can serve as an individualized screening framework to track subclinical perfusion dynamics, especially in patients with compromised retinal baselines. Full article

Background and Objectives: Type 2 diabetes mellitus (T2DM) causes retinal microvascular changes that precede clinically apparent diabetic retinopathy (DR). We aimed to identify which optical coherence tomography angiography (OCTA) biomarkers best distinguish eyes with T2DM without clinical DR from healthy controls and to evaluate machine learning classifiers trained on a comprehensive 68-parameter OCTA panel. Materials and Methods: In this prospective case–control study, 80 patients with T2DM without clinical DR and 33 controls underwent 3 × 3 mm macular OCTA using an Optovue RTVue Avanti System. After outlier screening, 221 eyes (155 T2DM, 66 controls) were analyzed. Sixty-eight OCTA parameters were extracted, covering FAZ morphometry (including foveal density FD-300), SCP and DCP vessel density and layer thickness, outer-retina and choriocapillaris flow, and a full retinal-thickness map. Between-group comparisons used the Mann–Whitney U test with Benjamini–Hochberg FDR correction. Logistic regression, random forest, and XGBoost classifiers were evaluated with patient-grouped 10-fold cross-validation; feature importance was quantified via SHAP. Results: Forty-two of 68 parameters reached FDR significance (q < 0.05). Deep capillary plexus vessel density was the most discriminative family (whole image rb = −0.66, q = 2.5 × 10⁻¹³; parafovea rb = −0.64). FD-300 was reduced in T2DM (median 47.55% vs. 51.86%; rb = −0.57; q = 1.0 × 10⁻¹⁰) and emerged as the top SHAP feature (mean |SHAP| = 0.81). FAZ circularity decreased without FAZ-area enlargement, and outer-retina flow was paradoxically elevated (rb = +0.39), consistent with a projection artifact. XGBoost using all 68 features achieved a patient-grouped cross-validated AUC of approximately 0.91, compared with 0.85 for conventional SCP + DCP whole-image density. No parameter correlated with current HbA1c in T2DM (all q > 0.98), and the well-controlled (<7%) and poorly controlled (≥7%) subgroups were indistinguishable across five of six principal biomarkers, consistent with metabolic memory. FD-300 remained independent after adjustment for hypertension, hyperlipidemia, and age (OR = 0.76; 95% CI 0.69–0.84; p < 0.001). Conclusions: A multi-compartment OCTA panel outperforms conventional two-layer vessel-density metrics in detecting preclinical diabetic microvasculopathy, although external validation is required before clinical use. FD-300 is the single most informative biomarker, while choriocapillaris and retinal thickness measures provide complementary, compartment-specific signals. Because the OCTA signature is decoupled from the current HbA1c, screening should not be deferred in well-controlled T2DM. Full article

The myocardium possesses one of the highest vascular densities in the body. The outermost wall layer of large and medium-sized vessels, the adventitia, forms a critical interface between the vasculature and the myocardium and serves as a reservoir for stem and progenitor cells capable of differentiating into all vascular wall lineages as well as innate immune cells, including macrophages. Current cardiac organoid models intrinsically develop networks of endothelial cords and small capillary-like structures that resemble cardiac microvessels. However, these microvessels mostly lack an adventitial compartment in vivo. Here, we present a potential alternative assembloid strategy that combines vascular segments from mouse and human origin with either cardiomyocytes or cardiac spheroids derived from human induced pluripotent stem cells, thereby incorporating large diameter vessels and the vascular adventitia into a cardiac tissue model. Within the assembloids, the myocardial component remained contractile and connected to the vascular adventitia, which displayed cellular sprouting toward the hiPSC-derived cardiac tissue. Immunostaining for vascular and immune markers revealed that the adventitia gave rise to endothelial sprouts and macrophage-like cells which integrated into the myocardial tissue. In summary, we present proof of concept for complex assembloids composed of vessel segments and human iPSC-derived cardiomyocytes which contain and maintain an in vivo-like adventitial compartment. We suggest this model may serve as a platform for investigating myocardial–stromal interactions, cardiac tissue repair, and functional remodeling under both physiological and pathological conditions. Furthermore, the incorporation of large-lumen vessel segments may enable future experimental perfusion, rendering the model particularly suitable for drug testing via intravascular delivery. Full article

Purpose: We investigated the association between age and retinal microvasculature parameters as measured by optical coherence tomography angiography (OCTA) and the modifying effect of diabetes status on this association. Methods: In this serial, cross-sectional study, 3 × 3 mm² macular OCTA images were obtained from healthy adults and adults with diabetes mellitus (DM) with no diabetic retinopathy (DR) or with mild non-proliferative DR (NPDR). The parameters analyzed included foveal avascular zone (FAZ) area and perimeter, vessel density (VD), vessel length density (VLD), and flow index (FI) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The associations between OCTA parameters and age were explored using multivariable linear regression models. Results: For the included 1855 patients (1855 eyes) (49% male; mean age: 55 years), the results were as follows: no diabetes (N = 217), DM no DR (N = 1352), and mild NPDR (N = 286). Increasing age was significantly associated with decreased SCP and DCP VD and VLD in the diabetic and non-diabetic groups. The slope of association between SCP and DCP FI and age in the diabetic patients was significantly different than that in the control patients. Conclusions: The strength of the association between aging and OCTA parameters differed significantly between the controls and those with early retinopathy, pointing to a potentially altered retinal vascular homeostasis secondary to diabetic pathophysiology. This finding offers insight into the early pathological biomarkers of DR and may guide early DR management for patients based on personalized risk scores. Full article

Background: The aim of this study was to assess the macular vasculature and retinal thickness using optical coherence tomography angiography (OCTA) in patients with migraine with aura (MA) and migraine without aura (MO) compared with healthy controls (HCs). Methods: A prospective cohort study included 37 MO patients, 34 MA patients, and 34 HCs. Vessel density (VD) in the superficial and deep retinal plexuses, radial peripapillary capillaries (RPC), optic nerve head (ONH), and foveal avascular zone (FAZ) was measured. The retinal thickness, retinal nerve fiber layer (RNFL) thickness, visual field parameters, and body mass index (BMI) were also evaluated. Results: Significantly lower macular superficial VD in the whole image was observed in the MA group compared with both the MO and HCs. MO patients showed higher RPC VD in the inferior quadrant compared with HCs. No significant differences were found in the RNFL thickness, deep plexus, FAZ area, non-flow area, or visual field parameters. In the MA group, the FAZ area showed a significant inverse correlation with the BMI, and a higher incidence of comorbidities was observed, particularly of Hashimoto’s thyroiditis. Conclusions: These findings suggest that migraine subtypes are associated with distinct retinal microvascular patterns detectable via OCTA. Reduced macular perfusion in MA and increased peripapillary perfusion in MO may reflect subtype-specific vascular dysregulation. OCTA may therefore serve as a noninvasive biomarker for detecting early microvascular alterations in migraine. Full article

Background/Objectives: To evaluate the associations between corneal topographic irregularity, higher-order aberrations (HOAs), and posterior segment structural and microvascular parameters in keratoconus using optical coherence tomography (OCT) and OCT angiography (OCTA). Methods: In this cross-sectional study, 81 eyes with keratoconus and 60 healthy control eyes underwent corneal topography and wavefront analysis, spectral-domain OCT with enhanced depth imaging, and OCTA. Retinal layer thicknesses, choroidal thickness and area metrics, choroidal vascularity index (CVI), and OCTA-derived vascular parameters were analyzed. Associations were assessed using Spearman correlation analysis with false discovery rate (FDR) correction. Results: Compared with controls, keratoconus eyes showed significantly increased corneal curvature, corneal irregularity indices, and HOAs (all p < 0.001). Structural OCT analysis demonstrated preserved inner retinal layers, whereas outer nuclear layer thickness was reduced (p < 0.001) and overall outer retinal layer thickness was increased (p = 0.005). Choroidal thickness and both total and luminal choroidal areas were significantly greater in keratoconus eyes (all p ≤ 0.011), while CVI did not differ between groups (p > 0.05). OCTA revealed reduced superficial capillary plexus vessel density at the whole image and perifoveal regions (all p < 0.001), whereas deep capillary plexus and foveal avascular zone metrics were largely preserved. Correlation analyses identified only weak and inconsistent associations between corneal parameters, HOAs, and posterior segment measurements, none of which remained statistically significant after FDR correction. Conclusions: Despite pronounced anterior segment deformation and optical degradation, posterior segment structural and microvascular alterations in keratoconus are limited and weakly related to corneal disease severity. These findings support a predominantly anterior segment centered pathophysiology of keratoconus and highlight the importance of stringent multiple-comparison control in multimodal imaging studies. Full article

Background: Attention deficit hyperactivity disorder (ADHD) lacks objective biomarkers that may complement clinical diagnosis. Optical coherence tomography angiography (OCTA) enables non-invasive quantitative assessment of retinal microvasculature and has emerged as a potential tool to explore neurovascular features associated with neurodevelopmental disorders. The aim of this study was to comparatively evaluate macular and peripapillary OCTA parameters in individuals with ADHD and neurotypical controls. Methods: This comparative case–control study involved 200 eyes (100 from 50 patients with ADHD and 100 from 50 neurotypical controls) belonging to the same well-characterized cohort previously evaluated using structural optical coherence tomography (OCT). Macular and peripapillary OCTA scans were obtained, and quantitative parameters related to vessel density, perfusion density, and peripapillary flow metrics of the superficial retinal capillary plexus were analyzed separately for right and left eyes. Group comparisons were performed using independent-samples t-tests and analysis of covariance adjusted for age, sex, and axial length, with correction for multiple comparisons. Results: After adjustment for age, sex, and axial length, no OCTA parameter showed statistically significant between-group differences after correction for multiple comparisons. Across parameters, mean differences were small and did not provide statistical evidence of an effect under the prespecified analytical framework. Conclusions: Superficial OCTA-derived microvascular parameters did not demonstrate robust between-group differences in ADHD in this cohort. These results suggest that when restricted to the superficial capillary plexus, OCTA metrics are unlikely to serve as standalone biomarkers for ADHD. Full article

Background/Objectives: Optical coherence tomography angiography (OCTA) enables noninvasive quantitative assessment of the retinal microvasculature and is widely used in diabetic retinopathy (DR). However, OCTA-derived metrics are highly dependent on post-processing techniques, particularly vessel binarization. This study aimed to compare local and global binarization methods applied after Frangi filtering for vessel enhancement in parafoveal vessel density analysis. Methods: This cross-sectional study included 69 participants: 17 healthy controls and 52 diabetic patients, classified as the following: no DR (n = 14), non-proliferative DR (NPDR, n = 18), or proliferative DR (PDR, n = 20). All subjects underwent comprehensive ophthalmological examination and OCTA imaging of the superficial capillary plexus using a Topcon OCTA system. Images were processed using a custom MATLAB protocol. Following Frangi filtering, five binarization methods were applied: three local (Phansalkar, local Otsu, adaptive mean) and two global (global mean and global Otsu). Parafoveal vessel density was quantified within the four inner quadrants of the ETDRS grid. Results: Statistically significant differences in vessel density were consistently observed between PDR group and both the control and no DR groups across all local binarization methods. Among global methods, only global Otsu thresholding detected a significant difference between PDR and control. The most robust differences were predominantly identified in the nasal and inferior quadrants. Conclusions: Local adaptive binarization methods demonstrated superior sensitivity and structural preservation for parafoveal vessel density analysis in DR. Global methods showed limited discriminative capability. These findings support the preferential use of local adaptive techniques for reliable OCTA-based vascular assessment in diabetic retinopathy. Full article

Background/Objectives: Optical coherence tomography-angiography (OCT-A) is a non-invasive method of visualizing the capillary system. As vascular dysregulation impacts glaucoma pathogenesis, the aim of this study was to evaluate APSified-BMO-based-peripapillary vessel density (VD) in patients with ocular hypertension (OHT), pre-perimetric-open-angle glaucoma, as well as primary (POAG) and secondary (SOAG) open-angle glaucoma in comparison to healthy controls using OCT-A. Methods: The present study included 180 eyes from 115 patients of the Erlangen Glaucoma Registry, divided into 35 eyes with OHT, 16 pre-perimetric-OAG eyes, 64 OAG eyes—which were subdivided into 37 POAG and 27 SOAG eyes—and 65 healthy controls. All subjects underwent measurements of the retinal nerve fiber layer (RNFL), inner nuclear layer (INL), retinal ganglion cell (RGC) layer, and Bruch membrane opening–minimum rim width (BMO-MRW). APSified-BMO-based-peripapillary vessel density (VD) was visualized by using OCT-A and quantified using the Erlangen Angio Tool. Results: Mean APSified-BMO-based peripapillary VD showed a significant correlation with age (p < 0.0001). Considering the age effect, mean APSified-BMO-based peripapillary VD of OAG was significantly lower compared to healthy eyes (p < 0.0001) and OHT (p = 0.016). Subgroup analysis yielded a significant difference in mean APSified-BMO-based peripapillary VD between controls and POAG (p = 0.001) and SOAG (p = 0.018), respectively. In addition, a significant difference was observed between OHT and POAG patients (p = 0.036). No significant differences were observed between the OHT, pre-perimetric-OAG, and healthy eyes, respectively. Conclusions: As peripapillary VD was significantly decreased in glaucoma patients compared to controls, the data might suggest that peripapillary VD might be useful for monitoring glaucoma progress. Full article

Background/Objectives: To comprehensively evaluate longitudinal retinal and choroidal vascular changes after phacoemulsification using automated optical coherence tomography angiography (OCTA) analysis and to investigate clinical factors influencing these changes. Methods: This retrospective study included 26 subjects (31 eyes) who underwent uncomplicated phacoemulsification. OCTA was performed at baseline and at 1 day, 1 week, 1 month, and 2 months postoperatively. Automated quantitative analysis was applied to assess vessel density- and structure-related parameters in the superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris, and Haller layer. Longitudinal changes were analyzed using repeated-measures analysis of variance, with time × clinical factor interactions evaluated for diabetes mellitus, anesthesia method, and sex. Inter-layer associations were assessed using Spearman correlation analysis. Results: Significant longitudinal changes were observed in retinal layers. In the SCP, vessel density increased from 42.59 ± 1.46 at baseline to 44.10 ± 1.44 at 2 months (p = 0.002), accompanied by increases in vessel length and node counts (all p < 0.001). In the DCP, vessel density increased from 34.66 ± 5.98 to 38.65 ± 4.83 (p < 0.001). In contrast, choriocapillaris-related parameters showed no significant overall time effect. In the Haller layer, mean vessel diameter decreased significantly over time (p < 0.001), while density-related metrics remained unchanged. ΔVAD demonstrated positive correlations between adjacent layers (SCP–DCP and DCP–choriocapillaris) and a negative correlation between choriocapillaris and Haller layers. Diabetes mellitus showed no significant longitudinal effect, whereas retrobulbar anesthesia and sex significantly modified selected choroidal trajectories. Conclusions: Automated and integrated OCTA analysis revealed layer-dependent retinal and choroidal vascular responses after phacoemulsification, with coordinated changes confined mainly to anatomically adjacent layers and selective modulation by clinical factors. Full article

Background: Diabetic retinopathy (DR) is a leading cause of vision loss worldwide. Microvascular changes precede clinically detectable DR, creating an opportunity for early diagnosis and intervention. Optical coherence tomography angiography (OCTA) enables noninvasive, quantitative assessments of retinal and choroidal microcirculation and has emerged as a promising tool for identifying early biomarkers of DR. The goal of this study was to review the literature on OCTA-derived biomarkers associated with preclinical diabetic retinopathy in patients with type 1 and type 2 diabetes mellitus. Methods: This descriptive literature review summarizes current evidence regarding OCTA-derived biomarkers associated with preclinical diabetic retinopathy in patients with type 1 and type 2 diabetes mellitus. A search of the PubMed/MEDLINE database was performed to identify original studies published between 2015 and 2025 evaluating OCTA parameters in diabetic patients without clinically detectable diabetic retinopathy. The findings were synthesized qualitatively due to methodological heterogeneity among studies in terms of OCTA devices, imaging protocols, and analyzed parameters. Results: The reviewed studies consistently reported early microvascular abnormalities detectable by OCTA prior to the development of clinically visible diabetic retinopathy. The most frequently described changes included reduced vessel density (VD) and perfusion parameters, enlargement and increased irregularity of the foveal avascular zone (FAZ), areas of capillary non-perfusion, and alterations in vascular network geometry and complexity. These changes were most consistently observed in the deep capillary plexus (DCP), suggesting that this vascular layer may be particularly susceptible to early diabetic microvascular damage. Conclusions: This review provides a comprehensive synthesis of OCTA-derived biomarkers associated with early retinal microvascular alterations in diabetic patients without clinically detectable diabetic retinopathy. By integrating findings from recent studies, the review highlights the potential role of OCTA in identifying preclinical microvascular changes and discusses current methodological challenges and future research directions. Full article

Background: The eye has shown potential as a reliable, readily accessible and clinically relevant site for investigating patients with multiple sclerosis (pwMS). Optical coherence tomography angiography (OCTA) shows promise in revealing new metabolic and vascular elements driving multiple sclerosis (MS) disease pathology. This study aimed to explore correlations between OCTA parameters and clinical characteristics in newly diagnosed relapsing–remitting MS (RRMS) patients. Methods: In this cross-sectional study, forty-one newly diagnosed RRMS patients underwent comprehensive evaluations, including neurological examinations, functional and cognitive tests (9-Hole Peg Test, Montreal Cognitive Assessment), and OCT/OCTA scans. Multiple regression analyses assessed correlations between OCT/OCTA parameters and baseline clinical characteristics. Results: Lower superficial capillary plexus (SCP) vessel density was associated with longer disease duration, higher EDSS scores (visual, pyramidal, cerebellar, ambulation), and impaired 9-Hole Peg Test performance, especially in the non-dominant hand. Higher values of choriocapillaris (CC) flow voids correlated with worse cognitive performance (MoCA). Structural OCT parameters showed limited clinical correlations. Conclusions: OCTA-derived parameters are associated with disability, fine motor function, and cognitive performance in newly diagnosed RRMS patients without prior ON. These findings suggest that retinal vascular alterations may reflect early neurodegenerative processes and provide complementary information beyond structural OCT metrics. OCTA may represent a sensitive, non-invasive imaging biomarker for patient assessment in early MS. Full article

Background/Objectives: This study investigates the normative data and determinants of retinal and choroidal vessel density (VD) in Tibetan children using optical coherence tomography angiography (OCTA). Methods: This study recruited students from primary schools in Lhasa who underwent OCTA encompassing VD in the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) and choriocapillaris (CC) in the macular region, as well as refractive status, axial length, and systemic examinations. Results: This study included a total of 645 children who met the criteria. The results showed that VD in the fovea was significantly higher in the SCP than in the DCP, while CC had the highest VD in the fovea. Correlation analysis revealed strong correlations in VD among all quadrants of the SCP, DCP, and CC, as well as significant correlations between corresponding regions of the SCP and DCP. VD showed no significant association with age, sex, axial length, or spherical equivalent. Foveal VD in both the SCP and DCP was positively correlated with oxygen saturation. No consistent correlation was found between choroidal or retinal thickness and VD in any layer. Conclusions: The identified link between systemic oxygen saturation and foveal vascular density offers a novel perspective on human adaptation to chronic hypoxia, positioning the retinal microcirculation as a sensitive indicator of systemic oxygen homeostasis. Full article