Corneal Ulcer Research Articles

Oral bacteria may affect conjunctival microorganisms in brachycephalic dogs: a preliminary study.

To evaluate the prevalence of oral bacteria in the conjunctiva of brachycephalic and nonbrachycephalic dogs. 12 brachycephalic (9.58 ± 3.55 years) and 12 nonbrachycephalic (8.33 ± 4.92 years) dogs without systemic disease, regardless of breed and sex, were included in the study, and half of the dogs in each group had periodontitis. This prospective study investigated clinical data including craniofacial ratio, ophthalmic examination results, and periodontal status of the included dogs. Bacterial samples were collected by swabbing the oral mucosa and conjunctival surfaces. The presence and quantity of bacteria were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 16S rRNA sequencing analysis, and the 10-fold dilution method. Statistical analyses were performed to assess correlations and factors influencing the presence of oral bacteria in the conjunctiva. The most common bacteria in the conjunctival flora in both groups were Micrococcus luteus, Corynebacterium spp, and Staphylococcus spp. The prevalence of oral bacteria on the conjunctival surface was 33%, with a significantly higher incidence in brachycephalic dogs (P = .027). Oral bacteria detected in the conjunctiva were predominantly Frederiksenia canicola, Neisseria spp, and Moraxella spp. Multiple regression analysis identified age, craniofacial ratio, and gingival index as factors influencing the presence of oral bacteria in the conjunctival flora. Oral resident bacteria have often been isolated from severe infectious corneal ulcers. This study provided evidence that brachycephalic dogs may require dental prophylaxis to reduce their oral bacterial load and that the association of oral bacteria in ocular diseases should be considered.

Automated Measurement and Three-Dimensional Fitting of Corneal Ulcerations and Erosions via AI-Based Image Analysis

Purpose Artificial intelligence (AI)-tools hold great potential to compensate for missing resources in health-care systems but often fail to be implemented in clinical routine. Intriguingly, no-code and low-code technologies allow clinicians to develop Artificial intelligence (AI)-tools without requiring in-depth programming knowledge. Clinician-driven projects allow to adequately identify and address real clinical needs and, therefore, hold superior potential for clinical implementation. In this light, this study aimed for the clinician-driven development of a tool capable of measuring corneal lesions relative to total corneal surface area and eliminating inaccuracies in two-dimensional measurements by three-dimensional fitting of the corneal surface. Methods Standard slit-lamp photographs using a blue-light filter after fluorescein instillation taken during clinical routine were used to train a fully convolutional network to automatically detect the corneal white-to-white distance, the total fluorescent area and the total erosive area. Based on these values, the algorithm calculates the affected area relative to total corneal surface area and fits the area on a three-dimensional representation of the corneal surface. Results The developed algorithm reached dice scores >0.9 for an automated measurement of the relative lesion size. Furthermore, only 25% of conventional manual measurements were within a ± 10% range of the ground truth. Conclusions The developed algorithm is capable of reliably providing exact values for corneal lesion sizes. Additionally, three-dimensional modeling of the corneal surface is essential for an accurate measurement of lesion sizes. Besides telemedicine applications, this approach harbors great potential for clinical trials where exact quantitative and observer-independent measurements are essential.

PARALYSIE COMPLETE DU NERF OCULOMOTEUR III CAUSEE PAR UN ZONA OPHTALMIQUE A PROPOS DUN CAS

Ophthalmic herpes zoster, a manifestation of the reactivation of the varicella-zoster virus in the region of the trigeminal nerve, is primarily diagnosed based on the clinical characteristics of skin lesions and their localization. Ocular complications, including oculomotor paralysis, require early antiviral treatment to minimize ocular damage. We report the case of a 38-year-old woman presenting typical symptoms of ophthalmic herpes zoster, associated with complete oculomotor nerve III palsy and zoster encephalitis. Antiviral treatment with acyclovir led to a significant improvement. However, the patient retained corneal anesthesia resulting in the formation of a neurotrophic corneal ulcer. The risk of ocular complications associated with ophthalmic herpes zoster is real. The most serious are corneal complications and oculomotor paralysis, highlighting the crucial importance of early antiviral treatment to prevent these complications which can adversely affect the functional prognosis of the eye.

Discovery and Verification of Sjögren's Syndrome Protein Biomarkers in Tears by Targeted LC-MRM.

Sjögren's syndrome (SS) is an autoimmune rheumatic disorder characterized by exocrine gland dysfunction, mainly from the lacrimal and salivary glands. The disease causes severe aqueous dry eye syndrome (DED) and is associated with high rates of complications, including corneal ulceration, scaring, and perforation. Systemic complications may occur as well as a higher risk of developing lymphoma. Diagnosis of SS-DED is often delayed and difficult to establish. With the aim of discovering biomarkers to help discriminate SS-DED patients, a combination of untargeted and targeted LC-MS/MS analyses were performed on tear samples collected on Schirmer strips and subjected to tryptic digestion. Following the analysis of three cohorts and the development of two targeted LC-sMRM methods for the verification of putative biomarkers found in the first cohort of samples, 64 proteins could be linked to Sjögren's syndrome, in the hopes of helping to confirm diagnoses as well as potentially stratifying the severity of disease in these patients. Proteins that were increased in SS-DED showed activation of the immune system and alterations in homeostasis. Several proteases and protease inhibitors were found to be significantly changing in SS-DED, as well as a consistent decrease in specific proteins known to be secreted by the lacrimal gland.

Burn-Induced Cicatricial Eyelid Retraction: A Challenging Case and Review of Management Principles.

Thermal and chemical burns can result in cicatricial eyelid retraction, characterized by an abnormal resting position of the eyelid margin and increased palpebral fissure height. Eyelid retraction often leads to exposure keratopathy, which can cause complications ranging from mild dry eye to globe-threatening ulceration and perforation. Prompt intervention includes aggressive lubrication, moisture chambers, eyelid tarsorrhaphy, and retraction repair surgery. Discussed here is a burn patient that developed severe cicatricial eyelid retraction and ectropion, leading to severe exposure keratopathy and infectious corneal ulceration with perforation. The patient required aggressive medical intervention, as well as 2 surgeries to restore the normal eyelid anatomy to protect the globe.

Application of conjunctival graft surgery in the treatment of corneal ulcers in dogs

The study of conjunctival graft surgery for treating corneal ulcers in dogs was conducted at Alpha Pet Veterinary Clinic and Bang Pham Veterinary Hospital from August 2021 to August 2022. Dogs were clinically examined with corneal ulcers and corneal perforations, corneal reflexes, and then fluorescein 2% reagent was used to examine and measure the diameter of the corneal damaged area by using Castroviejo calipers. The surgical method of conjunctival stem grafting was applied and evaluated effects of treatment on corneal ulcers in dogs. A total of 3,024 dogs were examined and treated during the study period. There were 195 dogs with eye diseases, accounting for 6.45% of the cases. The rate of corneal ulcers was 15.90% (31/195 cases). Among the corneal ulcer cases, conjunctival graft surgery was performed in 14 cases. The successful rate of conjunctival stem grafting was 71.43%. The complication rate of conjunctival stem grafting was 42.86%, in which 2 cases of mild complications were successfully treated. The average wound healing duration was 39.45 days. The occurrence of complications depended on the types of complication. Mild complications including suture detachment and corneal edema appeared after 2.5 to 5.5 days while corneal epithelial cysts and ocular edema occurred at 22 to 42 days after surgery. Therefore, this method could be used in treatment of corneal ulcers, particularly in cases of deep ulcers or corneal perforations that required to directly connect to blood vessels.

Real-life experience on the effectiveness of conjunctival flap and amniotic membrane graft in the treatment of refractory fungal corneal ulcer.

To evaluate and compare the results of the conjunctival flap (CF) and cryopreserved amniotic membrane graft (AMG) in the management of fungal corneal ulcers either with complications or non-responsive to medical treatment. A retrospective observational study. Medical records of 30 patients with culture-positive fungal corneal ulcer treated with either CF or AMG (15 eyes in each group) in real world settings were retrieved for analysis. After the surgical procedure, patients were followed up on days 1, 7, 14, 21, 30, 60, 90, 120, and 180 to explore the outcomes of the operations along with complications. Infecting fungi were of genus Fusarium (n = 11), Aspergillus (n = 10), Mucor (n = 4) and Penicillium (n = 10). The most common indication was resistant ulcer with perforation. After the procedure, epithelization was completed in 11(73.33%) patients in the CF, and 13 patients in the (86.67%) AMG group. Visual acuity improvement was significantly better in the latter group (CF: 1 [6.67%] vs. AMG: 7 [46.67%], p = 0.023). Flap failure occurred in 4 patients (26.67%) from the CF and 2 (13.33%) from the AMG group. No significant differences were found between the two groups regarding success rate (p = 0.651), epithelialization time (p = 0.691), healing of corneal ulcer (p = 0.651), and postoperative stability (p = 0.651) of the flaps. CF and AMG are both effective for the management of refractory fungal corneal ulcers. However, AMG appears to improve visual acuity better than CF.

Corneal Complications Related to Dupilumab Use.

The aim of this report is to describe atypical corneal complications associated with dupilumab use. This is a series of four cases of adult patients with infiltrative or ulcerative keratitis secondary to dupilumab use. All four patients in this series were prescribed dupilumab for the treatment of atopic dermatitis and developed infiltrative or ulcerative corneal lesions. In all cases, corneal disease was successfully managed with immediate discontinuation of dupilumab and topical steroid treatment. In two cases, the patient also received antibiotic eye drops for infection precautions. Although dupilumab is most commonly associated with conjunctivitis, physicians should be aware of potential severe corneal complications for early identification and intervention.

Prognostic indicators of corneal ulcer clinical outcomes at a tertiary care center in the Bronx, New York

PurposeCorneal ulcers frequently result in ocular morbidity and may lead to permanent visual impairment if severe or untreated. This study aims to evaluate the association of patient factors and ocular exam findings on clinical outcomes for patients diagnosed with a corneal ulcer at a tertiary care center in the Bronx, New York.MethodsA retrospective chart review was conducted on all ambulatory and admitted patients diagnosed with a corneal ulcer (identified using ICD-10 code H16.0) at Montefiore Medical Center, Bronx, NY between 2016–2022. Patient demographics, presence of known risk factors, characteristics of subsequent clinical course, and microbiological studies were noted. Clinical outcomes following treatment were longitudinally evaluated and categorized based upon the following criteria: 1) ‘No Surgical Intervention’: No severe complications or surgery required after presentation, 2) ‘Surgical Intervention’: Decline in BCVA with surgery required for a severe complication.ResultsThe search criteria identified 205 patients (205 eyes) with the diagnosis of a corneal ulcer. Mean age was 55.3 ± 21.1 years (mean ± SD). Mean ulcer area at presentation was 7 ± 10.5 mm2. Mean LogMAR at presentation was 1.2 ± 1, and following treatment, improved to 1.0 ± 1. ‘Surgical Intervention’ outcome was associated with advanced age (p = 0.005), presence of ocular surface disease (p = 0.008), central location of ulcer (p = 0.014), greater ulcer area at presentation (p = 0.003), worse visual acuity at presentation (p < 0.001), and isolation of fungi (p = 0.004).ConclusionIdentification of risk factors associated with a poor clinical prognosis can guide treatment and inform expectations for patients diagnosed with a corneal ulcer. Our study highlights the importance of timely diagnosis, work-up, and initiation of appropriate management, particularly in vulnerable populations where access to specialty care is logistically challenging.

How does atmospheric pressure cold helium plasma affect the biomechanical behaviour on alkali-lesioned corneas?

BackgroundMelting corneal ulcers are a serious condition that affects a great number of animals and people around the world and it is characterised by a progressive weakening of the tissue leading to possible severe ophthalmic complications, such as visual impairment or blindness. This disease is routinely treated with medical therapy and keratoplasty, and recently also with alternative regenerative therapies, such as cross-linking, amniotic membrane transplant, and laser. Plasma medicine is another recent example of regenerative treatment that showed promising results in reducing the microbial load of corneal tissue together with maintaining its cellular vitality. Since the effect of helium plasma application on corneal mechanical viscoelasticity has not yet been investigated, the aim of this study is first to evaluate it on ex vivo porcine corneas for different exposition times and then to compare the results with previous data on cross-linking treatment.Results94 ex vivo porcine corneas divided into 16 populations (healthy or injured, fresh or cultured and treated or not with plasma or cross-linking) were analysed. For each population, a biomechanical analysis was performed by uniaxial stress-relaxation tests, and a statistical analysis was carried out considering the characteristic mechanical parameters. In terms of equilibrium normalised stress, no statistically significant difference resulted when the healthy corneas were compared with lesioned plasma-treated ones, independently of treatment time, contrary to what was obtained about the cross-linking treated corneas which exhibited more intense relaxation phenomena.ConclusionsIn this study, the influence of the Helium plasma treatment was observed on the viscoelasticity of porcine corneas ex vivo, by restoring in lesioned tissue a degree of relaxation similar to the one of the native tissue, even after only 2 min of application. Therefore, the obtained results suggest that plasma treatment is a promising new regenerative ophthalmic therapy for melting corneal ulcers, laying the groundwork for further studies to correlate the mechanical findings with corneal histology and ultrastructural anatomy after plasma treatment.

P109 Ocular manifestation of rheumatoid arthritis

Abstract Background/Aims Ocular manifestation associated with rheumatoid arthritis (RA) is common and should be systematically investigated by an ophthalmological examination. It may precede or complicate the disease. It manifests as a dry-eye syndrome in 38% to 45% of cases, scleritis in 0.2 to 6.3% of cases, episcleritis in 0.17 to 3.7% of cases, and peripheral ulcerative keratitis in 3% of cases. The aim of this study was to describe ocular involvement in RA and to identify factors predictive of its occurrence. Methods This is a retrospective study of patients with RA defined according to the ACR- EULAR 2010 criteria, followed up in the internal medicine department between 2015 and 2022. Patients were divided into two groups: G0 including patients without ocular involvement and G1 including patients with ocular involvement. Results Eighty patients were diagnosed, 65 women and 15 men, giving a sex ratio (F/H) of 4.33. The mean age was 60.79 years [extremes: 30-90 years]. The mean age of disease onset was 46.34 years [extremes: 22-82 years]. Among our 80 patients, 20 had RA-related ocular involvement (25%). These included 18 women and two men. Ocular involvement consisted of dry-eye syndrome (17 cases), superficial punctate keratitis (4 cases), corneal perforation (one case), and unilateral diffuse scleritis (one case). The ocular examination had also revealed corticosteroid adverse effects: corticosteroid-induced cataract (four cases) and corticosteroid-induced glaucoma (three cases). Sjogren’s syndrome associated with RA was present in 76.47% of cases. There was no difference between the two groups in terms of age (62.25 vs. 44.22 years, p = 0.943), age of disease onset (47, 23 years vs. 44.22 years, p = 0.569), rheumatoid factor level (335.29 IU/L vs. 329.15 IU/L, p = 0.393) and anti-CCP antibody level (225.08 IU/L vs. 119.23 IU/L, p = 0.070). CRP was significantly higher in patients with no ocular involvement (225.08 mg/l vs. 118.23 mg/l, p = 0.007). erosive character was observed more in G0 than in G1, but without any significant difference, respectively 85.29% vs. 68.42%; p = 0.146. Conclusion According to our study, a quarter of patients followed for RA had ocular manifestations dominated mainly by dry syndrome. However, no predictive risk factor was found for this condition, be it clinical, immunological, or radiological. Disclosure I. Fenniche: None. Z. Aydi: None. M. Somai: None. F. Daoud: None. B. Ben dhaou: None. S. Kochbati: None. I. Rachdi: None. F. Boussema: None.

Dexamethasone sodium phosphate loaded nanoparticles for prevention of nitrogen mustard induced corneal injury

Nitrogen mustard (NM) is a potent vesicating chemical warfare agent that is primarily absorbed through skin, inhalation, or ocular surface. Ocular exposure of NM can cause acute to chronic keratopathy which can eventually lead to blindness. There is a current lack of effective countermeasures against ocular exposure of NM despite their imperative need. Herein, we aim to explore the sustained effect of Dexamethasone sodium phosphate (DSP)-loaded polymeric nanoparticles (PLGA-DSP-NP) following a single subconjunctival injection in the management and prevention of corneal injury progression upon exposure to NM. DSP is an FDA approved corticosteroid with proven anti-inflammatory properties. We formulated PLGA-DSP-NP with zinc chelation ion bridging method using PLGA polymer, with particles of approximately 250 nm and a drug loading of 6.5 wt%. Under in vitro sink conditions, PLGA-DSP-NP exhibited a sustained drug release for two weeks. Notably, in NM injured cornea, a single subconjunctival (SCT) injection of PLGA-DSP-NP outperformed DSP eyedrops (0.1%), DSP solution, placebo NP, and saline, significantly mitigating corneal neovascularization, ulceration, and opacity for the two weeks study period. Through PLGA-DSP-NP injection, sustained DSP release hindered inflammatory cytokine recruitment, angiogenic factors, and endothelial cell proliferation in the cornea. This strategy presents a promising localized corticosteroid delivery system to effectively combat NM-induced corneal injury, offering insights into managing vesicant exposure.

CD3ε of a pan T cell marker involved in mouse Aspergillus fumigatus keratitis.

To explore whether CD3ε is involved in the adaptive immunity of Aspergillus fumigatus (A. fumigatus) keratitis in mice and the role of innate and adaptive immunity in it. Mice models of A. fumigatus keratitis were established by intra-stromal injection and corneal epithelial scratching. Subconjunctival injections of natamycin, wedelolactone, LOX-1 inhibitor (poly I) or Dectin-1 inhibitor (laminarin) were used to treat mice with A. fumigatus keratitis. Mice were pretreated by intraperitoneal injection of anti-mouse CD3ε. We observed the corneal infection of mice under the slit lamp microscope and made a clinical score. The protein expression of CD3ε and interleukin-10 (IL-10) was determined by Western blotting. With the disease progresses, the degree of corneal opacity and edema augmented. In the intra-stromal injection models, CD3ε protein expression began to increase significantly on the 2nd day. However, in the scraping epithelial method models, CD3ε only began to increase on the 3rd day. After natamycin treatment, the degree of corneal inflammation in mice was significantly attenuated on the 3rd day. After wedelolactone treatment, the severity of keratitis worsened. And the amount of CD3ε protein was also reduced, compared with the control group. By inhibiting LOX-1 and Dectin-1, there was no significant difference in CD3ε production compared with the control group. After inhibiting CD3ε, corneal ulcer area and clinical score increased, and IL-10 expression was downregulated. As a pan T cell marker, CD3ε participate in the adaptive immunity of A. fumigatus keratitis in mice. In our mice models, the corneas will enter the adaptive immune stage faster. By regulating IL-10, CD3ε exerts anti-inflammatory and repairs effects in the adaptive immune stage.

Evaluation of Moringa Oleifera Leaf Extract for its In vitro Antibacterial Properties, Mechanism of Action, and In vivo Corneal Ulcer Healing Effects in Rabbits' Eyes.

M. oleifera is the most adapted tree species in different medicinal eco-systems and has resilience against climate changes. This multiple-use tree provides healthy foods, snacks, honey, and fuel. Besides this, it has immense promising applicationsby offering antimicrobial and antibacterial activities for targeted uses. This validates the court of Hippocrates that let food be the medicine and medicine be the food for which moringa qualifies. In view of this, the antioxidant and in vitro antibacterial potency of the hydro-ethanolic extract of M. oleifera was evaluated on clinically isolated multidrug-resistant strains of Staphylococcus aureus. Furthermore, in vivo, the healing response of M. oleifera extract was analysed on corneal ulcers induced in rabbit eyes infected with methicillin-resistant Staphylococcus aureus. TheM. oleifera extract exhibited exponential antioxidant activity. In-vitro antibacterial activity was evaluated by agar well diffusion assay showing zone of inhibition ranging from 11.05±0.36 to 20±0.40 mm at concentrations of 20, 40, 80, and 160 mg/ml, whereas, in our finding, no zone of inhibition was observed below 20 mg/ml concentration, which indicated that there is threshold limit below which the antibacterial activity of M. oleifera extract is not observed. Furthermore, continuous application of 3% and 5% M. oleifera extract (eye drop) four times a day for 14 consecutive days showed a significant healing response of the eyes of rabbits with corneal ulcers. These results suggest that M. oleifera extract could be a viable alternative to existing antibacterial therapies for corneal ulcers. Additionally, there is a possibility of commercial formulation of M. oleifera extract in the form of deliverable pharmaceutical products; therefore, it should be explored further.

Peripheral ulcerative keratitis associated with tralokinumab therapy: a case report and review of IL-13 inhibitor-associated ocular surface disease

BackgroundDupilumab and tralokinumab are interleukin-binding monoclonal antibodies used to treat systemic atopic disease. Use of these medications in management of atopic dermatitis (AD) is known to cause conjunctivitis. Dupilumab therapy has also been associated with more severe ocular surface disease, which has not previously been described in association with tralokinumab. This report describes a case of tralokinumab-associated conjunctivitis and peripheral ulcerative keratitis and reviews the spectrum and proposed mechanisms of ocular surface disease triggered by these medications.Case presentationA 61-year-old male with no rheumatologic or ocular history presented with bilateral papillary conjunctivitis and right eye peripheral ulcerative keratitis (PUK). PUK was arrested using oral corticosteroids and doxycycline, and long-term control of papillary conjunctivitis was achieved using topical tacrolimus ointment, allowing continuation of effective AD management with tralokinumab.ConclusionThis case report documents ulcerative keratitis occurring in association with tralokinumab therapy for AD, which has previously been described with dupilumab but not tralokinumab. This report demonstrates the need for vigilant ocular surface monitoring for patients on tralokinumab and illustrates successful management and long-term control of adverse ocular events associated with this medication.

Equine keratomycosis due to Aspergillus flavus in Argentina

A 9-year-old gelding presented a corneal ulcer unresponsive to treatment in his right eye. The trauma was caused by vegetal material. The ophthalmologic exam revealed paraxial corneal opacity, whitish discharge, peripheral oedema, congestion of conjunctival vessels and corneal angiogenesis. Microscopic examination of smears revealed the presence of neutrophils and fungal hyphae. On day 3 of culture, several small white fluffy colonies that rapidly turned to pale green were detected. These colonies were isolated to study their micro and macromorphology. Microscopic examination revealed the presence of colourless, thick-walled, roughened conidiophores, ranging from 340 to 1650 μm in length, with globose to sub-globose vesicles, ranging from 22 to 48 μm in diameter. Vesicles had one or two series of phialides. Conidia were globose, olive-green with slightly rough, thin walls that ranged from 3 to 7 μm in diameter. Molecular identification was also performed. Both techniques confirmed the presence of Aspergillus flavus complex. Topical treatment with natamycin resulted in healing within 10 days. To our knowledge, this is the first case of equine keratomycosis reported in Argentina.

Classification and Determination of Severity of Corneal Ulcer with Vision Transformer Based on the Analysis of Public Image Dataset of Fluorescein-Stained Corneas.

A corneal ulcer is a condition in which an injury to the corneal surface occurs as a result of infection. This can lead to severe vision loss and even blindness. For this reason, early diagnosis of this disease is of great importance. Deep learning algorithms are used in many critical health applications and are used effectively in the early diagnosis stages of diseases. Thus, a deep learning algorithm was applied in this study and corneal ulcer and severity were predicted. The study consisted of four stages over three different scenarios. In the first scenario, the types of corneal ulcers were predicted. In the second scenario, the grades of corneal ulcer types were classified. In the last scenario, the severity of corneal ulcers was classified. For each scenario, data were obtained in the first stage and separated according to the relevant labels. In the second stage, various image processing algorithms were employed, and images were analyzed. At this stage, the images were also augmented by various processes. In the third stage, ViT architecture, a new deep learning model, was used, and the images were classified. In the last stage, the performance of the classifier was determined by accuracy, precision, recall, F1-score, and AUC score. At the end of the study, the ViT deep learning model performed an effective classification, and accuracy scores of 95.77% for the first scenario, 96.43% for the second scenario, and 97.27% for the third scenario were calculated.

Extracellular Vesicles Isolated from Equine Adipose-Derived Stromal Stem Cells (ASCs) Mitigate Tunicamycin-Induced ER Stress in Equine Corneal Stromal Stem Cells (CSSCs).

Corneal ulcers, characterized by severe inflammation of the cornea, can lead to serious, debilitating complications and may be vision-threatening for horses. In this study, we aimed to investigate the role of endoplasmic reticulum (ER) stress in corneal stem progenitor cell (CSSC) dysfunction and explore the potential of equine adipose-derived stromal stem cell (ASC)-derived extracellular vesicles (EVs) to improve corneal wound healing. We showed that CSSCs expressed high levels of CD44, CD45, and CD90 surface markers, indicating their stemness. Supplementation of the ER-stress-inducer tunicamycin to CSSCs resulted in reduced proliferative and migratory potential, accumulation of endoplasmic reticulum (ER)-stressed cells in the G0/G1 phase of the cell cycle, increased expression of proinflammatory genes, induced oxidative stress and sustained ER stress, and unfolded protein response (UPR). Importantly, treatment with EVs increased the proliferative activity and number of cells in the G2/Mitosis phase, enhanced migratory ability, suppressed the overexpression of proinflammatory cytokines, and upregulated the anti-inflammatory miRNA-146a-5p, compared to control and/or ER-stressed cells. Additionally, EVs lowered the expression of ER-stress master regulators and effectors (PERK, IRE1, ATF6, and XBP1), increased the number of mitochondria, and reduced the expression of Fis-1 and Parkin, thereby promoting metabolic homeostasis and protecting against apoptosis in equine CSSCs. Our findings demonstrate that MSCs-derived EVs represent an innovative and promising therapeutic strategy for the transfer of bioactive mediators which regulate various cellular and molecular signaling pathways.

Understanding Acanthamoeba Keratitis: An In-Depth Review of a Sight-Threatening Eye Infection.

Acanthamoeba keratitis (AK) is a rare but potentially sight-threatening corneal infection caused by the Acanthamoeba parasite. This microorganism is found ubiquitously in the environment, often in freshwater, soil, and other sources of moisture. Despite its low incidence, AK presents significant challenges due to delayed diagnosis and the complex nature of therapeutic management. Early recognition is crucial to prevent severe ocular complications, including corneal ulceration and vision loss. Diagnostic modalities and treatment strategies may vary greatly depending on the clinical manifestation and the available tools. With the growing reported cases of Acanthamoeba keratitis, it is essential for the ophthalmic community to thoroughly understand this condition for its effective management and improved outcomes. This review provides a comprehensive overview of AK, encompassing its epidemiology, risk factors, pathophysiology, clinical manifestations, diagnosis, and treatment.

Corneal ulcers and the risk of visual impairment in a matched cohort study in Nepal

PurposeWe estimated the association between corneal ulcer and two outcomes: visual impairment and vision-related quality of life. We investigated for differential effects by rural/urban location. DesignPopulation-based matched prospective cohort study. MethodsWe followed 540 incident corneal ulcer cases identified in a cluster randomized trial in Nepal. Cases were pair-matched to individuals without incident corneal ulcers by age, sex and location using incidence density sampling. Clinical examinations were performed to assess outcomes in both groups after 12 months, which included visual acuity and a modified version of the Hong Kong vision-related quality of life questionnaire. Results392 matched pairs had complete outcome data and were included in the analyses. Median age was 42 years (interquartile range [IQR]: 28, 53) and 63.8 % were female. After controlling for education and occupation, corneal ulcer was associated with an approximately 1-line reduction in visual acuity (0.11 logMAR units, 95 % CI 0.06 to 0.15, P < 0.001), and with an increased risk of low vision/blindness (adjusted risk ratio 1.89, 95 % CI 1.44 to 2.48, P < 0.001). Corneal ulcer was associated with lower vision-related quality of life on the 20-question questionnaire (adjusted mean difference in score -1.69, 95 % CI -2.78 to -0.61, P = 0.002). We were unable to demonstrate effect modification for any outcome by rural/urban status. ConclusionsWe observed worse visual acuity and lower vision-related quality of life among those with incident corneal ulcers compared to those without. The population-based design, which captured the full spectrum of disease, confirms that corneal ulcers are an important cause of vision loss in the general population of Nepal and highlights the need for effective community-based corneal ulcer prevention interventions.