Corneal and Conjunctival Foreign Bodies
Foreign bodies on the cornea and conjunctiva are the com-monest ocular emergency encountered by general practitioners and ophthal-mologists.
Airborne foreign bodies and metal splinters from grinding or cut-ting disks in particular often become lodged in the conjunctiva or cornea or burn their way into the tissue.
The patient experiences a for-eign-body sensation with every blink of the eye. This is accompanied by epi-phora (tearing) and blepharospasm. Depending on the time elapsed since the injury, i.e., after a few hours or several days, conjunctival or ciliary injection will be present (Figs. 18.4a and b). The foreign bodies on the conjunctiva or cornea are themselves often so small that they are visible only under loupe magnification. There may be visible infiltration or a ring of rust. Where there is no visible foreign body but fluorescein dye reveals vertical corneal stria-tions, the foreign body will be beneath the tarsus (see Fig. 5.11).
A foreign-body sensation with every blink of the eye accompanied by epiphora, blepharospasm, and vertical striations on the surface of the cornea are typical signs of a subtarsal foreign body.
Corneal and conjunctival foreign bodies.The foreign body ispried out of its bed with a fine needle or cannula. The defect created by the foreign body will often be contaminated with rust or infiltrated with leuko-cytes. This defect is carefully reamed out with a drill (Fig. 18.4c) and treated with an antibiotic eye ointment and bandaged if necessary.
Subtarsal foreign bodies.Everting the upper and lower eyelids will usuallyreveal the foreign body, which may then be removed with a moist cotton swab. An antibiotic eye bandage is placed until the patient is completely free of symptoms.