Ophthalmologic Approach to Chemical Burns Medication

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.

Class Summary

Prevent ocular surface infection and effectively lubricate the eye.

Erythromycin ophthalmic

Macrolide broad-spectrum antibiotic.

Ciprofloxacin HCl (Ciloxan)

Fluoroquinolone broad-spectrum bacteriocidal antibiotic.

Class Summary

Carbonic anhydrase inhibitors reduce aqueous humor production, which then reduces IOP.

Methazolamide (Neptazane)

Reduces aqueous humor formation by inhibiting enzyme carbonic anhydrase, which results in decreased IOP.

Acetazolamide (Diamox)

Decreases secretion of aqueous humor, lowering IOP.

Class Summary

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.

Homatropine (Isopto Homatropine)

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.

Scopolamine ophthalmic (Isopto Hyoscine)

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).

Class Summary

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.

Ascorbic acid (Ce-vi-sol, Cecon, Cevi-Bid)

Water-soluble vitamin that serves as a cofactor regulating collagen synthesis.

Class Summary

Topical beta-blockers reduce aqueous humor production, which then reduces IOP.

Timolol maleate 0.25%, 0.5% (Betimol, Istalol, Timoptic, Timoptic XE)

May reduce elevated and normal IOP, with or without glaucoma, by reducing production of aqueous humor or by outflow.

Levobunolol hydrochloride 0.25%, 0.5% (Betagan)

Nonselective beta-adrenergic blocking agent that lowers IOP by reducing aqueous humor production and possibly increasing outflow of aqueous humor.

Betaxolol ophthalmic (Betoptic S)

Selectively blocks beta 1-adrenergic receptors with little or no effect on beta 2-receptors. Reduces IOP by reducing production of aqueous humor.

Class Summary

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.

Prednisolone acetate 1% (Pred Forte, Econopred)

Decreases inflammation and corneal neovascularization.

Fluorometholone acetate 0.1% (FML, FML Forte, Flarex)

Decreases inflammation and corneal neovascularization.

Rimexolone 1% (Vexol)

Decreases inflammation and corneal neovascularization.