Search Results (75)

Background: Amyotrophic lateral sclerosis (ALS) is increasingly recognized as a multisystem disorder involving neurovascular dysfunction. The retina allows in vivo assessment of neurovascular changes. This study evaluated retinal structural and microvascular alterations in ALS using optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A). Methods: This cross-sectional study included 46 participants with ALS and 19 healthy controls. Retinal thickness and vascular density in the superficial and deep retinal capillary plexuses and the choriocapillaris were quantified using OCT and OCT-A. Group comparisons and logistic regression analyses were performed to assess associations with ALS. Subgroup analyses were conducted according to clinical phenotype. Results: In total, 124 eyes were analyzed. ALS was associated with increased average retinal thickness (p = 0.023) and reduced vascular density in the superficial retinal capillary plexus (p = 0.005), deep retinal capillary plexus (p < 0.001), and choriocapillaris (p = 0.004). In logistic regression analyses, retinal thickness was positively associated with ALS status (OR = 1.42, p = 0.023), whereas higher vascular density in the superficial plexus, deep plexus, and choriocapillaris was associated with lower odds of ALS. No significant differences were observed between bulbar- and spinal-onset ALS phenotypes. Conclusions: ALS is associated with structural and microvascular retinal alterations detectable by OCT and OCT-A. These findings support the presence of systemic neurovascular dysfunction and highlight retinal imaging as a promising, non-invasive approach for investigating disease mechanisms and developing potential biomarkers. Full article

Background: Chronic kidney disease (CKD) is associated with systemic microvascular dysfunction, yet the relationship between retinal changes and mineral metabolism disturbances across CKD treatment modalities remains incompletely characterized. Methods: We performed a baseline cross-sectional analysis of 77 participants (29 hemodialysis [HD] patients, and 48 kidney transplant recipients [KTR]) who underwent 7 × 7 mm structural optical coherence tomography (OCT) and 6 × 6 mm OCT angiography (OCTA) imaging. Structural parameters included central macular thickness (CMT), ganglion cell layer plus inner plexiform layer (GCL+), ganglion cell complex (GCL++), and subfoveal choroidal thickness (SCT). Microvascular parameters included superficial and deep capillary plexus vessel density (SVPD, DVPD), choriocapillaris density (CCD), and foveal avascular zone (FAZ) area. Serum mineral metabolism markers were correlated with retinal findings. Eyes were analyzed separately as the primary approach, while generalized estimating equation (GEE) models adjusted for age, sex, body mass index, diabetes, and hypertension (HTN) were used for confirmation. Results: FAZ area, SVPD, DVPD, CCD, GCL+, GCL++, and CMT did not differ significantly between cohorts in either per-eye analyses or adjusted GEE models. SCT was lower in HD patients than in KTR in the right eye (p = 0.019) and remained significantly higher in KTR in the adjusted GEE models (p = 0.016), a difference that persisted after excluding participants with diabetes and after adjustment for HTN grade. HTN grade was associated with FAZ area in HD and SCT in KTR. Serum magnesium was inversely associated with FAZ area in HD (B = −95.27, p = 0.034) and positively associated with GCL+ in KTR (B = 10.55, p = 0.048). Conclusions: Retinal microvascular and inner-retinal structural parameters were largely comparable between HD patients and KTR, with SCT the only parameter showing a consistent between-cohort difference (higher in KTR). Serum magnesium and HTN grade were the metabolic and clinical variables most consistently associated with retinal measures. 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

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: 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: Mixed connective tissue disease (MCTD) is a rare systemic autoimmune disease which presents with clinical features that overlap with at least two connective tissue disorders, including systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis (PM), dermatomyositis (DM), and rheumatoid arthritis (RA). It is characterized by the presence of anti-ribonucleoprotein (anti-U1RNP) antibodies. The mechanism of the vasculopathy associated with MCTD remains largely unknown. Optical coherence tomography angiography (OCTA) is a non-invasive imaging method of the microvasculature of the retina and choroid, providing the assessment of retinal perfusion. Objectives: The aim of the study was to evaluate the optical coherence tomography angiography (OCTA) parameters in patients with mixed connective tissue disease compared to healthy individuals. Methods: In this study, we compared the following parameters between patients with MCTD and healthy subjects: foveal avascular zone (FAZ), FAZ perimeter (PERIM), flow density (FD), choriocapillaris flow area (CCFA), outer retina flow area (ORFA), and foveal and parafoveal mean superficial and deep vessel density. Results: Parafoveal mean superficial vessel density and parafoveal mean deep vessel density were significantly lower in the MCTD group than in controls. The FAZ, FAZ PERIM, and FD values in the patients with MCTD were lower than in the control group and statistically significant for all parameters. Conclusions: The present study’s findings suggest the presence of ocular vascular abnormalities in patients suffering from MCTD. These abnormalities are characterized by decreased retinal vessel density and lower choriocapillaris flow. The results of the study demonstrate the significant role of OCTA in the diagnosis and monitoring of microvascular changes in patients with MCTD. 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

Background: Haemodialysis (HD) superimposes additional circulatory stress on the microvasculature, leading to endothelial dysfunction, which plays a key role in the development of haemodialysis-associated multiorgan dysfunction. This study was undertaken to evaluate the effect of a single HD session on retinal and choroidal microcirculation, using optical coherence tomography angiography (OCTA) in relation to changes in the blood levels of selected biochemical modulators of endothelial function. Methods: The vessel density (VD) of 35 patients was evaluated before and after a single HD session, using OCTA in the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC). Retinal thickness (RT) and choroidal thickness (CT) were also assessed. Asymmetric dimethylarginine (ADMA), endothelin-1 (ET-1) and malondialdehyde (MDA) levels, oxidative stress (OS) status and systemic parameters were assessed before and after a single HD session. The correlation between changes in these parameters and changes in selected OCTA parameters was tested. Results: A single HD session resulted in a significant increase in RT and a decrease in CT. In addition to increased oxidative and osmotic stress resulting from a significant reduction in plasma osmolality, the HD session was associated with a significant increase in ET-1 levels and a decrease in ADMA levels. These biochemical changes correlated with changes in RT and CT, as well as with changes in VD in the retinal capillary plexuses and the CC. Increased ET-1 levels and decreased plasma osmolality were identified as predictors of RT increase, whereas increased MDA levels corrected serum creatinine-predicted CT reduction. Conclusions: Changes in ADMA and ET-1 and OS, as well as osmotic stress induced by a single HD session, affect the eye microcirculation and morphology of the retina and choroid. OCTA examination is a promising method for assessing microcirculation in HD patients. Full article

Background/Objectives: This study aimed to prospectively assess the incidence of retinal embolization and to evaluate the vascular and structural changes in the retina and choroid in 52 patients with asymptomatic severe carotid artery disease who underwent carotid artery revascularization. Methods: In our study, 35 patients underwent carotid endarterectomy (CEA) and 17 underwent carotid artery stenting (CAS). Biomicroscopy, fundoscopy, optical coherence tomography (OCT), and OCT-angiography (OCTA) were performed at baseline and 1 month after revascularization. Results: The subfoveal choroidal thickness (SFCT), peripapillary choroidal thickness inferior to the optic nerve head (ppCTi), total overall average retinal vascular density (rVDtot), and total overall average choriocapillaris vascular density (ccVDtot) of the eyes ipsilateral to the operated carotid artery increased significantly after revascularization, whereas a statistically significant increase was also found in the SFCT, rVDtot, and ccVDtot of the contralateral eyes in the overall cohort. Comparing the two study groups, we found that the SFCT, superior and inferior peripapillary choroidal thicknesses (ppCTs, ppCTi), rVDtot, and ccVDtot increased in both groups after revascularization, but significantly only in the CEA group. Furthermore, the temporal choriocapillaris vascular density (ccVDt) increased significantly after revascularization in both groups to a similar degree. Conclusions: Carotid artery revascularization led to a statistically significant increase in retinal and choroidal vascular densities, which indicates significantly improved ocular perfusion. The analysis of the findings of the two study groups suggests the superiority of CEA in terms of improving ocular perfusion in asymptomatic severe carotid artery disease. The rate of retinal embolization was similar in both surgical groups. 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

Background/Objectives: The aim of this study was to investigate quantitative differences in optical coherence tomography angiography (OCTA) between diabetic patients and healthy controls and to identify the early OCTA biomarkers for diabetic macular changes. Methods: Ophthalmological examination and OCTA were performed on two groups of diabetic patients (with and without mild diabetic retinopathy) and healthy controls. Macular, foveal, perifoveal, and parafoveal vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ), and flow area in the choriocapillaris were calculated. Results: A total of 431 eyes of 233 participants were analyzed. The VD in the SCP in the whole macula was the lowest in the DM + DR group and lower than in the DMnoDR group; however, in the fovea, it was the highest in the DM + DR group and higher than in the DMnoDR group. The VD in the SCP in the parafovea was lower in the DM + DR group than in the DMnoDR group, and in the perifovea, it was lower in the DMnoDR group than in the control group. The VD in the DCP in the macula, parafovea, and perifovea was lower in the DM + DR group than in the DMnoDR and control groups. The FAZ and flow areas in the choriocapillaris were smaller in the DM + DR group than in both the DMnoDR and control groups. Conclusions: VD reduction in the SCP and the DCP of the macular and parafoveal regions, as well as in the DCP of the perifoveal region, may indicate progression of diabetic retinopathy from subclinical to clinical stages; however, an increase in the foveal region in the SCP can be a compensatory mechanism. VD reduction in the perifovea and whole macula in the SCP can be a screening factor for subclinical macular changes. FAZ reduction before clinical signs of retinopathy may be an early compensatory vascular mechanism. Full article

Purpose: To analyze the retinal and choriocapillaris changes in diabetic patients with no or with early signs of diabetic retinopathy using high-definition (HD) angio optical coherence tomography angiography (OCTA) software and spectral-domain (SD) OCT. Methods: A total of 112 eyes (54 eyes from 27 diabetic patients and 58 eyes from 29 control subjects) were included in this retrospective cross-sectional study of healthy and diabetic adults. Retinal microvascular changes were assessed by using HD-OCTA software to calculate vascular density (VD) and foveal avascular zone (FAZ). SD-OCT was used to assess retinal thickness and volume in parafovea as well as ganglion cell complex (GCC) parameters. Results: The VD-whole image was significantly higher in the healthy control group (MW z = 1109.5, p = 0.012; t = 2.611, p = 0.010). Also, VD-parafovea was significantly higher in the healthy subjects (MW z = 1053.5, p = 0.004; t = 3.207, p = 0.002). GCC focal loss volume (FLV) was significantly decreased in diabetic patients (p = 0.051). Non-flow FAZ did not show a statistically significant difference between groups, although the FAZ was larger in the diabetic patients. Conclusions: Diabetic patients with no or early signs of diabetic retinopathy have decreased VD compared to healthy individuals. They also present retinal changes at the GCC that are correlated with initial neurodegeneration. HD-OCTA and SD-OCT can detect vascular changes and structural signs of retinal neurodegeneration before clinically apparent diabetic retinopathy. Potentially, these methods may offer new biomarkers for monitoring disease progression and visual prognosis. Full article

Background/Objectives: The aim of this study was to quantify the interscan variability of vascular perfusion in patients with diabetic retinopathy (DR) using sequential optical coherence tomography angiography (OCT-A) scans. Methods: Patients with low-grade DR (DRSS score 20) underwent five sequential OCT-A imaging sessions. Vessel perfusion density (VPD) values of the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), and choriocapillaris (CC) were computed using ImageJ Version 1.54 software via a binarization process. The binarized images were analyzed to compute VPD using vessel density plugins. Inter-session variability was assessed using the coefficient of variation (CV) and intraclass correlation coefficient (ICC). The results were compared with an age-matched group of healthy controls. Results: A total of 16 eyes from 16 patients with DR (6 females, 37.5%) and 16 eyes from healthy controls (6 females, 37.5%) were included. Mean VPD values for SCP, ICP, DCP, and CC in patients with DR were 23.64, 13.64, 15.31, and 36.57, respectively. Corresponding values for the healthy subjects were 37.65, 23.32, 22.05, and 49.00, respectively. No significant differences were found in VPD across consecutive scanning sessions (p > 0.05) in either group. However, significant differences in VPD were observed between patients who were healthy and patients with diabetes. Conclusions: Sequential OCT-A imaging demonstrated no significant inter-session variability in both healthy subjects and subjects with diabetes. The Spectralis OCT-A system showed high reliability for imaging both healthy and diseased conditions. Full article

Objectives: The aim of this study was to investigate retinal and choroidal microvascular changes in patients with axial spondyloarthritis (axSpA) treated with long-term anti-TNF therapy and NSAIDs and in healthy control subjects using optical coherence tomography angiography (SS-OCT-A). Methods: A total of 162 eyes from 81 participants were included: 52 eyes from 26 axSpA patients treated with anti-TNF therapy (≥5 years), 44 eyes from 22 axSpA patients treated with NSAIDs, and 66 eyes from 33 healthy control subjects. SS-OCT-A imaging was used to assess retinal thickness, ganglion cell layer thickness, retinal nerve fiber layer thickness, and the vessel densities of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC). Disease activity was assessed with ASDAS-CRP. Results: Both axSpA subgroups showed a significant expansion of the foveal avascular zone and reduced SCP and DCP densities compared to the controls. The CC vessel density was higher in axSpA patients than in healthy subjects. The anti-TNF group had a lower CC vascular density than the NSAIDs group. The disease duration correlated with a decreased central DCP density and increased paracentral SCP and CC densities. Conclusions: SS-OCT-A revealed subclinical retinal and choroidal changes in axSpA patients, highlighting the impact of chronic inflammation on the retinal vasculature. While anti-TNF therapy effectively controls systemic inflammation, it cannot completely prevent microvascular changes. Further studies are needed to assess the clinical relevance of these results. Full article

Background: To investigate the retinochoroidal and optic nerve head (ONH) microstructural and microvascular age-related changes in healthy subjects by examining the ganglion cell–inner plexiform layer thickness (GC-IPLT), vessel density (VD), and their ratio. Methods: In this cross-sectional study, 203 subjects (20–69 years old) were divided into five age groups: 20–29 (G1), 30–39 (G2), 40–49 (G3), 50–59 (G4), and 60–69 (G5) (G5). Following a thorough ophthalmological examination, enhanced depth imaging optical coherence tomography (EDI-OCT) scanning was performed along with OCT angiography (OCTA) in a 6 × 6 mm² scanning area. Results: After adjusting for axial length the GC-IPLT varied significantly among groups, with thickness peaking in G3 (39.63 ± 1.14 µm) and then decreasing to the lowest in G5 (34.15 ± 5.93 µm) (p = 0.008). The whole, foveal, parafoveal, and perifoveal superficial and deep capillary plexus (SCP and DCP) VDs all varied significantly among groups, peaking in G2 and falling to their lowest in G5 (p < 0.05). No significant differences existed among groups regarding the GC-IPLT/whole SCP VD (p = 0.163) or GC-IPLT/whole DCP VD (p = 0.258) ratios. The foveal VDs in a 300-μm wide region surrounding the foveal avascular zone (FAZ) (FD-300) varied significantly among groups, peaking in G1 (57.06 ± 0.58) and dropping to its lowest in G5 (53.54 ± 0.59) (p < 0.05). The choriocapillaris flow differed significantly among groups, peaking in G1 (20.39 ± 0.15 mm²) and dropping to its lowest in G5 (19.24 ± 0.16 mm²) (p < 0.001). Conclusions: The retinochoroidal microstructure and microvasculature ratios display an inverted U-shaped pattern with age, which could be linked to a considerably decreased GC-IPLT versus capillary plexus VDs with age, notably in subjects in their sixties. Full article