Search Results (679)

Diabetic retinopathy (DR) remains a major cause of vision loss in patients with diabetes, and earlier recognition of retinal vascular abnormalities may improve risk stratification and clinical follow-up. Optical coherence tomography angiography (OCTA) provides a noninvasive way to visualize the retinal microvasculature and may detect DR-related changes before they are evident on routine clinical assessment. In this work, we investigated whether dividing OCTA images into anatomically defined retinal regions could improve DR classification and clarify which regions carry the greatest discriminative information. The study included 188 OCTA images: 67 from normal eyes, 57 from eyes with mild DR, and 64 from eyes with moderate DR. Each image was divided into seven concentric regions centered on the fovea, and vessel-density features were extracted from each region. Ten machine learning classifiers were trained and compared at the regional level. For each region, the best-performing classifier was retained, and the final prediction was obtained with a majority-voting ensemble. To examine model behavior, Local Interpretable Model-Agnostic Explanations (LIME) were applied. Performance was also compared with that of a transfer-learning MobileNet model trained on whole OCTA images. On the held-out patient-level test set, the ensemble model achieved 97% accuracy, 98% precision, 97% recall, and a 97% F1-score for three-class classification. These results were higher than those obtained with the tested whole-image transfer-learning baselines. The interpretability analysis consistently identified the parafoveal regions as the most informative for classification. Among the seven regions, Region 3 showed the highest overall contribution, followed by Regions 2 and 5, whereas Region 5 became more influential in moderate DR. These results suggest that regional analysis of OCTA-derived vessel density can improve both classification performance and interpretability in DR assessment. The findings also indicate that parafoveal vascular alterations carry substantial discriminative value in distinguishing normal, mild DR, and moderate DR cases. Validation in larger, independent cohorts from multiple centers will be necessary to confirm the generalizability of these findings. Full article

Photodynamic therapy (PDT) has already gained immense attention in the anti-tumor field due to its low toxicity and non-invasiveness compared to traditional treatment methods. Therefore, the development of efficient photosensitizers is crucial for the advancement of photodynamic therapy. Although phthalocyanines (Pcs) have attracted huge attention as efficient photosensitizers, their clinical applications are hindered by poor solubility and a tendency to aggregate. Herein, two different Pcs that have different polarities were loaded into bacterial cellulose nanoparticles via non-covalent interactions. The aggregation behaviors and singlet oxygen production efficiencies were studied, as well as the influence of the Pc polarity on loading ratios. It was observed that octa-propylsulfonyl phthalocyanine ZnPc(SO₂Pr)₈, which has a more polar structure, loaded more on bacterial cellulose nanocrystal. Also, singlet oxygen generation efficiency of ZnPc(SO₂Pr)₈ was harmoniously increased with the loading ratio. The result indicated that both of the phthalocyanine/bacterial cellulose nanocrystal (Pc/BCNs) systems produced singlet oxygen and could be used as potential photosensitizers in PDT, especially ZnPc(SO₂Pr)_8, due to the high loading ratio. Full article

Background/Objectives: This study aimed to develop a nomogram-based prediction tool to estimate visual field (VF) progression in patients with bilateral myopic normal-tension glaucoma (mNTG) by integrating key structural and vascular parameters. Methods: This retrospective cohort study included 150 eyes from 75 treatment-naïve patients with mNTG. All subjects were followed for at least five years with at least six reliable VF examinations. Key structural features, including the lamina cribrosa steepness index (LCSI) via enhanced-depth imaging optical coherence tomography (OCT) and choroidal microvascular dropout (cMvD) via OCT angiography (OCTA), were evaluated. VF progression was determined by event-based glaucoma progression analysis (GPA). To construct the predictive nomogram, clustered logistic regression with forward selection and 1000 bootstrap iterations was used to identify independent predictors. Results: Of the 150 eyes, 58 (38.7%) exhibited VF progression. Multivariable analysis identified steeper LCSI and the presence of parapapillary cMvD at baseline as significant independent predictors of progression. The resulting nomogram demonstrated excellent predictive accuracy, with an AUC of 0.922 and a C-index of approximately 0.92, indicating strong discriminative ability. Conclusions: This nomogram, incorporating structural (LCSI) and vascular (cMvD) markers, may offer a useful individualized tool for predicting VF progression in mNTG. This tool could assist in the early identification of high-risk patients and supports personalized treatment planning to optimize long-term visual outcomes. 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

Craniopharyngioma (CP) is a rare benign tumor of the sellar and suprasellar region that often compresses the optic pathways, causing significant visual impairment in both children and adults. The early detection and monitoring of optic nerve involvement are essential for preserving visual function. Optical coherence tomography (OCT) and OCT angiography (OCTA) are noninvasive, high-resolution imaging modalities that provide quantitative assessment of retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC), and retinal microvasculature. Thinning of the RNFL and GCC correlates with visual field defects and reduced visual acuity and may also serve as a predictor of postoperative visual recovery. OCTA reveals microvascular alterations that may precede structural damage and, together with other imaging parameters, can be used to estimate the likelihood of visual improvement after neurosurgery. This review summarizes current evidence on the use of OCT and OCTA in CP, highlighting their applications in assessment of optic pathway involvement, preoperative evaluation, postoperative monitoring, and risk stratification. Based on our clinical experience, we propose a table with recommended OCT parameters and follow-up intervals. Importantly, OCT should be interpreted alongside the visual acuity, visual field testing, and fundus examination for comprehensive assessment. Future directions include the standardization of imaging protocols and prospective multicenter studies, and integration of OCTA metrics into predictive models of visual outcomes. OCT and OCTA provide objective, reproducible biomarkers that support individualized patient care and may improve visual prognosis in CP. Full article

Objectives: The aim of this study was to evaluate macular vessel area densities (superficial and deep) and foveal avascular zone (FAZ) measurements using OCT-A in the eyes of primary progressive multiple sclerosis (PPMS) patients receiving Ocrelizumab treatment with or without optic nerve involvement. Methods: The medical records of PPMS patients who received Ocrelizumab treatment at least once were reviewed. Retinal nerve fiber layer (RNFL) thickness measurements and OCT-A analysis were conducted on the PPMS patients and on age-matched healthy individuals. The patient group was divided into two subgroups: eyes with optic neuritis (PPMS+ON) and eyes without ON (PPMS-ON). Central and mean superficial vessel area (SVA) and deep vessel area (DVA) densities, as well as foveal avascular zone (FAZ) measurements, were analyzed. All parameters were statistically compared between groups and subgroups. Results: A total of 38 PPMS patients receiving Ocrelizumab treatment and 31 healthy individuals were included in this study. Statistically significant differences were observed between the groups in terms of best corrected visual acuity (BCVA), RNFL thickness, and the superficial vessel area densities for all parts except for the central part. In terms of deep vessel area densities, differences were found in the central and inferior parts. The mean FAZ area also showed a statistically significant difference between groups. Mean RNFL thickness differed significantly between the subgroups. Mean nasal, temporal, inferior part, and total superficial vessel area densities were statistically different between the subgroups. The central and inferior parts of the deep vessel area densities showed statistically significant differences. The mean FAZ area was also statistically different between the subgroups. Conclusions: The findings suggest that macular superficial and deep vascular densities are affected in PPMS patients receiving the same therapy modality and that previous optic neuritis may influence the results. 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: Anterior segment optical coherence tomography (AS-OCT) and optical coherence tomography angiography (AS-OCTA) have enhanced the evaluation of the cornea, ocular surface, and ocular surface diseases (OSD), offering high-resolution structural and anterior segment vascular imaging. This review summarizes recent advances in these modalities and their clinical applications. Methods: A comprehensive literature search was conducted using PubMed, Web of Science, and Google Scholar with the terms OCT, OCTA, anterior segment, and ocular surface disease. Studies published in the past five years were included, emphasizing more recent developments such as ultra-high-resolution AS-OCT (UHR-AS-OCT) and swept-source AS-OCTA technologies. Results: UHR-AS-OCT provides non-invasive, sub-micron imaging of the cornea and the ocular surface, including tear film morphology and epithelial thickness to correlate with clinical tests such as tear break-up time, and fluorescein staining. Advances in AS-OCTA allow dye-free, depth-resolved imaging of corneal and conjunctival vasculature. These vascular biomarkers have shown promising utility in conditions such as limbal stem cell deficiency, chemical ocular injury, and ocular surface squamous neoplasia. Improvements in image acquisition, motion correction, and segmentation algorithms have enhanced accuracy and repeatability, supporting broader clinical translation. Conclusions: AS-OCT and AS-OCTA have become useful adjunctive imaging tools for the cornea and ocular surface evaluation. Their non-invasive, quantitative, and reproducible metrics may enable earlier diagnosis, objective staging, and longitudinal monitoring of OSD. Integration of OCT-based imaging with artificial intelligence and multimodal data, including tear proteomics and meibography, may optimize personalized treatment for ocular surface disorders. 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/Objectives: Rosacea is a chronic inflammatory dermatosis that may involve the eye, causing surface and adnexal damage that can precede cutaneous signs. Detecting subclinical ocular changes is clinically important because early ocular surface dysfunction may be missed on routine examination yet progress to corneal complications, allowing earlier preventive management when identified. We prospectively evaluated subclinical ocular alterations in cutaneous rosacea using a combined, fully non-invasive high-tech imaging workflow—tear film interferometry, infrared meibography, and exploratory retinal optical coherence tomography angiography (OCT-A)—including patients without clinically evident ocular involvement. Methods: Sixteen patients with cutaneous rosacea (mean age 44.3 ± 11.2 years; 4 males, 12 females) were enrolled and divided into: Group 1—rosacea with clinically evident ocular involvement (n = 11); Group 2—rosacea without clinical ocular involvement (n = 5). Six age-matched healthy subjects served as controls (Group 3). All underwent LipiView II^® interferometry and meibography to quantify lipid-layer thickness (LLT, nm) and meibomian gland (MG) loss score (1 = normal–4 = severe), plus retinal OCT-A (Optovue Inc., Fremont, CA, USA). ANOVA with post hoc Tukey test assessed inter-group differences. Results: OCT-A showed no significant alterations in superficial or deep retinal plexuses across groups (p > 0.05). Conversely, LLT was significantly reduced in both rosacea groups vs. controls (OD: 45.5 ± 21.4 nm and 67.4 ± 10.1 nm vs. 92.7 ± 8.2 nm; OS: 40.4 ± 15.3 nm and 66.4 ± 10.1 nm vs. 96.0 ± 6.7 nm; p < 0.001). MG score was markedly higher (worse) in rosacea (OD: 3.63 ± 0.50 and 3.20 ± 0.83 vs. 1.83 ± 0.75; OS: 3.45 ± 0.68 and 3.40 ± 0.54 vs. 1.66 ± 0.81; p < 0.001). Ocular symptoms were reported by 85% of patients yet slit-lamp examination revealed surface alterations in 58% of asymptomatic cases. Conclusions: Tear film interferometry and meibography detect early ocular surface impairment in rosacea—even in the absence of clinical signs—while retinal microvasculature appears unaffected. Routine ophthalmologic screening of all rosacea patients could enable prompt treatment of subclinical dysfunction, potentially preventing corneal complications. Retinal OCTA metrics were not significantly different in this small pilot cohort, and these negative findings should be interpreted cautiously pending larger studies. 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: Our study aimed to evaluate whether OCTA can detect retinal dysfunction in hypertensive patients with atherosclerotic plaque in order to improve early detection of vascular changes and to better adjust treatment protocols. Therefore, we can potentially reduce the rate of ocular, cardiovascular and cerebral complications of hypertension and of dyslipidemia. Methods: We performed a study on hypertensive patients with dyslipidemia undergoing specific treatment. Ten OCTA parameters, the presence of carotid plaque on carotid Doppler ultrasound and three types of antihypertensive drugs were analyzed. An increased carotid intima-media thickness (IMT) (≥1.0 mm) or the presence of carotid plaque was defined as subclinical atherosclerosis. We correlated classes of medication with OCTA parameters and with Doppler assessment. Results: In the final study, we included 196 eyes of 98 patients; 51 subjects had carotid plaques. Three groups were formed: antihypertensive monotherapy, including Angiotensin-converting enzyme inhibitor (ACEI) or Calcium channel blocker (CCB) + statins, and combined antihypertensive therapy, including ACEI/Angiotensin Receptor Blocker (ARB) + statins. We found statistically significant results in the presence of atherosclerotic plaques as follows: increased avascular zone (FAZ) and decreased vascular flow area (VFA) in the ACEI group, increased FAZ Circularity and a reduction in Density Total in the CCB lot, higher values of non-flow area (NFA), FAZ Area and decreased Density Total in the ACEI/ARB group. Conclusions: The strongest correlations we found were between increased hypertension, decreased retinal microcirculation and the presence of atherosclerotic plaques in patients using combined antihypertensive therapy and statins. The results indicate that subjects with multiple therapies, advancing hypertensive retinopathy and atherosclerotic carotid plaques display a deficit in retinal vascularization. OCTA can provide early detection of microvascular changes in hypertension associated with dyslipidemia and carotid plaques. Thus, by correlating OCTA and carotid Doppler ultrasound, antihypertensive and statin therapy can be adjusted and disease risk stratification can be obtained. Full article