Search Results (1,349)

Blue-light stimulation of the optic disc has been suggested as a means of myopia prevention by activating dopaminergic amacrine cells via intrinsically photosensitive retinal ganglion cells. This prospective, adequately powered study investigated this approach by examining its effects on pattern electroretinogram (PERG) N95 amplitude and choroidal thickness (ChT), established biomarkers associated with retinal ganglion cell function and myopia progression, respectively. Forty-six healthy adults received one minute of 450 nm blue-light stimulation to either the optic disc or central retina of the right eye, with the fellow left eye serving as control. PERG responses were measured before and 20 min after stimulation (N = 15 per stimulation location), while ChT, using swept-source optical coherence tomography images, was measured before, 20, and 60 min after stimulation (N = 8 per stimulation location). Only retinal stimulation significantly increased PERG N95 amplitude (baseline 16.16 µV, post-stimulation 17.61 µV [p = 0.01]), whereas optic disc stimulation did not (baseline 18.71 µV, post-stimulation 18.81 µV [p = 0.76]). Neither optic disc nor retinal stimulation significantly changed ChT at any time point. No significant differences were observed between myopic and non-myopic participants. Our findings do not support the hypothesis that short-duration blue-light stimulation of the optic disc is a viable strategy to activate retinal dopaminergic pathways for myopia prevention. Full article

Recent advances in artificial intelligence (AI) have transformed ophthalmic diagnostics, particularly for retinal diseases. In this prospective, non-randomized study, we evaluated the performance of an AI-based software system against conventional clinical assessment—both quantitative and qualitative—of optical coherence tomography (OCT) images for diagnosing diabetic macular edema (DME). A total of 700 OCT exams were analyzed across 26 features, including demographic data (age, sex), eye laterality, visual acuity, and 21 quantitative OCT parameters (Macula Map A X-Y). We tested two classification scenarios: binary (DME presence vs. absence) and multiclass (six distinct DME phenotypes). To streamline feature selection, we applied paraconsistent feature engineering (PFE), isolating the most diagnostically relevant variables. We then compared the diagnostic accuracies of logistic regression, support vector machines (SVM), K-nearest neighbors (KNN), and decision tree models. In the binary classification using all features, SVM and KNN achieved 92% accuracy, while logistic regression reached 91%. When restricted to the four PFE-selected features, accuracy modestly declined to 84% for both logistic regression and SVM. These findings underscore the potential of AI—and particularly PFE—as an efficient, accurate aid for DME screening and diagnosis. Full article

Introduction: Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is a benign proliferation of the melanin-producing retinal pigment epithelium (RPE). Although often a benign and incidental finding, multifocal CHRPE may mimic lesions associated with familial adenomatous polyposis (FAP). Case Description: We describe an 8-year-old girl presenting with optic disc pallor and widespread multifocal bear track CHRPE observed bilaterally on dilated fundoscopy. Fundus autofluorescence (FAF) imaging showed uniform areas of hypoautofluorescence corresponding to the bear track lesions. Spectral domain optical coherence tomography (SD-OCT) demonstrated normal lamination without atrophy. The full-field electroretinogram (ffERG) was within normal limits. Whole-genome sequencing (WGS) revealed a likely pathogenic heterozygous variant in the STAG2 gene (c.3222dup, p.Ser1075IlefsTer12). Conclusions: We present a rare case of bilateral, panretinal bear track CHRPE in a child with a likely pathogenic variant in STAG2. Using multimodal imaging, we contrast bear track lesions of the retina with FAP-associated CHRPE. We also present possible ophthalmic manifestations in carriers of pathogenic STAG2 variants. Full article

This work presents an image processing algorithm for the segmentation of the personalized mapping of retinal nerve fiber layer (RNFL) bundle trajectories in the human retina. To segment RNFL bundles, preprocessing steps were used for noise reduction and illumination correction. Blood vessels were removed. The image was fed to a maximum–minimum modulation algorithm to isolate retinal nerve fiber (RNF) segments. A modified Garway-Heath map categorizes RNF orientation, assuming designated sets of orientation angles for aligning RNFs direction. Bezier curves fit RNFs from the center of the optic disk (OD) to their corresponding end. Fundus images from five different databases (n = 300) were tested, with 277 healthy normal subjects and 33 classified as diabetic without any sign of diabetic retinopathy. The algorithm successfully traced fiber trajectories per fundus across all regions identified by the Garway-Heath map. The resulting trace images were compared to the Jansonius map, reaching an average efficiency of 97.44% and working well with those of low resolution. The average mean difference in orientation angles of the included images was 11.01 ± 1.25 and the average RMSE was 13.82 ± 1.55. A 24-2 visual field (VF) grid pattern was overlaid onto the fundus to relate the VF test points to the intersection of RNFL bundles and their entry angles into the OD. The mean standard deviation (95% limit) obtained 13.5° (median 14.01°), ranging from less than 1° to 28.4° for 50 out of 52 VF locations. The influence of optic parameters was explored using multiple linear regression. Average angle trajectories in the papillomacular region were significantly influenced (p < 0.00001) by the latitudinal optic disk position and disk–fovea angle. Given the basic biometric ground truth data (only fovea and OD centers) that is publicly accessible, the algorithm can be customized to individual eyes and distinguish fibers with accuracy by considering unique anatomical features. Full article

Purpose: To investigate genotype–phenotype correlations in PRPH2-retinopathies in a cohort of 36 patients from the Oxford Eye Hospital and report on novel pathogenic variants. Methods: Clinical data, including best corrected visual acuities (BCVA), fundus autofluorescence (FAF), and optical coherence tomography (OCT) imaging, were analysed. Genetic testing was performed using next-generation sequencing (NGS). Results: In this cohort, 26 different PRPH2 variants, including 8 novel variants, were identified. Variants were clustered in the D2 loop of the protein. A diverse range of phenotypes were observed: pseudo-Stargardt pattern dystrophy (PSPD) (47.2%), adult-onset vitelliform macular dystrophy (AVMD) (22.2%), pattern dystrophy (PD) (25.0%), atypical macular dystrophy (2.8%), and retinitis pigmentosa (RP) (2.8%). The mean age of symptom onset was 44.0 ± 14.4 years. Mean BCVA was 0.20 ± 0.54 logMAR OD and 0.14 ± 0.29 logMAR OS at baseline and 0.33 ± 0.40 logMAR OD and 0.32 ± 0.40 logMAR OS after a mean follow up duration of 6.0 ± 3.2 years (range 1–11 years). A thickened ellipsoid zone (EZ) was noted in 34/36 patients with a mean EZ thickness of 44.3 ± 11.3 µm OD and 42.7 ± 11.6 µm OS. No clear genotype–phenotype correlations were observed. Conclusions: The significant phenotypic range described in this study is consistent with the previously reported phenotypic variability in PRPH2 retinopathy and emphasises the complexity of establishing genotype–phenotype correlations in this disease. The thickness of the EZ on OCT may serve as a useful biomarker in distinguishing PRPH2 retinopathy from other phenocopies. These findings contribute to improved understanding of PRPH2 retinopathy and help inform diagnosis and genetic counselling. Full article

Underwater fish image segmentation is the key technology to realizing intelligent fisheries and ecological monitoring. However, the problems of light attenuation, blurred boundaries, and low contrast caused by complex underwater environments seriously restrict the segmentation accuracy. In this paper, RetinalConet, an underwater fish segmentation network based on bionic retina dual-channel and multi-module cooperation, is proposed. Firstly, the bionic retina dual-channel module is embedded in the encoder to simulate the separation and processing mechanism of light and dark signals by biological vision systems and enhance the feature extraction ability of fuzzy target contours and translucent tissues. Secondly, the dynamic prompt module is introduced, and the response of key features is enhanced by inputting adaptive prompt templates to suppress the noise interference of water bodies. Finally, the edge prior guidance mechanism is integrated into the decoder, and low-contrast boundary features are dynamically enhanced by conditional normalization. The experimental results show that RetinalCoNet is superior to other mainstream segmentation models in the key indicators of mDice, reaching 82.3%, and mIou, reaching 89.2%, and it is outstanding in boundary segmentation in many different scenes. This study achieves accurate fish segmentation in complex underwater environments and contributes to underwater ecological monitoring. Full article

Syphilis is a systemic infection with a broad spectrum of ocular involvement that can affect every segment of the eye. Clinical presentations range from interstitial keratitis, conjunctivitis, episcleritis, and scleritis to anterior, intermediate, and posterior uveitis; acute syphilitic posterior placoid chorioretinitis; retinitis; retinal vasculitis; neuroretinitis; optic neuritis; exudative retinal detachment; and optic nerve dysfunction. These manifestations may occur at any stage of infection and are frequently nonspecific, contributing to diagnostic delays. Diagnosis requires a high index of suspicion and is established by combined non-treponemal and treponemal serologic testing, with cerebrospinal fluid analysis when neurosyphilis is suspected. Multimodal imaging, including optical coherence tomography, fluorescein angiography, fundus autofluorescence, and visual field testing, enhances the detection of subclinical and atypical diseases. Management mandates prompt intravenous penicillin G, with adjunctive corticosteroids to mitigate Jarisch–Herxheimer reactions and control inflammation; ceftriaxone or doxycycline serve as alternatives for penicillin-allergic patients. Long-term follow-up with serial serologies and neurologic evaluation is essential to detect relapse or progression to neurosyphilis. Despite effective therapy, diagnostic delays contribute to irreversible visual loss in a significant proportion of cases. This review integrates current knowledge on ocular syphilis, emphasizing its varied presentations and the importance of early recognition to prevent vision-threatening complications, and calls for multidisciplinary, mechanism-based research to optimize outcomes. We conducted a literature search in Pubmed and Embase for articles published between 2000 and 2025, using the terms “ocular syphilis,” “syphilitic uveitis,” and “neurosyphilis,” with a focus on epidemiology, clinical features, diagnostics, therapeutics, and co-infections. Full article

Background/Objectives: Glucagon-like peptide-1 (GLP-1) is an endogenous hormone with receptors widely expressed across multiple organs. GLP-1 receptor agonists (GLP-1RAs), primarily used for diabetes management, have demonstrated anti-inflammatory and antioxidant properties beyond glucose regulation. This study explores the protective effect of semaglutide, a GLP-1RA, in reducing oxidative stress and promoting wound healing in human dermal fibroblasts. Additionally, it assesses whether semaglutide offers the direct protection of retinal endothelial cells under oxidative stress. Methods: Human dermal fibroblasts and retinal endothelial cells were treated with semaglutide at concentrations ranging from 0 to 45 pg/mL for 24 h under oxidative stress induced by hydrogen peroxide (H₂O₂). Cell viability and ATP levels were measured via MTT and ATP assays. Apoptosis was evaluated using propidium iodide staining. Intracellular reactive oxygen species (ROS) and mitochondrial superoxide were assessed through confocal microscopy with specific fluorescent probes. Wound healing was tested using scratch assays, with closure monitored over time and quantified with ImageJ (version 1.51). Gene expression levels of antioxidants, extracellular matrix components, inflammatory cytokines, and MMPs (MMP3, MMP9) were determined via real-time PCR. Results: Semaglutide significantly improved cell viability and ATP production under oxidative stress (p < 0.001), while reducing apoptosis and intracellular ROS levels. It notably accelerated fibroblast wound closure, achieving near-complete restoration. Gene analysis revealed increased expression of antioxidant and ECM-related genes, along with decreased pro-inflammatory cytokines and MMPs, indicating reduced inflammation and enhanced tissue remodeling. Conclusions: Semaglutide offers robust antioxidative and cytoprotective effects in dermal fibroblasts and retinal endothelial cells, promoting wound healing. These findings highlight its therapeutic potential for diabetic foot ulcers and diabetic retinopathy, supporting further in vivo investigation. Full article

Presbyopia is a ubiquitous age-related condition characterized by reduced near focusing ability due to lenticular stiffening. Pharmacologic agents such as pilocarpine have re-emerged as a less-invasive treatment option by inducing miosis and thereby enhancing depth of focus. However, the optimal pharmacologically induced pupil size that balances improved near vision with sufficient retinal illuminance remains undetermined. In this work, we present for the first time a direct integration of advanced theoretical modeling with a systematic synthesis of clinical trial outcomes to define the optimal target pupil size for pharmacologic presbyopia correction. We modeled visual performance using the Visual Strehl Ratio of the Optical Transfer Function (VSOTF) and convolved images of optotypes across a range of pupil diameters from 1.5 mm to 3.5 mm. This combined optical–clinical approach allowed us to quantitatively compare modeled image quality and depth of focus predictions with real-world clinical efficacy data from pilocarpine-based interventions. Simulations showed that smaller pupil sizes (1.5–2.5 mm) significantly extended depth of focus compared to standard multifocal optics while maintaining image quality within acceptable limits. These findings align with clinical trials of pilocarpine formulations, which commonly achieve post-treatment pupil diameters in the 2.0–2.5 mm range and are associated with clinically meaningful gains in near vision. Our analysis uniquely demonstrates that these clinically achieved pupil sizes closely match the theoretically optimal 2.0–3.0 mm range identified in our modeling, strengthening the evidence base for drug design and patient selection. These results reinforce the role of pharmacologically controlled pupil size as a central target in presbyopia management. By explicitly linking predictive optical modeling with aggregated clinical outcomes, we introduce a novel framework to guide future pharmacologic development strategies and refine clinical counseling in the emerging era of presbyopia therapeutics. 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

Background and Clinical Significance: Central serous chorioretinopathy (CSCR) and hydroxychloroquine (HCQ) retinopathy can both cause outer retinal changes in systemic lupus erythematosus (SLE) patients treated with HCQ and corticosteroids. Differentiating between transient steroid-induced CSCR and irreversible HCQ toxicity is critical to avoid unnecessary discontinuation of essential therapy. Case Presentation: Three female SLE patients (ages 47, 41, and 37) on long-term HCQ (25, 9, and 6 years, respectively) and recent or ongoing low-dose prednisolone presented with unilateral OCT findings, parafoveal or pericentral photoreceptor defects, with the fellow eye unaffected. Review of clinical history and serial imaging revealed transient subretinal fluid in all cases, associated with recent corticosteroid use or dose escalation. Subsequent tapering or cessation of steroids led to resolution of the fluid, and earlier OCT scans confirmed normal outer retinal morphology, indicating that these changes were residual effects of resolved CSCR rather than HCQ toxicity. In Cases 1 and 2, the best-corrected visual acuity (BCVA) in the affected eye declined from 20/22 to 20/40 during the CSCR episode and improved to 20/30 and 20/25, respectively, after subretinal fluid resolution. In Case 3, by contrast, BCVA remained stable at 20/20 throughout the pre-, during-, and post-CSCR periods. Conclusions: Resolved CSCR can mimic HCQ retinopathy. These cases emphasize the importance of detailed medication history, serial multimodal retinal imaging, and comparison with prior and fellow-eye scans to distinguish resolved CSCR from HCQ retinopathy. Such thorough evaluation and careful differential diagnosis help ensure appropriate management—avoiding unnecessary HCQ discontinuation while protecting both ocular and systemic health. Full article

The retinal vasculature provides a unique and non-invasive window into the health of the circulatory system. Josef Flammer, a pioneer in ocular vascular research, was the first to systematically describe how the state of retinal blood vessels reflects broader cardiovascular health. Because the retina is the only part of the human body where blood vessels can be visualized non-invasively, it serves as a valuable proxy for understanding microvascular conditions elsewhere, including the heart, brain, and lymphatics. Recent work has shown that retinal vasculature can be used as a proxy for microcirculatory dysfunction in other body systems, and that treatment using medical doses of vitamins can restore microcirculation, easing symptoms in disorders as diverse as glaucoma, AMD, and lymphedema without the need of pharmacological agents. The advent of machine learning tools to read retinal images promises both early detection of conditions and simplified monitoring of treatment progression. Full article

Optical coherence tomography (OCT) is a leading imaging technique for diagnosing retinal disorders such as age-related macular degeneration and diabetic retinopathy. Its ability to detect structural changes, especially in the optic nerve head, has made it vital for early diagnosis and monitoring. This paper surveys techniques for ocular disease prediction using OCT, focusing on both hand-crafted and deep learning-based feature extractors. While the field has seen rapid growth, a detailed comparative analysis of these methods has been lacking. We address this by reviewing research from the past 20 years, evaluating methods based on accuracy, sensitivity, specificity, and computational cost. Key diseases examined include glaucoma, diabetic retinopathy, cataracts, amblyopia, and macular degeneration. We also assess public OCT datasets widely used in model development. A unique contribution of this paper is the exploration of adversarial attacks targeting OCT-based diagnostic systems and the vulnerabilities of different feature extraction techniques. We propose a practical, robust defense strategy that integrates with existing models and outperforms current solutions. Our findings emphasize the value of combining classical and deep learning methods with strong defenses to enhance the security and reliability of OCT-based diagnostics, and we offer guidance for future research and clinical integration. Full article

Optical coherence tomography (OCT) acquisitions often reduce lateral sampling density to shorten scan time and suppress motion artifacts, but this strategy degrades the signal-to-noise ratio and obscures fine retinal microstructures. To recover these details without hardware modifications, we propose MGFormer, a lightweight Transformer for OCT super-resolution (SR) that integrates a multi-granularity attention mechanism with tensor distillation. A feature-enhancing convolution first sharpens edges; stacked multi-granularity attention blocks then fuse coarse-to-fine context, while a row-wise top-k operator retains the most informative tokens and preserves their positional order. We trained and evaluated MGFormer on B-scans from the Duke SD-OCT dataset at $2\times$, $4\times$, and $8\times$ scaling factors. Relative to seven recent CNN- and Transformer-based SR models, MGFormer achieves the highest quantitative fidelity; at $4\times$ it reaches 34.39 dB PSNR and 0.8399 SSIM, surpassing SwinIR by +0.52 dB and +0.026 SSIM, and reduces LPIPS by 21.4%. Compared with the same backbone without tensor distillation, FLOPs drop from 289G to 233G (−19.4%), and per-B-scan latency at $4\times$ falls from 166.43 ms to 98.17 ms (−41.01%); the model size remains compact (105.68 MB). A blinded reader study shows higher scores for boundary sharpness (4.2 ± 0.3), pathology discernibility (4.1 ± 0.3), and diagnostic confidence (4.3 ± 0.2), exceeding SwinIR by 0.3–0.5 points. These results suggest that MGFormer can provide fast, high-fidelity OCT SR suitable for routine clinical workflows. Full article

Diabetic retinopathy (DR), a critical ocular disease that can lead to blindness, demands early and accurate diagnosis to prevent vision loss. Current automated DR diagnosis methods face two core challenges: first, subtle early lesions such as microaneurysms are often missed due to insufficient feature extraction; second, there is a persistent trade-off between model accuracy and efficiency—lightweight architectures often sacrifice precision for real-time performance, while high-accuracy models are computationally expensive and difficult to deploy on resource-constrained edge devices. To address these issues, this study presents a novel deep learning framework integrating depthwise separable convolution and a multi-view attention mechanism (MVAM) for efficient DR diagnosis using retinal images. The framework employs multi-scale feature fusion via parallel 3 × 3 and 5 × 5 convolutions to capture lesions of varying sizes and incorporates Gabor filters to enhance vascular texture and directional lesion modeling, improving sensitivity to early structural abnormalities while reducing computational costs. Experimental results on both the diabetic retinopathy (DR) dataset and ocular disease (OD) dataset demonstrate the superiority of the proposed method: it achieves a high accuracy of 0.9697 on the DR dataset and 0.9669 on the OD dataset, outperforming traditional methods such as CNN_eye, VGG, and UNet by more than 1 percentage point. Moreover, its training time is only half that of U-Net (on DR dataset) and VGG (on OD dataset), highlighting its potential for clinical DR screening. Full article