Merck Manual

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Professional Version

Corneal Foreign Bodies in Small Animals


Sara M. Thomasy

, DVM, PhD, DACVO, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, and Department of Ophthalmology and Vision Science, School of Medicine, University of California, Davis

Reviewed/Revised Mar 2020 | Modified Nov 2022
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Corneal foreign bodies are frequently observed in domestic animals. They are usually organic material, but sand, metal, and glass foreign bodies are also seen. Presenting signs include variable blepharospasm, tearing, and a variable reflex uveitis (aqueous flare, miosis, iridal swelling, ocular hypotony, and possible hypopyon).

Foreign bodies can be identified on the conjunctival surface, in the posterior third eyelid fornix, or on or in the cornea. Those 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. It is imperative that the location of the foreign body (ie, depth within the cornea) be established prior to its removal. If in doubt, it should be assumed that it penetrates into the anterior chamber.

The corneal wound is apposed with simple interrupted 7-0 to 9-0 absorbable sutures. Postoperative therapy typically includes topical and systemic broad-spectrum antibiotics, mydriatics, and systemic NSAIDs. Prognosis for vision is usually good. Infrequent complications include variable corneal scar formation, septic endophthalmitis, cataract formation, and secondary glaucoma.

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