Search Results (121)

Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality that can provide rich three-dimensional microvascular information of fundus in ophthalmic imaging. However, various imaging artifacts may be generated during OCTA data acquisition and processing, originating from a number of factors such as multiple light scattering, tissue motion, improper device operation and signal processing algorithms. Artifacts can detrimentally affect the qualitative interpretation of clinical pathologies and quantitative evaluation of vasculature parameters. This article firstly introduces the OCTA acquisition process and sources of artifacts, and then describes four different categories of artifacts in detail, mainly including light propagation and signal intensity-related artifacts, tissue motion artifacts, improper operation artifacts, and signal processing-related artifacts. Corresponding methods for the identification and processing of these artifacts are also presented. Furthermore, this article also details some recent progress in leveraging artificial intelligence (AI) technology in the identification and suppression of artifacts, showcasing its potential as a powerful tool in OCTA artifact processing. The development of artifact suppression techniques enables OCTA to reliably evaluate fundus diseases and monitor their progression. This development facilitates broader and deeper applications of OCTA in both research and clinics of ophthalmology. Full article

Background/Objectives: Exudative age-related macular degeneration (AMD) is a disease of choroidal neovascularization that causes blindness. Current treatments to preserve vision in this prevalent and blinding condition are repeat intraocular injections of anti-vascular endothelial growth factor medicines for a patient’s lifetime to preserve and prevent vision loss leading to blindness. Rifampicin, a small-molecule antibiotic, has previously been reported to exhibit anti-angiogenic properties and a topical safety profile that is well-tolerated. Based on this evidence, we investigated the feasibility of formulating rifamycin as an ophthalmic drop capable of delivering therapeutic concentrations to the posterior segment of the eye. Methods: Inhibition of neovascularization by administration of rifampicin was analyzed in the rat oxygen-induced retinopathy (OIR) and mouse laser-induced choroidal neovascularization (CNV) models. Pharmacokinetic (PK) studies were conducted in mice, rats, and rabbits by dosing various formulations containing rifampicin, and the compound was quantified by LC/MS analysis. Results: Results from dose escalation studies in the mouse laser-induced CNV model suggested the minimum effective dose of rifampicin required for inhibiting neovascularization in subretinal tissues to be 0.7 mg/kg, which is substantially lower than the 20 mg/kg dosage approved for infectious disease treatments. The previous studies did not report the minimum effective dose in the anti-angiogenesis effects. The effective area under the concentration-time curve (AUC) in the sub-retina was evaluated as 0.27 h·ng/mg. In rabbits, rifampicin was delivered to the sub-retina by a single topical application of various formulations in a dose-dependent manner. The topical application of the formulations containing 1% rifampicin, which was well-tolerated in clinical trials previously reported for ocular trachoma, achieved subretinal delivery approximately 2–32 times greater than the effective AUC. Plasma exposure of the compound by the topical application was evaluated to range approximately 0.5–10 ng/mL. Conclusions: Rifampicin was delivered to the sub-retina in rabbits with an efficiency greater than the effective dose required for inhibiting neovascularization. Limited amounts of plasma exposure by the topical application were detected. These results suggested the therapeutic potential of the rifampicin formulations for the topical treatment of exudative macular degeneration. Full article

This review provides a comprehensive evaluation of the current state of polyvinyl alcohol (PVA)-based membranes, emphasizing their significance in membrane technology for various applications. The analysis encompasses both experimental and theoretical research articles, with a focus on recent decades, aiming to elucidate the potential and limitations of different fabrication approaches, structure–property relationships, and their applicability in the real world. The review begins by examining the advanced polymeric materials and strategies employed in the design and processing of membranes with tailored properties. Fundamental principles of membrane processes are introduced, with a focus on general modeling approaches for describing the fluid transport through membranes. A key aspect of discussion is the distinction between the membrane performance and process performance. Additionally, an in-depth analysis of PVA membranes in various applications is presented, particularly in environmental fields (e.g., fuel cell, water treatment, air purification, and food packaging) and biomedical domains (e.g., drug delivery systems, wound healing, tissue engineering and regenerative medicine, hemodialysis and artificial organs, and ophthalmic and periodontal treatment). Special attention is given to the relationship between membranes’ characteristics, such as material composition, structure, and processing parameters, and their overall performance, in terms of permeability, selectivity, and stability. Despite their promising properties, enhanced through innovative fabrication methods that expand their applicability, challenges remain in optimizing long-term stability, improving fouling resistance, and increasing process scalability. Therefore, further research is needed to develop novel modifications and composite structures that overcome these limitations and enhance the practical implementation of PVA-based membranes. By offering a systematic overview, this review aims to advance the understanding of PVA membrane fabrication, properties, and functionality, providing valuable insights for continued development and optimization in membrane technology. Full article

Human space exploration presents an unparalleled opportunity to study life in extreme environments—but it also exposes astronauts to physiological stressors that jeopardize key systems like vision. Corneal health, essential for maintaining precise visual acuity, is threatened by microgravity-induced fluid shifts, cosmic radiation, and the confined nature of spacecraft living environments. These conditions elevate the risk of corneal abrasions, infections, and structural damage. In addition, Spaceflight-Associated Neuro-Ocular Syndrome (SANS)—while primarily affecting the posterior segment—has also been potentially linked to anterior segment alterations such as corneal edema and tear film instability. This review examines these ocular challenges and assesses current mitigation strategies. Traditional approaches, such as terrestrial eye banking and corneal transplantation, are impractical for spaceflight due to the limited viability of preserved tissues, surgical complexities, anesthetic risks, infection potential, and logistical constraints. The paper explores emerging technologies like 3D bioprinting and stem cell-based tissue engineering, which offer promising solutions by enabling the on-demand production of personalized corneal constructs. Complementary advancements, including adaptive protective eyewear, bioengineered tear substitutes, telemedicine, and AI-driven diagnostic tools, also show potential in autonomously managing ocular health during long-duration missions. By addressing the complex interplay of environmental stressors and biological vulnerabilities, these innovations not only safeguard astronaut vision and mission performance but also catalyze new pathways for regenerative medicine on Earth. The evolution of space-based ophthalmic care underscores the dual impact of space medicine investments across planetary exploration and terrestrial health systems. Full article

Mitochondria are vital organelles responsible for ATP production and metabolic regulation, essential for energy-intensive cells such as retinal ganglion cells. Dysfunction in mitochondrial oxidative phosphorylation or mitochondrial DNA (mtDNA) pathogenic variants can disrupt ATP synthesis, cause oxidative stress, and lead to cell death. This has profound implications for tissues such as the retina, optic nerve, and retinal pigment epithelium, which are dependent on robust mitochondrial function. In this review, we provide a comprehensive compilation of pathogenic variants in the mtDNA associated with various ophthalmic diseases, including Leber’s hereditary optic neuropathy, chronic progressive external ophthalmoplegia, Leigh syndrome, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, among others. We highlight the genetic variants implicated in these conditions, their pathogenic roles, and the phenotypic consequences of mitochondrial dysfunction in ocular tissues. In addition to well-established mutations, we also discuss the emerging evidence of the role of mtDNA’s variants in complex multifactorial diseases, such as non-arteritic anterior ischemic optic neuropathy, primary open-angle glaucoma, and age-related macular degeneration. The review aims to serve as a valuable resource for clinicians and researchers, providing a detailed overview of mtDNA pathogenic variants and their clinical significance in the context of mitochondrial-related eye diseases. Full article

Ophthalmic diseases such as glaucoma, age-related macular degeneration (ARMD), and optic neuritis involve complex molecular and cellular disruptions that challenge current diagnostic and therapeutic approaches. Advanced artificial intelligence (AI) and machine learning (ML) models offer a novel lens to analyze these diseases by integrating diverse datasets, identifying patterns, and enabling precision medicine strategies. Over the past decade, applications of AI in ophthalmology have expanded from imaging-based diagnostics to molecular-level modeling, bridging critical gaps in understanding disease mechanisms. This paper systematically reviews the application of AI-driven methods, including reinforcement learning (RL), graph neural networks (GNNs), Bayesian inference, and generative adversarial networks (GANs), in the context of these ophthalmic conditions. RL models simulate transcription factor dynamics in hypoxic or inflammatory environments, offering insights into disrupted molecular pathways. GNNs map intricate molecular networks within affected tissues, identifying key inflammatory or degenerative drivers. Bayesian inference provides probabilistic models for predicting disease progression and response to therapies, while GANs generate synthetic datasets to explore therapeutic interventions. By contextualizing these AI tools within the broader framework of ophthalmic disease management, this review highlights their potential to transform diagnostic precision and therapeutic outcomes. Ultimately, this work underscores the need for continued interdisciplinary collaboration to harness AI’s potential in advancing the field of ophthalmology and improving patient care. Full article

Corneal injury is prevalent in ophthalmology, with mild cases impacting vision and severe cases potentially resulting in permanent blindness. In clinical practice, standard treatments for corneal injury involve transplantation surgery combined with pharmacological therapy. However, surgical sutures exhibit several limitations, which can be overcome using tissue adhesives. With recent advances in biomedical materials, the use of ophthalmic tissue adhesives has expanded beyond wound closure, including tissue filling and drug delivery. Furthermore, the use of tissue adhesives has demonstrated promising outcomes in drug delivery, ophthalmic disease diagnosis, and biological scaffolds. This study briefly introduces common adhesion mechanisms and their applications in ophthalmology, aiming to increase interest in tissue adhesives and clinical ophthalmic treatment. Full article

Background/Objectives: Diabetes is a well-recognised factor inducing a plethora of corneal alterations ranging from dry eye to reduced corneal sensibility, epithelial defects, and reduced cicatrisation. This cohort study aimed to assess the efficacy of a novel ophthalmic solution combining cross-linked hyaluronic acid (CHA), chondroitin sulfate (CS), and inositol (INS) in managing diabetes-induced corneal alterations. Specifically, it evaluated the solution’s impact on the tear breakup time (TBUT), the ocular surface disease index (OSDI), and corneal sensitivity after three months of treatment. Additionally, the solution’s potential to promote wound healing was examined. Methods: Two different populations were retrieved from the database; the first one was composed of 20 diabetic subjects treated for three months with the ophthalmic CAH-CS (OPHTAGON srl, Rome, Italy), while the second group was composed of 20 diabetic subjects who did not want to use any eye lubricant or other treatment. The outcome measures were the TBUT, the OSDI score, and the corneal sensitivity measured using a Cochet–Bonnet aesthesiometer. To investigate the wound-healing properties, in vitro tests were conducted using two cell lines, comparing the results of scratch tests with and without the solution. Results: The results indicate that CHA-CS significantly improved the tear film stability, as evidenced by an increased TBUT and a reduction in dry eye symptoms reflected by lower OSDI scores. Moreover, the solution was associated with an enhanced corneal sensitivity in treated patients. In wound-healing assays, CHA-CS promoted cell motility, suggesting a supportive role in tissue repair compared to untreated cells. Conclusions: Collectively, the results suggest that CHA-CS could serve as an innovative tool for the treatment of diabetic patients with corneal alterations and delayed corneal sensitivity. Clinical trial registration number: Clinical Trial.gov NCT06573606. Full article

Introduction: During the COVID-19 pandemic, reducing aerosol-generating procedures became fundamental, particularly in ophthalmic surgeries traditionally performed under general anesthesia (GA). Regional anesthesia, such as sub-Tenon’s block (STB), is widely used in vitreoretinal surgeries, offering a safer alternative by avoiding airway manipulation. However, the altered orbital anatomy in patients with previous scleral explant surgery creates unique challenges to STB application. This study aims to evaluate the effectiveness, safety, and feasibility of STB in patients after encircling band surgery. Methods: This retrospective analysis included 46 patients with a history of scleral explant surgery, undergoing vitreoretinal procedures at the Bern University Hospital. All procedures were conducted under STB with either analgosedation or GA for additional support when required. An ophthalmic surgeon or an experienced anesthesiologist performed the STBs. Data collected included block success rate, procedural difficulty, incidence of chemosis, and patient satisfaction. The Institutional Ethics Committee approved this study, and all participants provided informed consent. Results: STB was successfully administered in 93.5% of cases, with only three unsuccessful blocks. Block placement was rated as easy in 55% of cases, moderately difficult in 28%, and difficult in 17%. Chemosis was observed in 24% of patients, with severe cases in only 4%. Patient satisfaction scores were high, with most patients expressing satisfaction with the STB procedure. Conversion to GA was required in only one case due to alcohol withdrawal-related agitation. Discussion: The high success rate and minimal complications suggest that STB is a feasible and safe alternative to GA in patients with prior scleral buckling surgery. The altered orbital anatomy presents potential challenges, including scar tissue and compartmentalization, which may lead to patchy anesthesia. However, the use of STB avoids the risks associated with GA and may be especially beneficial for elderly or frail patients. Future studies should further investigate the hemodynamic implications of STB in these cases and the potential for ultrasound-guided techniques to improve accuracy and safety. Full article

Local anesthetics are commonly used in ophthalmic surgery. However, their use can affect the healing process. This study aimed to investigate the potential impact of anesthetic substances at clinically relevant concentrations and incubation times (3 min), specifically oxybuprocaine (OBPC, 0.4%), lidocaine (LIDO, 2%), and bupivacaine (BUPI, 0.5%), either alone or supplemented with hylase (HYLA, 30 I.E.), on corneal epithelium structure, cell viability, and wound healing. To assess the potential cytotoxicity of these anesthetic substances, viability and colony-forming efficiency (CFE) assays were conducted using the human telomerase-immortalized corneal epithelial (hTCEpi) cell line. Additionally, the toxicity of these substances was evaluated using a 3D human tissue-specific corneal epithelial construct as well as a porcine corneal culture model. The results indicate that OBPC (Novesine^® 0.4%) exhibited significant cytotoxicity in 2D and 3D corneal epithelial cell culture models and delayed wound healing in the ex vivo porcine corneal organ culture model. In contrast, LIDO, BUPI, and HYLA were less cytotoxic to corneal cells, with no observed impact on wound healing in the porcine corneal organ culture model. In summary, local anesthetics commonly used in eye surgery are generally considered safe. However, the application of OBPC (Novesine^® 0.4%) may delay wound healing. Full article

Sjögren’s disease (SjD), or primary Sjögren’s syndrome (pSS), is a heterogeneous chronic autoimmune disorder with multiple clinical manifestations that can develop into non-Hodgkin’s lymphoma in mucosa-associated lymphoid tissue. SjD is one of the autoimmune diseases with the maximum delayed diagnosis due to its insidious onset, heterogeneous clinical features and varied course. It is increasingly recognized that extraglandular manifestations represent a clinical challenge for patients with SjD. The European League Against Rheumatism (EULAR) Sjögren’s Syndrome (SS) Disease Activity Index (ESSDAI) is a systemic disease activity index designed to measure disease activity in patients with primary Sjogren’s syndrome. It consists of 12 domains: cutaneous, pulmonary, renal, articular, muscular, peripheral nervous system, central nervous system, hematological, glandular, constitutional, lymphadenopathy and lymphoma, biological. More than a quarter of patients with pSS may have systemic features that are not included in the ESSDAI classification, i.e., various cardiovascular, ophthalmic, ENT, and other systemic or organ involvement that increase the magnitude of the systemic phenotype in the disease. The ESSDAI also excludes the gastrointestinal (GI) tract, and unfortunately, GI manifestations are not routinely assessed. Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal disorders, impairing quality of life and consuming a large volume of medical resources. Recently carried out the Mendelian randomized trial confirmed the causal link between SjD and gastroesophageal reflux disease (GERD) and showed that GERD is a risk factor for SjD. This review aims to provide an overview of the research describing evidenced based links between Sjögren’s disease and gastroesophageal reflux disease, with the intention of ensuring that any systemic pathology in Sjögren’s disease is properly assessed and that management of the disease is directed towards the patient. A comprehensive literature search was carried out on PubMed, Web of Science, Scopus and the Cochrane Library databases. Two researchers searched for published studies indexed from inception to 1 September 2024 using the keywords ‘Sjögren’s syndrome’ OR ‘Sjögren’s disease’ AND ‘gastroesophageal reflux disease’ AND ‘microbiota’ OR microbiota dysbiosis’. We limited our search for scientific articles to human studies, and only included articles in English. Overall, there is a lack of evidence-based studies assessing the association between GERD and Sjögren’s disease and the changes in the microbiota associated with GERD in a multidisciplinary setting. Such studies are needed for the future, as this will improve the early diagnosis of Sjögren’s disease and the personalized management of the disease. Full article

Plaque radiotherapy is an effective treatment modality for medium-sized ocular tumors such as uveal melanoma. The authors review the available literature and concisely summarize the current state of the art of ophthalmic plaque brachytherapy. The choice of radioisotope, which includes Ruthenium-106 and Iodine-125, depends on the intended treatment duration, tumor characteristics, and side effect profiles. Ophthalmic plaques may be customized to allow for the delivery of a precise radiation dose by adjusting seed placement and plaque shape to minimize collateral tissue radiation. High dose rate (HDR) brachytherapy, using beta (e.g., Yttrium-90) and photon-emitting sources (e.g., Ytterbium-169, Selenium-75), allows for rapid radiation dose delivery, which typically lasts minutes, compared to multiple days with low-dose plaque brachytherapy. The efficacy of Ruthenium-106 brachytherapy for uveal melanoma varies widely, with reported local control rates between 59.0% and 98.0%. Factors influencing outcomes include tumor size, thickness, anatomical location, and radiation dose at the tumor apex, with larger and thicker tumors potentially exhibiting poorer response and a higher rate of complications. Plaque brachytherapy is effective for selected tumors, particularly uveal melanoma, providing comparable survival rates to enucleation for medium-sized tumors. The complications of plaque brachytherapy are well described, and many of these are treatable. Full article

Dry eye disease is a multifactorial condition characterised by tear film instability, hyperosmolarity and ocular surface inflammation. Understanding the epidemiology of dry eye disease and recognising both modifiable and non-modifiable risk factors can assist eye care practitioners in assessing, treating, and managing patients with the condition. This review considers current knowledge surrounding its incidence and prevalence, as well as associated demographic, systemic, ocular, and iatrogenic, and lifestyle-related modifiable risk factors. Population-based prevalence estimates vary according to the diagnostic criteria used to define dry eye disease, as well as severity and demographic characteristics of the population. Considering recent data and variable population demographics, conservative prevalence estimates suggest that 10–20% of the population over 40 years of age report moderate to severe symptoms and/or seek treatment for dry eye disease. Individuals with specific non-modifiable demographic risk factors may be at increased risk of developing dry eye disease. Advanced age, female sex and East Asian ethnicity have been identified as key non-modifiable demographic features predisposing individuals to dry eye disease. Systemic conditions that have been associated with an increased risk of dry eye disease include migraine, Sjögren syndrome, connective tissue disorders, mental health disorders, diabetes mellitus and androgen deficiency. Medications that may contribute to this risk include antidepressants, antihistamines, and hormone replacement therapy. Ocular and iatrogenic risk factors of dry eye disease include blepharitis, Demodex infestation, ocular surgery, blink completeness, contact lens wear, and topical ophthalmic medications. A range of modifiable lifestyle factors that can increase the risk of dry eye disease have also been identified, including low humidity environments, digital screen use, quality of sleep, diet, and eye cosmetic wear. Dry eye is a common disease affecting millions globally. Increasing knowledge regarding its associated risk factors can better prepare the eye care practitioner to successfully manage patients with this ocular surface disease. Full article

A complete understanding of neural crest cell mechanodynamics during ocular development will provide insight into postnatal neural crest cell contributions to ophthalmic abnormalities in adult tissues and inform regenerative strategies toward injury repair. Herein, single-cell RNA sequencing in zebrafish during early eye development revealed keratin intermediate filament genes krt8 and krt18a.1 as additional factors expressed during anterior segment development. In situ hybridization and immunofluorescence microscopy confirmed krt8 and krt18a.1 expression in the early neural plate border and migrating cranial neural crest cells. Morpholino oligonucleotide (MO)-mediated knockdown of K8 and K18a.1 markedly disrupted the migration of neural crest cell subpopulations and decreased neural crest cell marker gene expression in the craniofacial region and eye at 48 h postfertilization (hpf), resulting in severe phenotypic defects reminiscent of neurocristopathies. Interestingly, the expression of K18a.1, but not K8, is regulated by retinoic acid (RA) during early-stage development. Further, both keratin proteins were detected during postnatal corneal regeneration in adult zebrafish. Altogether, we demonstrated that both K8 and K18a.1 contribute to the early development and postnatal repair of neural crest cell-derived ocular tissues. Full article