Search Results (683)

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

Objectives: Topical lubricants are the fundamental treatment for dry eye disease (DED). However, the molecular mechanisms underlying their efficacy remain unknown. Here, the protective effects of Thealoz^® Duo with 3% trehalose and 0.15% hyaluronic acid are investigated in DED patients by a longitudinal clinical study and subsequent elucidation of the tear proteome and cell signaling changes. Methods: Participants were classified as moderate to severe DED (DRY, n = 35) and healthy (CTRL, n = 23) groups. Specific DED subgroups comprising evaporative (DRYlip) and aqueous-deficient with DRYlip (DRYaqlip) were also classified. Only DED patients received Thealoz^® Duo. All participants were clinically examined before (day 0, T1) and after the application of Thealoz^® Duo at day 28 (T2) and day 56 (T3). Next, 174 individual tear samples from all groups at three time-points were subjected to proteomics analysis. Results: Clinically, Thealoz^® Duo significantly improved the ocular surface disease index at T2 vs. T1 (DRY, p = 1.4 × 10⁻²; DRYlip, p = 9.2 × 10⁻³) and T3 vs. T1 (DRY, p = 2.1 × 10⁻⁵; DRYlip, p = 1.2 × 10⁻⁴), and the tear break-up time at T3 vs. T1 (DRY, p = 3.8 × 10⁻²; DRYlip, p = 1.4 × 10⁻²). Thealoz^® Duo significantly ameliorated expression of inflammatory response proteins (p < 0.05) at T3, which was observed at T1 (DRY, p = 3.4 × 10⁻⁴; DRYlip, p = 7.1 × 10⁻³; DRYaqlip, p = 2.7 × 10⁻⁸). Protein S100-A8 (S100A8), Alpha-1-antitrypsin (SERPINA1), Annexin A1 (ANXA1), and Apolipoprotein A-I (APOA1) were found to be significantly reduced in all the DED subgroups. The application of Thealoz^® Duo showed the therapeutic characteristic of the anti-inflammatory mechanism by promoting the expression of (Metalloproteinase inhibitor 1) TIMP1 in all the DED subgroups. Conclusions: Thealoz^® Duo substantially improved the DED symptoms and restored the functionality of the tear lipid layer to near normal in DRYlip and DRY patients by ameliorating inflammation. Notably, this study unravels the novel mechanistic alterations underpinning the healing effects of Thealoz^® Duo in DED subgroups in a time-dependent manner, which supports the improvement in corresponding clinical attributes. Full article

Biological extracellular vesicles in tear fluids, such as exosomes, are thought to have physiological functions in the management of healthy ocular surface epithelium, including corneal epithelium. However, the physiological roles of tear extracellular vesicles in the ocular surface remain unclear. In this study, we investigated the physiological function of tear extracellular vesicles in mouse tear fluids in the ocular surface epithelium in vitro. Morphological analysis of the isolated extracellular vesicles from mouse tear fluids was performed using nanoparticle tracking analysis and transmission electron microscopy. The identified particles were characterised by immunoblotting for exosomal markers. After confirming the uptake of tear exosomes in cultured corneal epithelial cells, gene expression changes in mouse cultured corneal epithelial cells after tear exosome treatment were analysed. Immunostaining analysis was performed to confirm cell proliferation in the cultured corneal epithelial cells with tear exosome treatment. Tear fluids from mice contain nanoparticles with exosome-like morphologies, which express the representative exosomal markers CD9 and TSG101. The extracellular vesicles can be taken up by cultivated murine corneal epithelial cells in vitro and induce expression changes in genes related to the cell cycle, cell membranes, microtubules, and signal peptides. Treatment with the tear extracellular vesicles promoted cell proliferation of cultured murine corneal epithelial cells. Our study provides evidence that murine tear fluids contain extracellular vehicles like exosomes and they may contribute to the maintenance of the physiological homeostatic environment of the ocular surface. Full article

Background/Objectives: The purpose of this study was to clinically characterize the lacrimal functional unit (LFU) of patients with chronic ocular pain associated with dry eye disease (DED). Methods: Ninety-three participants were included in this cross-sectional study: 28 patients with chronic ocular pain associated with DED (pain-DED), 35 patients with DED but no pain (no pain-DED), and 30 subjects without DED or ocular pain (controls). The following examinations were performed: symptom questionnaires, visual function assessment, tear meniscus, ocular surface evaluation, meibography, corneal sensitivity, Schirmer test, and in vivo corneal confocal microscopy. Results: Both DED groups presented increased DED-related symptoms (p < 0.001), corneal staining (p < 0.001), Meibomian gland loss (p < 0.010), and dendritic cell density (p < 0.001) compared with controls. Comparing both DED groups, the pain-DED group showed higher DED-related symptoms (p < 0.002) and increased microneuroma density (p < 0.001). Additionally, significant positive correlations were observed between symptom questionnaires and corneal staining (vs. OSDI: r = 0.514, p < 0.001; vs. m-SIDEQ: r = 0.504, p < 0.001; vs. NRS: r = 0.361, p < 0.001; vs. WBFPRS: r = 0.317, p = 0.002), dendritic cell density (vs. OSDI: r = 0.429, p < 0.001; vs. m-SIDEQ: r = 0.440, p < 0.001), and microneuroma density (vs. NRS: r = 0.405, p < 0.001; vs. WBFPRS: r = 0.416, p < 0.001). Conclusions: Differences in the LFU, especially in the morphology of sub-basal corneal nerves, are related to the presence of DED and chronic ocular pain and, along with ocular clinical questionnaires, can help phenotype these patients. Full article

Background and Objectives: To clinically validate a semi-automatic measurement of Tear Meniscus Central Area (TMCA) to differentiate between Non-Aqueous Deficient Dry Eye (Non-ADDE) and Aqueous Deficient Dry Eye (ADDE) patients. Materials and Methods: 120 volunteer participants were included in the study. Following TFOS DEWS II diagnostic criteria, a battery of tests was conducted for dry eye diagnosis: Ocular Surface Disease Index questionnaire, tear film osmolarity, tear film break-up time, and corneal staining. Additionally, lower tear meniscus videos were captured with Tearscope illumination and, separately, with fluorescein using slit-lamp blue light and a yellow filter. Tear meniscus height was measured from Tearscope videos to differentiate Non-ADDE from ADDE participants, while TMCA was obtained from fluorescein videos. Both parameters were analyzed using the open-source software NIH ImageJ. Results: Receiver Operating Characteristics analysis showed that semi-automatic TMCA evaluation had significant diagnostic capability to differentiate between Non-ADDE and ADDE participants, with an optimal cut-off value to differentiate between the two groups of 54.62 mm² (Area Under the Curve = 0.714 ± 0.051, p < 0.001; specificity: 71.7%; sensitivity: 68.9%). Conclusions: The semi-automatic TMCA evaluation showed preliminary valuable results as a diagnostic tool for distinguishing between ADDE and Non-ADDE individuals. Full article

This study aimed to comprehensively review surgical interventions for ocular surface diseases (OSDs), including dry eye syndrome (DES), exposure keratopathy, Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and ocular graft versus host disease (oGVHD), and to highlight the indications, contraindications, outcomes, and complications of various oculoplastic procedures used in their management. A narrative review was performed based on expert-guided selection of relevant studies retrieved from PubMed, Scopus, and Web of Science. Relevant keywords included “ocular surface disease”, “dry eye syndrome”, “exposure keratopathy”, “thyroid eye disease (TED)”, “neurotrophic keratopathy (NK)”, “Stevens-Johnson syndrome”, “toxic epidermal necrolysis”, “punctal occlusion”, “tarsorrhaphy”, “botulinum toxin”, “eyelid loading”, “retractor weakening”, “corneal neurotization (CN)”, “amniotic membrane transplantation (AMT)”, “conjunctival flap”, “ocular graft versus host disease”, and “salivary gland transplantation (SGT)”. Studies addressing surgical approaches for OSDs were included. In conclusion, surgical options for OSDs offer significant benefits when non-invasive treatments fail. Surgical techniques such as punctal occlusion, eyelid fissure narrowing, AMT, and conjunctival flap procedures help stabilize the ocular surface and alleviate symptoms. Advanced methods like CN and SGT target the underlying pathology in refractory cases such as oGVHD. The outcomes vary depending on the disease severity and surgical approach. Each procedure carries specific risks and requires individualized patient selection. Therefore, a tailored approach based on clinical condition, anatomical involvement, and patient factors is essential to achieve optimal results. Ongoing innovations in reconstructive surgery and regenerative medicine are expected to further improve outcomes for patients with OSDs. Full article

Corneal sensitivity is an important indicator of corneal health and innervation. Corneal hypoesthesia may be an early indicator of corneal diseases such as neurotrophic keratopathy. Various instruments have been used to measure corneal sensitivity, the first being the Cochet–Bonnet aesthesiometer. Over the years, new devices employing different stimuli have been developed, such as the gas-based Belmonte aesthesiometer, the Swiss liquid-jet aesthesiometer, and the most recently released corneal Brill aesthesiometer. In this review, the progress and advancement of aesthesiometers since their introduction is described. The mechanism, advantages, and disadvantages of these aesthesiometers are discussed and compared. We also report the relationship between corneal sensitivity and corneal innervation in various conditions, including diabetes mellitus, Fuchs’ endothelial dystrophy, dry eye disease, glaucoma, keratoconus, herpes simplex keratitis, post-refractive surgery, and ocular graft-versus-host disease. Through this review, we aim to highlight the importance of the assessment of corneal sensitivity and innervation in the diagnosis, treatment, and monitoring of anterior and posterior segment ocular disorders. Full article

Tear film alterations are commonly associated with ocular pathology. The tear film plays a vital role in maintaining the optical properties of the cornea and contains essential elements required for healing and preserving the integrity of the ocular surface. As a biological fluid, the tear film is easily collected using non-invasive techniques, making it a promising candidate for analysis and often referred to as an ideal biofluid. Several studies have attempted to identify biomarkers in the tear film that could be linked to systemic or ocular disorders, with the goal of developing tools for diagnosis or even early prevention. The quality and quantity of the tear film are influenced by hormonal status, emotional experiences related to social and familial events, and the work environment. Systemic disorders are often reflected at the ocular level through alterations in the tear film. Obesity is a well-recognized public health concern, extensively studied and investigated, much like other common systemic conditions. The presence of low-grade, chronic inflammation associated with excess body weight has been validated in several studies. The strategies for preventing obesity induced dry eye disease are based on regular physical activity, maintaining adequate hydration through sufficient fluid intake, weight loss, and the supplementation of essential fatty acids. This narrative literature review aims to highlight the tear film alterations associated with obesity. The article is intended for ophthalmologists, general practitioners, nutritionists, and researchers. Full article

Dry eye disease (DED) is a hallmark of primary Sjögren’s disease (SjD) and often resists conventional treatments like lubricant eye drops. Insulin nanoemulsions offer a potential solution by improving drug penetration and retention on the ocular surface. In animal models, insulin has shown benefits in promoting tear secretion and corneal healing. This study evaluated the safety and efficacy of insulin nanoemulsion eye drops (20 IU/mL, three times daily for 30 days) in patients with SjD. Thirty-two patients were randomized in a double-masked design to receive either insulin or placebo drops. Symptoms (assessed by OSDI questionnaire) and objective measures (tear film breakup time, corneal and conjunctival staining, and Schirmer Test) were recorded at baseline, after 4 weeks of treatment, and at a 4-week follow-up. Twenty-three participants completed the study. Both groups showed significant improvement in symptoms and objective signs after treatment (p < 0.05), but no significant differences were found between the insulin and placebo groups. No clinically relevant adverse effects were reported. Insulin nanoemulsion eye drops are safe for SjD patients, but their therapeutic advantage remains unclear. Further studies with larger samples, extended follow-up, and dose adjustments are needed to better understand their potential. Full article

Background/Objectives: Dry eye disease (DED) is a multifactorial condition with complex pathophysiology involving tear film instability, ocular surface inflammation, and nerve dysfunction. This review summarizes current evidence on the different available therapies targeting these mechanisms. Methods: A review of clinical studies evaluating treatment outcomes for therapies targeting aqueous tear deficiency, Meibomian gland dysfunction, ocular surface inflammation, and ocular pain was conducted, with an emphasis on randomized controlled trials and meta-analyses where available. Results: Artificial tears provide symptomatic relief with limited impact on tear film stability. Punctal plugs improve tear retention but show variable efficacy across studies. Treatments targeting MGD—such as lipid-based lubricants, eyelid hygiene, thermal pulsation (LipiFlow, iLux), and intense pulsed light (IPL)—demonstrate improvements in gland function, though outcomes vary. Anti-inflammatory agents including cyclosporine, lifitegrast, and short-term corticosteroids improve ocular surface signs, with mixed symptom relief. Biologic therapies like autologous serum tears and platelet-rich plasma show promise for both signs and symptoms, but data remain inconsistent. Nerve-targeted therapies, including oral neuromodulators (gabapentin, antidepressants), botulinum toxin, and transcutaneous nerve stimulation, have shown potential for managing neuropathic ocular pain, although randomized data are limited. Overall, variability in study designs, patient populations, and outcome measures highlights the need for more rigorous research. Conclusions: Personalized, mechanism-based treatment strategies are essential for optimizing outcomes in DED. Future research should prioritize well-designed, controlled studies to clarify the role of emerging therapies and guide the individualized management of this heterogeneous condition. Full article

Spaceflight-associated dry eye syndrome (SADES) has been reported among astronauts during both International Space Station (ISS) and Space Transportation System (STS) missions. As future missions extend beyond low Earth orbit, the physiological challenges of spaceflight include microgravity, radiation, and environmental stressors, which may further exacerbate the development of ocular surface disease. A deeper understanding of the underlying pathophysiology, along with the exploration of innovative countermeasures, is critical. In this review, we examine nanomedicine as a promising countermeasure for managing ophthalmic conditions in space, with the goal of enhancing visual health and mission readiness for long-duration exploration-class missions. Full article

Sjögren’s syndrome (SS) is a chronic autoimmune disease primarily affecting the lacrimal and salivary glands, characterized by ocular and oral dryness. Beyond exocrine dysfunction, SS may also involve multiple organs and systems, contributing to systemic complications that impair a patient’s quality of life. Among these, ocular inflammation represents a significant clinical challenge, manifesting as dry eye disease and other vision-affecting complexities. Despite advances in SS understanding, the inflammatory mechanisms driving ocular manifestations remain incompletely elucidated. This review aims to clarify the key inflammatory pathways underlying ocular complications in SS and the clinical implications. Additionally, it discusses both conventional and novel therapeutic strategies focusing on mitigating SS-associated ocular inflammation, including targeted immunomodulatory agents, regenerative medicine, and innovative drug delivery systems. By integrating current knowledge from recent studies, this review attempts to provide researchers and clinicians with a comprehensive resource for optimizing SS treatment approaches. The advancement of targeted therapies and emerging mitigation strategies holds promise for improving patient outcomes and enhancing SS management. Full article

Dry eye disease (DED) is characterized by tear film instability and oxidative stress-induced epithelial damage. This study was conducted to compare the therapeutic effects of 2% rebamipide (REB) and 3% diquafosol (DQS) on oxidative stress-related apoptotic damage of the ocular surface in DED. Human corneal epithelial cells (HCECs) were exposed to hyperosmotic stress in vitro and treated with REB or DQS. Cell viability and cleaved caspase-3 expression were evaluated using the MTT assay and Western blotting. DED was induced in vivo in C57BL/6 mice using subcutaneous scopolamine injection. Thereafter, the mice were assigned to normal control (NC), dry eye (DE), DQS-treated (DQS), or REB-treated (REB) groups. Clinical evaluations, including measurement of tear film break-up time, corneal smoothness, and the lipid layer, were performed on days 7 and 14. In addition, CD4⁺ IFN-γ⁺ T cells, inflammatory cytokines, reactive oxygen species (ROS), lipid peroxidation markers, and corneal apoptosis were analyzed on day 14. Glycocalyx integrity and goblet cell density were also evaluated. The results indicate that REB improved HCEC survival and suppressed cleaved caspase-3 expression more effectively than DQS (p < 0.05). Both treatments improved clinical outcomes in the murine dry eye model; however, REB showed superior efficacy in reducing ROS levels, lipid peroxidation, and apoptosis, and in preserving corneal glycocalyx integrity and conjunctival goblet cell density. These findings highlight the therapeutic potential and protective effects of REB against oxidative stress-related damage and apoptosis in DED. Full article

The ocular surface is susceptible to a wide spectrum of inflammatory, degenerative, and neurotrophic diseases that can impair vision. The complex pathophysiology and limited therapeutic options associated with these conditions continue to pose significant clinical challenges. Nerve Growth Factor (NGF), a neurotrophin initially recognized for its role in neuronal survival and differentiation, has emerged as a key regulator of ocular surface homeostasis and repair. Beyond its neurotrophic functions, NGF is suggested to influence epithelial proliferation, immune responses, tear secretion, and angiogenesis. Experimental and clinical studies have implicated NGF in both the pathogenesis and potential treatment of various ocular surface diseases, including allergic conjunctivitis, neurotrophic keratopathy (NK), immune-mediated and herpetic keratitis, and dry eye disease (DED), as well as post-surgical corneal wound healing. Notably, recombinant human NGF (rhNGF, cenegermin) has been approved as the first topical biologic therapy for NK. Despite encouraging clinical outcomes, challenges such as high treatment costs, limited long-term data, and potential proangiogenic effects remain. This review consolidates current evidence on the role of NGF in ocular surface health and disease, highlighting its biological mechanisms, clinical applications, and future therapeutic potential. Full article

Background/Objectives: Chronic neuropathic ocular pain (NOP) can manifest concurrently with dry eye (DE) symptoms following ocular surgical procedures. Due to its low prevalence, NOP remains an underrecognized and underdiagnosed postoperative complication, leading to suboptimal management. This study evaluated the long-term evolution of symptoms, signs, and tear biomarkers in patients with NOP and DE after corneal refractive surgery (RS). Methods: Patients with chronic NOP and persistent DE-related symptoms after corneal RS were assessed in two visits (V1 and V2), at least two years apart. Symptoms (DE, pain, anxiety, and depression) were measured with specific questionnaires. Clinical examination included a slit-lamp ocular surface evaluation, corneal sensitivity measurement, and subbasal corneal nerve plexus evaluation. Basal tear samples were collected, and a 20-plex cytokine panel and Substance P (SP) were assayed. Results: Twenty-three patients (35.57 ± 8.43 years) were included, with a mean time between visits of 4.83 ± 1.10 years. DE symptoms, measured with the Ocular Surface Disease Index questionnaire, improved at V2 (p < 0.001), along with a reduction in anxiety and depression levels, measured with the Hospital Anxiety and Depression Scale (p = 0.027). Corneal staining also decreased (p < 0.001), while subbasal nerve plexus parameters and corneal sensitivity remained unchanged. Tear analysis revealed increased concentrations of fractalkine/CX3CL1 (p = 0.039), interleukin (IL)-1 receptor antagonist (Ra) (p = 0.025), IL-10 (p = 0.002), and SP (p < 0.001). Conclusions: Symptom improvement may result from better control of underlying pathologies or natural disease progression. However, the increased levels of SP and fractalkine/CX3CL1 suggest sustained neurogenic inflammation, while elevated IL-1Ra and IL-10 indicate a potential compensatory anti-inflammatory response. Full article