Search Results (3,950)

Ascorbic acid (AA) or vitamin C is an important biomolecule that plays a crucial role in biological and physiological systems. Deficiency and/or excess of AA in the body can lead to severe diseases such as scurvy and gastrointestinal complications. Therefore, it is crucial to monitor the levels of AA in the body and supplements. Polyvinylpyrrolidone nickel oxide nanoparticles (PVP-NiONPs) are prepared and evaluated for their potential as nanozymes with peroxidase-like activity. o-Phenylenediamine (OPD) was used as a chromogen in the presence of hydrogen peroxide. The oxidized OPD was produced by ROS from PVP-NiONPs and H₂O₂. This was monitored using UV-vis spectra and by colour changes using the naked eye. AA reduced the oxidized OPD during its sensing. The UV-vis signal was linear for AA concentrations ranging from 40 µM to 400 μM. The limit of detection (LOD) for AA was calculated to be 0.11 μM using 3σ and the limit of quantification (LOQ) was 0.36 μM using 10σ indicating a very high sensitivity. The colorimetric sensor showed good reproducibility and a recovery rate between 92.3% and 102.6%, indicating high accuracy and reliability. The findings of this work confirmed that PVP-NiONPs possess enzyme-like activity and are a promising alternative for the quantitative, on-site detection of ascorbic acid. Full article

Ocular diseases like age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma and cataracts are major causes of visual impairment all over the world and are closely linked to oxidative stress, inflammation and mitochondrial dysfunction. This narrative review critically summarizes the available evidence on how various natural bioactive compounds, such as carotenoids, polyphenols, flavonoids, omega-3 fatty acids and botanical extracts, can affect important molecular pathways associated with ocular degeneration. Their antioxidant, anti-inflammatory, anti-angiogenic and neuroprotective properties are given particular emphasis, especially regarding the Nrf2, NF-κB and VEGF signaling pathways. This review is different from past reviews that simply discuss the potential of bioactives in the general nutritional context; rather, it unfolds the disease-specific mechanisms and compound-specific molecular actions and gives special attention to recent advances in nano-delivery systems and precision nutrition strategies to increase the bioavailability and therapeutic targeting of these nutrients in the eyes. Moreover, it offers a framework for a comparison of evidence between preclinical and clinical studies, as well as identifying current translational gaps, including limited bioavailability and a lack of long-term clinical trials, and suggesting future directions such as genotype-guided nutrition and microbiome-informed interventions. In general, this review provides a mechanistic and translational overview of how dietary bioactive compounds relate to eye health and offers the perspective of their possible use in prevention and complementary treatment for vision-related diseases. Full article

Background: Retinal and optic nerve disorders remain major causes of visual morbidity worldwide. Ocular fundus flavoprotein fluorescence (FPF) imaging has emerged as a potential noninvasive biomarker of mitochondrial dysfunction for earlier detection and evaluation of disease severity. Methods: We conducted a Systematic Scoping Review of the diagnostic and correlational utility of quantitative FPF parameters in retinal and optic nerve diseases compared with healthy controls. Following PRISMA-ScR guidelines, we searched MEDLINE, Web of Science, Scopus, and CENTRAL for peer-reviewed human studies available online before 31 December 2025. Results: Seventeen studies were included, encompassing 1914 eyes and 1339 participants, and were predominantly cross-sectional. In healthy eyes, mean macular and optic nerve head FPF intensity were reported as 24.1 ± 12.2 gsu and 30.6 ± 14.6 gsu, respectively. Higher signals were reported in several disorders, including diabetes mellitus (76.0 [67.0–92.0] gsu), neovascular age-related macular degeneration (67.47 ± 17.77 gsu), and retinitis pigmentosa (50.5 ± 12.2 gsu). However, lower, unchanged, or stage-dependent signals were also observed within the same disease categories. Interpretation across studies was limited by substantial heterogeneity in patient selection, disease definitions, imaging protocols, control groups, and FPF outcome metrics. The precise cellular and sublayer origin of the detected signal also remains challenging to determine. Conclusions: Ocular fundus FPF imaging provides promising metabolic insight into retinal and optic nerve diseases. However, current evidence remains heterogeneous and largely cross-sectional, limiting clinical interpretability and generalizability. Longitudinal studies, technical standardization, and multimodal integration are needed to define reproducible disease-specific FPF profiles and improve translational applicability. Full article

Lipid keratopathy is an uncommon corneal disorder characterized by stromal lipid deposition that may cause progressive corneal opacity and visual impairment. We report a case of advanced bilateral lipid keratopathy with severe visual-axis involvement. At presentation, best-corrected visual acuity (BCVA) was counting fingers in the right eye and 0.1 Snellen (1.0 logMAR) in the left eye. Slit-lamp examination and anterior segment optical coherence tomography (AS-OCT) demonstrated dense stromal lipid deposits involving the visual axis in both eyes. The patient underwent staged bilateral penetrating keratoplasty, with procedures performed three months apart. Postoperatively, corneal transparency improved in both eyes. At 6 months, BCVA was 0.5 Snellen (0.3 logMAR) in the right eye and 0.7 Snellen (0.15 logMAR) in the left eye. Residual visual limitation was attributed mainly to coexisting cataract, and sequential cataract surgery was planned. Together, the clinical photographs and AS-OCT scans illustrate an uncommon presentation of visually disabling bilateral lipid keratopathy, characterized by dense central stromal lipid deposition involving both visual axes and profound preoperative visual loss. The case is clinically noteworthy because it combines severe bilateral disease, close clinical–tomographic correlation, and sequential penetrating keratoplasty performed as a staged visual rehabilitation strategy, resulting in restoration of graft clarity and meaningful visual improvement during postoperative follow-up. Full article

Purpose: To evaluate the clinical efficacy and safety of eye drops containing lyophilized amniotic membrane (AM) in the treatment of dry eye disease (DED), with a focus on tear film stabilization and epithelial–immune balance. Methods: In this prospective cohort study, 40 patients (80 eyes) with DED were followed over six visits. The primary outcome was tear break-up time (TBUT). Secondary outcomes included corneal and conjunctival staining graded by the Oxford scale, meibomian gland parameters, corneal sensitivity (Cochet–Bonnet esthesiometry), best-corrected visual acuity, intraocular pressure (IOP), and Schirmer I test. Continuous variables were analyzed using repeated-measures ANOVA with Greenhouse–Geisser correction and Bonferroni post hoc testing; ordinal outcomes were analyzed using the Friedman test with Dunn–Bonferroni correction. Results: TBUT increased significantly in both eyes (OD: +5.3 s; OS: +4.9 s; both p < 0.001; ηp² ≈ 0.33). Corneal and conjunctival staining scores decreased (p < 0.001), meibomian gland quality and expressibility improved (p < 0.001), and corneal sensitivity increased (p < 0.001), while visual acuity and IOP remained stable. Schirmer I values showed no significant change. The combined pattern of changes (TBUT ↑, staining ↓, meibum/expressibility ↑, sensitivity ↑) indicates tear film stabilization and ocular surface improvement with a preserved safety profile. Conclusions: Lyophilized AM eye drops significantly prolong TBUT and improve clinical signs of DED, presumably by restoring the extracellular matrix (ECM) niche and the heavy-chain hyaluronan/pentraxin 3 (HC-HA/PTX3) complex, reducing proteolytic burden, and promoting a pro-resolving immune balance, with potential neurotrophic effects. These findings support the adjunctive use of AM-derived eye drops within contemporary TFOS DEWS II-based management algorithms for dry eye disease. Full article

Background/Objectives: To explore potential dry eye-related ocular surface functional alterations in women at the time of first diagnosis of endometriosis or adenomyosis in a real-world clinical setting. Methods: This was a cross-sectional case–control study. Patients were evaluated at the time of initial diagnosis, prior to initiation of any hormonal therapy, to reflect real-world clinical conditions. Participants underwent a standardized ocular surface assessment comprising the Ocular Surface Disease Index (OSDI) questionnaire, Schirmer test, and multimodal TearCheck^® analysis, including Non-Invasive Break-Up Time (NIBUT), Tear Film Stability Evaluation (TFSE), Meibography, and Abortive Blinking^®. Results: A total of 71 women were included: 41 with endometriosis or adenomyosis and 30 without known gynecological disease. Patients reported significantly higher OSDI scores than controls (p < 0.05). Objective testing demonstrated lower Schirmer values, reduced tear film stability, and more pronounced Meibomian gland dropout in the patient group (all p < 0.05). Differences were consistently observed across both subjective and objective parameters. Conclusions: Women with endometriosis and/or adenomyosis exhibited significantly altered ocular surface parameters compared with women without known gynecological disease. These findings suggest a possible association between gynecological disease and ocular surface dysfunction. Greater awareness of potential ocular involvement may encourage closer collaboration between gynecology and ophthalmology in the care of affected patients. Full article

Background/Objectives: To investigate the scleral inferior rectus–optic nerve distance (SIROND) and its association with intraocular pressure (IOP) elevation during upward gaze in patients with thyroid eye disease (TED), based on magnetic resonance imaging (MRI) examinations. Methods: This prospective study included 20 eyes (13 patients) diagnosed with active TED. All patients underwent orbital MRI in both primary and upward gaze positions before and 6 months after steroid pulse therapy. The SIROND was measured on MRI. IOP was recorded in both gazes. Changes in SIROND, inferior rectus (IR) muscle volume, proptosis, optic disc and scleral morphology, and IOP were analyzed pre- and post-treatment. Results: SIROND significantly decreased from primary gaze to upward gaze both before and after treatment (p < 0.001). Following steroid pulse therapy, there were significant reductions in IR muscle volume and proptosis (p < 0.05). Correspondingly, SIROND significantly increased in both primary and more in upward gaze post-treatment (p < 0.05). Although IOP during upward gaze was significantly higher than that in primary gaze both before and after treatment (p < 0.001), the gaze-related difference in IOP (p = 0.059), as well as SIROND, tended to be smaller after treatment (p < 0.001). A larger reduction in gaze-related pre-treatment SIROND was associated with greater IOP elevation in upward gaze (p = 0.038). MRI showed no evidence of globe compression by the IR muscle, and optic disc morphology remained unchanged following treatment. Conclusions: SIROND may serve as supportive radiological evidence for IOP elevation induced by upward gaze in patients with TED. Full article

Acute lymphoblastic leukemia (ALL) is a malignant neoplasm of the blood and bone marrow characterized by the uncontrolled proliferation of precursor cells of B- or T-lymphocyte lineage. Usually, the disease arises because of spontaneous mutations in bone marrow cells. Risk factors include genetic predisposition, exposure to ionizing radiation, prior chemotherapy or radiotherapy, and certain environmental factors. Clinical manifestations may include recurrent infections, anemia, and an increased tendency toward bleeding and stroke. A 12-year-old boy presented to the emergency department with a sudden decrease in visual acuity in the right eye. Best-corrected visual acuity (BCVA) in the right eye was 0.02, and intraocular pressure (IOP) was 16 mmHg. Ophthalmologic examination revealed a macular hemorrhage in the right eye. Blood samples were obtained for laboratory analysis. Complete blood count demonstrated leukocytosis with a white blood cell (WBC) count of 362.58 × 10³/µL, thrombocytopenia with a platelet (PLT) count of 87 × 10³/µL, hemoglobin (Hgb) level of 8.7 g/dL, and a red blood cell (RBC) count of 3.46 × 10⁶/µL. The patient was subsequently referred to the Department of Pediatric Hematology, where the diagnosis of acute lymphoblastic leukemia of B-cell precursor origin was confirmed. Appropriate systemic therapy targeting the underlying disease was initiated. Full article

Exophiala endophthalmitis of exogenous origin is an exceptionally rare but severe ocular infection, characterized by diagnostic delays, limited therapeutic guidance, and frequently poor outcomes. Herein, we report one new case of an 80-year-old woman who presented with severe fungal keratitis progressing to endophthalmitis two years after an uncomplicated cataract surgery. The condition was initially misdiagnosed and treated with topical antibiotics and corticosteroids. By cultivation, microscopy, histopathological, and PCR analysis of the samples, Exophiala dermatitidis was identified as the causative agent. Despite targeted antifungal therapy with voriconazole, the disease rapidly progressed, resulting in corneal perforation and evisceration of the affected eye. The number of confirmed cases of this infection remains very limited. To address this gap, we conducted a structured review of all reported instances of exogenous Exophiala endophthalmitis, in which Exophiala dermatitidis emerged as the predominant causative species. Common predisposing factors included corneal barrier disruption, ocular surgery, diabetes mellitus, and corticosteroid use. Diagnostic confirmation was frequently delayed, and treatment outcomes varied. Amphotericin B-based regimens were associated with poor results, whereas voriconazole, particularly when combined with surgical intervention, demonstrated more favorable outcomes. Exogenous Exophiala endophthalmitis remains underrecognized, with limited evidence to guide management. This entity should be considered in postoperative or trauma-associated intraocular inflammation, and current evidence supports azole-based therapy combined with surgical intervention when indicated. Full article

Objectives: To validate claims-based algorithms for identifying thyroid eye disease (TED) cases and assess whether machine learning can improve case identification in a large, linked real-world dataset. Methods: Using a large, linked database from Komodo Health^® and Academy IRIS^® Registry, we evaluated six rule-based algorithms incorporating Graves’ disease (GD), eye symptoms and signs. The IRIS Registry’s curated data, based on confirmed TED diagnoses from medical notes, served as the reference standard. Additionally, we developed supervised machine learning models using demographic, diagnostic, procedural, and medication data. Feature selection was performed using recursive feature elimination to rank predictive codes and construct a simplified, interpretable model. Cross-validation was used to assess model performance and compare performance with the rule-based algorithms. Results: The rule-based algorithms demonstrated a trade-off between sensitivity and specificity, with some achieving high specificity but limited sensitivity. Algorithm 1 had the highest sensitivity (48.7%) but lower specificity (59.9%) and PPV (75.8%). Algorithms 2–5 demonstrated higher specificity (87.2–93.5%) but lower sensitivity (17.8–27.0%). Algorithm 6 improved sensitivity (33.4%) compared to Algorithms 2–5 while maintaining high specificity (86.8%) and a strong PPV (86.7%). Machine learning models demonstrated similar trade-offs. One model achieved improved specificity (77.2%) with sensitivity of 49.3%, outperforming Algorithm 1 in specificity while matching its sensitivity. Another model maximized specificity (91.7%) and PPV (89.8%) at a reduced sensitivity of 28.5%. These results highlight the flexibility of machine learning models in adjusting performance to address different research objectives. Conclusions: This study evaluated existing rule-based algorithms for identifying TED cases in claims data, revealing trade-offs between sensitivity and specificity. Machine learning models provide additional flexibility, allowing performance to be tailored to specific research use cases. While no single method consistently outperformed others across all metrics, both rule-based and machine learning approaches demonstrated value in improving TED case identification using real-world data sources. Full article

Rationale and objectives: Parkinson’s disease (PD) significantly affects visual function, especially convergence and eye movements, impacting tasks such as reading. The objective was to investigate preliminarily the impact of the use of digital visual training in PD patients with associated convergence insufficiency (CI). Materials and methods: Pre–post pseudo-experimental pilot study to evaluate the impact of a novel digital therapy system (video game for use on a mobile phone or tablet) in 13 patients with PD and CI, with a mean age of 67 years. A comprehensive visual assessment was performed before and after a 6-week home-based visual rehabilitation, including measurement of near point of convergence (NPC), near positive fusional vergence (PFV), oculomotor tests (NSUCO and King-Devick tests), and symptom assessments with two validated questionnaires (CISS and SQVD). Results: Treatment adherence was variable, ranging from 0.8% to 124.7%. Despite this, significant improvements were found after therapy in break (p = 0.022) and recovery points of the NPC (p = 0.007), as well as break (p = 0.003) and recovery points in near PFV (p < 0.001). In the NSUCO test, the total score improved significantly from 23.9 ± 4.2 to 26.2 ± 3.7 after therapy (p = 0.003). Furthermore, a significant reduction in the total King-Devick test time was observed, decreasing from 79.4 ± 28.8 s to 69.0 ± 21.5 s with therapy (p = 0.034). Finally, symptom questionnaire scores also decreased significantly with therapy (CISS p = 0.037, SQVD p < 0.001). Conclusions: The digital vision therapy system evaluated seems to improve oculomotor control and reduce visual symptoms associated with CI in PD patients. Studies with larger sample sizes and a control group are needed to fully validate the therapeutic effectiveness of this tool. Full article

Background/Objectives: General-purpose and domain-specific multimodal foundation models show considerable promise in medical image analysis. In this study, we evaluated the classification accuracy of diabetic retinopathy vs. normal fundus images using general-purpose conversational models (Gemini 3 Flash, GPT-5.2, and Pixtral-Large), a medical conversational model (MedGemma-1.5), and its image-encoder (MedSigLIP), as well as ophthalmology-specific models (RETFound and EyeCLIP). Methods: We applied zero-/few-shot to general-purpose conversational models, linear probing, and fine-tuning approaches to domain-specific models for evaluation purposes. Results: We found that the zero-shot accuracies for Pixtral-Large (70.7%) and fine-tuned RETFound (77.1%) were comparable but lower than those of GPT-5.2 (77.9%), MedGemma-1.5 (88.2%), and Gemini 3 (88.5%) as well as the fine-tuned EyeCLIP (85.8%) and MedSigLIP (94.8%). The accuracy gains from few-shot prompting were substantial for Pixtral-Large (+7.4%) but were limited for GPT-5.2 (+3.6%), Gemini 3 (−3.4%), and MedGemma-1.5 (−1.1%). Embedding-based linear probing further improved accuracy over fine-tuning for RETFound (+9.7%) and yielded only marginal gains for EyeCLIP (+2.3%) but did not benefit MedSigLIP (−0.8%). Overall, with minimal prompting enhancement, general-purpose conversational models such as Gemini 3 and GPT-5.2 achieved performance comparable to ophthalmology-specific models that were either fine-tuned or enhanced via embedding-based linear probing, but remained inferior to MedSigLIP and its conversational counterpart, MedGemma-1.5. Conclusions: The findings highlight a trade-off between specialization and flexibility, where domain-specific models provide higher accuracy and stability, while general-purpose multimodal models offer greater accessibility, adaptability, and interactive reasoning, serving as complementary tools for retinal disease screening and clinical decision support. Full article

Background: Dry eye disease (DED) is a multifactorial disease. Numerous risk factors might cause DED, including indoor air pollution, such as incense. Incense (Bakhoor) is widely used in many cultures, including Saudi Arabia, although its smoke contains toxic chemicals that pose serious health hazards. This research investigates the link between the Schirmer II test and tear fluid proteins in DED patients. The study focuses on identifying the ocular examinations, hypothesizing that incense smoke, particularly from synthetic types, exacerbates DED. Methods: This pilot cross-sectional study was conducted at King Abdulaziz Medical City (KAMC) in Jeddah, Saudi Arabia. Participants were recruited from the Cornea and Ophthalmology Clinics. Eye assessments analyzed tear protein concentrations, including tear collection using Schirmer II test strips and tear break-up time (TBUT). The study included DED patients who used incense. Tear fluid from the Schirmer test of 20 randomly selected patients was used for protein analysis of total protein, lactoferrin, and Immunoglobulin E. Inclusion criteria were male and female subjects aged 18 years or older, diagnosed with DED, and using incense. The sample size was 55 participants, selected via convenience sampling. Subjective data were collected through questionnaires, as well as objective data from the tear test and the sample and analyzed with SPSS. Descriptive and inferential statistics were used, with statistical significance set at p-value < 0.05. Results: The Ocular Comfort Index (OCI) categories showed that 21.8% had no symptoms, 40.0% had low symptoms, 30.9% had moderate symptoms, and 7.3% reported high symptoms. TBUT values and Schirmer test scores decreased with increasing OCI severity, with no statistical significance. The mean (SD) of total protein in the right and left eyes for high OCI was 7.19 (1.39) and 7.42 (0.91), respectively, with no statistical significance. The immunoglobulin E levels in the right and left eyes for high OCI were 301.71 (55.97) and 301.71 (47.14), respectively, with no statistical significance. The mean (SD) of lactoferrin in the right and left eyes for high OCI was 163.77 (10.42) and 159.43 (1.68), respectively, with no statistical significance. Conclusions: The study findings demonstrate alignment in incense-using patients between subjective OCI symptom scores and objective clinical diagnostic measures. Specifically, higher OCI scores are associated with lower TBUT and Schirmer II test values, as well as changes in tear biomarkers such as IgE and lactoferrin. These findings emphasize the potential of using simple screening methods combined with bioanalytical markers for early detection of ocular surface disease. This highlights the potential health risks associated with incense exposure, particularly for individuals predisposed to DED. The urgency for further research to explore the long-term effects of incense on ocular health and to raise awareness about its potential impact on populations with high incense usage cannot be overstated. Full article

Background/Objectives: This study aimed to evaluate the relationship between cumulative occupational exposure and ocular surface alterations in Colombian tomato farm workers, using data collected through a cross-sectional survey. In addition, the study sought to explore how occupational exposure duration may support risk stratification and targeted preventive strategies in this vulnerable population. Methods: A cross-sectional observational study was conducted involving 72 tomato farm workers in Colombia. Participants were grouped according to duration of agricultural work experience (<15 years vs. ≥15 years). Clinical assessments included slit lamp examination, tear film break-up time (BUT), Schirmer test, and fluorescein staining. Subjective symptoms were evaluated using the McMonnies Dry Eye Questionnaire. Ocular surface alterations, including conjunctival changes and Meibomian gland dysfunction, were documented and statistically analyzed between groups. Results: Workers with ≥15 years of experience reported significantly higher dry eye symptom scores (McMonnies mean = 8.19 ± 2.54) than those with <15 years (mean = 6.59 ± 2.61; p = 0.006). Schirmer test scores were lower in the experienced group (16.30 ± 11.48 mm vs. 22.71 ± 11.20 mm; p = 0.018), indicating reduced tear production. Bulbar conjunctival alterations and Meibomian gland obstruction were significantly more frequent in the experienced group (p = 0.002 and p = 0.013, respectively). No significant differences were found in BUT or eyelid findings. Conclusions: Long-term agricultural work was associated with increased dry eye-related symptoms and clinical signs of ocular surface compromise among Colombian tomato farm workers. From a personalized medicine perspective, occupational exposure duration may represent a useful risk-stratification factor to identify workers who could benefit from targeted screening, preventive counseling, protective interventions, and individualized follow-up. These findings support the implementation of tailored occupational eye health strategies to reduce cumulative ocular surface damage in vulnerable rural populations. Full article

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and newer dual-incretin therapies have become central to the treatment of diabetes mellitus and obesity, with benefits extending beyond glycemic control. Their expanding use has prompted growing interest in their potential ocular effects. Experimental data support plausible protective mechanisms, including reduction in oxidative stress and neuroprotective effects on retinal and optic nerve tissues. Clinical evidence, however, remains heterogeneous. In diabetic retinopathy, the main concern appears to be transient early worsening associated with rapid glycemic improvement rather than direct retinal toxicity. A potential semaglutide-associated signal for non-arteritic anterior ischemic optic neuropathy has raised concern, although the absolute risk appears low and causality remains unproven. Emerging studies also suggest possible beneficial associations with glaucoma, ocular surface diseases, and certain retinal vascular outcomes, whereas the evidence regarding age-related macular degeneration and cataract remains conflicting or preliminary. Overall, ocular outcomes associated with incretin-based therapies seem to reflect a complex interplay among drug-specific pharmacology, systemic metabolic changes, and individual patient susceptibility rather than a class effect. Baseline ophthalmic assessment and individualized follow-up may be advisable in selected high-risk patients. Further prospective ophthalmology-focused studies are needed to clarify long-term safety and identify the patients most likely to benefit or develop adverse events. Full article