Search Results (592)

Diabetes mellitus (DM) is a chronic metabolic disorder that can induce systemic and ocular complications. Among the latter, an increase in central corneal thickness (CCT) has been reported, potentially affecting endothelial function and increasing the risk of ocular disease. This study aimed to determine the impact of DM on CCT and to assess its correlation with diabetes duration and glycosylated hemoglobin (HbA1c) levels. A systematic literature search was conducted in Web of Science (1980–2025) following a PICO-based strategy. Observational studies evaluating CCT in diabetic patients were included. Data were analyzed using a random-effects model. Statistical heterogeneity was assessed with χ² test, p values, and I² index. Publication bias was evaluated using Begg’s funnel plot and Egger’s regression test. Twenty-nine studies were included in the meta-analysis. Diabetic patients showed significantly higher CCT values compared to controls, particularly in those with long-standing DM (p < 0.001) and poor glycemic control (HbA1c, p < 0.001). Egger’s regression suggested an association between increasing CCT, disease duration, and HbA1c levels, while funnel plot asymmetry indicated potential publication bias. CCT appears to increase in patients with long-term DM and inadequate glycemic control. These findings highlight the relevance of CCT assessment as a potential indicator of corneal changes in diabetic patients. Full article

This comprehensive review examines the multifaceted interactions between influenza viruses and the ocular system, integrating viral pathogenesis, clinical manifestations, and vaccine-related considerations. Influenza A subtypes (H7, H1N1, H5N1) and influenza B viruses induce a spectrum of ocular complications, from mild conjunctivitis—predominantly associated with H7 avian strains—to sight-threatening disorders like uveal effusion syndrome, acute macular neuroretinopathy, and optic neuritis. Experimental evidence confirms viral replication in human corneal and retinal cells, with H7N7 demonstrating unique tropism for ocular tissues via NF-κB-mediated inflammatory pathways. Clinical cases highlight direct viral invasion and immune-mediated mechanisms, such as Vogt–Koyanagi–Harada disease exacerbation and retinal vasculitis. Rarely, influenza vaccination has been linked to oculorespiratory syndrome, uveitis, and demyelinating events, though large-scale epidemiological studies (e.g., WHO safety reports) confirm vaccines’ favorable risk–benefit profile, distinguishing true adverse events from temporal associations. This synthesis emphasizes the need for ophthalmologists to prioritize surveillance during influenza seasons, integrating diagnostic tools like conjunctival RT-PCR and optical coherence tomography. Future research should focus on defining viral receptor-binding mechanisms in ocular tissues and developing targeted therapies for severe retinopathies, while reinforcing vaccination as a cornerstone of public health despite rare ocular risks. Full article

Percocypris pingi was listed in the China Vertebrate Red List in 2015, and albino P. pingi exhibits remarkable ocular phenotypes due to melanin synthesis defects, including the deficiency of melanin granules in the iris and retinal pigment epithelium (RPE). However, the regulatory mechanism of pigment loss in the eyes of albino P. pingi has not yet been clarified. This study systematically revealed the potential mechanisms underlying the obstruction of ocular melanin synthesis in albino P. pingi through histopathological analysis, transcriptomics, and proteomics techniques. The results showed that the synergistic effects of abnormal H⁺ transport mediated by SLC45A2, excessive activation of retinol metabolism, and cytoskeletal transport disorders led to the inhibition of tyrosinase activity and retention of pigment granules, ultimately causing melanin deficiency in the eyes. This study first elucidates the molecular network of ocular albinism in fish from a multi-omics perspective, providing a new perspective for the mechanistic research of pigmentation disorders in vertebrates. Full article

Although conventional medicine has seen substantial progress in recent years, there is a growing interest in nutraceuticals, bioactive compounds derived from natural sources such as plants, fruits, and cereals, due to their potential therapeutic applications. These substances have garnered increasing attention for their capacity to support ocular health and to aid in the prevention and management of age-related eye disorders, including age-related macular degeneration (AMD), cataracts, and glaucoma. This review provides a comprehensive and detailed analysis of selected nutraceuticals related to ocular health and diseases. It aims to define their pharmacodynamic properties, to elucidate the molecular and cellular mechanisms underlying their effects and to critically evaluate the current evidence regarding their potential clinical applications. By integrating findings from both preclinical and clinical studies, this review seeks to offer insights into the role of these nutraceuticals in the prevention, management, and adjunctive treatment of various ocular disorders, thereby suggesting future research directions and clinical practice. Notable attention is given to their antioxidant, anti-inflammatory, and neuroprotective properties, which are believed to contribute to the preservation of visual function and the deceleration of disease progression. Elucidating the medicinal benefits of these compounds may open new pathways for complementary or alternative strategies in the prevention and treatment of ocular diseases. Full article

Background/Objectives: Chronic central serous chorioretinopathy (cCSC) is a vision-threatening disorder characterized by persistent subretinal fluid (SRF). While several treatment options exist, their efficacy varies, and optimal management remains uncertain. This retrospective pilot study aimed to evaluate the efficacy and safety of intravitreal brolucizumab in patients with symptomatic cCSC without pachychoroid neovasculopathy (PNV). Methods: In total, 15 eyes of 15 patients diagnosed with symptomatic cCSC without PNV were treated with a single intravitreal injection of brolucizumab. Patients were followed for six months. Primary outcomes included resolution of SRF and changes in central subfield thickness (CST) and subfoveal choroidal thickness (SCT). Best-corrected visual acuity (BCVA) and ocular safety profiles were also assessed. Results: Complete SRF resolution was observed in 14 of 15 eyes (93.3%) within six months. Mean CST significantly decreased from 317.13 ± 73.40 µm to 205.53 ± 20.17 µm (p < 0.001), and mean SCT from 475.87 ± 107.66 µm to 390.13 ± 121.67 µm (p < 0.001). BCVA improved in 12 eyes (80.0%) and remained stable in 3 eyes; however, the mean improvement (logMAR 0.34 ± 0.33 to 0.14 ± 0.13) was statistically significant (p = 0.007). No significant ocular adverse events were reported. Conclusions: Intravitreal brolucizumab may be an effective and safe treatment for reducing SRF and choroidal thickness in patients with cCSC without PNV. Larger, controlled studies are needed to validate these findings. Full article

Hydrogel-based vitreous substitutes have been considered as a potential solution for the treatment of retinal disorders, especially when the natural vitreous body is damaged due to trauma, disease, or surgery. With their high-water content, biocompatibility, and tunable mechanical properties, these hydrogels offer a promising alternative to traditional vitreous substitutes. This review explores the role of polymers and crosslinkers in the development of hydrogel-based substitutes, focusing on how these components contribute to the structure and function of hydrogels. The choice of natural polymers, such as hyaluronic acid and collagen, or synthetic ones, such as polyethylene glycol and polyvinyl alcohol, is crucial to mimic the transparency and flexibility of the vitreous body. Crosslinking methods, including physical, chemical, and enzymatic approaches, help control the gelation process and enhance the mechanical strength of the hydrogel. Furthermore, this review demonstrates how these hydrogels interact with biological tissues, which enhances biocompatibility, cell growth, and tissue repair. This review also discusses the challenges and future directions in improving these hydrogels, particularly in terms of long-term stability, integration with ocular tissues, and appropriate mechanical properties. Overall, hydrogel-based vitreous substitutes have significant potential to improve surgical outcomes and restore vision for patients with vitreous injury. Full article

Glaucoma is traditionally classified as an ocular disease characterized by progressive retinal ganglion cell (RGC) loss and optic nerve damage. However, emerging evidence suggests that its pathophysiology may extend beyond the eye, involving trans-synaptic neurodegeneration along the visual pathway and structural changes within central brain regions, including the lateral geniculate nucleus and visual cortex. In this narrative review, we have used the phrase ‘brain involvement’ to underscore central changes that accompany or follow retinal ganglion cell loss; we have not intended to redefine glaucoma as a primary cerebral disorder. Neuroimaging studies and neurocognitive assessments in adult glaucoma patients, primarily older individuals with primary open-angle glaucoma reveal that glaucoma patients may exhibit alterations in brain connectivity and cortical thinning, aligning it more closely with neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. This evolving neurocentric perspective raises important questions regarding shared mechanisms—such as mitochondrial dysfunction, chronic inflammation, and impaired axonal transport—that may link glaucomatous optic neuropathy to central nervous system (CNS) pathology. These insights open promising therapeutic avenues, including the repurposing of neuroprotective and neuroregenerative agents, targeting not only intraocular pressure (IOP) but also broader CNS pathways. Furthermore, neuroimaging biomarkers and brain-targeted interventions may play a future role in diagnosis, prognosis, and individualized treatment. This review synthesizes current evidence supporting glaucoma as a CNS disease, explores the mechanistic overlap with neurodegeneration, and discusses the potential clinical implications of glaucoma within a neuro-ophthalmologic paradigm. 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

Alzheimer’s disease (AD) is the leading cause of dementia worldwide and is becoming one of the most morbid diseases of this century. Recently, ocular research in AD has gained significance, as the eye, due to its close relationship with the brain, can reflect the presence of neurological disorders. Several studies have reported alterations in various ocular structures in AD, ranging from tear fluid to the retina. These changes, particularly in the retina and the optic nerve, along with cerebral atrophy affecting visual brain areas, may lead to visual dysfunctions. This narrative review summarizes and critically examines current evidence on these impairments and explores their possible underlying mechanisms. A decrease in visual acuity, contrast sensitivity, and color vision has been observed, primarily associated with retinal ganglion cell loss or damage. Furthermore, alterations in the visual field, ocular motility, and visual perception have been recorded, mainly resulting from cortical changes. These optical parameters frequently correlate with patients’ cognitive status. In conclusion, these findings highlight the importance of developing strategies to preserve visual function in these patients, helping to prevent further deterioration in their quality of life, and emphasize the potential of visual function assessment as a tool for diagnosis or predicting AD progression. Full article

Schizophrenia is a complex disorder that affects mental organization and cognitive functions, including concentration and memory. One notable manifestation of cognitive changes in schizophrenia is a diminished ability to scan and perform tasks related to visual inspection. From the three evaluable aspects of the ocular movements (saccadic, smooth pursuit, and fixation) in particular, smooth pursuit eye movement (SPEM) involves the tracking of slow moving objects and is closely related to attention, visual memory, and processing speed. However, evaluating smooth pursuit in clinical settings is challenging due to the technical complexities of detecting these movements, resulting in limited research and clinical application. This pilot study investigates whether the quantitative metrics derived from eye-tracking data can distinguish between patients with schizophrenia under treatment and healthy controls. The study included nine healthy participants and nine individuals receiving treatment for schizophrenia. Gaze trajectories were recorded using an eye tracker during a controlled visual tracking task performed during a clinical visit. Spatiotemporal analysis of gaze trajectories was performed by evaluating three different features: polygonal area, colocalities, and direction difference. Subsequently, a support vector machine (SVM) was used to assess the separability between healthy individuals and those with schizophrenia based on the identified gaze trajectory features. The results show statistically significant differences between the control and subjects with schizophrenia for all the computed indexes (p < 0.05) and a high separability achieving around 90% of accuracy, sensitivity, and specificity. The results suggest the potential development of a valuable clinical tool for the evaluation of SPEM, offering utility in clinics to assess the efficacy of therapeutic interventions in individuals with schizophrenia. Full article

This case report presents a unique constellation of symptoms—including dry eye disease, visual and general asthenia, sleep disturbances, and restless legs syndrome—in a patient with a recent history of coronavirus disease 2019 (COVID-19) infection. While these symptoms have individually been associated with either COVID-19 or long COVID, their concurrent presentation and the simultaneous, positive response across all manifestations to a combined therapeutic regimen have not been previously described in a single case. The patient demonstrated notable improvement in both ocular and systemic symptoms following a six-week treatment with topical tear substitutes and oral administration of melatonin, and a multivitamin supplement including B-complex vitamins, antioxidants, and neuroprotective agents (Colinplus Delta^®, Farmaplus Italia Srl, Via Giovanni Porzio 4, 80143 Napoli, Italy). This response suggests a possible shared pathophysiological mechanism underlying these manifestations, potentially involving post-viral neuroinflammation, immune dysregulation, oxidative stress, or autonomic dysfunction. This case report highlights the need for an increased awareness of the interconnected nature of ocular and neurological symptoms in long COVID and supports further research into non-invasive, multimodal treatment strategies for this emerging clinical spectrum. Full article

Introduction: Downbeat nystagmus (DBN) is an ocular motor disorder characterized by persistent to-and-fro eye movements with a slow phase directed upwards and a corrective fast phase downwards. DBN in the context of myelin oligodendrocyte glycoprotein-associated disorder (MOGAD) represents a rare clinical presentation. Case Presentation: A 24-year-old male with MOGAD presented with DBN, status epilepticus, and longitudinally extensive transverse myelitis (LETM). Intervention: The clinical course, diagnostic findings, and management approach are described in detail within the full report. Outcomes: The patient at follow-up was able to ambulate independently, and his nystagmus had improved. He continued to demonstrate transient DBN on supine positioning and head-shaking test. Conclusions: This case report contributes to the understanding of DBN as a manifestation of MOGAD. The accompanying literature review examines the neuroanatomy, pathophysiology, and emerging therapeutic approaches for DBN, providing context for this unusual presentation. Full article

Background/Objectives: Keratoconus is a progressive corneal disorder characterized by thinning and conical protrusion of the cornea, resulting in visual impairment. This study aimed to evaluate retrobulbar blood flow characteristics in patients with symmetric and asymmetric keratoconus and to compare these parameters with those of healthy individuals. Methods: Participants aged 18–40 years were recruited and categorized into three groups: symmetric keratoconus, asymmetric keratoconus, and healthy controls. Color Doppler ultrasonography was used to measure the pulsatility index (PI) and resistive index (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery (PCA). Retrobulbar hemodynamic parameters were analyzed and compared across groups using appropriate statistical methods. Results: The ophthalmic artery PI (oaPI) and central retinal artery PI (craPI) were significantly elevated in both symmetric keratoconus patients and the affected eyes of asymmetric keratoconus patients compared to the control group (p < 0.05). In contrast, the oaPI in the unaffected eyes of asymmetric keratoconus patients was significantly lower than that of controls (p < 0.05). Conclusions: The elevated oaPI and craPI values observed in keratoconus patients suggest that the disease may involve not only corneal structural abnormalities but also alterations in ocular blood flow. These findings may imply a potential vascular component in keratoconus pathophysiology. Full article

Cell-based therapies emerge as potential treatment options for various debilitating diseases. Preclinical research and clinical studies involving cells increased exponentially in the past decade. In addition to cell-based approaches, the use of extracellular vesicles (EVs), which are released by nearly all cell types, emerged as a promising cell-free alternative. Those approaches are also being explored in the field of ophthalmology. Several clinical trials involving EVs are underway to develop potential treatments for advanced ocular surface diseases, including corneal disorders, injuries, and dry eye disease. The cargo carried by EVs has been shown to include a diverse array of functional molecules such as transcription factors, cytokines, growth factors, mRNA, tRNA, rRNA, miRNA, and fragments of dsDNA. While the molecular composition of EVs is already well characterised, the specific activity of these molecules upon delivery to recipient cells remains poorly understood. In this review, we summarise recent studies investigating the bioactive molecules within EVs shown to influence or modulate cellular activity on the ocular surface. Among these, various miRNAs have most commonly been identified as therapeutic agents targeting distinct molecular pathways. The EVs studied were predominantly derived from various mesenchymal stem cells. Full article