Corneal Foreign Bodies
Corneal foreign bodies are seen most frequently in dogs, cats, and horses. They are usually organic material, but sand, metal, and glass foreign bodies are also seen. Presenting signs include variable blepharospasm, tearing, and a variable secondary iridocyclitis (aqueous flare, miosis, iridal swelling, ocular hypotony, and possible hypopyon). Ophthalmic examination reveals a foreign body on the conjunctival surface, in the posterior third eyelid fornix, or on or in the cornea. Foreign bodies that adhere to the ocular surfaces are usually removed under topical anesthesia with either vigorous irrigation or small serrated ophthalmic forceps. If the foreign body has embedded within the deeper corneal layers or has penetrated into the anterior chamber, general anesthesia is required for careful removal from either the anterior corneal surface or the anterior chamber. The corneal wound is apposed with simple interrupted 7-0 to 8-0 absorbable sutures. Postoperative therapy includes topical and systemic broad-spectrum antibiotics, mydriatics, systemic NSAIDs, and if necessary, drugs to reduce intraocular pressure. Prognosis for vision is usually good. Infrequent complications include variable corneal scar formation, septic endophthalmitis, cataract formation, and secondary glaucoma.