Search Results (1,156)

Background/Objectives: Corneal epithelial thickness (CET) alterations reflect distinct mechanisms in aqueous-deficient and evaporative dry eye disease (DED) subtypes. In this study, we compare the CET profiles between patients with Sjögren’s syndrome (SS) and those with meibomian gland dysfunction (MGD) to elucidate the underlying mechanisms. Methods: We retrospectively analyzed 30 patients with SS and 30 age- and sex-matched with MGD. Assessments included corneal staining, Ocular Surface Disease Index (OSDI), tear meniscus height (TMH), non-invasive breakup time, lipid layer thickness (LLT), and anterior segment optical coherence tomography (AS-OCT) CET mapping. Regional CET and superior–inferior asymmetry were compared. Results: The SS group exhibited higher corneal staining scores (2.18 ± 1.23 vs. 1.03 ± 1.18, p = 0.001) and lower TMHs (0.14 ± 0.06 vs. 0.18 ± 0.07 mm, p = 0.013), while the MGD group reported greater OSDI scores (40.39 ± 22.49 vs. 31.25 ± 22.81, p = 0.029). A significantly thinner central epithelium (p = 0.043) and localized inferior paracentral thinning (2–5 mm zone, p = 0.008) were noted in SS. Corneal staining was identified as the primary independent predictor of central and inferior CET reduction in both groups. In the MGD group, LLT was associated with the preserved inferior CET (p = 0.045) and superior–inferior thickness difference (p = 0.015). Conclusions: Distinct structural signatures are observed between DED subtypes. SS features central/inferior thinning from aqueous deficiency-mediated friction, whereas MGD shows a relatively preserved epithelial thickness influenced by LLT. Regional CET analysis may provide mechanistic insights into DED subtyping. Full article

Background: Meibomian gland dysfunction (MGD) is a major contributor to evaporative dry eye disease, yet reported prevalence estimates vary widely across studies, largely due to differences in diagnostic criteria, study populations, and settings. We conducted a systematic review and meta-analysis to synthesize available evidence on the prevalence of MGD in adults aged ≥40 years and to examine sources of heterogeneity across studies. Methods: We systematically searched PubMed, Web of Science, Scopus, and Google Scholar from inception to November 2025 for observational studies reporting the prevalence of MGD in adult populations. Random-effects meta-analysis of proportions was performed. Subgroup analyses were conducted by study setting and diagnostic approach. Between-study heterogeneity was quantified using the I² statistic. Results: Eight observational studies from Singapore, Spain, Russia, Iran, China, Japan, and New Zealand, comprising 20,518 participants, met inclusion criteria. Reported prevalence of MGD varied substantially across studies. The pooled prevalence estimate was 87.08% (95% CI: 65.32–96.02%); however, heterogeneity was extreme (I² > 99%), indicating substantial variability across populations and study methods. This pooled estimate should be interpreted with caution and not as a single representative global prevalence. Studies using clinical signs alone tended to report higher prevalence than those incorporating both signs and symptoms. Differences in study setting and diagnostic definitions accounted for a significant proportion of heterogeneity. Conclusions: MGD appears to be commonly detected in adults aged ≥40 years; however, prevalence estimates vary markedly depending on diagnostic criteria and study design. Given the extreme heterogeneity, pooled prevalence estimates should be interpreted with caution and not as a single global prevalence value. Standardized diagnostic definitions and population-based studies using harmonized methodologies are needed to generate more comparable and clinically interpretable estimates of MGD burden. Full article

Background: Graft-versus-host disease is the most common complication after allogeneic hematopoietic stem cell transplantation. While ocular graft-versus-host disease typically manifests as dry eye syndrome and anterior segment involvement, posterior segment complications are rare. Previously reported posterior segment complications in graft-versus-host disease have been limited to acute presentations with significant functional visual impairment. Methods: A 41-year-old man developed progressive retinal nerve fiber layer and ganglion cell layer loss four years after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia. The patient had established chronic graft-versus-host disease with cutaneous involvement and ocular surface disease. Results: Despite preserved visual acuity and visual fields, and only subtle functional involvement on visual evoked potentials, optical coherence tomography revealed significant reduction in retinal nerve fiber layer thickness and ganglion cell layer. Magnetic resonance imaging showed no optic nerve or brain abnormalities. Conclusions: This case describes an uncommon presentation of chronic, subclinical posterior segment involvement in chronic GVHD and suggests that optical coherence tomography may detect progressive structural retinal changes in the absence of clinically evident visual impairment, supporting its potential role in longitudinal monitoring. Full article

Background/Objectives: To evaluate the relationships between meibomian gland dysfunction (MGD), ocular surface parameters, and matrix metalloproteinase-9 (MMP-9)-mediated inflammation in glaucoma patients, we specifically assessed the impact of prostaglandin analogue use, preservative exposure, and number of medications. Methods: This retrospective cross-sectional study included patients treated with topical antiglaucoma medications for at least six months. Meibomian gland expressibility, meibum quality, and MGD grade were assessed along with tear film break-up time (TBUT), Schirmer I test, and Oxford staining score. Tear MMP-9 levels were measured using a Point-of-Care immunoassay (InflammaDry^®) and graded on a 0 to 4 scale. Results: Elevated MMP-9 grades were significantly correlated with worsening meibum expressibility, meibum quality, and MGD grade (all p < 0.001), whereas no significant associations were found with traditional parameters such as TBUT and Schirmer I test. Prostaglandin analogue use was associated with worse meibomian gland parameters and higher MMP-9 levels compared to non-use. Patients receiving preservative-containing medications exhibited poorer meibomian gland parameters and MMP-9 levels, as well as worse corneal staining scores. An increased number of medications was associated with a stepwise deterioration in meibomian gland function and elevated MMP-9 levels. Conclusions: Prostaglandin analogue use, preservative exposure, and increased number of medications are significant factors associated with the exacerbation of MGD and ocular surface inflammation. Semi-quantitative grading of tear MMP-9 revealed a stepwise association with meibomian gland dysfunction severity that was not detected by conventional dry eye metrics, indicating that MMP-9 may be considered a potential indicator of subclinical ocular surface inflammation in glaucoma patients. Full article

Here, we describe vision health in aging adults living with HIV (PLWH) and comparable people without HIV (PWOH) from the MACS/WIHS Combined Cohort Study (MWCCS). PLWH and PWOH aged 60 years and older were recruited from Baltimore/Washington, DC, from September 2021 to September 2023. Exact matching and sample weights were used to create age-balanced comparisons. Visual impairment (VA worse than 20/40 after refraction or CS worse than 1.50 logCS in the better eye) and the presence of eye pathology were assessed. We studied 74 PLWH (97% virally suppressed) and 65 PWOH, aged 61 to 79 years, 36% Black, and 87% male. For PLWH and PWOH, distance VA impairment was noted in 4% vs. 1%, respectively, and uncorrected refractive error in 15% vs. 5%. More than half had signs of dry eye disease (63% for PLWH and 51% for PWOH). About half of PLWH had developed at least an early stage of cataract, compared to 20% of PWOH. Posterior chamber abnormalities were observed in 4% and 0%, and glaucomatous changes in 19% and 25% of PLWH and PWOH, respectively. The need for eyecare was high among this sample of PLWH with viral suppression and PWOH. Full article

At present, the clinical management of ocular inflammatory diseases predominantly relies on chemically synthesized therapeutic agents. Although these therapies demonstrate established efficacy, their long-term use is associated with substantial economic burden. In addition, they may cause ocular side effects and systemic adverse reactions involving the cardiovascular, hepatic, and renal systems. In contrast, natural products have attracted increasing attention in recent years because many are accessible, relatively cost-effective, and potentially well tolerated. Studies indicate that various natural products exert anti-inflammatory and immunomodulatory effects by inhibiting inflammatory signaling pathways such as NF-κB and MAPK, regulating immune cell function and alleviating oxidative stress responses. These multifunctional properties support their potential therapeutic value in various inflammatory diseases. Notably, several natural products have shown potential benefits in clinical trials; however, their investigation and application in ocular diseases remain relatively limited. In this review, we focus on uveitis and dry eye disease (DED) as representative ocular disease models and systematically summarize the current research progress on four natural products—Paeonia lactiflora extracts, resveratrol and its derivatives, curcumin, and boswellic acids in experimental studies of ocular diseases. We particularly focus on their effects in alleviating ocular surface inflammation and intraocular inflammatory responses through their immunomodulatory mechanisms. This review aims to provide a mechanistic framework for understanding the potential role of natural products as complementary or alternative strategies to current therapeutic approaches, while informing the development of novel therapeutics and future research directions in ocular diseases. Full article

The ocular surface system, essential for maintaining visual function, is highly susceptible to a range of ocular surface diseases (OSDs) that significantly impair patients’ quality of life. Current treatments for OSDs often face limitations including low bioavailability, A lack of targeted delivery, and an inadequate capacity to fully address the complex pathophysiology involving inflammation, oxidative stress, and impaired tissue repair. In recent years, exosomes have emerged as promising cell-free therapeutic platforms for OSDs. This review evaluates their therapeutic potential across the OSD spectrum, focusing on three key aspects: mechanisms—modulation of inflammation, oxidative stress, and tissue repair via bioactive cargo; applications—preclinical therapeutic effects in dry eye disease, corneal injury, keratitis, and transplant rejection; and optimization strategies—engineering approaches and biomaterial integration to enhance stability, targeting, and ocular retention. We also discuss critical challenges in standardization, scalable production, and clinical translation, highlighting future directions for exosome-based OSD therapies. Full article

Background/Objectives: To investigate whether chronic cosmetics use near or directly on the eyelid margin contributes to tear film instability and meibomian gland dysfunction. Methods: Subjects were enrolled in one of three groups: those who rarely wear makeup (No-M), those who wear it frequently but only outside the eyelid margin (Min-M), and those who wear it frequently and directly on the eyelid margin (W-M). Subjects were assessed for dry eye signs and symptoms by a masked examiner. Lipid layer thickness (LLT), tear meniscus height, meibomian gland excreta grade, number of glands secreting, corneal and conjunctival staining and tear breakup time were assessed. Results: 10 No-M, 18 Min-M, and 21 W-M subjects completed the study. Average fluorescein breakup time was 4.6 s in each group (p = 0.839, 1-way ANOVA). There were higher scores (worse findings) in the marginal eyeliner sample for symptoms (modified Schein, OSDI, SPEED), Oxford and total NEI staining and lower lid meibomian secretions. The W-M group demonstrated a statistically significant increase in the meibomian gland excreta grade (a worsening) compared to the No-M group (mean grades 1.2 and 0.55 respectively; Tukey test, adjusted p < 0.05, 95% CI 0.055–1.187). LLT, tear breakup time, eyelid marginal signs, and meibomian gland dropout had no differences among groups. Conclusions: Eyeliner wear both outside and on the eyelid margin demonstrated increased ocular staining and decreased gland excretion quality, compared to non-makeup users. The meibomian gland excreta decrement may lead to worsening meibomian gland function and potentially glandular atrophy over time. Full article

Objectives: To assess diurnal changes, topographical differences, and day-to-day repeatability of ocular surface epithelial immune cell (EIC) density and morphology in dry eye disease (DED). Methods: Sixteen participants with moderate-to-severe DED (mean (SE) age 49.4 (4.2) years) underwent in vivo confocal microscopy at three timepoints (day-1 morning and evening and day-2 morning) at six locations: central cornea, inferior whorl, inferior cornea, and temporal cornea, limbus and conjunctiva. Diurnal and topographical variation in EIC density and morphology were analyzed using linear mixed-effects models with adjusted pairwise comparisons. Day-to-day repeatability was assessed using the coefficient of repeatability (CoR) for density and Cohen’s kappa for morphology. Results: EIC density and morphology varied by location (p < 0.001) but not by timepoint at any location (p = 0.59–0.90). Density was highest at the inferior cornea (model-estimated mean: 101.2 (SE: 21.7) cells/mm²) and temporal limbus (104.3 (22.7) cells/mm²), and lowest at the central cornea (26.8 [5.1] cells/mm² and inferior whorl (38.3 [8.2] cells/mm²; all pairwise, p < 0.001). EICs with large bodies were more frequent in conjunctiva (100%), inferior cornea (94%), and temporal cornea (87%), than in central cornea (34%) and whorl (19%) (all p ≤ 0.007). EICs with dendrites, and with long dendrites were similarly distributed (p < 0.001). Bland–Altman analysis showed low mean bias and EIC density was more repeatable at the central (CoR ± 23.8 cells/mm²) and temporal cornea (±27.5 cells/mm²) than the inferior cornea (±47.9 cells/mm²) or temporal conjunctiva (±42.3 cells/mm²). Morphology agreement was substantial to near-perfect (κ = 0.71–0.97). Conclusions: In DED, EIC density and morphology are diurnally stable and maintain topographic distribution patterns similar to healthy eyes. Day-to-day repeatability show location dependent patterns. The study provides feasibility data for using IVCM for EIC metrics in disease monitoring. Full article

Dry eye disease (DED) is a complex, multifactorial, progressive disease that has consequences both for individuals and society. Symptoms reported by patients include discomfort in the eye and periodic blurred vision, while in the broader perspective, the disease is associated with economic burdens and challenges for healthcare systems. Globally, dry eye disease remains a growing problem observed in many countries. It is estimated that symptoms of dry eye syndrome occur in approximately 10 to 20 per cent of people over the age of 40. This prevalence is on the rise, which is associated with both the aging population and increased incidence among younger adults. In this group, factors such as contact lens wear and prolonged use of digital devices are considered to be contributing factors. Further epidemiological studies, conducted in different regions of the world, covering diverse populations and a wide range of age groups, with a particular focus on younger cohorts, may contribute to a more accurate understanding of the prevalence of dry eye disease. There are more and more methods of diagnosing DED. In addition to well-known procedures like the Schirmer test or tear break-up time, there are also methods that focus on the evaluation of the tear film or imaging of the ocular surface. Moreover, usage of artificial intelligence is also playing a significant role in it. However, the key issue in individual cases is introducing the most effective treatment based on combining available substances, including corticosteroids, antibiotics and supplements, which leads to a reduction in inflammation and improvement in visual comfort. Full article

Ocular diseases pose significant therapeutic challenges due to the eye’s intricate anatomy and efficient physiological clearance mechanisms, which result in the rapid elimination of topically administered drugs and an overall bioavailability of less than 5%. Anterior segment disorders—including keratitis, glaucoma, and dry eye syndrome—account for the majority of ophthalmic conditions and are primarily managed with pharmacological agents. However, due to extremely low drug bioavailability and poor patient compliance, their therapeutic outcomes often result in a decreased disease control rate or require early surgical interventions. Nebulized drug delivery, particularly employing advanced vibrating mesh technology, has emerged as a promising strategy to overcome these limitations. By converting liquid formulations into a uniform aerosol of micron-sized (1–10 μm) droplets, this approach achieves extensive and consistent coverage of the ocular surface, increases the absorption contact area, prolongs drug residence time, and ultimately enhances drug bioavailability. Preliminary clinical evidence indicates that nebulized therapies outperform traditional eye drops by achieving higher drug concentrations in the aqueous humor and demonstrating superior pharmacodynamic profiles and patient tolerability—particularly in conditions such as dry eye syndrome and glaucoma. This review presents a comprehensive overview of the mechanistic principles, technological advancements, and translational applications of nebulization-based ocular drug delivery systems. We place special emphasis on the integration of next-generation platforms that incorporate microelectromechanical systems (MEMS) and intelligent sensing technologies, enabling precision medicine approaches tailored to individual ocular pathophysiological characteristics. By bridging biomedical engineering and clinical ophthalmology, these innovations not only optimize existing therapeutic regimens but also pave the way for non-invasive delivery of complex biologics and gene therapies—potentially reshaping the landscape of anterior segment drug delivery. Full article

Dry eye disease (DED) is an ocular surface disorder characterized by tear film instability, inflammation, epithelial damage, and neurosensory abnormalities. Due to its multifactorial etiology and pathophysiology, conventional therapies that focus on lubrication and immunosuppression often fall short in addressing the neuropathic component of ocular pain experienced by a growing subset of patients. Recent developments in sensory neuroscience have highlighted the pivotal role of ion channels in mediating ocular surface homeostasis, pain signaling, and inflammation. This review examines the role of the following major ion channel families in the pathophysiology of DED and neuropathic ocular pain: transient receptor potential (TRP) channels, voltage-gated sodium (Nav) channels, and purinergic P2X receptors. The review details their anatomical distribution, molecular function, and responses to environmental stimuli such as heat, cold, osmolarity, and injury. Current treatments, such as artificial tears, anti-inflammatory drops, and systemic neuromodulators, are also reviewed in relation to their effects on ion channel modulation. Additionally, emerging therapies that directly target sensory transduction pathways are introduced. This review highlights the therapeutic potential of ion channel modulation in personalizing treatment for patients with ocular surface pain, particularly those with neuropathic features unresponsive to standard care. Full article

Background: Dry Eye Disease (DED) is a multifactorial disorder characterized by tear film instability and ocular surface inflammation. Murine models based on environmental stress are widely used to mimic evaporative DED, although many focus on limited disease features. This study aimed to provide an integrated characterization of ocular surface alterations induced by chronic desiccating stress. Methods: Adult mice were housed in a Controlled-Environmental Chamber (CEC) with low humidity and increased airflow for up to 21 days and sacrificed after 14 or 21 days. Corneal damage was assessed by fluorescein staining. Conjunctival histology was evaluated for epithelial morphology, goblet cell (GC) size, and mucin composition. Complement fractions C3 and C5a were assessed by immunohistochemistry. Expression of inflammatory markers (Major Histocompatibility Complex, Class II, DR, HLA-DR; interleukin-1β, IL-1β; tumor necrosis factor-α, TNF-α) was quantified by Real-Time PCR (RT-PCR) in corneal and conjunctival epithelium. Results: Fluorescein staining revealed progressive corneal epithelial damage over time. Histological analysis demonstrated conjunctival epithelial alterations characterized by a significant reduction in GC size and in neutral mucin-positive GCs, consistent with mucin remodeling of the ocular surface epithelium. Increased epithelial deposition of complement fractions C3 and C5a was observed, while molecular analysis confirmed upregulation of inflammatory markers, including HLA-DR, IL-1β, and TNF-α. Collectively, these findings indicate that the model captures key pathophysiological components of DED. Conclusions: The CEC model reproduces major features of evaporative DED, including epithelial damage, GC remodeling, immune activation, and inflammation. As a non-invasive desiccating stress model, it represents a relevant experimental platform for studying ocular surface inflammation and for preclinical evaluation of therapeutic strategies. Full article

Zanthoxylum planispinum var. dingtanensis (hereafter Z. planispinum) is a pioneer plant for the ecological restoration of karst rocky desertification, offering both ecological rehabilitation and economic benefits. Due to the combined pressure from soil degradation and fruit harvesting, nutrient depletion and quality decline have intensified. Therefore, investigating the effects of fertilization on pericarp yield and quality provides the scientific basis for its precise fertilization. This study examined a Z. planispinum plantation subjected to five treatments in 2021: no fertilization (CK); organic fertilizer + chemical fertilizer + sprinkler irrigation (T1); chemical fertilizer + sprinkler irrigation (T2); chemical fertilizer alone (T3); and legume (soybean) intercropping + chemical fertilizer + sprinkler irrigation (T4). It explored the intrinsic relationships between fruit quality and soil physicochemical properties, identified key soil factors, and conducted a comprehensive quality evaluation, providing a scientific basis for precise fertilization in karst regions. The results indicated that (1) whole-fruit water content ranged from 61.30% to 64.37%, showing no significant differences, while variations were observed in the other phenotypic traits. T1 exhibited the highest values for Hydroxy-β-sanshool (2.42 mg·g⁻¹), Hydroxy-ε-sanshool (0.80 mg·g⁻¹), essential oil content (8.57%), and fresh weight per plant (9.9 kg). After long-term soybean intercropping, pericarp thickness reached its maximum (0.45 mm), but the content of aroma compounds decreased significantly. Compared to the other four treatments, the unfertilized control (CK) showed significantly higher values for the pericarp dry weight ratio, proportion of closed-eye peppercorns, and relative content of d-limonene, with increases of 5.5–13.94%, 130.91–568.42%, and 8.74–14.46%, respectively. (2) An inhibitory effect was observed between pericarp numbing compounds and soil calcium/phosphorus levels, while the synthesis of aroma compounds was constrained by the soil C/N ratio. Soil P/K ratio was identified as the dominant factor affecting overall quality. (3) The comprehensive fruit quality index ranked as follows: T1 (1.2933) > T3 (0.666) > T2 (0.5285) > CK (−1.1555) > T4 (−1.2098). Therefore, the T1 treatment is recommended for promotion as the fertilization management practice for Z. planispinum plantations in karst regions. Full article