Ocular chemical burns in the workplace: Epidemiological characteristics

Alkali injury-induced pathological lymphangiogenesis in the iris facilitates the infiltration of T cells and ocular inflammation

Inflammatory lymphangiogenesis is intimately linked to immune regulation and tissue homeostasis. However, current evidence has suggested that classic lymphatic vessels are physiologically absent in intraocular structures. Here, we show that neolymphatic vessels were induced in the iris after corneal alkali injury (CAI) in a VEGFR3-dependent manner. Cre-loxP-based lineage tracing revealed that these lymphatic endothelial cells (LECs) originate from existing Prox1+ lymphatic vessels. Notably, the ablation of iridial lymphangiogenesis via conditional deletion of VEGFR3 alleviated the ocular inflammatory response and pathological T cell infiltration. Our findings demonstrate that iridial neolymphatics actively participate in pathological immune responses following injury and suggest intraocular lymphangiogenesis as a valuable therapeutic target for the treatment of ocular inflammation.

Clinical outcomes of vacuum-dehydrated amniotic membrane (Omnigen) mounted on contact lens (Omnilenz) in eyes with acute chemical eye injuries

BACKGROUND

Omnigen is a vacuum-dehydrated amniotic membrane transplant. It can be delivered to the eye pre-mounted on a special bandage contact lens (Omnilenz) that enables its application without the need for sutures or glue; the aim of this study is to evaluate the short-term clinical outcomes of Omnilenz-Omnigen complex in eyes with acute chemical injury (CEI).

METHODS

A prospective interventional study included patients with different grades of acute CEI attending the casualty between July 2021 and November 2022. All patients received first aid measures followed by the application of Omnilenz-Omnigen within the first 2 days. Patients were followed up for at least 1 month. Primary outcomes include epithelial defect and limbal ischemia. Secondary outcomes include best-corrected visual acuity (BCVA) and tolerability.

RESULTS

The study included 23 eyes of 21 patients with acute CEI mostly due to alcohol (34.8%). After the 1st application, the size of the epithelial defect showed a statistically significant reduction (p = 0.016) with improvement in BCVA (p < 0.001). Restoration of the limbal vascularity was obtained in 56.5% of the eyes. Repeated application of Omnilenz was required in 5 eyes (21.7%). The size of the epithelial defect was reduced after the second application (p = 0.504) with improved BCVA (p = 0.185). After 1st month, complete epithelial healing was achieved in all the eyes. Mild limbal ischemia persists in 3 (13%) of the eyes. Final BCVA showed statistically significant improvement (p < 0.001). None of the patients develops any serious complications.

CONCLUSION

Omnilenz proved to be easy to apply and well tolerated by patients, with promising clinical outcomes.

Chemical toxic exposures and chronic ocular pain

Chronic ocular pain is a common, debilitating chronic pain condition with significant morbidity and negative impact in patients' quality of life. Several, diverse types of insults to the ocular surface can lead to acute, and under certain conditions to chronic ocular pain, and these include toxic irritants. Exposure of ocular surface to toxic irritants, in addition to direct tissue injury, carries the capacity to generated intense immune and neuronal responses with hyper-excitability, sensitization and chronic pain. Because, chronic ocular pain subsequent to toxic exposures is relatively unrecognized clinical entity, this brief review highlights pertinent concepts of its epidemiology, pathogenesis/pathophysiology, clinical progression, with recommendations for its clinical management that clinicians may find helpful. Suppression of pain signaling, generating neuronal sensitization, and prevention of chronicity of neuropathic pain is particularly emphasized in this respect.

Causal factors of work-related chemical eye injuries reported to the Dutch Poisons Information Center

This study investigated the circumstances of chemical occupational eye exposures reported to the Dutch Poisons Information Center. During a 1-year prospective study, data were collected through a telephone survey of 132 victims of acute occupational eye exposure. Victims were often exposed to industrial products (35%) or cleaning products (27%). Most patients developed no or mild symptoms. Organizational factors (such as lack of work instructions (52%)), and personal factors (such as time pressure and fatigue (50%), and not adequately using personal protective equipment (PPE, 14%), were the main causes of occupational eye exposures. Exposure often occurred during cleaning activities (34%) and personal factors were reported more often during cleaning (67%) than during other work activities (41%). Data from Poison Control Centers are a valuable source of information, enabling the identification of risk factors for chemical occupational eye exposure. This study shows that personal factors like time pressure and fatigue play a significant role, although personal factors may be related to organizational issues such as poor communication. Therefore, risk mitigation strategies should focus on technical, organizational, and personal factors. The need to follow work instructions and proper use of PPE should also have a prominent place in the education and training of workers.

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

Demographic profile and clinical characteristics of patients presenting with acute ocular burns

Purpose

To study and compare the demographic and clinical profile of acute ocular burns (AOB) in children and adults.

Methods

This retrospective case series included 271 children (338 eyes) and 1300 adults (1809 eyes) who presented to two tertiary eye care centers within one month of sustaining AOB. Data regarding demographics, causative agents, severity of injury, visual acuity (VA), and treatment were collected and analyzed.

Results

Males were more commonly affected particularly among adults (81% versus 64%, P < 0.00001). Among children, 79% sustained domestic injuries, whereas 59% of adults had work-place injuries (P < 0.0001). Most cases were due to alkali (38%) and acids (22%). Edible lime (chuna, 32%), superglue (14%), and firecrackers (12%) in children, and chuna (7%), insecticides, lye, superglue (6% each), toilet cleaner (4%) and battery acid (3%) in adults, were the main causative agents. The percentage of cases with Dua grade IV-VI was greater in children (16% versus 9%; P = 0.0001). Amniotic membrane grafting and/or tarsorrhaphy were needed in 36% and 14% of affected eyes in children and adults, respectively (P < 0.00001). The median presenting VA was logMAR 0.5 in children and logMAR 0.3 in adults (P = 0.0001), which improved significantly with treatment in both groups (P < 0.0001), but the final VA in eyes with Dua grade IV-VI burns was poorer in children (logMAR 1.3 versus logMAR 0.8, P = 0.04).

Conclusion

The findings clearly delineate the at-risk groups, causative agents, clinical severity, and treatment outcomes of AOB. Increased awareness and data-driven targeted preventive strategies are needed to reduce the avoidable ocular morbidity in AOB.

Epidemiological features and management of eye burn patients in Wuxi, China

Background

The current study aimed to analyse epidemiological data on eye burns in Wuxi, China, for the years 2015–2021, and to provide insight into the development of appropriate prevention strategies.

Methods

A retrospective study was conducted on 151 hospitalised patients with eye burns. Data collected included gender, age, the monthly distribution of incidence, cause of eye burn, the site of eye burn, the type of surgery, visual outcome, the length of hospital stay and the cost of hospital admission. Statistical analysis was performed using SPSS V.19.0 and Graph Pad Prism V.9.0.

Results

In a total of 151 eye burn patients, 130 were males (86.09%) and 21 were females (13.91%). The proportion of patients classified as grade III was the greatest (46.36%). The average age of our hospitalised patients with eye burns was 43.72 years and the average length of hospital stay was 17 days. The number of injuries was highest in September (14.6%). Among eye burn patients, workers and farmers became the most common occupations (62.91%, 12.58%). The most frequent cause of burns was alkali burns (19.21%), followed by acid burns (16.56%). When admitted to the hospital, patients’ average vision was 0.06, and 49% of them had a poor vision (<0.3, ≥0.05).

Conclusion

With an investigation of 7-year hospitalisation data, the current study provided a fundamental reference for epidemiological features and management of eye burns in Wuxi, China, which could contribute to the development of treatment and prevention strategies.

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 ınjury of intraocular structures were found to have a great influence on the outcome of their visual acuity.

The Possible Protective Effect of Boric Acid in an Alkaline-Induced Corneal Neovascularization Rat Model

It is known that boric acid (BA) exerts it antioxidant and anti-inflammatory effects by activating the activating transcription factor 4 (ATF4) and nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway. This pathway has been reported to control antioxidant status in the eye. The aim of this study was to investigate the possible preventive effects of boric acid administration on oxidative damage and corneal neovascularization (CNV). Sixteen adult female Wistar albino rats were divided into two groups: (I) control (n = 8); the CNV model was applied to the right eye of the rats, and the left eyes were used as healthy controls. (II) CNV + BA (n = 8): After the CNV model was applied to the right eyes, a single subconjunctival dose (0.05 mL) of 0,018 g/mL BA was injected into the right and left eyes of the rats. Biochemical, histopathological, and immunohistochemical analyses were performed. Moderate VEGF positivity was observed in the vessels of the CNV group, a decrease in vessel proliferation, and weak VEGF positivity in the CNV + BA group. The TAS level in the CNV + BA group was significantly higher than that in the other groups. The TOS level was significantly higher in all groups than it is in the control group. The OSI value was increased in all groups when compared to the control group, but only the CNV and BA groups were statistically significant. BA not only reduced alkaline-induced corneal damage histologically but also showed a protective effect on oxidative stress biochemically.

Perfluorodecalin-based oxygenated emulsion as a topical treatment for chemical burn to the eye

Chemical injuries to the eye are emergencies with limited acute treatment options other than prompt irrigation and can cause permanent vision loss. We developed a perfluorodecalin-based supersaturated oxygen emulsion (SSOE) to topically deliver high concentration of oxygen to the eye. SSOE is manufactured in hyperbaric conditions and stored in a ready-to-use canister. Upon dispensation, SSOE rapidly raises partial oxygen pressure 3 times over atmospheric level. SSOE is biocompatible with human corneal cells and safe on mouse eyes in vivo. A single topical application of SSOE to the eye after alkali injury significantly promotes corneal epithelial wound healing, decreases anterior chamber exudation, and reduces optical opacity and cataract formation in mice. SSOE treatment reduces intraocular hypoxia, cell death, leukocyte infiltration, production of inflammatory mediators, and hypoxia-inducible factor 1-alpha signaling, thus hastening recovery of normal tissue integrity during the wound healing process. Here, we show that SSOE is an effective topical therapeutic in the acute treatment of ocular chemical injuries.

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.

Description of Main Predictors for Taking Sick Leave Associated with Work-Related Eye Injuries in Spain

Recent studies in Spain have shown that males, younger workers, and people involved in manual jobs had the highest risk of suffering a work-related eye injury (WREI). This study aims to assess the predictors of sick leave associated with WREI and to compare them with risk factors of initial injury. A retrospective and descriptive study of WREI that causes sick leave of one or more days among workers from an insurance labor mutual company in Spain was conducted over a period from 2008 to 2018. The variables of the study were sex, age, occupation, and type of injury. A total of 9352 (18.6% of 50,265 WREI) cases and 113,395 total days of sick leave were observed, with an estimated EUR 4,994,009.59 of associated labor cost. The main predictors of sick leave related to WREI were found to be female (highest incidence; 25.9 (95% CI (24.8–27.1))), >55 years of age (highest incidence; 20.5 (95% CI (19.3–21.7))), not working in the industry (lowest incidence; 13.8 (95% CI (13.3–14.2))), and not suffering “other disorders of conjunctiva” (lowest incidence; 5.7 (95% CI (4.7–6.8))). The consequences associated with WREI are worse for female and older workers, despite the main risk of suffering WREI being observed in males and younger workers.

Current status of emergency treatment of chemical eye burns in workplaces

Chemical eye burns present an avoidable, but frequent, occupational injury with potentially detrimental consequences for the quality of life and occupational rehabilitation of the injured. A periodical review of guidelines is required to assure the optimal emergency management. We reviewed the literature with emphasis on current German guidelines, primarily MEDLINE. If the crucial first-line measure, the injury prevention has failed and an eye burn has been sustained, the immediate and copious rinsing of the eye is the pivotal emergency treatment modality. Whereas the immediacy and sufficiency of the emergency rinsing are largely unanimous, there is an ongoing debate about the benefits and risks of specific rinsing solutions, and regular updates on guidelines and recommendations for the emergency treatment are warranted. The easiest and readily available rinsing solution is tap water, which fulfils the crucial criteria conveniently in most industrialized countries: purity, sterility, and neutral pH. Other rinsing solutions are proposing higher osmolality to stabilize the physiological pH, because of their superior buffering capacity. However, there is no compelling evidence for a substantial benefit, and some reports suggest that there could be unwanted side effects. In combination with the substantially increased expenditure and a more complex handling procedure, currently a general recommendation of any other solution than tap water is not warranted.

Chemical eye injury: pathophysiology, assessment and management

Chemical eye injury (CEI) is an acute emergency which can threaten sight and life. These commonly occur at home or the workplace with the former being generally mild and the latter more severe and bilateral. Major workplace accidents involve other parts of the body and can be associated with inhalation or ingestion of the chemical. Alkali injuries cause damage by saponification of tissue and deeper penetration as a consequence. Acid injuries cause rapid coagulation of tissue, which impedes penetration and limits damage. Irritants such as alcohols, cause superficial epithelial denudation. Severe chemical insult can affect all anterior segment structures causing iris, pupil and lens abnormalities. Eye pressure is variably affected and can be low or high or start as one and rapidly change to the other. Chorioretinal changes in the form of vasculopathy are seen and ascribed to be secondary to anterior segment inflammation rather than due to the direct effect of CEI. Final outcome related to structure and function is determined by the injurious agent, duration of exposure, nature of treatment and the rapidity with which it is instituted. Prevention of further damage by profuse and prolonged eye wash, after ascertaining pH of both eyes, together with exploration and removal of all particulate matter, is the key. Other management principles include a complete and thorough assessment, control of inflammation, facilitation of healing and prevention and management of sequelae and complications. Intraocular pressure is often forgotten and must be assessed and managed. Management often requires a multidisciplinary approach.

Agents Involved and Severity of Acute Ocular Exposure Reported at a Poison Control Center

PURPOSE

The aim was to identify severity factors useful in the initial management of patients with acute ocular exposure while considering both categories of products involved and circumstances of exposure.

METHODS

A retrospective study over a one-year period that included patients who benefited from the poison center services for eye exposure to a chemical substance.

RESULTS

Within a year, 1582 patients were identified. The sex ratio (M/F) was 0.8. The mean age was 28.5 ± 20.3 years. Among children, those under 4 years represented the most significant age category (n = 277; 50.1%). Exposure to chemicals were mild (n = 1342, 84.8%). Adults over 65 years appeared to be more likely to have severe ocular damage (OR: 4.75; [2.26; 9.98]). Unintentional exposures were the most frequent (n = 1548; 97.8%). Ocular exposure primarily occurred at home (n = 937; 59.2%), and at the workplace (n = 396; 25%) which was associated with a higher risk of severe injury (OR: 2.93 [2.16; 3.97]). Cleaning products accounted for 31.2% of exposure cases (n = 457). Exposure to disinfectants is a risk factor of more severe injuries (OR: 1.48 [1.002; 2.19] p = .0472) whereas pH and severity of injuries were not statistically significant.

CONCLUSIONS

Our study showed the very wide variety of products involved in ocular exposures. Clinicians should pay attention to factors associated with severe injury, including young and old age, work-related injury, substances such as disinfectants, in addition to previously known factors such as acids and bases.