Eye burns: an emergency and continuing problem

Early findings in a randomised controlled trial on crosslinking protocols using isoosmolar and hypoosmolar riboflavin for the treatment of progressive keratoconus

PURPOSE

To present baseline characteristics and to present the perioperative corneal thickness during corneal crosslinking (CXL) treatment for progressive keratoconus and to describe how the addition of sterile water (SW) efficaciously can maintain the corneal thickness. The treatment efficacy will be evaluated when the 1-year follow-up is complete.

METHODS

A randomised clinical study using epithelium-off CXL with continuous UVA irradiation (9 mW/cm2) and two kinds of riboflavin solutions: (i) isoosmolar dextran-based riboflavin (n = 27) and (ii) hypoosmolar dextran-free riboflavin (n = 27).

INCLUSION CRITERIA

progressive keratoconus with an increase in maximum keratometry value (Kmax) of 1.0 dioptre (12 months) or 0.5 dioptres (6 months). Corneae thinner than 400 μm were also included.

OUTCOME PARAMETERS

Perioperative corneal thickness and the effect of adding SW.

RESULTS

Seventy-four per cent of the patients in the isoosmolar group and 15% in the hypoosmolar group required the addition of SW, which effectively maintained a corneal thickness of 400 μm in all cases during CXL. The addition of SW was primarily needed during the irradiation procedure and not the preoperative soaking period.

CONCLUSIONS

Especially during the CXL irradiation phase, isoosmolar riboflavin causes a significant dehydrating effect leading to corneal thinning during CXL. The customised addition of SW is efficacious in maintaining the corneal thickness during CXL and could increase the safety of the procedure.

Thermoresponsive in-situ gel containing hyaluronic acid and indomethacin for the treatment of corneal chemical burn

Ocular chemical burns are prevalent injuries that must have immediate and effective treatment to avoid complications. Aiming to improve bioavailability and efficacy, a poloxamer-based thermoresponsive in-situ gelling system containing hyaluronic acid and indomethacin was developed. Formulations with different polymeric proportions were screened through rheological measurements resulting in an optimized system (F2) with gelling temperature of 34.2 ± 0.11 °C. Its maximum viscosity varied from 77.33 mPa (25 °C) to 82.95 mPa (34 °C) following a non-Newtonian profile and a pH of 6.86 ± 0.01. No incompatibilities were found after infrared analysis. Polarized light microscopy and cryo-transmission electron microscopy have demonstrated micelles of nano-sized dimensions (21.86 nm) with indomethacin entrapped in the core, forming a polymeric network under heating. In vitro tests revealed a cumulative release of 59.75 ± 3.17 % up to 24 h under a sustained release profile. Results from HET-CAM assay indicated that F2 was well tolerated. Corneal wound healing was significantly faster in animals treated with F2 compared to a commercial formulation and an untreated group. These findings suggests that F2 could be an efficient system to delivery drugs into the ocular surface improving wound healing.

Scleral contact lenses for optimal visual recovery in a case of severe acid burn with total lagophthalmos

Chemical injuries can severely damage the ocular surface. We present the case of a man in his 40s with severe periocular chemical injury with total lid loss and severe exposure keratopathy. He sustained burns to 45% of his body surface area and needed tracheostomy and multiple full-thickness skin grafts. Both eyes required surgery, Boston type 1 keratoprosthesis and penetrating keratoplasty for the right and left eye, respectively. There was melting in the right eye and a persistent epithelial defect in the left eye. Eventually, we suggested 18 mm diameter scleral contact lenses for both eyes to aid in ocular surface stabilisation. His best corrected visual acuity improved significantly with the scleral lenses to 20/100 and 20/320 in the right and left eyes, respectively. This case demonstrates that scleral lenses can treat the complications of exposure keratopathy and can improve vision. Therefore, they may be considered for rehabilitation of the ocular surface in eyes with severe chemical periocular injuries.

Defining corneal chemical burns: A novel exact and adjustable ocular model

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Novel method induces highly reproducible chemical injuries in an ex vivo cornea model.

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Initial corneal surface humidity is an important parameter for consistent injury.

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The application frequency of the corrosive has a major impact on the extent of injury.

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This automated method can provide a consistent baseline for further investigations.

Introduction

Live-animal-free ocular toxicity models and tests are a necessity in multiple branches of medicine, industry and science. Corneal models with adjustable ranges of injury severities do not exist. In this work, a novel and precise and dose - response method to induce and observe ex vivo corneal chemical burns has been established.

Methods

The EVEIT (Ex Vivo Eye Irritation Test) is based on an ex vivo corneal organ model for rabbit corneas from food industry. Further, a highly precise three – axis workstation has been employed to apply liquid corrosive, sodium hydroxide (NaOH), droplets in a nanolitre (nL) range onto the corneal surface. Optical Coherence Tomography (OCT) has been used to observe and quantify the elicited changes in the corneal layers.

Results

The speed and intervals of single nanodroplet application played a crucial role in the extent of the corneal changes. Similar total volumes applied at low frequencies elicited deep and extensive changes in the corneal layers whereas high application frequencies elicited comparatively superficial changes. Increasing NaOH concentrations effected measurably increasing corneal changes. Increasing the volume of applied NaOH also showed an increase in corneal changes.

Conclusions

OCT imaging proved to be effective in observing, documenting and quantifying the changes in the corneal layers. The ex vivo model, in conjunction with the novel application method was able to induce and display distinctive and consistent correlations between NaOH volume, concentration and elicited corneal changes. This ex vivo ocular chemical burn model provides a consistent in vitro basis for pharmaceutical and toxicological experiments and investigations into corneal chemical burn mechanisms and treatment.

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.

A Novel Therapeutic Approach to Corneal Alkaline Burn Model by Targeting Fidgetin-Like 2, a Microtubule Regulator

Purpose

The purpose of this study was to determine the efficacy of nanoparticle-encapsulated Fidgetin-like 2 (FL2) siRNA (FL2-NPsi), a novel therapeutic agent targeting the FL2 gene, for the treatment of corneal alkaline chemical injury.

Methods

Eighty 12-week-old, male Sprague-Dawley rats were divided evenly into 8 treatment groups: prednisolone, empty nanoparticles, control-NPsi (1 µM, 10 µM, and 20 µM) and FL2-NPsi (1 µM, 10 µM, and 20 µM). An alkaline burn was induced onto the cornea of each rat, which was then treated for 14 days according to group assignment. Clinical, histopathologic, and immunohistochemical analyses were conducted to assess for wound healing. FL2-NPsi-mediated knockdown of FL2 was confirmed by in vitro quantitative polymerase chain reaction (qPCR). Toxicity assays were performed to assess for apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling [TUNEL] assay) and nerve damage (whole mount immunochemical staining). Statistical analyses were performed using Student's t-test and ANOVA.

Results

Compared with controls, FL2-NPsi-treated groups demonstrated enhanced corneal wound healing, with the 10 and 20 µM FL2-NPsi-treated groups demonstrating maximum rates of corneal re-epithelialization as assessed by ImageJ software, enhanced corneal transparency, and improved stromal organization on histology. Immunohistochemical analysis of vascular endothelial cells, macrophages, and neutrophils did not show significant differences between treatment groups. FL2-NPsi was not found to be toxic to nerves or induce apoptosis (p = 0.917).

Conclusions

Dose-response studies found both 10 and 20 µM FL2-NPsi to be efficacious in this rat model. FL2-NPsi may offer a novel treatment for corneal alkaline chemical injuries.

Translational Relevance

Basic cell biology findings about the microtubule cytoskeleton were used to design a therapeutic to enhance corneal cell migration, highlighting the promise of targeting microtubules to regulate corneal wound healing.

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.

Management Strategies of Ocular Chemical Burns: Current Perspectives

Ocular chemical burns are absolute ophthalmic emergencies and require immediate management to minimize devastating sequelae. Management of alkali and acid burns is started at the scene of the accident by copious irrigation. Treatment is directed at improving epithelial integrity and stromal stability, reduction of undue inflammation, and prevention or timely management of complications. To ascertain the best possible outcome, numerous biological medications and surgical interventions have been merged into conventional therapeutic regimens. These include autologous and umbilical cord serum preparations, platelet-rich plasma, amniotic membrane transplantation, limbal stem-cell transplantation, and anti-angiogenic agents.

Glaucoma after ocular chemical burns: Incidence, risk factors, and outcome

Effects of chemical injuries on the cornea and limbus have been widely studied; however, little is known about glaucoma after ocular chemical injuries. We herein investigated the incidence, risk factors, and outcome of glaucoma in patients with ocular chemical burns. Medical records were reviewed of patients who visited our clinic for chemical injuries to the ocular surface. Patients were divided into glaucoma and non-glaucoma groups based on high intraocular pressure (IOP) readings. Clinical characteristics, treatment method, and therapeutic and visual outcomes were compared between the two groups. Of 29 patients (40 eyes), 9 patients (15 eyes, 37.5%) were diagnosed with glaucoma at 2.64 ± 2.92 months after injury. Factors associated with glaucoma included male gender (p = 0.0114), bilateral ocular involvement (p = 0.0478), severe ocular surface involvement (Dua grades IV-VI, p = 0.0180), poor initial visual acuity (p = 0.0136), high initial IOP (p < 0.0001), pupil involvement at initial examination (p = 0.0051), and the need for amniotic membrane transplantation in the acute stage (p = 0.0079). At final follow-up, IOP was uncontrolled in 3 eyes (20.0%), and visual acuity was worse in the glaucoma group than in the non-glaucoma group (logMAR 2.94 ± 1.86 vs 0.34 ± 0.69, p < 0.0001). These findings suggest that careful evaluation and intensive treatment for glaucoma are essential in patients with severe ocular burns.

Ocular Exposures Reported to Poison Control Centers From 2011 to 2015

PURPOSE

To identify and characterize the ocular exposures reported to poison control centers over a 5-year period from 2011 to 2015 in the United States.

DESIGN

Pooled cross-sectional study.

SUBJECTS

Callers to poison control centers.

METHODS

We retrospectively analyzed data from 477 274 calls for ocular exposure to the National Poison Data System. Major medical outcomes, reason for exposure, location of exposure, and causative xenobiotic were evaluated.

RESULTS

A mean volume of 95 454 calls per year were reported to poison control centers, with most exposures occurring unintentionally, at home, and predominantly in children under 5 years of age. Most serious adult exposures occurred at work owing to alkali exposures. There was an increasing incidence in exposures in those over 64 years old. The most common treatment provided was irrigation and wash for the affected eye.

CONCLUSIONS

Children under 5 are most susceptible; they may have permanent disability owing to laundry detergent exposure; and concerted intervention is needed in this age group. Many serious adult exposures occurred at work owing to alkali exposures.

Chemical Burns of the Eye

Chemical burns of the eye are one of the most common eye injuries. The extent of the ocular surface damage is influenced by the type, temperature, volume, and pH of the corrosive substance and duration of exposure. Limbal ischemia found on eye assessment is the primary determinant of eventual visual outcome. Eye irrigation must be instituted immediately at the scene of exposure and continued in the emergency department to reduce visual impairment. Traditionally lactated Ringer's and normal saline have been used as irrigation fluids, although one systematic review demonstrates similar outcomes with other irrigation fluids. The Morgan Lens is a device that can be utilized to allow the provider to perform "hands free" eye irrigation. Complications of chemical burns are more common with alkali burns as these substances destroy the corneal epithelium and allow this corrosive base substance to penetrate deeper into the cornea.

Mechanisms of Retinal Damage after Ocular Alkali Burns

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.

The Ocular Surface and How It Can Influence the Outcomes of Keratoprosthesis

Severe ocular diseases may result in partial or complete limbal cell deficiency. Besides conservative options, treatment options include conjunctival replacement procedures and limbal autografting. Limbal allografts are an option in patients with bilateral limbal cell deficiency. In many of these cases, a keratoprosthesis (KPro) is the last option to restore functional vision in patients with severe corneal blindness with no other options.

Current and Upcoming Therapies for Ocular Surface Chemical Injuries

Chemical injuries frequently result in vision loss, disfigurement, and challenging ocular surface complications. Acute interventions are directed at decreasing the extent of the injury, suppressing inflammation, and promoting ocular surface re-epithelialization. Chronically, management involves controlling inflammation along with rehabilitation and reconstruction of the ocular surface. Future therapies aimed at inhibiting neovascularization and promoting ocular surface regeneration should provide more effective treatment options for the management of ocular chemical injuries.

Optical coherence tomography analysis of hydrofluoric acid decontamination of human cornea by mannitol solution

PURPOSE

To evaluate the efficacy of mannitol solution as a decontamination agent on the chemical burn of the human corneas.

METHODS

Eight donor corneas from an eye bank were exposed to 25μl of 2.5% hydrofluoric acid (HF) solution on a filter paper for 20s. Three eyes were rinsed with 1000ml of mannitol 20% for 15min immediately after removal of the filter paper, 3 other were rinsed with sodium chloride (NaCl) 0.9% (1000ml for 15min) and two eyes were not rinsed. Microstructural changes were monitored in the time domain by optical coherence tomography (OCT) imaging for 75min.

RESULTS

NaCl reduced the penetration depth to approximately half the thickness of the cornea at 15min; scattering within the anterior cornea was higher than that for the unrinsed eye. With mannitol, no increased scattering was observed in the posterior part of the corneal stroma within a time period of 1h after rinsing. OCT images revealed low-scattering intensity within the anterior stroma at the end of the rinsing period.

CONCLUSION

In eye bank human corneas, mannitol proved to be an efficient agent to decontaminate HF burn.

The ocular surface chemical burns

Ocular chemical burns are common and serious ocular emergencies that require immediate and intensive evaluation and care. The victims of such incidents are usually young, and therefore loss of vision and disfigurement could dramatically affect their lives. The clinical course can be divided into immediate, acute, early, and late reparative phases. The degree of limbal, corneal, and conjunctival involvement at the time of injury is critically associated with prognosis. The treatment starts with simple but vision saving steps and is continued with complicated surgical procedures later in the course of the disease. The goal of treatment is to restore the normal ocular surface anatomy and function. Limbal stem cell transplantation, amniotic membrane transplantation, and ultimately keratoprosthesis may be indicated depending on the patients' needs.

Analysis of medical expenditure and socio-economic status in patients with ocular chemical burns in East China: a retrospective study

Background

Little has been known regarding the relationship between ocular chemical injury and victims’ medical expenditure, income loss and socio-economic status changes. So we conduct this retrospective cross-sectional study in patients with ocular chemical burns in East China.

Methods

Fifty-six patients were enrolled and required to complete a self-report questionnaire consisting of the following contents: entire expenditure on medical treatment; the victims’ personal and household per capita income, and income loss caused by the injury; and the changes of socioeconomic status as well.

Results

The median expense of medical treatment was CNY 40,000 (approximately US$5,900). The medical expenditure rose significantly with increased injury severity, prolonged hospital stay, and increased frequency of surgery. More than half victims (51.8 %, 29/56) paid all or the majority of medical expense by themselves. The expense of only 5 victims was mainly paid by medical insurance, accounting for less than ten percent (8.9 %, 5/56). The victims’ personal and household per capita income both decreased significantly after the injury, with the median reduction being CNY 24,000 and CNY 7,800 (approximately US$3600 and US$1200) per year respectively. The reduction amplitude of personal and household per capita income rose with increased injury severity and prolonged time of care required. The injury caused emotional depression or anxiety in 76.8 % (43/56) victims, and the relationship with their relatives got worse in 51.9 % (29/56) patients. Moreover, only 21.4 % (12/56) patients felt that the whole society gave them care and concern after the injury, whereas 46.4 % (26/56) and 28.6 % (16/56) felt indifference or discrimination from society as a whole (X² = 16.916, P = 0.028).

Conclusions

The medical expense was a huge economic burden to most victims of ocular chemical burns, and personal and household per capita income of the victims decreased significantly after injury, both of which had a close relationship with the injury severity. Formal legislation was urgently needed to compel the employer to purchase injury or medical insurance and provide more compulsory protection to the population working in high risk occupations. In addition, psychological counseling and instruction shouldn’t be neglected in the aid and treatment of victims.

[Recommendations for acute treatment for chemical and thermal burns of eyes and lids]

With these recommendations the authors want to improve the acute therapy of eye burns based on the literature and clinical experience. Due to the lack of studies with high evidential value we base these recommendations on the results of experimental work and reports of successfully treated eye burns. A development of this document by systematic research is necessary. Despite the limited knowledge, the collated facts are the current state of the art of treatment according to the knowledge and research of the authors. The most important clinical recommendation is to rinse a chemically or thermally burnt eye as soon and as extensively as possible. Any delay worsens the prognosis. Substances on the market for first aid have different levels of clinical evidence. Thus saline and amphoteric diphoterine have been evaluated in a prospective clinical study showing an advantage for the amphoter. Water, borate buffer, phosphate buffers and derivatives have never been proven to work in clinical applications. Nevertheless, they are recommended. Within experimental work in vitro we could show the value of polyvalent decontamination. Side-effects of phosphate buffers have been demonstrated in retrospective clinical and prospective experimental studies so that even in cases of beneficial effects on pH we cannot recommend these substances which propagate corneal calcification. Special types of burns, such as hydrofluoric acid need special treatment but as clinical studies are lacking only experimental data can offer suitable recommendations.

Glaucoma in eyes with severe chemical burn, before and after keratoprosthesis

PURPOSE

The purpose of this study was to evaluate the incidence of glaucoma in eyes with severe chemical burn, before and after keratoprosthesis.

METHODS

A retrospective chart review of 28 eyes of 23 patients with severe ocular chemical burns who had undergone Boston Keratoprosthesis (BKPro) surgery at the Massachusetts Eye and Ear Infirmary, between 1990 and 2010. The incidence and severity of the outcome of glaucoma, preoperatively and postoperatively, were reviewed. Related issues, such as type of chemical burn; visual acuity (VA); device retention rate; number and nature of previous, concomitant, and subsequent procedures; and incidence of other postoperative complications, were reviewed for a median follow-up time of 57 months.

RESULTS

The number of eyes with a preoperative history or signs of glaucoma was 21, 9 of which had glaucoma progression after BKPro implantation. In addition, 2 more eyes developed glaucoma postoperatively. Preoperative vision was counting fingers or worse in all eyes. Best-corrected postoperative VA ranged from no light perception to 20/20. Seventeen eyes (61%) achieved 20/60 or better VA at some point during their follow-up, but only 9 (32%) maintained 20/60 at the last follow-up. Of the 28 eyes, 6 had the BKPro replaced once and 1 had it replaced twice. Superimposed, 8 of the most severely burned patients developed retinal detachment postoperatively.

CONCLUSIONS

Glaucoma is very common in eyes with severe chemical burns. A keratoprosthesis can rehabilitate vision, but postoperative glaucoma can be difficult to manage.

A systematic review of methods of eye irrigation for adults and children with ocular chemical burns

AIM

To present the best available research evidence on eye irrigation methods for ocular chemical burns to facilitate better-informed clinical decisions.

METHODS

Randomized, quasi-randomized controlled trials and observational studies comparing the effectiveness of eye irrigation methods among adults or children as an active form of emergency treatment for ocular chemical burns were reviewed. Electronic databases in English and Chinese were searched from inception to June 2010. Two reviewers made independent decisions on whether to include each publication in the review and critically appraised the study quality independently. Given the clinical and methodological diversity among the studies, the review findings are presented in a narrative form.

RESULTS AND DISCUSSION

Four studies involving 302 adults and children were identified. The results of this review indicate that patients who underwent irrigation with tap water immediately following alkali burns at the scene of injury had significantly better clinical and ocular outcomes. The evidence also suggests that in hospital settings, more patients preferred balanced saline solution (BSS) plus than other irrigation fluids. Irrigation with diphoterine was found in one study that resulted in better ocular outcomes following grade 1 and 2 ocular burns. With regard to duration of eye irrigation, patients with ocular chemical burns treated with prolonged irrigation reported shorter duration of treatment at hospital and absence from work. The results should be treated with caution, as there were significant differences between the comparison groups in some studies.

IMPLICATIONS AND CONCLUSIONS

As prompt eye irrigation with tap water immediately after alkali burns had better outcomes, it would be important to commence eye irrigation immediately after burns are sustained. In this review, irrigating fluids including normal saline, lactated Ringer's, normal saline with sodium bicarbonate added, BSS Plus, and diphoterine solutions all yielded positive ocular outcomes suggesting for its use in hospital settings.

Causes of eye burns in children

OBJECTIVE

Eye burns can cause significant ocular morbidity and miss early detection if unsuspected. The objective was to ascertain the reported causes of burns to the eyes in children.

METHODS

Published literature on eye burns in children was searched from 1950 to July 2008 in MEDLINE and from 1982 to July 2008 in CINAHL (Cumulative Index to Nursing and Allied Health Literature) to identify all reported cases.

RESULTS

Forty-two articles from MEDLINE, 5 from CINAHL database, and 6 from the reference lists were included in the analysis. Eye burns in children were caused by thermal, electrical, microwaved food and drinks, and solar hazards. Chemical agents included household cleaning agents, industrial chemicals, certain medications, agricultural chemicals, and some miscellaneous agents. Biological agents reported were millipedes, snake venom, vesicatory insects, and Manchineel tree sap.

CONCLUSIONS

This article shows that children experience eye burns due to many preventable causes. Public education strategies should be implemented to prevent eye burns in children.

Eye irrigation for patients with ocular chemical burns: a systematic review

AIM

The aim of this systematic review is to present the best available research evidence on eye irrigation methods for ocular chemical burns.

INCLUSION CRITERIA

Randomized, quasi-randomized controlled trials and observational studies comparing the effectiveness of methods of eye irrigation among adults or children as an active form of emergency treatment for ocular chemical burns were considered for review. Studies were eligible for inclusion if methods of eye irrigation were examined within the following comparison categories: time to commence first eye irrigation; types, volumes, durations, flow rates and temperature of eye irrigating fluids; and comfort measures during eye irrigation. The types of outcome measures include immediate ocular outcomes and complications, clinical outcomes, self-reported outcomes, length of hospital stay and working days lost.

SEARCH STRATEGY

Electronic bibliographic databases in English and Chinese were searched from inception to June 2010 and yield 8,999 citations. Other sources were searched by hand to identify studies or additional relevant source materials. The reference lists and bibliographies of all articles retrieved were scrutinized to identify further studies and added a further 22 articles. A forward search on the authors of the studies identified was also performed.

METHODOLOGICAL QUALITY

A study eligibility verification form was developed for the assessment and two reviewers made independent decisions on whether to include each publication in the systematic review. Critical appraisals of study quality were undertaken independently by two reviewers using the Joanna Briggs Institute critical appraisal tools. Any disagreement that arose between the two reviewers was resolved by discussion.

DATA EXTRACTION

Data extraction was performed by one reviewer using a data extraction form developed for the systematic review. Another reviewer checked for accuracy.

DATA SYNTHESIS

Given the clinical and methodological diversity among the studies included in this review, the review findings are presented in a narrative form and no meta-analysis has been performed.

RESULTS AND DISCUSSION

A total of four studies involving 302 adults and children with ocular chemical burns met the inclusion criteria for the systematic review. One study determined the effects of prompt irrigation of the eyes with tap water immediately after alkali burns had been suffered at the scene of injury. The authors report that patients who underwent immediate irrigation had significantly better clinical and ocular outcomes. One study compared four ocular irrigation fluids administered in an emergency department and found more patients preferred a modified saline (balanced saline solution plus) than other type of irrigation fluids. Another study compare the effectiveness of two ocular irrigation fluids in hospital setting reported that for patients with grade 1 and 2 burns, the time elapsed to re-epithelialization was shorter in the group rinsing with diphoterine when compared with the group rinsing with normal saline. The results in another study demonstrated that patients with ocular chemical burns treated with prolonged irrigation reported shorter duration of treatment at the hospital and absence from work. However, the results should be treated with caution, as there were significant differences between the comparison groups in some studies, and incomplete details on methods of random assignment and a small sample size were issues of concern.

CONCLUSIONS

There is insufficient evidence to determine the optimal eye irrigation methods to improve ocular and clinical outcomes. Randomized trials using sample sizes with adequate power are needed to compare the clinical benefits of eye irrigation methods and further trials should take into account the potentially important factors such as the time to commence eye irrigation and cumulative effects of irrigating fluids that might affect the outcomes and adopt strategies to deal with them.

IMPLICATIONS FOR PRACTICE

Currently there is insufficient evidence to inform practice of eye irrigation among adults or children as an active form of emergency treatment for ocular chemical burns. Healthcare professionals need to continuously update themselves about the latest evidence on the optimal methods of eye irrigation in enhancing patient outcomes.

IMPLICATIONS FOR RESEARCH

More well designed randomized and quasi-experimental trials with adequate sample size are needed to further examine the effective methods of eye irrigation for ocular chemical burns. Future studies should provide sufficient information about the demographic and clinical data including the types and severity of ocular injuries, causative chemicals, first-aid management, and time elapsed to eye irrigation. Furthermore, a clear description of the eye irrigation protocol is crucial to facilitate comparisons across studies.

POTENTIAL CONFLICT OF INTERESTS

The authors of this systematic review do not have any type of conflict of interest.

Rinsing with isotonic saline solution for eye burns should be avoided

BACKGROUND

Recent approaches to emergency treatment of eye burns have given rise to many questions on the effectiveness of traditional rinsing solutions. This led us to study the use of isotonic saline solution and a recently introduced, highly effective solution, Cederroth Eye Wash, in the initial treatment of eye burns.

METHODS

A central area (Ø 10mm) of the cornea of isolated ex vivo rabbit eyes was burnt for 20s with 25+/-1.4 micro L of 2N NaOH. The anterior chamber pH was measured continuously via microelectrode. The corneas were immediately rinsed for 15 min with flow rates of 50, 100, 200, 300, 400, and 500 mL/min.

RESULTS

After 20 min measurement, no significant differences in intraocular pH were found between unrinsed eyes and eyes rinsed with isotonic saline solution at any flow rate. At all flow rates, Cederroth Eye Wash brought about a significant decrease (p<0.001; Tukey t-test).

CONCLUSIONS

Isotonic saline solution was ineffective in the emergency treatment of severe alkali eye burns in this ex vivo rabbit eye model. Cederroth Eye Wash, even at the lowest flow rate, significantly reduced intracameral pH. Thus a small amount of buffer solution effectively decontaminated the eye, whilst large amounts of saline solution did not.

Ophthalmologic procedures in the emergency department

Ophthalmologic emergencies account for up to 3% of visits to emergency departments in the United States. Although isolated ocular complaints are rarely life-threatening, they can lead to significant short- and long-term morbidity, including permanent visual loss. The role of the emergency physician in management of ocular emergencies is similar to that for other chief complaints: to recognize and diagnose emergency conditions, to provide appropriate initial therapy, and to ensure correct disposition. This article reviews several of the essential ophthalmologic procedures that are within the scope of emergency medical practice. Slit lamp examination, foreign body removal, use of ultrasound, tonometry, and other emergency ophthalmologic procedures are discussed.

Chemical, thermal, and biological ocular exposures

Chemical or radiant energy injuries to the eyes are considered ocular burns. The majority of these injuries are occupation-related. Chemical burns are by far more common and represent a true emergency. Thermal and UV injuries are associated with severe pain, but often result in less long-term sequelae than chemical injuries do. The term "biologic exposure" refers to an exposure to human blood or other body fluid. This article describes patterns of these injuries and exposures, with particular emphasis on emergent management and including acute diagnostic and treatment considerations.

Ocular effects of exposure to industrial chemicals: clinical management and proteomic approaches to damage assessment

Industrial chemicals in a variety of applications are often found in highly populated areas and their presence carries risks. The threat of serious consequences from inadvertent or intentional events involving hazardous chemicals is a possibility. Extremism and/or other illicit activities pose environmental threats from chemical exposures. We present here a review of the threat of ocular injury in small-and large-scale chemical releases and discuss mechanisms of damage and repair to the eyes. The emerging field of proteomics has been described in relation to its potential role in the assessment of ocular changes following chemical exposures and management of ocular trauma.

Dynamic analysis of chemical eye burns using high-resolution optical coherence tomography

The use of high-resolution optical coherence tomography (OCT) to visualize penetration kinetics during the initial phase of chemical eye burns is evaluated. The changes in scattering properties and thickness of rabbit cornea ex vivo were monitored after topical application of different corrosives by time-resolved OCT imaging. Eye burn causes changes in the corneal microstructure due to chemical interaction or change in the hydration state as a result of osmotic imbalance. These changes compromise the corneal transparency. The associated increase in light scattering within the cornea is observed with high spatial and temporal resolution. Parameters affecting the severity of pathophysiological damage associated with chemical eye burns like diffusion velocity and depth of penetration are obtained. We demonstrate the potential of high-resolution OCT for the visualization and direct noninvasive measurement of specific interaction of chemicals with the eye. This work opens new horizons in clinical evaluation of chemical eye burns, eye irritation testing, and product testing for chemical and pharmacological products.

Corneal calcification after chemical eye burns caused by eye drops containing phosphate buffer

PURPOSE

Chemical burns with calcium containing corrosives as well as irrigation with phosphate buffer solutions after eye burns bear the risk of corneal calcification. The aim of this study was to evaluate the correlation between the occurrence of corneal calcification after chemical injuries and the usage of phosphate buffer containing local therapeutics.

METHODS

We reviewed the data of 179 patients who have been treated in the University Eye Clinic Aachen, Germany, between 1941 and 2000. Only when the corrosive did not contain calcium and when the initial irrigating solution did not contain phosphate buffer, respectively, were patients included in the study. The cases were analyse, if the patient was treated with phosphate buffer containing eye drops/ointment during the first 7 days of hospitalization or as an out-patient, and if corneal calcification was visible by slit-lamp examination during the follow-up. Statistical analysis was performed using Fischer's exact test.

RESULTS

152 eyes were included. From 63 eyes treated with phosphate buffer containing eye drops, 31 eyes (49%) developed corneal calcification. From 89 eyes treated without phosphate buffer containing eye drops, only 23 eyes (26%) developed corneal calcification. The two-sided p-value of Fischer's exact test is 0.0036.

CONCLUSION

During follow-up after chemical eye burns, eye drops containing phosphate buffer double the risk of corneal calcification. We recommend avoiding these agents in order to prevent the burned cornea from additional opacity. Substances containing phosphate buffer are listed in this article.

Alkali Burns of the Eye: Effect of Immediate Copious Irrigation with Tap Water on Their Severity

PURPOSE

To examine the effect of immediate irrigation on ocular alkali burn.

METHODS

Information on the injury, immediate irrigation, and ocular findings was retrospectively obtained from each patient's record.

RESULTS

36 patients (49 eyes) irrigated their eyes with tap water (the irrigation group) and 17 patients (29 eyes) did not (no irrigation group). The mean age of patients in the irrigation and no irrigation groups was 30 and 53 years, respectively. According to Hugher's classification, 76% of eyes in the irrigation group had grade 1 injury, while 86% of eyes in the no irrigation group had grade 2 injuries. Mean time from the injury until healing was 8 days in the irrigation group and 29 days in the no irrigation group, respectively.

CONCLUSION

Immediate copious irrigation with tap water reduced the severity in alkali burns of the eye and shortened the healing time.

Emergency treatment of eye burns: which rinsing solution should we choose?

BACKGROUND

In the treatment of eye burns few data on the comparative application of rinsing solutions exist. We present experiments in vitro and ex vivo on the pH changes that can be achieved in alkali eye burns with currently distributed and propagated rinsing fluids like water, saline solution, Cederroth Eye Wash Solution (including borate buffer), Diphoterine, Ringers lactate solution and phosphate buffer.

METHODS

Titration curves in beakers are compared with ex vivo experiments on isolated rabbit eyes. We exposed eyes to burns from filter paper soaked in 2 mol NaOH, continuously measuring the anterior chamber pH by means of a micro pH electrode placed near the endothelium. In each experiment--repeated five times--the corneal burn of 20 s in 2 mol NaOH was followed by a period of 15 min of rinsing under a defined flow of 66 ml/min.

RESULTS

We found highly significant differences in intracameral pH related to different types of rinsing solutions. The return of the intracameral pH to normal was not achieved by any of the rinsing fluids, but the best results were noted for of Cederroth Eye Wash Solution (Cederroth Industrial Products, Upplands Väasby, Sweden) and the Diphoterine- and Previn solutions (Prevor, Cologne, Germany). Water played an intermediate role whereas saline and phosphate buffer were not efficient at lowering intracameral pH after alkali burns.

CONCLUSION

In alkali burns we recommend efficient buffering solutions. The tested isotonic phosphate buffer (PBS) was not effective at buffering the intraocular pH. Water was found to be much less efficient than Previn, Diphoterine or Cederroth Eye Wash solution in balancing intraocular pH.

Emergency care in facial trauma--a maxillofacial and ophthalmic perspective

Facial trauma, with or without life- and sight-threatening complications, may arise following isolated injury, or it may be associated with significant injuries elsewhere. Assessment needs to be both systematic and repeated, with the establishment of clearly stated priorities in overall care. Although the American College of Surgeons Advanced Trauma Life Support (ATLS) system of care is generally accepted as the gold standard in trauma care, it has potential pitfalls when managing maxillofacial injuries, which are discussed. Management of facial trauma can arguably be regarded as "facial orthopaedics", as both specialities share common management principles. This review outlines a working approach to the identification and management of life- and sight-threatening conditions following significant facial trauma.

Use of an amphoteric lavage solution for emergency treatment of eye burns. First animal type experimental clinical considerations

PURPOSE

Severe eye burns occur rarely, but are related to a poor prognosis in rehabilitation. As emergency treatment has been identified as decisive factor for the prognosis of eye burns, new first aid rinsing solutions should be considered carefully in their clinical action. In a first approach, the new drug Diphoterine was subjected to a comparison with saline solution to evaluate the effects in a model of severe eye burns.

METHODS

In a double-masked experiment 16 rabbits underwent a severe eye burn of one cornea followed by immediate rinsing with 0.9% sodium-chlorine solution (n=8) or Diphoterine (n=8). During 16 days after burn, an irrigation therapy with 0.9% saline solution three times daily 160 ml was applied in both groups following the recommendation of prolonged irrigation therapy performed in our clinic. In a similar setup, 16 eyes were subjected alkali burns with measurements of aqueous humor pH within 30s after burn and after a period of 5 min rinsing with 500 ml saline 0.9% or Diphoterine, respectively.

RESULTS

The result of the severe eye burn with an opaque cornea was similar in both groups. During rinsing no fibrin precipitates occurred in the Diphoterine rinsed group whereas this was detectable in all eyes rinsed with saline solution. After 16 days there was no difference between both groups indicating no harmful effect of Diphoterine as emergency treatment compared to saline 0.9%. After 30s of burn with 1N NaOH and rinsing with 500 ml of the specified solutions the anterior chamber pH was 10+/-0 in the saline group and 9.35+/-0.3 in the Diphoterine group showing efficacy of the buffering capacity of Diphoterine.

CONCLUSION

Diphoterine proves to be efficient in the primary treatment of burns. The anterior chamber pH could be lowered by 5min of rinsing. No harmful effects of Diphoterine could be observed compared to rinsing with saline solution in the course of an severe alkali burn of the cornea.