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Emergency and Acute Medicine – Corneal Burn
Definition and Mechanisms of Injury
A corneal burn results from inappropriate exposure of the cornea to chemical agents, extreme heat or cold, electrical current, or radiant energy, leading to injury of the corneal tissue and frequently extending to adjacent ocular structures. The severity of injury is determined by the duration of exposure, the nature of the offending agent, its concentration, and in chemical injuries, the pH and ionic properties of the solution.
Alkali burns are particularly dangerous because they cause an immediate rise in ocular pH and are highly lipid soluble, allowing rapid penetration through ocular tissues. Without prompt intervention, alkalis continue to penetrate deeper layers, with significant injury occurring in less than one minute. Calcium-based alkalis are a notable exception, as they penetrate less effectively due to soap formation; although they may cause marked corneal opacification, their overall prognosis is often better than that of other alkali burns. Acid burns cause rapid coagulation of corneal epithelial proteins, leading to opacification. This coagulation creates a barrier that limits deeper penetration, except in the case of hydrofluoric acid, which is lipophilic and behaves more like an alkali, penetrating rapidly and causing severe injury.
Thermal burns generally affect the eyelids more than the globe because of reflex blinking and the Bell phenomenon, in which the eyes roll upward and outward. When the cornea is involved, injury severity depends on the duration and intensity of heat exposure. Electrical injuries occur when current passes through the head with an entry point at or near the eye. Radiation injuries result from ultraviolet light exposure to the cornea.
Etiology and Sources of Exposure
Common alkali agents include ammonia found in fertilizers, refrigerants, household ammonia, and cleaning agents; potassium hydroxide; magnesium hydroxide from sparklers, flares, and fireworks; sodium hydroxide in drain cleaners; and lime compounds used in cement, plaster, mortar, and whitewash. Motor vehicle airbag deployment can also release nonspecific alkali during inflation.
Acid exposures include sulfuric acid from car batteries and toilet cleaners, sulfurous acid used as food preservatives, acetic acid in vinegar, bleach, and hydrofluoric acid used in glass etching, brick cleaning, metal electropolishing, brewery fermentation control, and rust removal. Thermal injuries may result from hot liquids, molten metal, flames, hot smoke or gases, flash burns, steam, or cigarette burns. Radiation injuries are associated with sun lamps, tanning booths, high-altitude sunlight, reflected ultraviolet light from snow or water, and arc welding. In pediatric cases, the possibility of abuse or neglect must always be considered.
Clinical Presentation
Patients often present with severe eye pain, photophobia, excessive tearing, and a foreign body sensation. Conjunctival injection, corneal edema, corneal opacification, and reduced visual acuity are common. More severe findings include limbal blanching, lens opacification, vesicle formation with clear or hemorrhagic fluid in hypothermal injuries, and necrosis of the iris or ciliary body.
The history should focus on identifying the type of exposure and, when possible, inspection of any containers brought by the patient to determine active and inactive ingredients. The vehicle of exposure should be clarified, as aerosols are common and propellants may cause intraocular foreign bodies or perforation. Duration of exposure, time to irrigation, symptom onset, pre-existing visual impairment, protective eyewear use, contact lens use, and treatments initiated prior to arrival should be documented.
Physical Examination and Diagnostic Evaluation
A complete ocular examination should be performed after adequate irrigation. Visual acuity should be assessed first, followed by inspection of the cornea, conjunctivae, and limbus under bright white light. Slit-lamp examination is essential to evaluate anterior segment inflammation. Fluorescein staining helps identify corneal epithelial defects, including punctate lesions with a discrete inferior border typical of ultraviolet radiation burns, and can be used to detect perforation with the Seidel test. Lens clarity and fundus appearance should be assessed when possible, and intraocular pressure should be measured, particularly in delayed presentations. Examination of the eyelids and eyelashes is important to identify retained particulate matter. In acid or alkali burns, ocular pH should be measured using litmus paper or pH indicator strips placed in the inferior conjunctival fornix.
In children, handheld slit lamps and Wood lamps are particularly useful to facilitate examination.
Differential Diagnosis
Conditions that may resemble corneal burns include viral keratitis, corneal ulcer, corneal erosion syndrome, corneal foreign body, corneal abrasion, and hypothermal injury.
Prehospital and Initial Management
At the scene, immediate irrigation for 15–30 minutes is critical unless other life-threatening conditions require urgent transport. Whenever possible, the offending substance container should be brought to the hospital. Continuous irrigation with water or normal saline should be maintained during transport.
Initial stabilization depends on the type of exposure. For unknown chemical exposures, acid or alkali injury should be assumed, and irrigation initiated with any available diluting fluid, preferably water or normal saline. Thermal injuries should be managed with cool, moist dressings and overlying ice packs.
Emergency Department Treatment
For chemical exposures, including alkalis, acids, and mace, continuous irrigation is performed until a target pH of 7.3–7.5 is achieved, typically requiring 1–2 liters of fluid over 30–60 minutes using a Morgan lens. Ocular pH should be checked every 30 minutes, with pH paper placed in the inferior conjunctival fornix, and rechecked at 5 and 30 minutes after irrigation to confirm normalization. Topical anesthetics such as proparacaine may be required to facilitate irrigation. The fornices must be carefully inspected with the eye moved through full range of motion to ensure complete removal of particulate material.
Prophylactic topical antibiotics targeting Staphylococcus and Pseudomonas species are recommended until epithelial healing is complete, commonly using gentamicin ointment in combination with erythromycin or bacitracin. Cycloplegic agents such as cyclopentolate or atropine are used to reduce pain and prevent posterior synechiae. Oral analgesics are often required. If intraocular pressure is elevated, immediate ophthalmologic consultation is necessary, and treatment may include acetazolamide and topical timolol. Topical corticosteroids may be used to control anterior uveitis only after consultation with ophthalmology. Eye patching and surgical intervention may be required in cases of corneal penetration. Mild injuries warrant ophthalmology consultation by phone, while all moderate to severe injuries require immediate ophthalmologic evaluation or transfer to a specialized eye center. Hydrofluoric acid burns require standard treatment plus 1% calcium gluconate eye drops and admission for systemic analgesia.
Thermal injuries are managed with frequent moist dressing changes, topical antibiotics four times daily, generous lubrication, and moisture chambers when eyelid injury is extensive. Steroids may be used for short durations under ophthalmologic guidance. Any second- or third-degree eyelid burn requires ophthalmology consultation. Cigarette ash or hot liquid splashes usually cause superficial epithelial injury and are treated similarly to corneal abrasions. Electrical injuries require irrigation, wound care, antibiotic ointment, cycloplegics if uveitis is present, and adequate analgesia. Radiation injuries are treated with topical anesthetics for examination, short-acting cycloplegics, antibiotic ointment, and oral opioids if pain is severe.
Medications
Common treatments include artificial tears, cycloplegics such as atropine, cyclopentolate, homatropine, or tropicamide, topical antibiotics including bacitracin, erythromycin, gentamicin, sulfacetamide, ciprofloxacin, and tobramycin, and short-term topical anesthetics for in-hospital use only.
Disposition and Follow-Up
Admission is indicated for patients with intractable pain, elevated intraocular pressure, corneal penetration requiring surgical intervention, hydrofluoric acid burns requiring observation, or suspected child abuse. All mild corneal burns may be discharged once stabilized. Mandatory ophthalmology follow-up within 12–24 hours is required for all patients and should be arranged prior to discharge.
Key Management Principles and Safety Considerations
In chemical exposures, ocular examination should be delayed until adequate irrigation has been completed. Any patient with a corneal epithelial defect requires ophthalmologic follow-up within 12–24 hours. Topical anesthetics should never be prescribed for outpatient use, as they delay epithelial healing and increase the risk of serious complications.
Definition and Mechanisms of Injury
A corneal burn results from inappropriate exposure of the cornea to chemical agents, extreme heat or cold, electrical current, or radiant energy, leading to injury of the corneal tissue and frequently extending to adjacent ocular structures. The severity of injury is determined by the duration of exposure, the nature of the offending agent, its concentration, and in chemical injuries, the pH and ionic properties of the solution.
Alkali burns are particularly dangerous because they cause an immediate rise in ocular pH and are highly lipid soluble, allowing rapid penetration through ocular tissues. Without prompt intervention, alkalis continue to penetrate deeper layers, with significant injury occurring in less than one minute. Calcium-based alkalis are a notable exception, as they penetrate less effectively due to soap formation; although they may cause marked corneal opacification, their overall prognosis is often better than that of other alkali burns. Acid burns cause rapid coagulation of corneal epithelial proteins, leading to opacification. This coagulation creates a barrier that limits deeper penetration, except in the case of hydrofluoric acid, which is lipophilic and behaves more like an alkali, penetrating rapidly and causing severe injury.
Thermal burns generally affect the eyelids more than the globe because of reflex blinking and the Bell phenomenon, in which the eyes roll upward and outward. When the cornea is involved, injury severity depends on the duration and intensity of heat exposure. Electrical injuries occur when current passes through the head with an entry point at or near the eye. Radiation injuries result from ultraviolet light exposure to the cornea.
Etiology and Sources of Exposure
Common alkali agents include ammonia found in fertilizers, refrigerants, household ammonia, and cleaning agents; potassium hydroxide; magnesium hydroxide from sparklers, flares, and fireworks; sodium hydroxide in drain cleaners; and lime compounds used in cement, plaster, mortar, and whitewash. Motor vehicle airbag deployment can also release nonspecific alkali during inflation.
Acid exposures include sulfuric acid from car batteries and toilet cleaners, sulfurous acid used as food preservatives, acetic acid in vinegar, bleach, and hydrofluoric acid used in glass etching, brick cleaning, metal electropolishing, brewery fermentation control, and rust removal. Thermal injuries may result from hot liquids, molten metal, flames, hot smoke or gases, flash burns, steam, or cigarette burns. Radiation injuries are associated with sun lamps, tanning booths, high-altitude sunlight, reflected ultraviolet light from snow or water, and arc welding. In pediatric cases, the possibility of abuse or neglect must always be considered.
Clinical Presentation
Patients often present with severe eye pain, photophobia, excessive tearing, and a foreign body sensation. Conjunctival injection, corneal edema, corneal opacification, and reduced visual acuity are common. More severe findings include limbal blanching, lens opacification, vesicle formation with clear or hemorrhagic fluid in hypothermal injuries, and necrosis of the iris or ciliary body.
The history should focus on identifying the type of exposure and, when possible, inspection of any containers brought by the patient to determine active and inactive ingredients. The vehicle of exposure should be clarified, as aerosols are common and propellants may cause intraocular foreign bodies or perforation. Duration of exposure, time to irrigation, symptom onset, pre-existing visual impairment, protective eyewear use, contact lens use, and treatments initiated prior to arrival should be documented.
Physical Examination and Diagnostic Evaluation
A complete ocular examination should be performed after adequate irrigation. Visual acuity should be assessed first, followed by inspection of the cornea, conjunctivae, and limbus under bright white light. Slit-lamp examination is essential to evaluate anterior segment inflammation. Fluorescein staining helps identify corneal epithelial defects, including punctate lesions with a discrete inferior border typical of ultraviolet radiation burns, and can be used to detect perforation with the Seidel test. Lens clarity and fundus appearance should be assessed when possible, and intraocular pressure should be measured, particularly in delayed presentations. Examination of the eyelids and eyelashes is important to identify retained particulate matter. In acid or alkali burns, ocular pH should be measured using litmus paper or pH indicator strips placed in the inferior conjunctival fornix.
In children, handheld slit lamps and Wood lamps are particularly useful to facilitate examination.
Differential Diagnosis
Conditions that may resemble corneal burns include viral keratitis, corneal ulcer, corneal erosion syndrome, corneal foreign body, corneal abrasion, and hypothermal injury.
Prehospital and Initial Management
At the scene, immediate irrigation for 15–30 minutes is critical unless other life-threatening conditions require urgent transport. Whenever possible, the offending substance container should be brought to the hospital. Continuous irrigation with water or normal saline should be maintained during transport.
Initial stabilization depends on the type of exposure. For unknown chemical exposures, acid or alkali injury should be assumed, and irrigation initiated with any available diluting fluid, preferably water or normal saline. Thermal injuries should be managed with cool, moist dressings and overlying ice packs.
Emergency Department Treatment
For chemical exposures, including alkalis, acids, and mace, continuous irrigation is performed until a target pH of 7.3–7.5 is achieved, typically requiring 1–2 liters of fluid over 30–60 minutes using a Morgan lens. Ocular pH should be checked every 30 minutes, with pH paper placed in the inferior conjunctival fornix, and rechecked at 5 and 30 minutes after irrigation to confirm normalization. Topical anesthetics such as proparacaine may be required to facilitate irrigation. The fornices must be carefully inspected with the eye moved through full range of motion to ensure complete removal of particulate material.
Prophylactic topical antibiotics targeting Staphylococcus and Pseudomonas species are recommended until epithelial healing is complete, commonly using gentamicin ointment in combination with erythromycin or bacitracin. Cycloplegic agents such as cyclopentolate or atropine are used to reduce pain and prevent posterior synechiae. Oral analgesics are often required. If intraocular pressure is elevated, immediate ophthalmologic consultation is necessary, and treatment may include acetazolamide and topical timolol. Topical corticosteroids may be used to control anterior uveitis only after consultation with ophthalmology. Eye patching and surgical intervention may be required in cases of corneal penetration. Mild injuries warrant ophthalmology consultation by phone, while all moderate to severe injuries require immediate ophthalmologic evaluation or transfer to a specialized eye center. Hydrofluoric acid burns require standard treatment plus 1% calcium gluconate eye drops and admission for systemic analgesia.
Thermal injuries are managed with frequent moist dressing changes, topical antibiotics four times daily, generous lubrication, and moisture chambers when eyelid injury is extensive. Steroids may be used for short durations under ophthalmologic guidance. Any second- or third-degree eyelid burn requires ophthalmology consultation. Cigarette ash or hot liquid splashes usually cause superficial epithelial injury and are treated similarly to corneal abrasions. Electrical injuries require irrigation, wound care, antibiotic ointment, cycloplegics if uveitis is present, and adequate analgesia. Radiation injuries are treated with topical anesthetics for examination, short-acting cycloplegics, antibiotic ointment, and oral opioids if pain is severe.
Medications
Common treatments include artificial tears, cycloplegics such as atropine, cyclopentolate, homatropine, or tropicamide, topical antibiotics including bacitracin, erythromycin, gentamicin, sulfacetamide, ciprofloxacin, and tobramycin, and short-term topical anesthetics for in-hospital use only.
Disposition and Follow-Up
Admission is indicated for patients with intractable pain, elevated intraocular pressure, corneal penetration requiring surgical intervention, hydrofluoric acid burns requiring observation, or suspected child abuse. All mild corneal burns may be discharged once stabilized. Mandatory ophthalmology follow-up within 12–24 hours is required for all patients and should be arranged prior to discharge.
Key Management Principles and Safety Considerations
In chemical exposures, ocular examination should be delayed until adequate irrigation has been completed. Any patient with a corneal epithelial defect requires ophthalmologic follow-up within 12–24 hours. Topical anesthetics should never be prescribed for outpatient use, as they delay epithelial healing and increase the risk of serious complications.
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