Small Flat Foreign Bodies
These are often vegetable matter. Apply several drops of local anaesthetic and under firm restraint or sedation the foreign body can often be wipe off with a sterile culture swab or flushed off with a stream of sterile Hartmanns solutions. Draw up 10 to 20 mls of Hartmanns solution, and break off a 22 gauge needle so as to leave just the hub. This can then be used to inject stream of water at the foreign body. They will often be easily flushed off.
Deep Foreign Bodies – ie within the cornea
Magnification eg an operating microscope will be required.
Do not try to pull the foreign body out with forceps unless it is protruding well away from the cornea. Often you will just push the foreign body deeper. Use a 26 gauge needle and at least 10 times magnification to try and dig out the foreign body. In many cases, you need to ‘dig’ out the surrounding cornea to create a pathway.
Intraocular foreign bodies
These are best referred to an experienced ophthalmologist. Recently we have removed a grass seed from the anterior chamber! You can call Animal Eye Care 9572 1966 any time for advice.
Management
Medical Treatment
1. Topical and systemic antibiotics. Topical broad spectrum antibiotics eg Tricin Eye Ointment will be needed. If there is evidence of infection, eg yellow discoloration to the corneal stroma then use fortified Gentamicin frequently. Oral doxycycline is commonly used.
2. Atropine to dilate the pupil and to reduce the corneal mediated trigeminal nerve induced miosis and uveitis.
3. Systemic anti-inflammatories eg. oral NSAIDs are indicated.
Then treat these cases like a corneal ulcer. Depending on the depth of the defect once the FB has been removed a TT – temporary tarsorrhaphy or a TEF - third eyelid flap may be indicated.
Beware: Foreign bodies especially those of vegetable origin may predispose to fungal keratitis.
