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Thermal burns:
The blink reflex usually causes the eye to close in response to a thermal stimulus. Thus, thermal burns tend to affect the eyelid rather than the conjunctiva or cornea. Eyelid burns should be cleansed thoroughly with sterile isotonic saline solution followed by application of an antimicrobial ointment (eg, bacitracin bid). Most thermal burns affecting the conjunctiva or cornea are mild and heal without significant sequellae. They are treated with oral analgesics (acetaminophen with or without oxycodone), cycloplegic mydriatics (eg, homatropine 5% qid), and topical ophthalmic antibiotics (eg, bacitracin/polymyxin B ointment or ciprofloxacin 0.3% ointment qid for 3 to 5 days).
Chemical burns:
Burns of the cornea and conjunctiva can be serious, particularly when strong acid or alkali is involved.
Burns should be irrigated with copious amounts of water or with 0.9% saline if available. The eye may be anesthetized with one drop of proparacaine 0.5%, but irrigation should not be delayed and should last for at least 30 min. Irrigation may be facilitated by using an irrigating lens placed under the lids. In acid and alkali burns, some experts suggest 1 to 2 h of irrigation; others recommend that the pH of the conjunctiva be measured with expanded pH paper (a type that measures pH over a limited range for more accurate assessment) and irrigation continued until pH is normal.
After irrigation, the conjunctival fornices should be examined for chemical embedded in the tissue and swept with a swab to remove trapped particles. The superior fornices are exposed by using double eyelid eversion (ie, first everting the eyelid and then inserting a swab under the everted eyelid and lifting it up until the fornix is visible).
Chemical iritis is suspected in patients with photophobia (deep eye pain with exposure to light) that develops hours or days after a chemical burn and is diagnosed by finding flare and WBCs in the anterior chamber during slit-lamp examination. Chemical iritis is treated by instilling a long-acting cycloplegic (eg, a single dose of homatropine 2% or 5% or scopolamine 0.25% solution). Because topical corticosteroids can cause corneal perforation after chemical burns, they should be given only by an ophthalmologist. Corneal epithelial defects are treated by applying an antibiotic ointment (eg, erythromycin 0.5%) 4 times a day until they are healed (eg, about 3 to 5 days in mild burns). Topical anesthetics should be avoided after initial irrigation; significant pain may be treated with acetaminophen with or without oxycodone.
Severe chemical burns require treatment by an ophthalmologist to save vision and prevent complications such as uveitis, perforation of the globe, and lid deformities. Patients with severe conjunctival hyperemia, ciliary flush (prominent conjunctival injection around the limbus), true photophobia (ie, not just sensitivity to light), avascular areas of conjunctiva, or loss of conjunctival or corneal epithelium as demonstrated by fluorescein staining should be examined by an ophthalmologist as soon as possible and no longer than 24 h after the exposure.
Last full review/revision September 2012 by Kathryn Colby, MD, PhD
Content last modified November 2012
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