The eyelids close quickly in a reflex reaction to protect the eyes from harm. However, irritating or harmful chemicals still sometimes get onto the surface of the eye, causing burns. The most dangerous chemical burns involve strong acids or alkali. Alkali substances include lye (caustic soda), which is found in many drain cleaners. Burns may involve liquids, which splash, or, less commonly, powdered material, which can blow into the eyes.
Severe chemical burns of the transparent dome on the front surface of the eye (cornea), especially alkali injuries, can lead to scarring, perforation of the eye, and blindness. Burns to the eye are very painful. Because the pain is so great, a person tends to keep the eyelids closed. Closed eyelids keep the substance against the eye for a prolonged period, which may worsen the damage.
A chemical burn of the eye is treated immediately, even before medical personnel arrive. The eye is opened and flushed (irrigated) with water or saline. When burns are caused by strong acids or alkali or other severely caustic substances, the eye should be irrigated continuously for 30 to 120 minutes. Irrigation can be continued where it began, in an ambulance, or in an emergency department. Because pain may make it difficult for the person to keep the injured eye open, another person may have to hold the eyelid open while the eye is irrigated. A doctor or other health care practitioner can instill an anesthetic drop in the eye to make it much easier to keep the injured eye open. In an emergency department, doctors often use a special irrigating device that looks like a large contact lens. The device is placed under the eyelids and connected to a bag of sterile saline. The saline drips out of the device and irrigates the eye.
After irrigation, the doctor examines the surface of the eye and the inside of the eyelid and removes any substance still embedded in the tissue. The inside of the eyelid is also swabbed to remove any tiny particles that may not be visible. A doctor may instill a drop of a drug (such as homatropine) that dilates the pupil, relaxing the muscles of the colored part of the eye (iris) and preventing them from having painful spasms. Although anesthetic eye drops relieve pain, they may also slow healing and are usually not given after the initial irrigation. Pain can be treated with acetaminophen or, if severe, acetaminophen with oxycodone. If the cornea is burned, an antibiotic ointment is put in the eye.
Severe burns need to be treated by an ophthalmologist (a medical doctor who specializes in diagnosing and treating eye disorders and doing eye surgery) within 24 hours to preserve vision and prevent major complications, such as damage to the cornea and iris, perforation of the eye, and deformities of the eyelid. Corticosteroid drops (such as prednisolone) may also be given by an ophthalmologist for a limited period of time. Severe burns require frequent eye examinations. Some chemical burns are so severe that even with the best treatment the eye can become blind.
Wearing safety glasses or a face shield when handling potentially hazardous chemicals is essential to help prevent chemical burns.
The blink reflex usually causes the eye to close in response to heat. Thus, thermal burns tend to affect the eyelid rather than the conjunctiva or cornea.
Eyelid burns are treated like other skin burns. Doctors clean eyelid burns and then apply an antibiotic to prevent infection. Burns of the conjunctiva or cornea are usually mild and cause no lasting damage to the eye. They may be painful, so people may need to take analgesics. Doctors may also give cycloplegic eye drops (such as cyclopentolate or homatropine) to prevent painful spasm of the muscles that constrict the pupil, as well as an antibiotic eye ointment to prevent infection.
Last full review/revision January 2013 by Kathryn Colby, MD, PhD