[Ocular burns: epidemiological, clinical, therapeutic and evolutionary aspects at the Cocody University Hospital, Côte d'Ivoire]. / Les brûlures oculaires : aspects épidémiologiques, cliniques, thérapeutiques et évolutifs au Centre hospitalier universitaire de Cocody, Côte d'Ivoire.

Justification: This study describes the socio-demographic characteristics, clinical, therapeutic, and evolutionary aspects of ocular burns to contribute to the improvement of their management. Method: A retrospective study was conducted in the Ophthalmology Department of the Cocody University Hospital (CHU) in Abidjan, Côte d'Ivoire, from January 1, 2020, to January 31, 2021. It focused on 49 patient records with ocular trauma, including 12 bilateral cases, totaling 61 eyes. For each patient, socio-demographic data, the nature of the traumatic agent, burn etiologies, ocular burn stage, initial and final uncorrected visual acuity of the affected eye, and treatment were collected. Results: The proportion of ocular burns was 11% out of 436 cases of ocular trauma that consulted in the department. The average age of patients was 27.9 years ± 14.2, ranging from 3 to 60 years, with a male predominance (70%). Students were the most frequent socio-professional category (39%). Work-related accidents were the predominant circumstances, in a third of cases. Chemical agents were the main traumatic agents, in 54% of cases. The average consultation time was 3.5 days ± 7.9, ranging from 1 to 60 days. Stage 1 of the Roper-Hall classification was the most observed stage (51% of cases). Initial visual acuity of the affected eye was less than 1/20 in 28% of cases. Treatment was mainly medical, and a third of treated eyes had a final acuity less than 1/20. Conclusion: Visual prognosis is influenced by burn stages, etiologies, and consultation time, varying according to social and geographical origins.

Evaluation of the Treatment Effects of Conditioned Medium from Human Orbital Adipose-Derived Stem Cells in a Corneal Alkali Burn Rabbit Model.

Purpose: This study aimed to evaluate the effects of a new treatment-conditioned medium from human orbital adipose-derived stem cells (OASC-CM)-on corneal recovery after alkali burns in a rabbit model. Methods: The corneal alkali burn rabbit model was established and treated with OASC-CM, conditioned medium from human abdominal subcutaneous adipose-derived stem cells (ABASC-CM), and fresh control culture medium (con-CM) three times a day for 7 days, respectively. Subsequently, the treatment effects were evaluated and compared through clinical, histological, immunohistochemical, and cytokine evaluations. Results: Clinically, OASC-CM alleviated corneal opacity and edema and promoted recovery of corneal epithelium defect. Histologically and immunohistochemically, OASC-CM inhibited neovascularization, conjunctivalization, and immuno-inflammatory reaction, while promoting corneal regeneration and rearrangement. Increased secretion of interleukin-10 and inhibited protein levels of cluster of differentiation 45, interferon-γ, and tumor necrosis factor-α were observed in the alkali-burned cornea after OASC-CM treatment, which might be the relevant molecular mechanism. Conclusions: OASC-CM showed significant effects on the recovery of rabbit corneal alkali burns and eliminated immunological and ethical limitations, representing a new option for corneal wound treatment.

Augenverätzungen.

Chemical burns of the ocular surface (CBOS) are emergencies of highest urgency. Therefore, an adequate emergency care is mandatory. Following a precise analysis of the initial damage, a staged therapeutic approach is used to prevent persistent impairment of the ocular surface. In the acute stage, the prevention of complications is targeted (symblepharon, conjunctival scarring, lacrimal stenosis, corneal ulceration, intraocular inflammation, elevated intraocular pressure, etc.). In later stages, if complications have developed, a secondary restoration of the ocular surface is focussed. Sometimes this requires several surgical interventions. Based on a review of international literature, this review highlights the pathophysiology according to different chemical agents, CBOS stages as well as main therapy strategies in early and advanced stages of CBOS. Acute treatment aims to lower inflammation, oxidative stress and tries to promote reepithelialisation. Besides conjunctival scarring, loss of goblet cells and corneal opacification a limbal stem cell insufficiency is the most harming complication. Several new techniques have been developed to recover the ocular surface with a sufficient and clear epithelial layer in order to avoid neovascularization of the cornea. The knowledge concerning the high risk potential for persistent visual impairment in CBOS patients and the ability for appropriate emergency care should be kept in every physician's mind dealing with CBOS.

Ocular Complications of Facial Burns in the Pediatric Population.

Pediatric ocular burns carry a risk of permanent vision impairment. This study identifies risk factors that place these patients at high risk of permanent visual complications. A retrospective review was conducted in our academic urban pediatric burn center. All 300 patients under 18 years of age admitted from January 2010 to December 2020 with periorbital or ocular thermal injuries were included. Variables analyzed included patient demographics, burn characteristics, ophthalmology consultation, ocular exam findings, follow up time period, and early and late ocular complications. Etiologies of burn injuries were as follows: 112 (37.5%) scald, 80 (26.8%) flame, 35 (11.7%) contact, 31 (10.4%) chemical, 28 (9.4%) grease, and 13 (4.3%) friction. Overall, 207 (70.9%) patients with ocular burns received an ophthalmology consult. Of these patients, 61.5% had periorbital cutaneous burns and 39.8% had corneal injuries, and only 61 (29.5%) presented for a follow-up visit. Ultimately, six had serious ocular sequelae, including ectropion, entropion, symblepharon, and corneal decompensation. While thermal burns involving the ocular surface and eyelid margins are relatively infrequent overall, they carry a small risk of serious to long-term sequelae. Recognizing those at greatest risk, and initiating appropriate early intervention is critical.

Ocular-periocular burns in a tertiary hospital: Epidemiologic characteristics.

PURPOSE: Ocular burns are ophthalmic emergencies that can cause devastating injuries. This study aimed to analyze the epidemiology, complications, and management of ocular-periocular burns. METHODS: A total of 193 patients with ocular-periocular burns were admitted to our tertiary hospital from January 2018 to December 2020. The demographic characteristics of the patients, injury variables, complications, and treatments were evaluated. RESULTS: There were 142 male (73.6%) and 51 female (26.4%) patients with a mean age of 32.53±17.75 years. The average total body surface area was 12% (range, 1-80%). Injuries were most common at work (52.3%) and home (36.3%). Thermal burns were the most common injuries (74.6%), followed by chemical (14.5%) and electrical burns (10.9%). Alkaline agents (75.0%), mainly sodium hydroxide and lime, were common in chemical burns. Superficial lid burns were significantly higher in the thermal group (p < 0.001), and grade III-IV corneal burns were significantly higher in the chemical group (p < 0.001). Various complications were developed in 50 (13%) eyes. Medical treatment only was performed in 318 (82.4%) eyes, and additional surgical treatment was performed in 64 (17.6%) eyes; however, 54 (14.0%) underwent more than one surgery. The most common complications were corneal scars (7.3%), limbal deficiency (4.1%), and ectropion (3.9%). The most frequent procedures performed were amniotic membrane transplantation (AMT) (11.9%) and tarsorrhaphy (6.7%). CONCLUSION: Chemical burns, limbal and conjunctival ischemia, and full-thickness eyelid defects had a poor prognosis. The degree of limbal deficiency and injury of intraocular structures were found to have a great influence on the outcome of their visual acuity.

Carbide Gun-Related Ocular Injuries: A Case Series.

PURPOSE: The purpose of this study was to report a case series of sight-threatening ocular injuries caused by calcium carbide guns used as fire crackers. METHODS: Medical records of 15 eyes of 14 patients with ocular injuries caused while using carbide guns, visiting the Institute, from January 2021 to January 2022, were retrospectively reviewed. The collected data included patients' demography (age, sex), presenting ophthalmic features, management, and outcome. Grade I and II ocular injuries were managed medically. All grade III-V injuries were managed using Amniotic Membrane Transplantation. RESULTS: All patients were male. The mean age of the patients was 23.57 ± 11.76 years. According to the Dua classification, 5 eyes (33.3%) had Grade I-II ocular surface burns, 3 eyes (20%) had grade III burns, and 7 eyes (46.6%) had grade IV-VI burns. Presenting visual acuity ranged between hand movements to 20/50, and in 6 eyes (40%), the visual acuity was ≤20/200. Five eyes were managed medically alone, and 10 (66.6%) eyes needed surgical intervention (Amniotic Membrane Transplantation). After a mean follow-up of 14.23 ± 11.92 weeks, complete epithelization was seen in 10 eyes (66.6%). Partial limbal stem cell deficiency and its sequelae such as conjunctivalization of the cornea were noted in 7 eyes (46.6%). CONCLUSIONS: Calcium carbide-related ocular injuries can result in corneal blindness secondary to limbal stem cell deficiency in young individuals. Loss of vision in this age group can lead to loss of economic productivity and cosmetic disfigurement. More advocacy efforts are thus needed to prevent these injuries.

Hypoxia-induced mesenchymal stem cells inhibit corneal fibroblast proliferation by regulating the WWP2/Notch1 axis.

Aim: This study aimed to explore the role of hypoxic mesenchymal stem cells (MSCs) in corneal alkali burns and the underlying mechanism. Materials & methods: Rat corneal fibroblasts were incubated with IL-6, followed by treatment with hypoxic MSC supernatant. A rat corneal alkali burn model was implemented and processed with hypoxic MSCs. The associated factors were detected by corresponding methods. Results: Hypoxic MSCs reduced the Notch1 level and the proliferation of rat corneal fibroblasts. Hypoxic MSCs or WWP2 overexpression in MSCs enhanced ubiquitination of Notch1. WWP2 interacted with Notch1, and WWP2 silencing reversed the effects of the hypoxic MSCs. Hypoxic MSC treatment in vivo decreased the corneal neovascularization scores and opacity scores. Conclusion: Hypoxic MSCs inhibited inflammation and alleviated corneal injury in alkali burns via the WWP2/Notch1 axis.

Acute ocular chemical burns are ophthalmic emergencies which require immediate diagnosis and treatment. Quiescent corneal cells differentiate into active fibroblast and myofibroblast phenotypes after corneal injury. Mesenchymal stem cells (MSCs) under hypoxia treatment are applied for the treatment of acute ocular chemical burns. We aimed to explore the role of hypoxic MSCs in corneal alkali burns and the underlying mechanism. The result showed that hypoxic MSCs reduced the proliferation of rat corneal fibroblasts, implying an anti-inflammatory effect. In vivo, treatment with hypoxic MSCs decreased the corneal neovascularization scores and opacity scores, indicating a protective effect on corneal alkali burns. We concluded that hypoxic MSCs could alleviate corneal injury in alkali burns and may be a promising therapeutic option for corneal alkali burns.

Effect of topical bovine colostrum in wound healing of corneal surface after acute ocular alkali burn in mice.

The purpose of this study was to evaluate the effect of bovine colostrum (BC) in the regeneration of corneal epithelial cells on an ocular alkali burn model. Twenty-four C57BL/6 mice were categorized into two gender/age-matched groups for treatment. Two days after inducing a corneal alkali burn in all left eyes with 4 µl of sodium hydroxide 0.15 mol/l, both eyes of group 1 were treated with BC 4 times per day, and both eyes of group 2 were treated with isotonic saline solution (SS). The epithelial defect was photographed and measured by fluorescein staining on days two, four, seven, and ten. Ocular burn damage was assessed with a pre-established classification in clock hours from the limbus. After 10 days both eyes were processed, half of the group's corneas were assessed histopathologically, and the other half was used for pro/anti-inflammatory cytokine quantification using ELISA. BC treated (Group 1) corneas revealed significantly improved fluorescein staining score for limbal involvement when compared to SS treated (Group 2) corneas at days 4 (p = 0.013), 7 (p < 0.001), and 10 (p < 0.001), respectively. No differences were noted in limbal involvement at day 2 between the two groups (p > 0.99). The overall change (difference in slope) in fluorescein staining for limbal involvement between days 2 and 10 was -0.1669 (p = 0.006). Histologic examinations and cytokine measurements of group 2 demonstrated a strong inflammatory component compared to group 1. Our data indicates that topical application of BC facilitates corneal re-epithelialization and wound healing by suppressing the inflammatory process in an ocular alkali burn model.

Ten Years of Pediatric Ocular Chemical Burn Experience in a Tertiary Eye Care Center in Turkey.

OBJECTIVES: To report 10 years of pediatric ocular chemical burn experience in a tertiary eye care center in Turkey. METHODS: Thirty-three patients aged 18 years and younger who presented with ocular chemical burn between 2011 and 2021 were enrolled. Demographic data and clinical characteristics of patients were reviewed. Limbal stem cell deficiency (LSCD) stage was assessed according to LSCD working group's staging system. The initial and final best-corrected visual acuities were recorded. RESULTS: The mean age was 10.4±5.5 (0.25-18) years with an F/M ratio of 12/21. Eleven (33.3%) of the patients were injured with acid and 5 (15.1%) with alkaline. The most common causative agent was nail polish remover (n=7, 21.2%), followed by cologne (n=5, 15.1%) and hand sanitizer (n=4, 12.1%). The severity of burn was ≥grade 4 in 20 patients (60.6%). Chemical injury resulted in LSCD in 18 patients (54.5%). Surgery was performed (LSCD ≥Stage 2 B) in 13 patients (39.3%); limbal stem cell transplantation (LSCT) (n=11), staged amniotic membrane transplantation, and symblepharon release (n=2). Penetrating keratoplasty after LSCT was performed in three of 11 patients. The mean follow-up time was 31.9±28.6 months (6-102.33) after the surgery. CONCLUSIONS: In pediatric population, accurate diagnosis and management of ocular chemical burns are challenging. Although the severity of burn and consequently LSCD rate seems to be high in children, comparative studies in a larger population are still needed.

Ocular Surface Characteristics and Colonization in a Burn Center: A Prospective Cohort Study.

We aimed to evaluate the characteristics and colonization by pathogenic microorganisms of the ocular surface in patients in a burn center and to determine their association with sedation, mechanical ventilation, and periocular burn. We prospectively evaluated 40 patients during an 8-mo period. Five evaluations where performed, at baseline and weekly on four more occasions or until hospital discharge or death. On each visit, we assessed periocular burn, lid position, Bell's phenomenon, Schirmer's test, presence of chemosis, conjunctival hyperemia, and exposure keratopathy; conjunctival fornix swabs were taken for microbiology culture. Also, we documented the level of sedation, mechanical ventilation status, and systemic and ocular treatment. Absent Bell's phenomenon and chemosis were significantly different at baseline in patients under mechanical ventilation, sedation, and in those with a periocular burn. The cumulative incidence of exposure keratopathy was 22.5% and the cumulative incidence of ocular surface colonization by pathogenic microorganisms was 32.5%. Both outcomes were associated with mechanical ventilation and periocular burn. The most frequent pathogenic microorganisms on the ocular surface were Candida parapsilosis, Acinetobacter baumanii, and Pseudomonas aeuroginosa. We did not observe any case of a persistent epithelial defect, infectious keratitis, corneal perforation or corneal opacity in this cohort. Results from our study may benefit future patients by allowing better risk stratification and treatment strategies for the ocular surface care in burn units.

Safety and feasibility of subconjunctival injection of mesenchymal stem cells for acute severe ocular burns: A single-arm study.

PURPOSE: To investigate the safety and feasibility of topical injection of bone marrow derived mesenchymal stem cells (BM-MSCs) in acute severe ocular burns. METHODS: In this open-label，single-arm study, subconjunctival injection of allogenic BM-MSCs combined with standard treatment was given to 16 patients with acute severe ocular burns (Dua's grade IV to VI) within 2 weeks after injury. The primary outcome was efficacy rate which referred to the proportion of complete corneal epithelialization patients without perforation. The secondary outcome was safety, visual acuity, the number of symblephara, and elevated intraocular pressure. RESULTS: One patient was lost to follow-up. During the follow-up period, no corneal perforation was developed. Complete corneal epithelialization was noted 8 (ranged 4-10 weeks) weeks after treatment in 13 eyes (81.3%). The efficacy rate was 87.5% (95% confidence interval, CI: 61.7-98.4). Hypopyon was detected and later well controlled in 1 eye. Partial or total limbal stem cell deficiency (LSCD) was noted in all eyes. Improvement of visual acuity was achieved in 5 out of 16 eyes (31.3%). Seven eyes' visual acuity was reached 0.1. Symblepharon with varied severity was noted in 5 eyes. Two eyes had elevated intraocular pressure. CONCLUSIONS: This study confirms the safety of subconjunctival injection of BM-MSCs as an innovative and convenient procedure in ocular burns. The overall result is promising considering the absence of perforation, the low severity of symblepharon and visual acuity improvement.

Fibrin-Plasma Rich in Growth Factors Membrane for the Treatment of a Rabbit Alkali-Burn Lesion.

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.

[Expert consensus on the clinical diagnosis and treatment of eye burns in China (2021)].

Eye burns, which are usually caused by chemicals such as acidic, alkaline and heat-related substances, are true medical emergencies. These substances can lead to potential permanent damage to the eyelids, cornea, ocular surface and intraocular tissues. In severe cases, eye burns may result in blindness. Currently, there is a lack of uniform and standardized guidelines for the diagnosis and treatment of eye burns. As a result, a considerable number of patients have a poor prognosis. Therefore, the Cornea Group of Chinese Ophthalmological Society has developed this consensus statement after thorough discussions, hoping to provide guiding opinions on the clinical diagnosis and treatment of eye burns. (Chin J Ophthalmol, 2021, 57:254-260).

PLGA nanoparticles containing Lingzhi extracts rescue corneal epithelial cells from oxidative damage.

Oxidative stress-related ocular surface epithelial damage can be initiated by ambient oxygen, UV radiation, and chemical burns. The oxidative damage to cornea can lead to inflammation and even vision loss. Lingzhi (Ganoderma lucidum) is a Chinese herbal drug and has been shown to prevent chronic diseases in clinical practices and has been proven to possess anti-oxidative and anti-inflammatory properties. In the study, we prepared poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) as a sustained drug release system of Lingzhi (LZH) to improve bioavailability. The particle size of developed NPs containing LZH (LZH-NPs) was ~184 nm with narrow size distribution. The results of cellular uptake revealed that using NPs as a drug delivery system could significantly increases the intracellular retention time. The results of the cell viability and chemiluminescence assay revealed that 5 µg/ml of LZH-NPs might be the threshold concentration for cultivation of corneal epithelial cells. After treating LZH-NPs in oxidative damaged cells, the results showed that the inflammation-related gene expression and DNA fragmentation level were both significantly decreased. Post-treatment of LZH-NPs in damaged corneal epithelial cells could increase the cell survival rate. In the rabbit corneal alkali burn model, topical instillation of LZH-NPs could promote corneal wound healing and decrease the inflammation. These results suggest that LZH-NPs may have the potential to treat ocular surface diseases caused by oxidative stress.

Alkali Burn Over a LASIK Flap.

PURPOSE: To describe the management and outcome of an ocular surface alkali burn in the setting of previous laser in situ keratomileusis (LASIK). METHODS: This is a case report and review of relevant literature. RESULTS: A 25-year-old man with a history of LASIK presented 4 weeks after a sodium hydroxide splash to his left eye with visual acuity of 20/60 and a nonhealing epithelial defect adjacent to sectoral inferior limbal ischemia in the setting of trichiasis from upper eyelid cicatricial entropion. After topical corticosteroids were discontinued following the repair of the entropion, the patient returned 3 days later with worsening vision and severe diffuse lamellar keratitis with the melting of the LASIK flap. After promptly lifting the flap and debriding the interface, inflammation was managed with oral, instead of topical, corticosteroids. Over several weeks, the epithelium healed, and inflammation and interface edema resolved. At 10 years of follow-up, the patient had developed a localized pseudopterygium with mild corneal neovascularization but maintained 20/20 uncorrected visual acuity. CONCLUSIONS: A chemical burn over a LASIK flap poses a challenge for managing corticosteroids, which are required to prevent diffuse lamellar keratitis but can also contribute to keratolysis beyond the first week after an alkali injury. Oral corticosteroid therapy may be beneficial in this situation, with a low threshold to lift the LASIK flap and debride the interface if inflammation occurs.

Subconjunctival Injection of Regulatory T Cells Potentiates Corneal Healing Via Orchestrating Inflammation and Tissue Repair After Acute Alkali Burn.

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.

Severe corneal burn due to the accidental application of salicylic acid packed in a plastic dropper bottle. / Quemadura corneal grave debida a la aplicación accidental de ácido salicílico envasado en un frasco gotero plástico

Eye burns due to the accidental application of pharmacological or nonpharmacological substances packaged in plastic dropper bottles have been described for more than three decades and continue to occur. These burns can cause potentially serious corneal injuries. We report the case of a patient who mistakenly applied salicylic acid to the right eye after confusing it with an eye lubricant, which caused him a severe corneal burn. Fortunately, after aggressive medical and surgical management (including oxygen therapy and amniotic membrane grafting), the visual results were good. We suggest conducting educational campaigns and taking legislative measures in our country to avoid packaging corrosive substances in this type of dropper bottle to reduce the risk of accidental burns.

Las quemaduras oculares por aplicación accidental de sustancias farmacológicas o no farmacológicas envasadas en frascos goteros plásticos, se han descrito desde hace más de tres décadas y siguen ocurriendo. Estas quemaduras pueden causar lesiones potencialmente graves de la córnea. Se presenta el caso de un paciente que se aplicó ácido salicílico en el ojo derecho al confundir el envase con el de un lubricante ocular, lo que le causó una grave quemadura corneal. Afortunadamente, tras un manejo médico y quirúrgico agresivo (incluida oxigenoterapia e injerto de membrana amniótica) los resultados visuales fueron buenos. Se sugiere hacer campañas educativas y adoptar normas en el país para evitar el envase de sustancias corrosivas en este tipo de frascos goteros, con el fin de disminuir el riesgo de quemaduras accidentales.