Search Results (904)

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

The eye, a complex organ essential for visual perception, is composed of diverse cell populations with specialized functions; however, the complex interplay between these cellular components and their underlying molecular mechanisms remains largely elusive. Traditional biotechnologies, such as bulk RNA sequencing and in vitro models, are limited in capturing cellular heterogeneity or accurately mimicking the complexity of human ophthalmic diseases. The advent of single-cell RNA sequencing (scRNA-seq) has revolutionized ocular research by enabling high-resolution analysis at the single-cell level, uncovering cellular heterogeneity, and identifying disease-specific gene profiles. In this review, we provide a review of scRNA-seq application advancement in ocular physiology and pathology, highlighting its role in elucidating the molecular mechanisms of various ocular diseases, including myopia, ocular surface and corneal diseases, glaucoma, uveitis, retinal diseases, and ocular tumors. By providing novel insights into cellular diversity, gene expression dynamics, and cell–cell interactions, scRNA-seq has facilitated the identification of novel biomarkers and therapeutic targets, and the further integration of scRNA-seq with other omics technologies holds promise for deepening our understanding of ocular health and diseases. Full article

The cornea, the transparent anterior window of the eye, critically refracts light and protects intraocular structures. Corneal pathologies, including trauma, infection, chemical injury, metabolic diseases, genetic conditions, and age-related degeneration, can lead to significant visual impairment. While penetrating keratoplasty or full-thickness corneal transplantation remains a standard and effective intervention for severe corneal dysfunction, limitations in donor tissue availability and the risk of immunogenic graft rejection necessitate alternative therapeutic strategies. Furthermore, for cases of isolated epithelial disfunction, a full-thickness cornea graft may not be required or effective. This review examines the potential of corneal epithelial constructs derived from autologous stem cells with functional barrier properties for corneal reconstruction and in vitro pharmacotoxicity testing. In this review, we delineate the current limitations of corneal transplantation, the advantages of stem cell-based approaches, and recent advances in generating engineered corneal epithelium. Finally, we address remaining technical challenges and propose future research directions aimed at clinical translation. Full article

Platelet-rich plasma (PRP) is widely applied in veterinary regenerative medicine due to its rich composition of growth factors that promote tissue repair. However, the direct pro-angiogenic function of canine PRP (cPRP) has not been thoroughly validated through controlled in vitro and in vivo experimentation. Human umbilical vein endothelial cells (HUVECs) were used to assess cell proliferation, migration, and tube formation after exposure to cPRP. In addition, a rabbit corneal micropocket assay was employed to evaluate in vivo angiogenic responses. Treatment with 20% cPRP significantly enhanced HUVEC proliferation and migration and induced robust tube formation. In the in vivo model, we observed dose-dependent neovascularization, with the earliest vascular sprouting seen on day 1 in the 40% group. Both models consistently demonstrated that cPRP stimulates vascular development in a concentration-dependent manner. This study provides novel evidence of cPRP’s capacity to induce neovascularization, supporting its therapeutic value for treating nonhealing wounds in dogs, especially in cases involving chronic inflammation, aging, or immune dysregulation. These findings offer a scientific foundation for the broader clinical application of cPRP in veterinary regenerative practice. Full article

Background/Objectives: Infectious endophthalmitis is a vision-threatening complication of intraocular surgery and intravitreal injections. Standard treatment involves intravitreal antibiotics; however, concerns regarding multidrug resistance and vancomycin-associated hemorrhagic occlusive retinal vasculitis (HORV) highlight the need for alternative antimicrobial strategies. This study aimed to evaluate the clinical efficacy and safety of a protocol combining intravitreal injection of 1.25% povidone-iodine (PI) with intraoperative irrigation using low concentrations of vancomycin and ceftazidime. Methods: We retrospectively analyzed 11 eyes from patients diagnosed with postoperative or injection-related endophthalmitis. Six of the eleven cases received an initial intravitreal injection of 1.25% PI, followed by pars plana vitrectomy with irrigation using balanced salt solution PLUS containing vancomycin (20 μg/mL) and ceftazidime (40 μg/mL). A second intravitreal PI injection was administered at the end of surgery in all cases. Additional PI injections were administered postoperatively based on clinical response. Clinical outcomes included best-corrected visual acuity (BCVA), microbial culture results, corneal endothelial cell density, and visual field testing. Results: All eyes achieved complete infection resolution without recurrence. The mean BCVA improved significantly from 2.18 logMAR at baseline to 0.296 logMAR at final follow-up (p < 0.001). No adverse events were observed on specular microscopy or visual field assessment. The protocol was well tolerated, and repeated PI injections showed no signs of ocular toxicity. Conclusions: This combination protocol provides a safe and effective treatment strategy for infectious endophthalmitis. It enables rapid and complete infection resolution while minimizing the risks associated with intravitreal antibiotics. These findings support further investigation of this protocol as a practical and globally accessible alternative to standard intravitreal antimicrobial therapy. Full article

Background and Objectives: Posterior chamber phakic implantable contact lenses (Phakic-ICL) are widely used for refractive correction due to their efficacy and safety, including minimal corneal endothelial cell loss. The Collamer-based EVO+ Visian implantable contact lens (ICL), manufactured from Collamer, which is a blend of collagen and hydroxyethyl methacrylate (HEMA), has demonstrated excellent long-term biocompatibility and optical clarity. Recently, hydrophilic acrylic Phakic-ICLs, such as the Implantable Phakic Contact Lens (IPCL), have been introduced. This study investigated the material differences among Phakic-ICLs and their interaction with fibronectin (FN), which has been reported to adhere to intraocular lens (IOL) surfaces following implantation. The aim was to compare Collamer, IPCL, and LENTIS lenses (used as control) in terms of FN distribution and cell adhesion using a small number of explanted Phakic-ICLs. Materials and Methods: Three lens types were analyzed: a Collamer Phakic-ICL (EVO+ Visian ICL), a hydrophilic acrylic IPCL, and a hydrophilic acrylic phakic-IOL (LENTIS). FN distribution and cell adhesion were evaluated across different regions of each lens. An in vitro FN-coating experiment was conducted to assess its effect on cell adhesion. Results: All lenses demonstrated minimal FN deposition and cellular adhesion in the central optical zone. A thin FN film was observed on the haptics of Collamer lenses, while FN adhesion was weaker or absent on IPCL and LENTIS surfaces. Following FN coating, Collamer lenses supported more uniform FN film formation; however, this did not significantly enhance cell adhesion. Conclusions: Collamer, which contains collagen, promotes FN film formation. Although FN film formation was enhanced, the low cell-adhesive properties of HEMA resulted in minimal cell adhesion even with FN presence. This characteristic may contribute to the long-term transparency and biocompatibility observed clinically. In contrast, hydrophilic acrylic materials used in IPCL and LENTIS demonstrated limited FN interaction. These material differences may influence extracellular matrix protein deposition and biocompatibility in clinical settings, warranting further investigation. Full article

Background: Patients with primary angle-closure disease (PACD), those with no history of acute angle-closure glaucoma or laser iridotomy, rarely present with prominent corneal endothelial cell density (CECD) loss. To identify factors associated with decreased CECD in PACD, anterior segment parameters were compared in patients with PACD and normal CECD and patients with PACD and decreased CECD, using anterior segment optical coherence tomography (AS-OCT). Patients and Methods: Ten patients with PACD and CECD of less than 1500/mm² without a history of cataract surgery, acute angle-closure glaucoma, or prior laser glaucoma procedures were identified at the Kyorin Eye Center from January 2018 to July 2023. Patients with an obvious corneal guttata or apparent corneal edema were also excluded. Seventeen patients with PACD and normal CECD (normal CECD group) were used as the control. Simultaneous biometry of all anterior segment structures, including the cornea, anterior chamber, and iris, were assessed using a swept-source AS-OCT system. Results: Corneal curvature radius was significantly larger in the decreased CECD group compared with the corneal refractive power in the normal CECD group (p = 0.022, Mann–Whitney test). However, no significant differences were detected in other anterior segment morphology parameters. Multiple regression analysis with CECD as the dependent variable revealed that a large corneal curvature radius was a significant explanatory variable associated with corneal endothelial loss. Conclusions: Flattened corneal curvature may be a risk factor for corneal endothelial loss in patients with PACD. Full article

Lacrimal cysts (dacryops), which involve lacrimal tissue, are uncommon in dogs with an obscure/unclear pathogenesis. Compared to the current available literature, this report describes the clinicopathologic and immunohistochemical features of two cases of unusual dacryops in brachycephalic dogs. A three-year-old male Cane Corso was referred with a 1-month history of swelling ventromedial to the left eye associated with blepharospasm and epiphora. Furthermore, a severe lower and upper eyelid entropion and a deep corneal ulcer were present. B-mode ultrasonography and a CT scan revealed a subcutaneous cyst, closely adherent to the maxillary bone. Surgical removal and the correction of entropion were performed. No recurrence and/or complication was detected by seven-year follow-up. Histopathology revealed a cystic structure with single- to double-cell-layered, nonciliated, cuboidal epithelia. Alcian blue stain revealed rare, disseminated goblet cells admixed with epithelial cells. The epithelium was strongly Cytokeratin-positive by immunohistochemistry and appeared lined by several layers of smooth muscle actin (SMA)-positive myoepithelial cells. A 1-year-old male French Bulldog with a 3-month lesion of the third eyelid of the right eye. The lesion (15 mm × 7 mm) beneath the conjunctiva appeared pale-pink, smooth, and multilobulated. Excision was performed by blunt dissection through the conjunctiva on the palpebral surface of the third eyelid. Recovery was uncomplicated, and no recurrence has been noted at three-year follow-up. Cytology of the cystic fluid and histopathology and immunohistochemistry of the cyst wall revealed findings for case 1. To further characterize the SMA-positive spindle cells located directly beneath the cyst-lining epithelium, double-color immunofluorescence for SMA and p63 (a myoepithelial cell marker) was performed on the sample from case 2. The analysis revealed that the SMA-positive cells lacked p63 expression, indicating a non-myoepithelial phenotype. The histological findings in our cases are consistent with previous reports of canine dacryops. The positivity of immunohistochemical staining for SMA in cells directly beneath the epithelium of dacryops in the cases here described in two brachycephalic dogs is consistent with previous reports in dogs and horses but in contrast with a retrospective study about a human dacryops. These results support the conclusion that the pathogenesis of dacryops in dogs should exclude failure of ductular “neuromuscular” contractility. 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

Nepafenac is an anti-inflammatory drug used in ophthalmology, marketed as a suspension due to its low aqueous solubility. A solution formulation could provide better bioavailability than suspension and facilitate single unit doses, avoiding the use of preservatives which are required to maintain sterility in multidose packaging. In this study, solubilization of nepafenac was achieved in the presence of randomly methylated β-cyclodextrin (RAMEB) and the actual complexation was assessed by NMR and phase-solubility studies. It was also found that the addition of hydrophilic polymers plays an important role in allowing increased solubilization of nepafenac at the same cyclodextrin concentration. Compared to complexes of nepafenac with other cyclodextrins, only 5% RAMEB was sufficient to solubilize 0.3% (w/v) nepafenac, enabling for the first time the development of an ophthalmic solution that proved chemically and physically stable for 12 months at 25 °C. The formulated solutions of nepafenac were tested for cytotoxicity on human corneal epithelial cells (HCE-2) and the results suggest their potential as a valuable and safe alternative to the commercially available 0.3% (w/v) suspension of the drug. Full article

Background/Objectives: The aim of this study is to compare the parameters of the corneal endothelium in a group of patients with well-controlled type 2 diabetes (study group) to those of patients who do not have type 2 diabetes (control group). Methods: The study aims to compare the corneal endothelium parameters of 80 eyes (80 patients) with well-controlled type 2 diabetes to 80 eyes (80 patients) without type 2 diabetes. The endothelial cell density (ECD), percentage of hexagonal cells (%HEX), coefficient of variation in cell size (CV), and central corneal thickness (CCT) were recorded using a non-contact specular microscope (Nidek CEM-530, Nidek Co., Ltd., Gamagori, Japan). Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were also measured. Results: The groups were matched for age and sex. A significantly lower ECD value was observed in the group of patients with type 2 diabetes (2480.76 cells/mm² ± 303.48) compared to the control group (2629.64 cells/mm² ± 304.73) (p = 0.002). BCVA was also significantly lower in the study group (0.44 ± 0.18) compared to the control group (0.50 ± 0.19) (p = 0.049). No statistically significant differences were found between the groups in terms of IOP, CV, %HEX, and CCT. Conclusions: Patients with well-controlled type 2 diabetes exhibit a lower ECD compared to individuals without diabetes, even in the absence of advanced diabetic complications. These subtle changes may have clinical implications for preoperative evaluation and long-term management in diabetic patients. The other morphological parameters of the corneal endothelium remain comparable between the groups. Full article

Cataract surgery, while commonly considered a routine, highly effective, and generally low-risk ophthalmic procedure, has been associated with corneal endothelial cell loss (ECL), a phenomenon particularly pronounced in patients with type 2 diabetes mellitus (DM2). This increased susceptibility in diabetic patients is often attributed to pre-existing corneal abnormalities, including compromised structural integrity and reduced endothelial cell density. Additionally, metabolic stress factors inherent to diabetes, such as chronic hyperglycemia and associated oxidative stress, further exacerbate endothelial vulnerability. Consequently, diabetic patients may experience significantly greater endothelial cell loss during and after cataract surgery, necessitating targeted surgical strategies and careful perioperative management to preserve corneal health and visual outcomes. This paper aims to conduct an extensive and detailed review of the existing scientific literature to thoroughly investigate the relationship between ECL and cataract surgery in patients diagnosed with DM2. This study conducts a critical evaluation to elucidate the mechanisms contributing to high endothelial vulnerability in individuals with diabetes. It systematically compares the rates of ECL observed in diabetic and non-diabetic populations undergoing cataract surgery, examines molecular alterations following the procedure in patients with and without DM2, identifies key risk factors influencing surgical outcomes, evaluates the impact of various surgical techniques, discusses preventative measures, and examines the long-term consequences of ECL in this specific population. Furthermore, this review analyzes the existing research to identify gaps in knowledge and suggest potential directions for future investigations. Full article

Fuchs endothelial corneal dystrophy (FECD) is a progressive corneal disease characterized by corneal endothelial cell (CEC) loss and guttae formation. Elevated levels of Transforming Growth Factor-Beta 1 and 2 (TGF-β1/-β2) have been reported in the aqueous humor (AH) of FECD patients and have been implicated with abnormal extracellular matrix (ECM) production, endothelial-to-mesenchymal transition (EndoMT), the unfolded protein response, and cell death. However, how TGF-β signaling affects cell migration in FECD remains to be elucidated. In this study, we found that TGF-β2 levels were significantly elevated in the AH of FECD patients compared to controls. We performed bulk RNA sequencing on FECD CECs treated with TGF-β1 or TGF-β2 and identified the epithelial-to-mesenchymal (EMT) pathway as one of the top dysregulated pathways. We found that TGF-β1 and TGF-β2 increased EMT markers, filamentous-actin (F-actin) expression and produced more EMT-like phenotype in FECD and control CECs. We also observed that TGF-β1 and TGF-β2 significantly increased FECD CEC migration speed as detected by scratch assay and individual cell tracking and promoted individual cellular migration behavior. This study provides novel insight into FECD pathogenesis and how increased TGF-β signaling promotes EndoMT and alters cellular migration in FECD CECs. Full article

Limbal dermoids are congenital, benign, choristomatous growths affecting the corneal-limbal junction. Conventional excision techniques often result in persistent epithelial defects, corneal thinning, and vascularization due to sectoral limbal stem cell deficiency. This study investigated a novel surgical approach for limbal dermoid excision, utilizing Bowman’s membrane lenticule and autologous limbal stem cell transplantation, aimed at improving epithelial healing and visual outcomes. Thirty-four subjects (24 females, 10 males; mean age 8.33 ± 6.47 years) with limbal dermoids underwent the procedure. After dermoid excision, a Bowman’s membrane lenticule was placed over the defect and tucked 1 mm beneath the surrounding tissue. Sectoral limbal reconstruction was then performed using the AutoSLET technique. Pre- and postoperative assessments included visual acuity, corneal thickness, and epithelialization time. Statistical analysis employed paired t-tests. The mean epithelialization time was 3.36 ± 0.74 weeks, indicating rapid healing. Best-corrected visual acuity (BCVA) significantly improved from a preoperative mean of 0.136 ± 0.121 decimal units to a postoperative mean of 0.336 ± 0.214 decimal units (p < 0.001). Corneal thickness also demonstrated a significant increase, rising from a preoperative mean of 294 ± 49.68 microns to a postoperative mean of 484 ± 5.037 microns (p < 0.001). There is a transient edema below the Bowman lenticule observed in many cases, which resolves with deposition of granulation tissue. The findings suggest that the combined use of Bowman’s membrane lenticule and autologous limbal stem cell transplantation offers a promising surgical strategy for limbal dermoid excision. This technique promotes rapid epithelialization and leads to significant improvements in visual acuity and corneal thickness compared to conventional methods. The utilization of Bowman’s membrane as a natural basement membrane and the direct application of limbal stem cells facilitate enhanced epithelial healing and visual rehabilitation. While the study is limited by its small sample size, the results demonstrate the potential of this novel approach in managing limbal dermoids effectively. Full article

Background/Objectives: This retrospective observational study evaluates the efficacy of Descemetorhexis without Keratoplasty (DSO) compared to Descemet Membrane Endothelial Keratoplasty (DMEK) in the management of Fuchs Endothelial Corneal Dystrophy (FECD). The outcomes were compared in terms of the corneal anatomical changes, visual results, and complication rates between the two surgical techniques for FECD. Methods: We conducted a retrospective, descriptive, observational study including 31 eyes from 26 patients who underwent either DSO (n = 16) or DMEK (n = 15) at the Department of Ophthalmology, Hospital Arruzafa. Patients were included if they had complete follow-up data at baseline, 6 months, and 1 year post-intervention. Their clinical information was collected from medical records and complementary tests, including the Snellen visual acuity test, Pentacam corneal tomography, and specular microscopy. Results: The average time to achieve best corrected distance visual acuity (CDVA) was significantly longer for DSO (7.44 ± 2.3 months) than for DMEK (5.73 ± 1.9 months, p = 0.004). Complication rates were higher in the DMEK group (26.7%), and in comparison, there was an absence of complications in the DSO group (p = 0.043). Corneal endothelial cell migration was confirmed in patients who underwent DSO, with a mean cell density of 817.17 ± 91.7 cells/mm² after one year. Conclusions: DSO effectively treated the selected patients with FECD who presented central guttata and corneal edema, achieving visual outcomes equivalent to those of DMEK while reducing complication rates. This technique eliminates the need for donor tissue and immunosuppressive medications, making it a viable alternative for specific cases. Full article