AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: J Bradley Randleman, MD, Assistant Professor, Department of Ophthalmology, Cornea, External Disease, and Refractive Surgery Section, Emory University School of Medicine
J Bradley Randleman is a member of the following medical societies: Alpha Omega Alpha, American Academy of Ophthalmology, American College of Surgeons, American Medical Association, and American Society of Cataract and Refractive Surgery
Coauthor(s):
Evan S Loft, MD, Staff Physician, Department of Ophthalmology, Emory University;
Geoffrey Broocker, MD, FACS, Chief of Service, Ophthalmology, Professor of Ophthalmology, Department of Ophthalmology, Emory University School of Medicine, Grady Memorial Hospital
Editors: Fernando H Murillo-Lopez, MD, Senior Surgeon, Unidad Privada de Oftalmologia CEMES; Simon K Law, MD, PharmD, Assistant Professor of Ophthalmology, Jules Stein Eye Institute; Chief of Section of Ophthalmology Surgical Services, Department of Veterans Affairs Healthcare Center, West Los Angeles; Christopher J Rapuano, MD, Professor, Department of Ophthalmology, Jefferson Medical College; Co-Chairman of the Cornea Service, Co-Chairman of Refractive Surgery Department, Wills Eye Hospital; Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri; Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Author and Editor Disclosure
Synonyms and related keywords:
chemical injuries, acid burns, alkaline burns, acid injury, alkali injury
Background
Chemical injuries to the eye represent one of the true ophthalmic emergencies. While almost any chemical can cause ocular irritation, serious damage generally results from either strongly basic (alkaline) compounds or acidic compounds. Alkali injuries are more common and can be more deleterious. Bilateral chemical exposure is especially devastating, often resulting in complete visual disability. Immediate, prolonged irrigation, followed by aggressive early management and close long-term monitoring, is essential to promote ocular surface healing and to provide the best opportunity for visual rehabilitation.
Pathophysiology
The severity of this injury is related to type, volume, concentration, duration of exposure, and degree of penetration of the chemical. The mechanism of injury differs slightly between acids and alkali.
Acid injury
Acids dissociate into hydrogen ions and anions in the cornea. The hydrogen molecule damages the ocular surface by altering the pH, while the anion causes protein denaturation, precipitation, and coagulation. Protein coagulation generally prevents deeper penetration of acids and is responsible for the ground glass appearance of the corneal stroma following acid injury. Hydrofluoric acid is an exception; it behaves like an alkaline substance because the fluoride ion has better penetrance through the stroma than most acids, leading to more extensive anterior segment disruption.
Alkali injury
Alkaline substances dissociate into a hydroxyl ion and a cation in the ocular surface. The hydroxyl ion saponifies cell membrane fatty acids, while the cation interacts with stromal collagen and glycosaminoglycans. This interaction facilitates deeper penetration into and through the cornea and into the anterior segment. Subsequent hydration of glycosaminoglycans results in stromal haze. Collagen hydration causes fibril distortion and shortening, leading to trabecular meshwork alterations that can result in increased intraocular pressure (IOP). Additionally, the inflammatory mediators released during this process stimulate the release of prostaglandins, which can further increase IOP.
Frequency
United States
Chemical injuries represent roughly 10% of patients seeking treatment for eye complaints at US hospitals. One study showed a 2% cumulative lifetime prevalence of chemical injuries to the eye.
Mortality/Morbidity
- More than 60% of injuries occur in workplace accidents, 30% occur at home, and 10% are the result of an assault.
- As many as 20% of chemical injuries result in significant visual and cosmetic disability; only 15% of patients with severe chemical injuries achieve functional visual rehabilitation.
Race
No overall racial predilection exists; however, young black males are more likely to have high-concentration, high-impact alkaline chemical injuries secondary to assault.
Sex
Males are 3 times more likely to experience chemical injuries than females.
Age
Chemical injuries can strike any population; however, most injuries occur in patients aged 16-45 years.
History
Most often, the patient gives a history of a liquid or a gas being splashed or sprayed into the eyes or of particles falling into the eyes. Regardless of the specific mechanism of injury, the patient's complaints are frequently related to the severity of the exposure. Common specific complaints elicited are as follows:
- Pain (often extreme)
- Foreign body sensation
- Blurred vision
- Excessive tearing
- Photophobia
- Red eye(s)
Physical
A thorough physical examination should be deferred until the affected eye is irrigated copiously, and the pH of the ocular surface is neutralized. After irrigation, a thorough eye examination is performed with special attention given to clarity and integrity of the cornea, degree of limbal ischemia, and IOP. The eye examination can be facilitated by using topical anesthetic drops to aid in patient comfort and cooperation. Common physical manifestations of chemical injuries to the eye include the following:
- Corneal epithelial defect: Corneal epithelial damage can range from mild diffuse punctate epithelial keratitis (PEK) to a complete epithelial defect. A complete epithelial defect may not take up fluorescein dye as rapidly as in a routine corneal abrasion; therefore, it may be missed. If an epithelial defect is suspected but not found on the initial evaluation, the eye should be reexamined after several minutes.
- Stromal haze: Haze can range from a clear cornea to a complete opacification with no view into the anterior chamber.
- Corneal perforation: A very rare finding at presentation, it is more likely to occur after the initial presentation (from days to weeks) in severely injured eyes that have poor healing capacity.
- Anterior chamber inflammatory reaction: This condition can present as varying degrees of inflammation (flare and cell) in the anterior chamber. This finding is more common with alkaline chemicals and is related to the greater depth of penetration.
- Increased IOP: This finding is related to both the degree of anterior segment inflammation and the degree of corneal collagen deformation and shortening, which essentially shrinks the anterior chamber, thus raising IOP and reducing uveoscleral outflow.
- Adnexal damage/scarring: Similar to chemical injuries on other skin areas, this finding can lead to severe exposure problems if eyelid scarring prevents proper closure, thereby exposing an already damaged ocular surface.
- Conjunctival inflammation: Varying degrees of conjunctival hyperemia and chemosis are possible, and even a mild chemical injury can elicit an exuberant conjunctival response.
- Perilimbal ischemia: The degree of limbal ischemia (blanching) is perhaps the most significant prognostic indicator for future corneal healing because the limbal stem cells are responsible for repopulating the corneal epithelium. The greater the extent of blanching, the worse the prognosis.
- Particles in the conjunctival fornices: This finding is more common with particulate injuries, such as plaster. If not removed, the residual particles can serve as a reservoir for continued chemical release and injury. These particles must be removed before ocular surface healing can begin.
- Decreased visual acuity: Initial visual acuity can be decreased because of epithelial defects, haze, increased lacrimation, or discomfort. In moderate-to-severe chemical burns seen soon after the injury, the corneal haze may be minimal on presentation with good vision, but it can increase significantly with time, severely reducing vision.
Causes
- Alkali
- Ammonia (most serious)
- Lye
- Potassium hydroxide
- Magnesium hydroxide
- Lime (most common)
- Common sources of alkali are as follows:
- Fertilizers
- Cleaning products (eg, ammonia)
- Drain cleaners (eg, lye)
- Oven cleaners
- Potash (eg, potassium hydroxide)
- Fireworks (eg, magnesium hydroxide)
- Cement (eg, lime)
- Acids
- Sulfuric acid
- Sulfurous acid (most common)
- Hydrofluoric acid (most serious)
- Acetic acid
- Chromic acid
- Hydrochloric acid
- Common sources of acids are as follows:
- Battery acid (sulfuric)
- Glass polish (hydrofluoric)
- Vinegar (acetic)
Conjunctivitis, Acute Hemorrhagic
Conjunctivitis, Allergic
Corneal Abrasion
Corneal Erosion, Recurrent
Corneal Foreign Body
Keratoconjunctivitis, Atopic
Keratoconjunctivitis, Epidemic
Keratoconjunctivitis, Sicca
Ulcer, Corneal
Lab Studies
- Periodically test the pH of the ocular surface, and continue irrigation until the pH reaches neutrality. No other laboratory tests are generally necessary unless other systemic injuries are concurrent.
Medical Care
- Remove inciting chemical (irrigation)
- Immediate copious irrigation remains the single most important therapy for treating chemical injuries. Effective irrigation dilutes and flushes away the inciting chemical.
- The injured eye is irrigated with a sterile balanced buffered solution, such as Ringer's lactate solution or normal saline solution. Immediately beginning irrigation, without waiting for the ideal fluid, is important; therefore, plain tap water is usually the solution of first choice for initial irrigation. Irrigation should be continued until the pH of the ocular surface is neutralized, usually using 1-2 liters of fluid.
- The irrigation solution must contact the ocular surface; therefore, the eye must remain open by means of a lid speculum, or, more ideally, the irrigation should be conducted with the use of special irrigating tubing (eg, Morgan lens). If available, the eye should be anesthetized prior to irrigation.
- Control inflammation
- Inflammatory mediators released from the ocular surface at the time of injury cause tissue necrosis and attract further inflammatory reactants, which can inhibit reepithelialization. Breaking this inflammatory cycle can enhance the rate of epithelial regrowth.
- Topical steroids, which have no direct effect on the rate of epithelial regrowth, are useful during the early recovery phase. Cycloplegics also reduce inflammation by stabilizing the blood-aqueous barrier.
- Prevent infection: The corneal epithelium serves as a barrier to infection. When this layer is absent, the eye is susceptible to infection. For prevention, the use of prophylactic topical antibiotics is warranted during the initial treatment stages.
- Reduce IOP: The use of aqueous suppressants is advocated to reduce IOP secondary to chemical injuries, both as an initial therapy and during the later recovery phase, if IOP is high (>30 mm Hg).
- Promote epithelial healing
- Once the inciting chemical has been completely removed, epithelial healing can begin. Chemically injured eyes have a tendency to poorly produce adequate tears; therefore, artificial tear supplements play an important role in healing.
- Ascorbate plays a fundamental role in collagen remodeling, leading to an improvement in corneal healing.
- Placement of a therapeutic contact lens until the epithelium has regenerated can be helpful in some patients.
- Control pain: Severe chemical burns can be extremely painful. Ciliary spasm can be managed with the use of cycloplegic agents; however, oral pain medication may be necessary initially to control pain.
Surgical Care
- Sweep fornices to remove retained particles. This technique is especially important when particulate matter (eg, plaster) is responsible for the injury. A moist sterile cotton swab can be used to sweep the superior and inferior fornices after instilling topical anesthesia.
- Debride necrotic conjunctival/corneal tissue. Removal of severely necrotic material from the ocular surface is necessary because this tissue can stimulate a more intense inflammatory reaction, which inhibits ocular surface regeneration.
- Lyse conjunctival adhesions. Adhesions are a later finding, and they can be managed with repeated lysis using a glass rod or a sterile cotton swab.
- Cyanoacrylate tissue adhesive may be applied for the treatment of corneal melting.
- In the acute phase, temporary amniotic membrane patching may be considered.
- Long-term surgical options include penetrating keratoplasty, limbal stem cell transplant, amniotic membrane transplant, cultivated corneal epithelial stem cell sheet transplant, or any combination of the above.
Consultations
In most instances, patients present to nonophthalmologists for their immediate care. At a minimum, patients with mild chemical injuries should have follow-up care arranged with an ophthalmologist. Any patient with a moderate-to-serious injury should be immediately evaluated and followed accordingly by an ophthalmologist. Other medical personnel may be needed as determined by the extent of the extraocular injuries sustained.
Medical therapy following irrigation in chemical injuries is geared toward promoting epithelial healing, preventing infection, preventing damage from increased IOP, and controlling pain.
Epithelial healing is promoted through aggressive lubrication, ascorbate replenishment, and judicious use of topical corticosteroids. Artificial tears and ointments are especially important with severely scarred and exposed eyes. Ascorbate, both oral and topical, aids in the synthesis of collagen fibrils. Topical steroids decrease ocular surface inflammation, facilitating new epithelial cell growth and ocular surface regeneration. The presence of epithelial defects and corneal exposure necessitates the use of prophylactic topical antibiotics to prevent infection in the already compromised eye.
Antibiotic ointments can serve the dual purpose of providing lubrication and preventing infection. Broad-spectrum antibiotic coverage is required to most effectively minimize infection.
Moderate and severe injuries often stimulate an increase in IOP due to anterior chamber inflammation and collagen fibril shortening. This condition is treated most effectively with aqueous suppressants, especially oral carbonic anhydrase inhibitors and topical beta-adrenergic blockers.
Inflamed eyes often experience ciliary spasm, which can be painful. This spasm is blocked by relatively long-acting mydriatic cycloplegics. In severe chemical injuries, oral pain medication may be required to comfort the patient.
Drug Category: Topical antibiotics
Prevent ocular surface infection and effectively lubricate the eye.
| Drug Name | Erythromycin ophthalmic ointment |
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| Description | Macrolide broad-spectrum antibiotic. |
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| Adult Dose | Apply approximately 1-cm ribbon to affected eye 4-8 times/d |
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| Pediatric Dose | Apply as in adults |
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| Contraindications | Documented hypersensitivity; viral, mycobacterial, or fungal infections of eye; patients using steroid combinations after uncomplicated removal of a foreign body from cornea should avoid using this product |
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| Interactions | None reported |
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| Pregnancy | B - Usually safe but benefits must outweigh the risks.
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| Precautions | Do not use topical antibiotics to treat ocular infections that may become systemic; prolonged or repeated antibiotic therapy may result in bacterial or fungal overgrowth of nonsusceptible organisms and may lead to a secondary infection (take appropriate measures if superinfection occurs) |
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| Drug Name | Ciprofloxacin HCl (Ciloxan) |
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| Description | Fluoroquinolone broad-spectrum bacteriocidal antibiotic. |
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| Adult Dose | Drops: 1 gtt in affected eye qid for prophylaxis
Ointment: Directly apply approximately 1-cm ribbon to the affected eye 4-8 times/d |
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| Pediatric Dose | <1 year: Not established
>1 year: 1-2 gtt qid |
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| Contraindications | Documented hypersensitivity |
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| Interactions | Specific drug interaction studies have not been conducted with ophthalmic ciprofloxacin |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Prolonged use may result in overgrowth of nonsusceptible organisms, including fungi; discontinue use at the first appearance of a skin rash or any other sign of hypersensitivity reaction |
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Drug Category: Carbonic anhydrase inhibitors
Carbonic anhydrase inhibitors reduce aqueous humor production, which then reduces IOP.
| Drug Name | Methazolamide (Neptazane) |
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| Description | Reduces aqueous humor formation by inhibiting enzyme carbonic anhydrase, which results in decreased IOP. |
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| Adult Dose | 50 mg PO bid/tid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; renal impairment |
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| Interactions | May increase toxicity of salicylate and digoxin; coadministration with other diuretics may induce hypokalemia; decreases effects of lithium and alters excretion of other drugs by alkalinizing urine |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Caution in respiratory acidosis and diabetes mellitus; impairs mental alertness and/or physical coordination; hematuria, glycosuria, polyuria, hepatic insufficiency, bone marrow suppression, thrombocytopenia/purpura, agranulocytosis, urticaria, pruritus, and rash may occur |
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| Drug Name | Acetazolamide (Diamox) |
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| Description | Decreases secretion of aqueous humor, lowering IOP. |
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| Adult Dose | 500 mg PO bid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; hepatic disease; severe renal disease; adrenocortical insufficiency; severe pulmonary obstruction |
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| Interactions | Can decrease therapeutic levels of lithium and alter excretion of drugs (eg, amphetamines, quinidine, phenobarbital, salicylates) by alkalinizing urine |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Patients with impaired hepatic function may go into coma; may cause substantial increase in blood glucose in some patients with diabetes |
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Drug Category: Cycloplegic mydriatics
Cycloplegic mydriatics reduce pain by blocking ciliary spasm, and they reduce intraocular inflammation by stabilizing the blood-aqueous barrier. Drugs from this category are chosen based on their duration of action. Intermediate-acting compounds, such as homatropine or scopolamine, are preferred to short-acting compounds, such as tropicamide, or extremely long-acting compounds, such as atropine sulfate.
| Drug Name | Homatropine 2%, 5% (Isopto Homatropine) |
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| Description | Blocks responses of sphincter muscle of iris and muscle of ciliary body to cholinergic stimulation, producing pupillary dilation (mydriasis) and paralysis of accommodation (cycloplegia).
Induces mydriasis in 10-30 min and cycloplegia in 30-90 min. These effects last up to 48 h. |
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| Adult Dose | 5% solution: 1 gtt bid/tid |
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| Pediatric Dose | 2% solution: 1 gtt bid/tid |
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| Contraindications | Documented hypersensitivity; narrow-angle glaucoma |
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| Interactions | None reported |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Caution in elderly persons where increased IOP may be present; toxic anticholinergic systemic adverse effects can occur but are rare when used sparingly; adverse effects are more common in children, especially infants; compressing lacrimal sac by digital pressure for 1-3 min following instillation minimizes systemic absorption |
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| Drug Name | Scopolamine 0.25% ( Isopto Hyoscine) |
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| Description | Anticholinergic agent that blocks constriction of sphincter muscle of iris and ciliary body muscle, which, in turn, results in mydriasis (dilation) and cycloplegia (paralysis of accommodation). |
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| Adult Dose | 1 gtt bid/tid |
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| Pediatric Dose | Administer as in adults |
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| Contraindications | Documented hypersensitivity; primary glaucoma or initial stages of the disease |
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| Interactions | None reported |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Avoid excessive systemic absorption by compressing lacrimal sac using digital pressure for 1-3 min after instillation; may produce drowsiness, blurred vision, or sensitivity to light (due to dilated pupils); observe caution while driving or performing other tasks requiring alertness, coordination, or physical dexterity |
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Drug Category: Ascorbate
Critical cofactor necessary for collagen fibril synthesis. Released from the damaged cornea and the anterior chamber, and it must be replenished to promote corneal wound healing.
| Drug Name | Ascorbic acid (Ce-vi-sol, Cecon, Cevi-Bid) |
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| Description | Water-soluble vitamin that serves as a cofactor regulating collagen synthesis. |
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| Adult Dose | 10% sodium ascorbate topical: 1 gtt q1h
Alternatively, 500-2000 mg PO qd/qid |
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| Pediatric Dose | 10% sodium ascorbate topical: 1 gtt q1h
Alternatively, 100-300 mg PO qd |
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| Contraindications | Documented hypersensitivity; primary glaucoma or initial stages of the disease |
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| Interactions | Large doses can impair warfarin GI absorption; may enhance iron tissue toxicity if used concurrently with deferoxamine |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Withdrawal scurvy may occur following prolonged high-dose oral intake; prolonged high doses may cause renal calculi, especially in patients with diabetes; less severe adverse effects (eg, diarrhea, dizziness, facial flushing) reported |
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Drug Category: Beta-adrenergic blockers
Topical beta-blockers reduce aqueous humor production, which then reduces IOP.
| Drug Name | Timolol maleate 0.25%, 0.5% (Betimol, Istalol, Timoptic, Timoptic XE) |
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| Description | May reduce elevated and normal IOP, with or without glaucoma, by reducing production of aqueous humor or by outflow. |
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| Adult Dose | 1 gtt qd/bid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; bronchial asthma; sinus bradycardia; second- and third-degree AV block; severe chronic obstructive pulmonary disease; overt cardiac failure; cardiogenic shock |
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| Interactions | May cause bradycardia and asystole when used in combination with systemic beta-blockers (may cause additive effects) |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Product may have sulfites, which may cause allergic-type reactions in susceptible patients; may exacerbate or precipitate heart block, asthma, chronic obstructive pulmonary disease, and mental changes (especially in elderly persons) |
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| Drug Name | Levobunolol hydrochloride 0.25%, 0.5% ( Betagan) |
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| Description | Nonselective beta-adrenergic blocking agent that lowers IOP by reducing aqueous humor production and possibly increasing outflow of aqueous humor. |
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| Adult Dose | 1 gtt qd/bid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; bronchial asthma; sinus bradycardia; second- and third-degree AV block; severe chronic obstructive pulmonary disease; overt cardiac failure; cardiogenic shock |
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| Interactions | May cause bradycardia and asystole when used in combination with systemic beta-blockers (may cause additive effects) |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Beta-blockade may potentiate muscle weakness that is consistent with certain myasthenic symptoms (eg, diplopia, ptosis, generalized weakness); product may have sulfites, which may cause allergic-type reactions in certain susceptible persons |
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| Drug Name | Betaxolol 0.25%, 0.5% (Betoptic S) |
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| Description | Selectively blocks beta 1-adrenergic receptors with little or no effect on beta 2-receptors. Reduces IOP by reducing production of aqueous humor. |
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| Adult Dose | 1 gtt bid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; bronchial asthma; severe chronic obstructive pulmonary disease; sinus bradycardia; second- and third-degree AV block; overt cardiac failure; cardiogenic shock |
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| Interactions | May have additive systemic effects if patient is already on systemic beta-blockers |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Beta-blockade may potentiate muscle weakness consistent with myasthenic symptoms; product may have sulfites, which may cause hypersensitivity reactions in susceptible persons |
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Drug Category: Topical corticosteroids
Steroids decrease ocular surface inflammatory response, facilitating earlier epithelial healing and regeneration. These medications must be tapered after 7-10 days because of the risk of corneal melting with prolonged use.
| Drug Name | Prednisolone acetate 1% (Pred Forte, Econopred) |
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| Description | Decreases inflammation and corneal neovascularization. |
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| Adult Dose | 1 gtt q1-6h based on severity of inflammation for first 7-10 d |
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| Pediatric Dose | Administer as in adults; caution in children <2 years |
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| Contraindications | Documented hypersensitivity; viral, fungal, or tubercular infections |
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| Interactions | May decrease efficacy of antiglaucoma agents |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
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| Precautions | Caution in hypertension; known to cause cataract formation with long-term use; suspect fungal invasion in any persistent corneal ulceration where a corticosteroid has been used or is in use (obtain fungal cultures when appropriate) |
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| Drug Name | Fluorometholone acetate 0.1% (FML, FML Forte, Flarex) |
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| Description | Decreases inflammation and corneal neovascularization. |
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| Adult Dose | 1 gtt q1-6h based on severity of inflammation for first 7-10 d |
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| Pediatric Dose | Administer as in adults; caution in children <2 years |
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| Contraindications | Documented hypersensitivity; viral, fungal, or tubercular infections |
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| Interactions | May decrease efficacy of antiglaucoma agents |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
|
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| Precautions | Caution in hypertension; known to cause cataract formation with long-term use; suspect fungal invasion in any persistent corneal ulceration where a corticosteroid has been used or is in use (obtain fungal cultures when appropriate) |
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| Drug Name | Rimexolone 1% (Vexol) |
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| Description | Decreases inflammation and corneal neovascularization. |
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| Adult Dose | 1 gtt q1-6h based on severity of inflammation for first 7-10 d |
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| Pediatric Dose | Administer as in adults; caution in children <2 years |
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| Contraindications | Documented hypersensitivity; viral, fungal, or tubercular infections |
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| Interactions | May decrease efficacy of antiglaucoma agents |
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| Pregnancy | C - Safety for use during pregnancy has not been established.
|
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| Precautions | Caution in hypertension; known to cause cataract formation with long-term use; suspect fungal invasion in any persistent corneal ulceration where a corticosteroid has been used or is in use (obtain fungal cultures when appropriate) |
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Further Inpatient Care
- In patients with severe chemical injuries, short hospitalization may be warranted to closely monitor IOP, integrity of the cornea, medication usage, and pain control.
Further Outpatient Care
- Close follow-up care is mandatory in the first weeks following a severe chemical injury to assess epithelial regeneration and corneal melting, to change medications, to control inflammation and IOP, and to prevent secondary infection. Patients should be under the care of an ophthalmologist during this critical period.
In/Out Patient Meds
- Prednisolone acetate 1% (1 gtt qid)
- Erythromycin ophthalmic ointment (4-8 times/d)
- Homatropine 5% or scopolamine 0.25% (1 gtt tid)
- Ascorbate (500 mg PO qid)
- Levobunolol hydrochloride 0.5% (1 gtt bid) or acetazolamide (500 mg PO bid) - Pressure lowering agents, such as levobunolol and acetazolamide, are only indicated if IOP is increased (>30 mm Hg).
Transfer
- After completing initial irrigation and treatment, patients should be transferred to facilities that have ophthalmologists available to assume care for them.
Deterrence/Prevention
- Education and training regarding the prevention of chemical exposures in the workplace can help prevent chemical injuries to the eye. Persons who may be exposed to chemicals in the workplace are advised to wear safety goggles.
Complications
- Primary complications
- Conjunctival inflammation
- Corneal abrasions
- Corneal haze and edema
- Acute rise in IOP
- Corneal melting and perforations
- Secondary complications
- Secondary glaucoma
- Secondary cataract
- Conjunctival scarring
- Corneal thinning and perforation
- Complete ocular surface disruption with corneal scarring and vascularization
- Corneal ulceration (sterile or infectious)
- Complete globe atrophy (phthisis bulbi)
Prognosis
- With chemical injuries, the severity correlates with the prognosis, especially with regard to the corneal integrity (corneal epithelial defects and stromal clarity) and the degree of limbal ischemia (blanching). Limbal stem cells provide the epithelial cells necessary for adequate corneal wound healing; therefore, the evaluation of limbal damage is especially important in determining the prognosis.
- Injuries can be graded from 0-5, as follows:
- Grade 0 - Minimal epithelial defect, clear corneal stroma, no limbal ischemia
- Grade 1 - Partial-complete epithelial defect, clear corneal stroma, no limbal ischemia
- Grade 2 - Partial-complete epithelial defect, mild stromal haze, none or only mild limbal ischemia
- Grade 3 - Complete epithelial defect, moderate stromal haze, less than one third of the limbus is ischemic
- Grade 4 - Complete epithelial defect, stromal haze blurring iris details, one third to two thirds of the limbus is ischemic
- Grade 5 - Complete epithelial defect, stromal opacification, greater than two thirds of the limbus is ischemic
- Grades 0-2 can be expected to heal well with proper care and follow-up examinations. The course for grades 3-5 is more tenuous and may require surgical intervention, either limbal stem cell transplantation or penetrating keratoplasty, to regenerate the corneal surface. Higher-grade injuries are more susceptible to secondary complications.
Patient Education
- If the injury resulted from a preventable accident, proper safety instruction should be provided.
- If a patient is left functionally monocular from an injury, the patient should be instructed in the use of safety eyewear (eg, polycarbonate lenses).
- For excellent patient education resources, visit eMedicine's Burns Center and Eye and Vision Center. Also, see eMedicine's patient education articles Chemical Burns, Chemical Eye Burns, and Eye Injuries.
Medical/Legal Pitfalls
- Failure to evaluate patients with extensive facial chemical injuries for other nonocular potentially life-threatening injuries
- Failure to thoroughly remove the inciting chemical from the ocular surface through extensive irrigation and removal of particulate matter from the fornices, which can worsen the injury
- Failure to closely observe the patient during the immediate recovery phase, which can lead to more severe secondary complications
- Failure to document whether or not the patient was properly using safety glasses at the time of injury, especially if the injury occurred at work
| Media file 1:
Alkali burn. Note the severe conjunctival reaction and stromal opacification blurring iris details inferiorly. |
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| Media file 2:
Severe chemical injury with early corneal neovascularization. |
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| Media file 3:
Complete cicatrization of the corneal surface following chemical injury. |
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Media type: Photo
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Burns, Chemical excerpt Article Last Updated: Sep 22, 2006
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