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Corrosive esophageal burn (CEB) is a disease with high mortality and morbidity rates. The aim of this study was to determine the efficacy of castor oil, in preventing stricture development at the experimental CEB model. In addition to studying standard histopathological damage data, neopterin, IL-33, and ST-2 proteins were also studied for the first time. Fifty Wistar-Albino rats were divided into randomized 5 groups. [Sham group (G1) (n:10), Control group (G2) (n:10), Early Stage Topical Application group (G3)(n:10), Late Stage Topical Application group (G4) (n:10), Oral Application group (G5) (n:10)]. Weight measurement, esophageal length, histopathological damage score (HDS) and total stenosis score (TSS), tissue caspase-3 and VEGF staining, tissue hydroxyproline (HYP), blood TNF-alpha, IL-6, IL-33, Neopterin, and ST-2 levels were measured. In the castor oil application groups, weight gain was observed, the acute phase reaction decreased, submucosal/tunica muscularis fibrosis (TMF) and muscularis mucosal damage (MMD) were reduced, and TSS and HDS decreased. While no significant difference was detected in the ST-2 protein, which was used for the first time in this study model, a significant increase in neopterin protein was observed in the application groups. Results indicate the nutritional contribution of castor oil, as well as its tissue healing and esophageal stricture-preventing efficacy at histopathological and immune-histochemical levels., (© 2024. The Author(s).)

Topical eye drop approaches to treat ocular inflammation in dry eyes often face limitations such as low efficiency and short duration of drug delivery. Nanofibers serve to overcome the limitation of the short duration of action of topical eye drops used against ocular inflammation in dry eyes. Several attempts to develop suitable nanofibers have been made; however, there is no ideal solution. Here, we developed polycaprolactone (PCL) nanofibers loaded with dexamethasone acetate (DEX), prepared by electrospinning, as a potential ocular drug delivery platform for corneal injury treatment. Thirty-nine Sprague Dawley rats (7 weeks old males) were divided into four treatment groups after alkaline burns of the cornea; negative control (no treatment group); dexamethasone eyedrops (DEX group); PCL fiber (PCL group); dexamethasone loaded PCL (PCL + DEX group). We evaluated therapeutic efficacy of PCL + DEX by examining the epithelial wound healing effect, the extent of corneal opacity and neovascularization. Additionally, various inflammatory factors, including IL-1β, were investigated through immunochemistry, western blot analysis, and quantitative real-time RT-PCR (qRT-PCR). PCL + DEX group showed histologically alleviated signs of corneal inflammation compared with DEX group, which showed a decrease in IL-1β and MMP9 in the corneal stroma. The quantitative expression on day 1 after alkaline burn of pro-inflammatory markers, including IL-1β and IL-6, in the PCL + DEX group was significantly lower than that in the DEX group. Notably, PCL + DEX treatment significantly suppressed neovascularization, and enhanced the anti-inflammatory function of DEX during the acute phase of ocular inflammation. Collectively, these findings suggest that PCL + DEX may be a promising approach to effective drug delivery in corneal burn injuries., (© 2024. The Author(s).)

Purpose: The purpose of this study was to evaluate the safety and efficacy of topical losartan in the therapeutic treatment of established corneal scaring fibrosis at 1 month after alkali burn in rabbits., Methods: Standardized alkali burns were performed in 1 eye of 24 rabbits with 0.75N NaOH for 15 seconds. Corneas were allowed to heal and develop scaring of the cornea for 1 month. Twelve eyes per group were treated with 50 µL of topical 0.8 mg/mL losartan in balanced salt solution (BSS), pH 7.0, and 12 eyes were treated with vehicle BSS 6 times per day. Six corneas were analyzed at 1 week or 1 month in each group. Standardized slit lamp photographs were obtained at the end point for each cornea and opacity was quantitated using ImageJ. Corneoscleral rims were cryofixed in optimum cutting temperature (OCT) solution and combined duplex immunohistochemistry for myofibroblast marker alpha-smooth muscle actin (α-SMA), mesenchymal cell marker vimentin, and TUNEL assay for apoptosis was performed on all corneas., Results: Topical losartan was effective in the treatment of established stromal fibrosis following alkali burn injury to the rabbit cornea. Stromal myofibroblast density was decreased and stromal cell apoptosis was increased (included both α-SMA-positive myofibroblasts and α-SMA-negative, vimentin-positive cells) at both 1 week and 1 month in the topical losartan-treated compared with vehicle-treated groups., Conclusions: Topical losartan is effective in the treatment of established stromal fibrosis in rabbits. Most myofibroblasts disappear from the stroma within the first month of losartan treatment. Longer treatment with topical losartan is needed to allow time for corneal fibroblast regeneration of the epithelial basement membrane (in coordination with epithelial cells) and the removal of disordered extracellular matrix produced by myofibroblasts.

Alkaline burns to the cornea lead to loss of corneal transparency, which is essential for normal vision. We used a rat corneal alkaline burn model to investigate the effect of ophthalmic trimebutine solution on healing wounds caused by alkaline burns. Trimebutine, an inhibitor of the high-mobility group box 1-receptor for advanced glycation end products, when topically applied to the burned cornea, suppressed macrophage infiltration in the early phase and neutrophil infiltration in the late phase at the wound site. It also inhibited neovascularization and myofibroblast development in the late phase. Furthermore, trimebutine effectively inhibited interleukin-1β expression in the injured cornea. It reduced scar formation by decreasing the expression of type III collagen. These findings suggest that trimebutine may represent a novel therapeutic strategy for corneal wounds, not only through its anti-inflammatory effects but also by preventing neovascularization., (© 2024. The Author(s).)

Background: Caustic ingestion is associated with long-term sequelae like esophageal stricture, gastric cicatrization, and long-term risk of dysplasia or even carcinoma. However, only a few small studies have explored histopathological aspects of caustic-induced esophageal/gastric injury., Materials and Methods: We retrospectively evaluated specimens of patients undergoing surgery due to caustic ingestion-related complications from 2008 to 2020. Pathological examination was conducted by two independent gastro-pathologists to evaluate the extent and depth of the caustic injury, presence or absence of tissue necrosis, type and degree of inflammation, or presence of any dysplastic cells., Results: A total of 54 patients underwent surgical exploration during the inclusion period and complete details of 39 specimens could be retrieved. The mean age of the included patients was 28.66 ± 9.31 years and 25 (64.1%) were male. The majority of patients (30; 76.9%) had a history of caustic ingestion more than three months before the surgery and the presence of long or refractory stricture was the most common indication for the surgery (20; 51.28%). In the resected specimen, a majority of patients had superficial esophageal or gastric ulcer (90.6%; 60.0%), transmural inflammation (68.8%; 65.6%), transmural fibrosis (62.5%; 34.4%), and hypertrophied muscularis mucosa (78.13%; 53.3%). However, none of the patients had dysplasia in the resected esophageal or gastric specimens., Conclusion: Caustic ingestion leads to mucosal ulceration, transmural inflammation, and transmural fibrosis which might be the reason for refractory stricture in such patients., (Copyright © 2024 Copyright: © 2024 Indian Journal of Pathology and Microbiology.)

Objective: To investigate the effects of emodin on alkali burn-induced corneal inflammation and neovascularization., Methods: The ability of emodin to target vascular endothelial growth factor receptor 2 (VEGFR2) was predicted by molecular docking. The effects of emodin on the invasion, migration, and proliferation of human umbilical vein endothelial cells (HUVEC) were determined by cell counting kit-8, Transwell, and tube formation assays. Analysis of apoptosis was performed by flow cytometry. CD31 levels were examined by immunofluorescence. The abundance and phosphorylation state of VEGFR2, protein kinase B (Akt), signal transducer and activator of transcription 3 (STAT3), and P38 were examined by immunoblot analysis. Corneal alkali burn was performed on 40 mice. Animals were divided randomly into two groups, and the alkali-burned eyes were then treated with drops of either 10 μM emodin or phosphate buffered saline (PBS) four times a day. Slit-lamp microscopy was used to evaluate inflammation and corneal neovascularization (CNV) in all eyes on Days 0, 7, 10, and 14. The mice were killed humanely 14 d after the alkali burn, and their corneas were removed and preserved at －80 ℃ until histological study or protein extraction., Results: Molecular docking confirmed that emodin was able to target VEGFR2. The findings revealed that emodin decreased the invasion, migration, angiogenesis, and proliferation of HUVEC in a dose-dependent manner. In mice, emodin suppressed corneal inflammatory cell infiltration and inhibited the development of corneal neovascularization induced by alkali burn. Compared to those of the PBS-treated group, lower VEGFR2 expression and CD31 levels were found in the emodin-treated group. Emodin dramatically decreased the expression of VEGFR2, p-VEGFR2, p-Akt, p-STAT3, and p-P38 in VEGF-treated HUVEC., Conclusion: This study provides a new avenue for evaluating the molecular mechanisms underlying corneal inflammation and neovascularization. Emodin might be a promising new therapeutic option for corneal alkali burns.

Background: Corneal alkali burns can lead to ulceration, perforation, and even corneal blindness due to epithelial defects and extensive cell necrosis, resulting in poor healing outcomes. Previous studies have found that chitosan-based in situ hydrogel loaded with limbal epithelium stem cells (LESCs) has a certain reparative effect on corneal alkali burns. However, the inconsistent pore sizes of the carriers and low cell loading rates have resulted in suboptimal repair outcomes. In this study, 4D bioprinting technology was used to prepare a chitosan-based thermosensitive gel carrier (4D-CTH) with uniform pore size and adjustable shape to improve the transfer capacity of LESCs., Methods: Prepare solutions of chitosan acetate, carboxymethyl chitosan, and β-glycerophosphate sodium at specific concentrations, and mix them in certain proportions to create a pore-size uniform scaffold using 4D bioprinting technology. Extract and culture rat LESCs (rLESCs) in vitro, perform immunofluorescence experiments to observe the positivity rate of deltaNp63 cells for cell identification. Conduct a series of experiments to validate the cell compatibility of 4D-CTH, including CCK-8 assay to assess cell toxicity, scratch assay to evaluate the effect of 4D-CTH on rLESCs migration, and Calcein-AM/PI cell staining experiment to examine the impact of 4D-CTH on rLESCs proliferation and morphology. Establish a severe alkali burn model in rat corneas, transplant rLESCs onto the injured cornea using 4D-CTH, periodically observe corneal opacity and neovascularization using a slit lamp, and evaluate epithelial healing by fluorescein sodium staining. Assess the therapeutic effect 4D-CTH-loaded rLESCs on corneal alkali burn through histological evaluation of corneal tissue paraffin sections stained with hematoxylin and eosin, as well as immunofluorescence staining of frozen sections., Results: Using the 4D-CTH, rLESCs were transferred to the alkali burn wounds of rats. Compared with the traditional treatment group (chitosan in situ hydrogel encapsulating rLESCs), the 4D-CTH-rLESC group had significantly higher repair efficiency of corneal injury, such as lower corneal opacity score (1.2 ± 0.4472 vs 0.4 ± 0.5477, p < 0.05) and neovascularization score (5.5 ± 1.118 vs 2.6 ± 0.9618, p < 0.01), and significantly higher corneal epithelial wound healing rate (72.09 ± 3.568% vs 86.60 ± 5.004%, p < 0.01)., Conclusion: In summary, the corneas of the 4D-CTH-rLESC treatment group were similar to the normal corneas and had a complete corneal structure. These findings suggested that LESCs encapsulated by 4D-CTH significantly accelerated corneal wound healing after alkali burn and can be considered as a rapid and effective method for treating epithelial defects., (© 2024. The Author(s).)

Toilet cleaner containing hydrochloric acid is a common item found in households all over the world. Due to the availability of the substance, it becomes one of the main contributors to corrosive damage to the gastrointestinal system. This study reports a case of a female in her 50s with an alleged history of ingestion of toilet cleaner an empty bottle of which was found together with a suicide note at the incident site. During the autopsy, the forensic expert made an intriguing observation regarding the dispersion of ingested acid to other organs without gastric perforation. Despite the absence of gastric perforation, the corrosive effects of the ingested acid were evident in various organs, including the liver and spleen. This phenomenon suggests a unique mechanism by which the acid is able to disperse and cause damage beyond the stomach, leading to widespread organ involvement. However, through a comprehensive analysis of the detailed history, typical macroscopic autopsy findings, and chemical analysis reports, it is possible to establish that the cause of death is corrosive acid poisoning. In such cases, further investigation is warranted to gain a better understanding of the underlying mechanisms responsible for the dispersion of the acid and its clinical implications. By delving deeper into these aspects, we can enhance our knowledge and contribute to the field of forensic medicine., (Copyright © 2024 by PTMSiK.)

Gallic acid, acting as an antioxidant, anti-precipitant and cytoprotective agent, was used as a possible remedial natural component for treating experimentally induced esophageal burn. Wistar rats (n=24) were divided into three groups. Control group was given 1 mL 0.9% NaCl. Experimental esophageal burn was induced with 1 mL 40% NaOH application to the esophagus in groups 2 and 3. Gallic acid® (20 mg/kg) was administered to the treated group via oral gavage for 10 days. Removed tissues were fixed and paraffin blocks were prepared. Histopathological examination was performed after the sections had been stained with hematoxylin-eosin. Tumor necrosis factor alpha and caspase-3 antibodies were used on immunohistochemical analysis. In the esophageal burn group, necrosis, degeneration and numerous apoptotic cells, as well as intense inflammatory cell infiltration and fibrosis in the muscle layer were observed under light microscope. In the treated group, remodeling of epithelial cells with marked reduction in the connective tissue collagen content was observed, as well as marked reduction in the volume of collagen and abundance of inflammatory cells in blood vessels. Gallic acid treatment may help heal esophageal burns and prevent complications., (Sestre Milosrdnice University Hospital.)

Background: Corneal neovascularization (CNV) can be caused by chemical burns. Macrophages are involved in angiogenesis and lymphangiogenesis during CNV. The aim of this study was to investigate whether Wilms' tumor 1-associated protein (WTAP) is involved in macrophage recruitment and VEGF secretion via N6-methyladenosine (m6A) modification., Methods: A CNV mouse model was established by corneal alkali burn. Tumor necrosis factor alpha (TNF-α) was used to stimulate vascular endothelial cells. m6A immunoprecipitation qPCR was used to determine the enrichment of m6A levels in mRNAs. The H3K9me3 enrichment in the promoter region of CC motif chemokine ligand 2 (CCL2) was detected by chromatin immunoprecipitation assay. The WTAP inhibition in vivo was performed using the adeno-associated virus., Results: In the alkali burn corneal tissues, angiogenesis and lymphangiogenesis were promoted as CD31 and LYVE-1 expressions were elevated, and the number of macrophages as well as WTAP expression were increased. Under the TNF-α stimulation, WTAP promoted the recruitment of endothelial cells to macrophages by promoting CCL2 secretion. Mechanistically, WTAP affected the enrichment of H3K9me3 at the CCL2 promoter by regulating the m6A level of SUV39H1 mRNA. The in vivo experiment showed that VEGFA/C/D secretion of macrophages was reduced after WTAP interference. Mechanistically, WTAP regulated the translational efficiency of HIF-1α via m6A modification., Conclusion: WTAP affected macrophage recruitment to endothelial cells via regulation of H3K9me3-mediated CCL2 transcription. WTAP also affected macrophage secretion of VEGFA/C/D via m6A-mediated translation regulation of HIF-1α. Both pathways were involved in the WTAP regulation of angiogenesis and lymphangiogenesis during CNV., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background and Objectives: Ocular alkaline burn is a clinical emergency that can cause permanent vision loss due to limbal stem cell deficiency and corneal neovascularization (CNV). Although the basic pathogenetic mechanisms are considered to be acute oxidative stress and corneal neovascularization triggered by inflammation, the underlying intracellular mechanisms have not been clearly elucidated. The aim of this study was to investigate the role of endoplasmic reticulum (ER) stress on inflammation and neovascularization, and the effect of the ER stress inhibitor salubrinal (SLB), as a novel treatment in a corneal alkaline burn model in rats. Methods: Chemical burns were created by cautery for 4 s using a rod coated with 75% silver nitrate and 25% potassium nitrate in the corneal center for the corneal neovascularization (CNV) model. Twenty-eight Wistar albino rats were divided into four groups: SHAM, CNV, CNV + SLB, and CNV + bevacizumab (BVC). After the CNV model was applied to the right eye, a single subconjunctival dose (0.05 mL) of 1 mg/kg salubrinal was injected into both eyes in the CNV + SLB group. A total of 1.25 mg/mL of subconjunctival BVC was administered to the CNV + BVC group. Fourteen days after experimental modeling and drug administration, half of the globes were placed in liquid nitrogen and stored at -20 °C until biochemical analysis. The remaining tissues were collected and fixed in 10% buffered formalin for histopathological and immunohistochemical analysis. Three qualitative agents from three different pathways were chosen: TNFR for inflammation, endothelial nitric oxide synthase (e-NOS) for vascular endothelial growth factor (VEGF)-mediated vascular permeability, and caspase-3 for cellular apoptosis. Results: Significantly lower caspase-3 and eNOS levels were detected in the CNV + SLB and CNV + BVC groups than in the CNV group. Additionally, histopathological evaluation revealed a significant decrease in neovascularization, inflammatory cell infiltration, and fibroblast activity in the CNV + SLB and CNV + BVC groups. The endoplasmic reticulum stress inhibitor, salubrinal, administered to the treatment group, attenuated apoptosis (caspase-3) and inflammation (e-NOS). In the control group (left eyes of the SLB group), salubrinal did not have a toxic effect on the healthy corneas. Conclusion: The ER stress pathway plays an important role in angiogenesis after alkaline corneal burns, and treatment with SLB modulates this pathway, reducing caspase-3 and eNOS levels. Further studies are needed to understand the molecular mechanisms altered by SLB-mediated therapy. The fact that more than one mechanism plays a role in the pathogenesis of CNV may require the use of more than one molecule in treatment. SLB has the potential to affect multiple steps in CNV pathogenesis, both in terms of reducing ER stress and regulating cellular homeostasis by inhibiting the core event of integrated stress response (ISR). Therefore, it can be used as a new treatment option and as a strengthening agent for existing treatments. Although blockade of intracellular organelle stress pathways has shown promising results in experimental studies, more in-depth research is needed before it can be used in routine practice. To the best of our knowledge, this study is the first to report the role of ER stress in corneal injury.

Water irrigation is an efficacious decontaminating method for dermis exposures to corrosive agents and hence has been widely applied to treat especially alkali burns. Nevertheless, once alkali has infiltrated the deep subcutaneous tissue, washing the tissue surface with water irrigation does not attenuate the damage progress. Therefore, significant efforts have been devoted to promising strategies aimed at removing the deeply infiltrated lye. According to a recent report, the negative pressure wound therapy (NPWT) reduces the pH value of the exudate from alkali-provoked burns thus accelerating wound healing. However, it remains to be ascertained whether or not NPWT coupled with water irrigation, that is, iNPWT, more effectively hinders the alkali injury deepening. In this study, we compared the effectiveness of an early application of water irrigation with or without NPWT in preventing the progressive deepening of the alkali burn in an animal model. Our histological examination results showed no appreciable difference in tissue injury depth, dermal retention, inflammatory cell infiltration, re-epithelization, and cellular function between iNPWT and water irrigation alone treatments. Thus, our results prove that the more expensive NPWT coupled with water irrigation does not more effectively hinder the alkali's injury deepening. Hence, iNPWT use should be more cautious in clinical practice., (© 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

The cornea, the transparent part of the eye, performs a significant function in eyesight by refracting the light to focus a visual image. Since the cornea is indispensable for vision, corneal inflammation may induce visual disturbance and blindness. Several investigations have reported that various corneal inflammatory diseases cause visual impairment and chronic inflammation of the cornea, which can lead to blindness. The present study aimed to assess the effect of adipose-derived mesenchymal stem cells (ADMSCs) on corneal healing after alkali injuries. Corneal alkali injuries were induced in the eyes of 20 rabbits. The MSC group (n=10) was treated with subconjunctival injections, while the control group (n=10) was left without any treatment. Rabbits underwent slit-lamp examination and photography and were evaluated for corneal neovascularization. Based on the histological evaluation, the eyes treated with MSCs showed better recovery. Furthermore, the MSC and control groups were significantly different in the degree of corneal neovascularization and re-epithelialization, as well as the elevation of the neovascular tissue at two and four weeks post-surgery., Competing Interests: The authors declare that they have no conflict of interest.

Aim: This study aimed to investigate the efficiency of topically applied pycnogenol (PYC) in healing the standardized alkaline corneal ulcer in diabetic and normal rats., Materials and Methods: The corneal alkali-burn injury (CA-I) model was unilaterally developed in Wistar rats by filter paper saturated with 0.01 M of NaOH and touching the eyes for 45 s. Rats were divided into four groups: Normal control (NC), normal PYC (NPYC), diabetic control (DC), and diabetic PYC (DPYC). Both NPYC and DPYC groups were daily treated with PY eye drops three times, whereas NC and DC ones were treated with ordinary saline for six successive days., Results: The wound healing of corneal epithelial was improved in the NPYC group compared to the NC group. Meanwhile, it was significantly improved (P < 0.05) in the DPYC group than in the DC group. Histological examination revealed that corneal re-epithelialization was more accomplished in the DPYC group than in the DC group. In addition, the inflammatory cells were augmented in the DC group more than those in the DPYC one., Conclusion: The findings obtained revealed the efficiency of PYC for enhancing the corneal re-epithelialization and reducing the inflammatory reaction post alkali burn in rats, and thus it could be beneficially valuable as a treatment for the diabetic keratopathy., (© 2022. The Author(s).)

Background: Apoptosis signal-regulating kinase 1-interacting protein 1 (AIP1) participates in inflammatory neovascularization induction. NADPH oxidase 4 (NOX4) produces reactive oxygen species (ROS), leading to an imbalance in nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) and NLR family pyrin domain containing 6 (NLRP6) expression. The mechanisms of AIP1, NOX4, ROS and inflammasomes in corneal neovascularization were studied herein., Methods: C57BL/6 and AIP1-knockout mice were used in this study. The alkali burn procedure was performed on the right eye. Adenovirus encoding AIP1 plus green fluorescence protein (GFP) (Ad-AIP1-GFP) or GFP alone was injected into the right anterior chamber, GLX351322 was applied as a NOX4 inhibitor, and then corneal neovascularization was scored. The expression of related genes was measured by quantitative real-time polymerase chain reaction, western blotting and immunofluorescence staining. 2',7'-Dichlorofluorescin diacetate staining was used to determine the ROS levels., Results: The expression of AIP1 was decreased, while that of cleaved interleukin-1β (clv-IL-1β) and vascular endothelial growth factor A (VEGFa) was increased after alkali burn injury. NOX4 expression was increased, the imbalance in NLRP3/NLRP6 was exacerbated, and corneal neovascularization was increased significantly in AIP1-knockout mice compared with those in C57BL/6 mice after alkali burns. These effects were reversed by AIP1 overexpression. NLRP3/NLRP6 expression was imbalanced after alkali burns. GLX351322 reversed the imbalance in NLRP3/NLRP6 by reducing the ROS levels. This treatment also reduced the expression of clv-IL-1β and VEGFa, suppressing neovascularization., Conclusions: AIP1 and NOX4 can regulate corneal inflammation and neovascularization after alkali burn injury. Based on the pathogenesis of corneal neovascularization, these findings are expected to provide new therapeutic strategies for patients. Corneal alkali burn injury is a common type of ocular injury that is difficult to treat in the clinic. The cornea is a clear and avascular tissue. Corneal neovascularization after alkali burn injury is a serious complication; it not only seriously affects the patient's vision but also is the main reason for failed corneal transplantation. Corneal neovascularization affects approximately 1.4 million patients a year. We show for the first time that AIP1 and NOX4 can regulate corneal inflammation and neovascularization after alkali burns. The expression of AIP1 was decreased, while that of clv-IL-1β and VEGFa was increased after alkali burns. We tried to elucidate the specific molecular mechanisms by which AIP1 regulates corneal neovascularization. NOX4 activation was due to decreased AIP1 expression in murine corneas with alkali burns. NOX4 expression was increased, the imbalance in NLRP3/NLRP6 was exacerbated, and corneal neovascularization was increased significantly in AIP1-knockout mice compared with those in C57BL/6 mice after alkali burns. These effects were reversed by AIP1 overexpression. Additionally, NLRP3/NLRP6 expression was unbalanced, with NLRP3 activation and NLRP6 suppression in the corneal alkali burn murine model. Eye drops containing GLX351322, a NOX4 inhibitor, reversed the imbalance in NLRP3/NLRP6 by reducing ROS expression. This treatment also reduced the expression of clv-IL-1β and VEGFa, reducing neovascularization. Therefore, we provide new gene therapeutic strategies for patients. With the development of neovascularization therapy, we believe that in addition to corneal transplantation, new drug or gene therapies can achieve better results. Video Abstract., (© 2022. The Author(s).)

Corneal neovascularization (CNV) is the major cause of blindness after eye injury; however, only several drugs can be applied and the invasive administration ways (i.e., intravitreal injection and subconjunctival injection) are used. Resveratrol is a highly effective anti-VEGF agent against CNV. However, its applications are limited due to its strong hydrophobicity and instability. Here, we developed a resveratrol-loaded ocular lamellar crystalline gel (ROLG) for high inhibition of CNV. ROLGs were composed of resveratrol, glyceryl monooleate (GMO), ethanol, and water, and their lamellar crystalline structures were identified by polarizing light microscopy and small-angle X-ray scattering. High drug loading (4.4 mg/g) of ROLGs was achieved due to the hydrogen bonding between GMO and resveratrol. Resveratrol showed sustained release with 67% accumulative release in 7 h, which was attributed to the slow erosion of gels. Resveratrol in ROLGs had a high corneal permeation 3 times higher than resveratrol in hyaluronic acid suspensions (RHSs). ROLGs were administered to rats only once a day because of their strong retention on the cornea surface. ROLGs were safe due to the very little contact of ethanol in ROLGs to the cornea. CNV post-rat corneal alkaline injury was highly inhibited by ROLGs, resulting from the attenuation of corneal VEGF expression and then corneal healing was improved. The ROLG was a promising ocular medicine for the prevention of CNV.

Introduction: Alcohol-based hand sanitizers (ABHS) are widely used for hand hygiene due to the coronavirus disease pandemic. However, risk awareness regarding its adverse effects is lacking. We aim to report a case of ocular chemical burn that showed severe clinical presentation associated with ABHS., Patient Concerns: A 5-year-old girl presented with severe left eye pain after 62% gel-type ABHS splashed into her eye., Diagnosis: On slit lamp examination, a near total corneal and conjunctival epithelial defect with limbal pale on the lower half of the cornea was noted. Severe ocular burn by ABHS was prominent with suspected limbal stem cell damage., Interventions: She was hospitalized and was prescribed topical medications including antibiotics, steroid eye drops with preservative-free artificial tears, and oral nonsteroidal anti-inflammatory drugs., Outcomes: Despite intensive medical treatments, the corneal and conjunctival epithelial defects showed no improvement up to the 4th hospital day. After additional instillation of autoserum eye drops to promote epithelial healing, the corneal epithelium barely recovered from the temporal limbus. On the third week of admission, the epithelial defect was completely resolved without corneal opacity, although with minimal symblepharon in the lower fornix., Conclusions: Gel-type ABHS can cause severe form of ocular chemical burn such as delayed ocular surface healing. In clinical setting, immediate and thorough rinsing of alcohol-based gel and early intensive treatment are crucial., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To test whether an acute corneal injury activates a proinflammatory reflex, involving corneal sensory nerves expressing substance P (SP), the hypothalamus, and the sympathetic nervous system., Methods: C57BL6/N (wild-type [WT]) and SP-depleted B6.Cg-Tac1tm1Bbm/J (TAC1-KO) mice underwent bilateral corneal alkali burn. One group of WT mice received oxybuprocaine before alkali burn. One hour later, hypothalamic neuronal activity was assessed in vivo by magnetic resonance imaging and ex vivo by cFOS staining. Some animals were followed up for 14 days to evaluate corneal transparency and inflammation. Tyrosine hydroxylase (TH), neurokinin 1 receptor (NK1R), and neuronal nitric oxide synthase (nNOS) expression was assessed in brain sections. Sympathetic neuron activation was evaluated in the superior cervical ganglion (SCG). CD45+ leukocytes were quantified in whole-mounted corneas. Noradrenaline (NA) was evaluated in the cornea and bone marrow., Results: Alkali burn acutely induced neuronal activation in the trigeminal ganglion, paraventricular hypothalamus, and lateral hypothalamic area (PVH and LHA), which was significantly lower in TAC1-KO mice (P < 0.05). Oxybuprocaine application similarly reduced neuronal activation (P < 0.05). TAC1-KO mice showed a reduced number of cFOS+/NK1R+/TH+ presympathetic neurons (P < 0.05) paralleled by higher nNOS expression (P < 0.05) in both PVH and LHA. A decrease in activated sympathetic neurons in the SCG and NA levels in both cornea/bone marrow and reduced corneal leukocyte infiltration (P < 0.05) in TAC1-KO mice were found. Finally, 14 days after injury, TAC1-KO mice showed reduced corneal opacity and inflammation (P < 0.05)., Conclusions: Our findings suggest that stimulation of corneal sensory nerves containing SP activates presympathetic neurons located in the PVH and LHA, leading to sympathetic activation, peripheral release of NA, and corneal inflammation.

Leucine-rich α-2-glycoprotein-1 (LRG1) is a novel profibrotic factor that modulates transforming growth factor-β (TGF-β) signaling. However, its role in the corneal fibrotic response remains unknown. In the present study, we found that the LRG1 level increased in alkali-burned mouse corneas. In the LRG1-treated alkali-burned corneas, there were higher fibrogenic protein expression and neutrophil infiltration. LRG1 promoted neutrophil chemotaxis and CXCL-1 secretion. Conversely, LRG1-specific siRNA reduced fibrogenic protein expression and neutrophil infiltration in the alkali-burned corneas. The clearance of neutrophils effectively attenuated the LRG1-enhanced corneal fibrotic response, whereas the presence of neutrophils enhanced the effect of LRG1 on the fibrotic response in cultured TKE2 cells. In addition, the topical application of LRG1 elevated interleukin-6 (IL-6) and p-Stat3 levels in the corneal epithelium and in isolated neutrophils. The clearance of neutrophils inhibited the expression of p-Stat3 and IL-6 promoted by LRG1 in alkali-burned corneas. Moreover, neutrophils significantly increased the production of IL-6 and p-Stat3 promoted by LRG1 in TKE2 cells. Furthermore, the inhibition of Stat3 signaling by S3I-201 decreased neutrophil infiltration and alleviated the LRG1-enhanced corneal fibrotic response in the alkali-burned corneas. S3I-201 also reduced LRG1 or neutrophil-induced fibrotic response in TKE2 cells. In conclusion, LRG1 promotes the corneal fibrotic response by stimulating neutrophil infiltration via the modulation of the IL-6/Stat3 signaling pathway. Therefore, LRG1 could be targeted as a promising therapeutic strategy for patients with corneal fibrosis.

Disorders of the transparent cornea affect millions of people worldwide. However, how to maintain and/or regenerate this organ remains unclear. Here, we show that Rela (encoding a canonical NF-κB subunit) ablation in K14 + corneal epithelial stem cells not only disrupts corneal regeneration but also results in age-dependent epithelial deterioration, which triggers aberrant wound-healing processes including stromal remodeling, neovascularization, epithelial metaplasia, and plaque formation at the central cornea. These anomalies are largely recapitulated in normal mice that age naturally. Mechanistically, Rela deletion suppresses expression of Aldh1a1, an enzyme required for retinoic acid synthesis from vitamin A. Retinoic acid administration blocks development of ocular anomalies in Krt14-Cre; Rela f/f mice and naturally aged mice. Moreover, epithelial metaplasia and plaque formation are preventable by inhibition of angiogenesis. This study thus uncovers the major mechanisms governing corneal maintenance, regeneration, and aging and identifies the NF-κB-retinoic acid pathway as a therapeutic target for corneal disorders., Competing Interests: QY, SB, GM, PZ, BL, JL No competing interests declared, (© 2021, Yu et al.)

The purpose of this work is to describe the use of Fibrin-Plasma Rich in Growth Factors (PRGF) membranes for the treatment of a rabbit alkali-burn lesion. For this purpose, an alkali-burn lesion was induced in 15 rabbits. A week later, clinical events were evaluated and rabbits were divided into five treatment groups: rabbits treated with medical treatment, with a fibrin-PRGF membrane cultured with autologous or heterologous rabbit Limbal Epithelial Progenitor Cells (LEPCs), with a fibrin-PRGF membrane in a Simple Limbal Epithelial Transplantation and with a fibrin-PRGF membrane without cultured LEPCs. After 40 days of follow-up, corneas were subjected to histochemical examination and immunostaining against corneal or conjunctival markers. Seven days after alkali-burn lesion, it was observed that rabbits showed opaque cornea, new blood vessels across the limbus penetrating the cornea and epithelial defects. At the end of the follow-up period, an improvement of the clinical parameters analyzed was observed in transplanted rabbits. However, only rabbits transplanted with cultured LEPCs were positive for corneal markers. Otherwise, rabbits in the other three groups showed positive staining against conjunctival markers. In conclusion, fibrin-PRGF membrane improved the chemically induced lesions. Nonetheless, only fibrin-PRGF membranes cultured with rabbit LEPCs were able to restore the corneal surface.

The long-term survival of biomaterial implants is often hampered by surgery-induced inflammation that can lead to graft failure. Considering that most corneas receiving grafts are either pathological or inflamed before implantation, the risk of rejection is heightened. Here, we show that bioengineered, fully synthetic, and robust corneal implants can be manufactured from a collagen analog (collagen-like peptide-polyethylene glycol hybrid, CLP-PEG) and inflammation-suppressing polymeric 2-methacryloyloxyethyl phosphorylcholine (MPC) when stabilized with the triazine-based crosslinker 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The resulting CLP-PEG-MPC implants led to reduced corneal swelling, haze, and neovascularization in comparison to CLP-PEG only implants when grafted into a mini-pig cornea alkali burn model of inflammation over 12 months. Implants incorporating MPC allowed for faster nerve regeneration and recovery of corneal sensation. CLP-PEG-MPC implants appear to be at a more advanced stage of regeneration than the CLP-PEG only implants, as evidenced by the presence of higher amounts of cornea-specific type V collagen, and a corresponding decrease in the presence of extracellular vesicles and exosomes in the corneal stroma, in keeping with the amounts present in healthy, unoperated corneas.

Purpose: Corneal alkali burns (CABs) are a common clinical ocular disease, presenting a poor prognosis. Although some long noncoding RNAs (lncRNAs) reportedly play a key role in epigenetic regulation associated with CABs, studies regarding the lncRNA signature in CABs remain rare and elusive., Methods: A CAB model was established in C57BL/6J mice and profiling of lncRNA expressions was performed by RNA-Seq. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to predicate the related pathological pathways and candidate genes. RT-qPCR was used to verify the expression pattern of lncRNAs and related mRNAs, both in vitro and in vivo. Data were statistically analyzed by GraphPad Prism version 6.0., Results: In all, 4436 aberrantly expressed lncRNAs were identified in CAB mice when compared with control mice. In the top 13 aberrantly expressed lncRNAs, Bc037156 and 4930511E03Rik were confirmed as the most significantly altered lncRNAs. Pathway analysis revealed that mitogen-activated protein kinase (MAPK) signaling pathway was most enriched. Following 4930511E03Rik siRNA treated, Srgn, IL-1β and Cxcr2 were significant upregulated in corneal epithelial cells, corneal keratocytes, and bone marrow dendritic cells, with NaOH treatment. Moreover, after Bc037156 siRNA treated, expression levels of IL-1β and Srgn were significantly downregulated in the three cell lines., Conclusions: Our study suggests that Bc037156 and 4930511E03Rik may be involved in inflammation, immune response, and neovascularization by regulating Srgn, IL-1β, and Cxcr2 expression after CAB. These candidate lncRNAs and mRNAs may be the potential targets for the treatment strategy of the alkali injured cornea.

Purpose: This study aimed to investigate the therapeutic effects and underlying mechanisms of locally delivered regulatory T cells (Tregs) on acute corneal wound healing after alkali burn., Methods: After corneal alkali burn, the mice were injected subconjunctivally with regulatory T cells (Tregs) isolated from syngeneic mice. The wound healing process was monitored by clinical manifestation, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). As amphiregulin (Areg) was significantly upregulated, its reparative function in injured corneas was suggested. The hypothesis was further verified via loss- and gain-of-function experiments by administrating the antibody of Areg (anti-Areg) and recombinant Areg (rmAreg)., Results: Subconjunctivally injected Tregs rapidly migrated to injured corneas. The mice treated with Tregs showed prominently reduced corneal opacity, alleviated edema, and faster re-epithelialization compared with the control group. Mechanistically, Treg treatment led to suppressed infiltration of inflammatory cells, along with improved proliferation and inhibited apoptosis of corneal epithelial cells. Tregs expressed upregulated functional markers, including Areg. Expectantly, the levels of Areg in corneas were dramatically higher in the Treg injection group, in line with better corneal restoration. Additional experiments showed that the administration of anti-Areg blunted the reparative effect of Tregs, while exogenous Areg enhanced it. Treg-treated corneas also exhibited less neovascularization and fibrosis at a later reconstruction stage of corneal repair., Conclusions: The findings showed that the subconjunctival injection of Tregs effectively promoted corneal wound healing by inhibiting excessive inflammation and enhancing epithelial regeneration, with an indispensable reparative role of Areg. Subsequent complications of corneal vascularization and fibrosis were therefore reduced.

Neutrophils are the first cells to migrate into the cornea in response to alkali burns, and excessive neutrophil infiltration is associated with inflammatory injury and a poorer prognosis. In an effort to understand the mechanisms underlying the inflammation mediated by neutrophils after alkali burns, we examined the role of alkali-activated neutrophils on human corneal epithelial cells (HCEs) proliferation and migration, as well as the effects of acetylsalicylic acid (ASA) and dexamethasone (DXM) on NETosis. We stimulated human neutrophils with sodium hydroxide (NaOH) and observed dose- and time-dependent neutrophil extracellular traps (NETs) formation. We also observed that ASA, but not DXM, significantly inhibited NaOH-induced NETosis. Furthermore, the activation of nuclear factor (NF)-κB, but not the production of reactive oxygen species, was involved in ASA-regulated NETosis. Moreover, NETs were found to be involved in alkali-activated neutrophils (ANs) induced neutrophil-HCE adhesion. ANs enhanced HCEs proliferation via phagocytosis. Meanwhile, ANs inhibited HCEs migration through the release of NETs, which was partially rescued by 5 mM ASA. In conclusion, ANs may interfere with HCEs proliferation and migration by phagocytosis and NETs formation, respectively. ASA may enhance HCEs migration by decreasing NETs formation through inhibition of NF-κB activation and could be a promising strategy for improving the prognosis of corneal alkali burns., (Copyright © 2020 Wan, Zhang, Yuan, Min, Mou and Jin.)

Glaucoma is a frequent and devastating long-term complication following ocular trauma, including corneal surgery, open globe injury, chemical burn, and infection. Postevent inflammation and neuroglial remodeling play a key role in subsequent ganglion cell apoptosis and glaucoma. To this end, this study was designed to investigate the amplifying role of monocyte infiltration into the retina. By using three different ocular injury mouse models (corneal suture, penetrating keratoplasty, and globe injury) and monocyte fate mapping techniques, we show that ocular trauma or surgery can cause robust infiltration of bone marrow-derived monocytes into the retina and subsequent neuroinflammation by up-regulation of Tnf, Il1b, and Il6 mRNA within 24 hours. This is accompanied by ganglion cell apoptosis and neurodegeneration. Prompt inhibition of tumor necrosis factor-α or IL-1β markedly suppresses monocyte infiltration and ganglion cell loss. Thus, acute ocular injury (surgical or trauma) can lead to rapid neuroretinal inflammation and subsequent ganglion cell loss, the hallmark of glaucoma. Infiltrating monocytes play a central role in this process, likely amplifying the inflammatory cascade, aiding in the activation of retinal microglia. Prompt administration of cytokine inhibitors after ocular injury prevents this infiltration and ameliorates the damage to the retina-suggesting that it may be used prophylactically for neuroprotection against post-traumatic glaucoma., (Copyright © 2020 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Purpose: This study investigated the role of S100 calcium binding protein A4 (S100A4) in corneal wound healing and the underlying mechanism of the S100A4-mediated PI3K/Akt/mammalian target of rapamycin (mTOR) pathway., Methods: The rabbit corneal alkali burn model was established in vivo. S100A4 expression, wound healing, inflammation, and autophagy in rabbit cornea after alkali burn were detected. The NaOH-treated rabbit corneal stromal cells (rCSCs) were transfected with overexpressed S100A4 or silencing S100A4 to examine the effect of S100A4 on corneal wound healing in vitro. The effect of S100A4 on cell viability, proliferation, migration, invasion, fibrosis, and autophagy of rCSCs after alkali burn was analyzed. Then the functional rescue experiments were carried out. The PI3K inhibitor, LY294002, was used to elucidate the PI3K/Akt/mTOR signaling pathway in rCSCs., Results: S100A4 silencing promoted rabbit corneal wound healing by inhibiting fibrosis and inflammation and promoting autophagy in alkali-burned cornea, corresponding to increased levels of LC3, Beclin 1, and Atg4B but lowered α-smooth muscle actin, TNF-ɑ, and p62 levels. Moreover, silencing S100A4 inhibited proliferation, migration, invasion, and fibrosis of NaOH-treated rCSCs and promoted the differentiation of rCSCs into corneal cells and the autophagy of damaged rCSCs. The inhibitory role of S100A4 in wound healing was achieved via activation of the PI3K/Akt/mTOR pathway., Conclusions: S100A4 silencing confers a promising effect on wound healing of alkali-burned cornea by blocking the PI3K/Akt/mTOR pathway, supporting the advancement of corneal gene therapies for wound healing.

Corneal chemical burns can lead to blindness following serious complications. As most of these complications are caused by failure of reepithelization during the acute phase, treatment at this stage is critical. Although there have been some studies on corneal injury recovery using adipose tissue-derived stem cells (ADSCs), none has reported the effect of topical cell-free conditioned culture media (CM) derived from ADSCs on corneal epithelial regeneration. Here, the best conditions for CM were selected and used for in vitro and in vivo experiments. Corneal burn in rats was induced using 100% alcohol. The chosen CM was administered to corneal burn rats (CM-treated [CT] group) four times a day for three days and this group was compared with the normal control and corneal burn (CB) groups. Biomicroscopic fluorescence images and the actual physical corneas were taken over time and used for analysis. mRNA levels of hepatocyte growth factor and epidermal growth factor (EGF) were significantly increased, whereas those of vascular endothelial growth factor, interleukin (IL)-1β, IL-6, IL-10, and matrix metalloproteinase-9 were significantly decreased in the CT group compared with those in the CB group. The numbers of proliferating cell nuclear antigen- and zonular occludens-1-positive cells in the CT group were significantly higher than those in the CB group. The macrophage-infiltrating corneas in the CT group expressed significantly more of the M2 marker arginase than corneas in the CB group. Optimal CM (× 0.5 concentration) treatment significantly accelerated the migration of corneal epithelial cells and induced upregulation of the expression of IL-6, EGF, and C-X-C chemokine receptor type 4 mRNAs. Overall, in this study, topical administration of cell-free CM promoted regeneration of the corneal epithelium after induction of chemical burns.

Peroxisome proliferator-activated receptor alpha (PPARα) and gamma (PPARγ) agonists have anti-inflammatory and anti-neovascularization effects, but few reports have tested the combination of PPARα and PPARγ agonists. In this study, we investigated the therapeutic effects of ophthalmic solutions of agonists of PPARα, PPARγ, and the combination in a rat corneal alkali burn model. After alkali injury, an ophthalmic solution of 0.05% fenofibrate (PPARα group), 0.1% pioglitazone (PPARγ group), 0.05% fenofibrate + 0.1% pioglitazone (PPARα+γ group), or vehicle (vehicle group) was topically instilled onto the rat's cornea twice a day. After instillation, upregulation was seen of PPAR mRNA corresponding to each agonist group. Administration of agonists for PPARα, PPARγ, and PPARα+γ suppressed inflammatory cells, neovascularization, and fibrotic changes. In addition, the PPARγ agonist upregulated M2 macrophages, which contributed to wound healing, whereas the PPARα agonist suppressed immature blood vessels in the early phase. Administration of PPARα+γ agonists showed therapeutic effects in corneal wound healing, combining the characteristics of both PPARα and PPARγ agonists. The results indicate that the combination of PPARα and γ agonists may be a new therapeutic strategy.

Corneal alkali burns are potentially blinding injuries. Alkali induces oxidative stress in corneas followed by excessive corneal inflammation, neovascularization, and untransparent scar formation. Molecular hydrogen (H 2 ), a potent reactive oxygen species (ROS) scavenger, suppresses oxidative stress and enables corneal healing when applied on the corneal surface. The purpose of this study was to examine whether the H 2 pretreatment of healthy corneas evokes a protective effect against corneal alkali-induced oxidative stress. Rabbit eyes were pretreated with a H 2 solution or buffer solution, by drops onto the ocular surface, and the corneas were then burned with 0.25 M NaOH. The results obtained with immunohistochemistry and pachymetry showed that in the corneas of H 2 -pretreated eyes, slight oxidative stress appeared followed by an increased expression of antioxidant enzymes. When these corneas were postburned with alkali, the alkali-induced oxidative stress was suppressed. This was in contrast to postburned buffer-pretreated corneas, where the oxidative stress was strong. These corneas healed with scar formation and neovascularization, whereas corneas of H 2 -pretreated eyes healed with restoration of transparency in the majority of cases. Corneal neovascularization was strongly suppressed. Our results suggest that the corneal alkali-induced oxidative stress was reduced via the increased antioxidant capacity of corneal cells against reactive oxygen species (ROS). It is further suggested that the ability of H 2 to induce the increase in antioxidant cell capacity is important for eye protection against various diseases or external influences associated with ROS production., Competing Interests: The authors declare no conflict of interest regarding the publication of this article., (Copyright © 2020 Cestmir Cejka et al.)

Button battery ingestions result in significant morbidity and mortality in children-before, during, and even after removal. The injuries created by a button battery lodged in the esophagus develop rapidly and can be severe. The current of the button battery, conducted through saliva and the tissue drives a highly alkaline caustic injury, leading to liquefactive tissue necrosis. In June 2018, new guidelines were released from the National Capital Poison Center, which include the use of preoperative protective, pH-neutralizing and viscous barrier interventions with honey and/or sucralfate administered within 12 h of ingestion. In addition, the use of postremoval irrigation of the esophagus with 50-150 mL 0.25% acetic acid is done in the operating room to help neutralize the site of tissue injury. Given that anesthesiologists play an important role in the management of esophageal foreign body removal, the entire specialty needs to be aware of the supporting data behind this and general perioperative considerations for management and potential complications of button battery ingestion.

There are many chemicals that can cause burns. Although they are generally acidic and basic in nature, there are more than one million known chemical compounds, of which 300 have been declared highly hazardous chemical substances by the National Fire Protection Society. Chemical burns account for approximately 10.7% of all burn injuries and 30% of deaths because of burns. Chemicals can be classified as acid, alkali, organic, and inorganic compounds. Acids act by denaturing and coagulating proteins. Alkaline burns cause deeper burns than acid burns., (© 2019 Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

Symblepharon due to chemical burns affects ocular surface health, and there are currently no satisfactory treatments. To improve our understanding of symblepharon, an appropriate animal model is urgently needed. We established a rabbit model of superior conjunctival sac alkaline burn to evaluate symblepharon severity. Alkali burns were induced in rabbits by contacting the superior conjunctival sac with 2 N NaOH-soaked semicircle filter paper (10 mm diameter) for 60 s, 90 s or 120 s. Clinical and histological features were examined, symblepharon severity was evaluated via conjunctival sac depth (grade I - IV) and volume measurements (grade a-d) post-injury at 4 weeks. With increasing alkali burn duration, corneal perforation and symblepharon severity increased. The 60 s group manifested a sub-conjunctiva scar. The 90 s group featured localized adhesion. The 120 s group was characterized by extensive scar hyperplasia and adhesion. The rabbit model exhibited stable and reliable symblepharon following an alkali burn of the superior conjunctival sac. For further research, 90 s is a suitable duration for conjunctival sac burn. The volume measured using conjunctival sac casting was considered when developing a successful evaluation system for symblepharon severity.

Background: Corrosive ingestion (CI) has short- and long-term consequences. The aim of this study was to assess the outcome of mucosal injury grade ≥ 2A., Methods: Consecutive patients between January 2008 and January 2015 who presented within 48 h of CI were included. Details of substance ingested, intent, symptoms, injury grade at endoscopy, and treatment were obtained by a review of medical records. Patients aged less than 15 years or injury grade less than 2A were excluded. Patients were followed up using a structured symptom-based questionnaire and barium swallow., Results: A total of 112 patients were admitted with CI during the study period. Eighty-two patients were included in the study. There was no relationship between the presence of symptoms or oral mucosal injury and the grades of gastrointestinal mucosal injury. Grades 2B and 3A were the most common grades of mucosal injury. Five patients died at index hospitalization. Patients were followed up for a median period of 31 months (6-72) during which 11 patients were lost to follow up. During follow up, 2 patients with high-grade injury died as a consequence of CI and 4 died of unrelated causes. Sixteen (26.6%) patients remained symptomatic. Forty-three patients underwent barium swallow. Esophageal stricture was identified in 11 patients, gastric stricture in 8, and combined esophageal and gastric in 2. High-grade esophageal mucosal injury was associated with a high risk of stricture formation (p = 0.02)., Conclusions: CI is associated with high immediate and long-term morbidity and mortality.

Severe corneal inflammation produces opacity or even perforation, scarring, and angiogenesis, resulting in blindness. In this study, we used the cornea to examine the effect of new anti-angiogenic chemopreventive agents. We researched the anti-angiogenic effect of two extracts, methanol (Met) and hexane (Hex), from the seed of Cucurbita argyrosperma , on inflamed corneas. The corneas of Wistar rats were alkali-injured and treated intragastrically for seven successive days. We evaluated: opacity score, corneal neovascularization (CNV) area, re-epithelialization percentage, and histological changes. Also, we assessed the inflammatory (cyclooxigenase-2, nuclear factor-kappaB, and interleukin-1β) and angiogenic (vascular endothelial growth factor A, VEGF-A; -receptor 1, VEGFR1; and -receptor 2, VEGFR2) markers. Levels of Cox-2 , Il-1β , and Vegf-a mRNA were also determined. After treatment, we observed a reduction in corneal edema, with lower opacity scores and cell infiltration compared to untreated rats. Treatment also accelerated wound healing and decreased the CNV area. The staining of inflammatory and angiogenic factors was significantly decreased and related to a down-expression of Cox-2 , Il-1β , and Vegf . These results suggest that intake of C. argyrosperma seed has the potential to attenuate the angiogenesis secondary to inflammation in corneal chemical damage.

Acute ocular chemical burns are ophthalmic emergencies requiring immediate diagnosis and treatment as they may lead to permanent impairment of vision. The clinical manifestations of such burns are produced by exacerbated innate immune response via the infiltration of inflammatory cells and activation of stromal fibroblasts. New therapies are emerging that are dedicated to repair mechanisms that improve the ocular surface after damage; for example, transplantation of stem cells (SC) has been successfully reported for this purpose. The pursuit of easily accessible, noninvasive procedures to obtain SC has led researchers to focus on human tissues such as amniotic membrane. Human amniotic mesenchymal SC (hAM-MSC) inhibits proinflammatory and fibrotic processes in different diseases. hAM-MSC expresses low levels of classical MHC-I and they do not express MHC-II, making them suitable for regenerative medicine. The aim of this study was to evaluate the effect of intracameral injection of hAM-MSC on the clinical manifestations, the infiltration of inflammatory cells, and the activation of stromal fibroblasts in a corneal alkali-burn model. We also determined the in vitro effect of hAM-MSC conditioned medium (CM) on α-SMA + human limbal myofibroblast (HLM) frequency and on release of neutrophil extracellular traps (NETs). Our results show that intracameral hAM-MSC injection reduces neovascularization, opacity, stromal inflammatory cell infiltrate, and stromal α-SMA + cells in our model. Moreover, in in vitro assays, CM from hAM-MSC decreased the quantity of α-SMA + HLM and the release of NETs. These results suggest that intracameral hAM-MSC injection induces an anti-inflammatory and anti-fibrotic environment that promotes corneal wound healing. Stem Cells Translational Medicine 2018;7:906-917., (© 2018 The Authors. Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

Chemical burn injury of the eye is a medical emergency that requires immediate intervention and structured ophthalmic assessment without unnecessary delay. Chemicals, alkali in particular but also acids, cause profound damage to the anatomy of the ocular surface or even deeper eye structures. The injury is potentially sight-threatening and can, in the worst cases, lead to loss of the eye. Reconstructive surgery is complex and often involves multiple surgeries but can give very good results in carefully selected cases. This article summarizes present evidence-based guidelines relevant for Swedish conditions and in use at St. Erik Eye Hospital in Stockholm.

Neprilysin (NEP), an ectoenzyme that modulates inflammation by degrading neuropeptides, was recently identified in the human corneal epithelium. The cornea expresses many NEP substrates, but the function of NEP in homeostatic maintenance and wound healing of the cornea is unknown. We therefore investigated the role of this enzyme under naive and injured conditions using NEP-deficient (NEP -/- ) and wild type (WT) control mice. In vivo ocular surface imaging and histological analysis of corneal tissue showed no differences in limbal vasculature or corneal anatomy between naive NEP -/- and WT mice. Histological examination revealed increased corneal innervation in NEP -/- mice. In an alkali burn model of corneal injury, corneal wound healing was significantly accelerated in NEP -/- mice compared to WT controls 3 days after injury. Daily intraperitoneal administration of the NEP inhibitor thiorphan also accelerated corneal wound healing after alkali injury in WT mice. Collectively, our data identify a previously unknown role of NEP in the cornea, in which pharmacologic inhibition of its activity may provide a novel therapeutic option for patients with corneal injury.

Background: Descemet's membrane detachment (DMD) is a rare complication after ocular chemical injury and its pathogenesis remains unclear. In this study, we reported two cases of DMD with traction demonstrated on Anterior segment optical coherence tomography (AS-OCT)., Case Presentation: Two patients sustained ocular chemical injury with 50% sodium hydroxide. In both cases, AS-OCT revealed detached Descemet's membrane that was adherent to the underlying iris tissue in the inferior quadrant at 45 days and 34 days after the injury respectively. The first case received intracameral tamponade with 12% C 3 F 8 gas and the second case received corticosteroid and sodium chloride 5% eye drops. However, DMD persisted in both cases., Conclusions: The atypical features of DMD on anterior segment optical coherence tomography in our cases suggested the presence of an inflammatory component caused adhesions and traction of iris to Descemet's membrane and prevented reattachment of DMD even with gas tamponade.

Competing Interests: Competing interests: None declared.

The research is based on the results of the examination and treatment of 156 patients who received treatment for extended benign esophageal strictures after corrosive injuries in the department of diseases of the esophagus and the gastrointestinal tract of the State Institution "V. T. Zaitsev Institute of General and Urgent Surgery of NAMS of Ukraine" for the period from 2000 to 2016. Surgical treatment by the developed in our hospital technique performed in the patients of the main group and the classical methods of surgery were used in the patients of comparison group. The developed in our clinic method of one-step transhital esophagogastroplasty with formation of a single anastomosis on the neck in patients with extended benign esophageal strictures after corrosive injuries in the state of compensation and subcompensation can be considered as a method of choice. Adequate preoperative verification of the type of extended damage by the cicatricial process of the upper part of digestive tract and the impossibility of eating in a natural way in the acute postburn period, as well as significant nutritive disorders in patients, provide the basis for two-step surgical treatment. This approach involves formation of gastrostomy at the first step for the restoration of trophological status of the patient and esophagoplasty at the second step. The two-step surgical treatment of patients with extended benign esophageal strictures after corrosive injuries with the formation of contact gastrostomy at first step and the implementation of esophagogastroplasty on the second step promotes improvement of treatment outcomes and life quality of the operated patients.

Purpose: The aim of this study was to evaluate the inhibitory effect of different concentrations of KH902 eye drops on rabbit corneal neovascularization (CNV) induced by alkali burn., Methods: Forty-eight adult rabbits were randomized into four groups after alkali burning: Group A (2.5 mg/ml), Group B (5 mg/ml), and Group C (10 mg/ml) by different concentrations of KH902 eye drops and Group D by saline solution as control with three times a day for 2 weeks. At days 7, 14, and 28, the anterior segment photographs, confocal microscopy, and histopathology were performed to evaluate corneal opacity, neovascularization, inflammatory cell density, vessel size, and edema. Immunohistochemistry was applied to analyze the vascular endothelial growth factor (VEGF) level., Results: (1) The CNV in the medicine-treated groups showed a reduction without obvious corneal side effects histologically. (2) Compared to the control group, the three medicine-treated groups showed a reduction in the VEGF levels and CNV areas on days 7, 14, and 28 and in the inflammatory cell density on days 14 and 28 (P < 0.01). The difference of inflammatory cell density between the three medicine-treated groups existed on day 14 (P < 0.01). There were differences in the VEGF levels between Groups A, B, and C on days 7, 14, and 28 (P < 0.01), not for Groups B and C on day 28 (P > 0.05)., Conclusion: KH902 eye drops in lower concentration showed an obvious reduction of the CNV growing for rabbit corneal alkali burn without side effects.

Caustic poisonings are still associated with many fatalities. Studies focusing on the elderly are rare. The purpose of the present study was to compare the clinical outcomes of caustic ingestion injury in elderly and non-elderly adults with regard to gender, intent of exposure, substance ingested, severity of mucosal injury, complications, and mortality. Caustic substance exposures reported to the National Toxicological Information Centre in Slovakia during 1998-2015 were reviewed retrospectively. The patients were divided into two groups: the non-elderly (<60 years) and elderly adults (≥60 years). The mortality rate in the elderly was significantly higher (elderly 23.0% vs. non-elderly 11.3%; p = 0.041). The risk of fatal outcome in the elderly was increased by acid ingestion (OR = 7.822; p = 0.002), particularly hydrochloric acid (OR = 5.714, p = 0.006). The incidence of respiratory complications was almost two times higher in the elderly was 31.1% vs. 17.4% for the non-elderly ( p = 0.037). Respiratory complications significantly correlated with an increased mortality rate ( p = 0.001) in the elderly whereas there was no association between GI complications and mortality in the elderly ( p = 0.480). Elderly patients with respiratory complications had the poorest clinical outcomes. The highest risk of complications and fatalities was observed in patients after hydrochloric acid ingestion., Competing Interests: The authors declare no conflict of interest.

Epidemiological studies have indicated that smoking is a pivotal risk factor for the progression of several chronic diseases. Nicotine, the addictive component of cigarettes, has powerful pathophysiological properties in the body. Although the effects of cigarette smoking on corneal re-epithelialization have been studied, the effects of nicotine on corneal wound healing-related neovascularization and fibrosis have not been fully demonstrated. The aim of this study was to evaluate the effects of chronic administration of nicotine on corneal wound healing following acute insult induced by an alkali burn. BALB/C female mice randomly received either vehicle (2% saccharin) or nicotine (100 or 200 μg/ml in 2% saccharin) in drinking water ad libitum. After 1 week, animals were re-randomized and the experimental group was subjected to a corneal alkali burn, and then nicotine was administered until day 14 after the alkali burn. A corneal alkali burn model was generated by placing a piece of 2 mm-diameter filter paper soaked in 1N NaOH on the right eye. Histopathological analysis and the expression level of the pro-angiogenic genes vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP9) revealed that chronic nicotine administration enhanced alkali burn-induced corneal neovascularization. Furthermore, the mRNA expression of the pro-fibrogenic factors α-smooth muscle actin (αSMA), transforming growth factor-β (TGF-β), and collagen α1 (Col1) was enhanced in the high-concentration nicotine-treated group compared with the vehicle group after corneal injury. Immunohistochemical analysis also showed that the αSMA-positive area was increased in chronic nicotine-treated mice after corneal alkali burn. An in vitro assay found that expression of the α3, α7, and β1 nicotinic acetylcholine receptor (nAChR) subunits was significantly increased by chemical injury in human corneal fibroblast cells. Moreover, alkali-induced fibrogenic gene expression and proliferation of fibroblast cells were further increased by treatment with nicotine and cotinine. The proliferation of such cells induced by treatment of nicotine and cotinine was reduced by inhibition of the PI3K and PKC pathways using specific inhibitors. In conclusion, chronic administration of nicotine accelerated the angiogenic and fibrogenic healing processes in alkali-burned corneal tissue.

Alkali burns to the eye constitute a leading cause of worldwide blindness. In recent case series, corneal transplantation revealed unexpected damage to the retina and optic nerve in chemically burned eyes. We investigated the physical, biochemical, and immunological components of retinal injury after alkali burn and explored a novel neuroprotective regimen suitable for prompt administration in emergency departments. Thus, in vivo pH, oxygen, and oxidation reduction measurements were performed in the anterior and posterior segment of mouse and rabbit eyes using implantable microsensors. Tissue inflammation was assessed by immunohistochemistry and flow cytometry. The experiments confirmed that the retinal damage is not mediated by direct effect of the alkali, which is effectively buffered by the anterior segment. Rather, pH, oxygen, and oxidation reduction changes were restricted to the cornea and the anterior chamber, where they caused profound uveal inflammation and release of proinflammatory cytokines. The latter rapidly diffuse to the posterior segment, triggering retinal damage. Tumor necrosis factor-α was identified as a key proinflammatory mediator of retinal ganglion cell death. Blockade, by either monoclonal antibody or tumor necrosis factor receptor gene knockout, reduced inflammation and retinal ganglion cell loss. Intraocular pressure elevation was not observed in experimental alkali burns. These findings illuminate the mechanism by which alkali burns cause retinal damage and may have importance in designing therapies for retinal protection., (Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this study is to explore the inhibitory effects of S100A4 gene silencing on alkali burn-induced corneal neovascularization (CNV) in rabbit models., Methods: Sixty-five rabbits were used to establish alkali-induced CNV models. After the operation, rabbits were given daily antibiotic eye drops and an eye ointment to prevent infection. The models were assigned to either an S100A4 siRNA or an empty vector group. Thirty rabbits were selected as the normal control group. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the mRNA expression of S100A4 , vascular endothelial growth factor (VEGF), and tumor necrosis factor-α (TNF-α) in corneal tissues. Immunohistochemistry was used to detect the protein expression of VEGF in corneal tissues, and an enzyme-linked immunosorbent (ELISA) assay was used to detect the protein expression of VEGF and TNF-α in the aqueous humor., Results: The qRT-PCR results showed that S100A4 mRNA expression was lower in the S100A4 siRNA group than in the empty vector group at 1, 3, 7, 14, and 28 days after an alkali burn. When compared with the empty vector group, the expression of VEGF and TNF-α mRNA was downregulated in the S100A4 siRNA group. The immunohistochemistry results revealed that VEGF protein expression was downregulated in the S100A4 siRNA group when compared to the empty vector group at 1, 3, 7, 14, and 28 days after an alkali burn. The ELISA results suggest that VEGF and TNF-α protein expression is downregulated in the S100A4 siRNA group in comparison to the empty vector group at 1, 3, 7, 14, and 28 days after an alkali burn., Conclusions: These findings indicate that S100A4 gene silencing can inhibit alkali burn-induced CNV in rabbits.

Biomedical applications of plasma require its efficacy for specific purposes and equally importantly its safety. Herein the safety aspects of cold plasma created with simple atmospheric pressure plasma jet produced with helium gas and electrode discharge are evaluated in skin damage on mouse, at different duration of exposure and gas flow rates. The extent of skin damage and treatments are systematically evaluated using stereomicroscope, labelling with fluorescent dyes, histology, infrared imaging and optical emission spectroscopy. The analyses reveal early and late skin damages as a consequence of plasma treatment, and are attributed to direct and indirect effects of plasma. The results indicate that direct skin damage progresses with longer treatment time and increasing gas flow rates which reflect changes in plasma properties. With increasing flow rates, the temperature on treated skin grows and the RONS formation rises. The direct effects were plasma treatment dependent, whereas the disclosed late-secondary effects were more independent on discharge parameters and related to diffusion of RONS species. Thermal effects and skin heating are related to plasma-coupling properties and are separated from the effects of other RONS. It is demonstrated that cumulative topical treatment with helium plasma jet could lead to skin damage. How these damages can be mitigated is discussed in order to provide guidance, when using atmospheric pressure plasma jets for skin treatments.

Corneal neovascularization may result in loss of corneal transparency and blindness. However, developing successful and inexpensive medical treatments for corneal neovascularization remains an unresolved issue. Recently, several studies have implicated miRNA functions in the regulation of cornea homeostasis. This study aimed to identify the miRNA expression profile in the neovascularized cornea after an alkali burn and to investigate the related underlying mechanisms. Here, alkali-burned corneas and matched normal tissues were pooled to perform miRNA sequencing. MiR-21 in alkali-burned cornea showed the greatest increment of abundance at 4 and 7 d after injury compared to the healthy cornea. The miR-21 expression was positively correlated with both the mRNA and protein level of key angiogenic factors including vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor-1α (HIF-1α). At 2 and 8 d after alkali burn, the mice received subconjunctival injections of antagomir-21 (1 or 5 nmol per injection). The injection of antagomir-21 (5 nmol) inactivated miR-21 and attenuated neovascularization progression by inhibiting the expression of VEGF-A and HIF-1α. Western blot analysis of the corneas demonstrated that antagomir-21 restored Sprouty 2/4 expression and silenced p-ERK activation. Therefore, these data reveal that antagomir-21 ameliorates the progression of corneal neovascularization likely via Sprouty 2/4-mediated inactivation of p-ERK. Delivery of antagomir-21 might be a potential therapeutic approach to prevent or treat visual loss caused by corneal neovascularization.

Accidental caustic ingestions are serious medical problems especially in childhood. Various treatment modalities are being used for the complications of caustic injuries such as stricture formation. The aim of this study is to establish whether ursodeoxycholic acid (UDCA) has protective effects on experimental corrosive esophagitis in rats. Twenty four Wistar-albino rats, weighing 220-240 g, were used in the study. Experimental animals were divided in three groups randomly: UDCA treatment group (Group T, n:8), control group (Group K, n: 8) and sham group (Group S, n: 8). In group T and S corrosive esophagitis was induced. UDCA (5 mg/kg) was performed to the group T for 10 days orally. All animals were sacrificed at the end of procedures and histopathological changes in esophageal tissue were scored by a single investigator who was blind to the groups. In group T inflammation was present in two rats, muscularis mucosa injury in two rats, grade 1 collagen deposition in six rats and grade 2 in two rats. In comparison with group S these were statistically significant (p value was 0.003, 0.003 and 0.015, respectively). UDCA has protective effect in experimental corrosive esophagitis., Key Words: Corrosive esophagitis, Rat, Stricture, Ursodeoxycholic acid.