Foreign bodies that penetrate the eyeball are rare but can lead to a serious infection and complications including a risk of developing blindness.
(See also Overview of Eye Injuries.)
Explosions and any tool with a metal-on-metal mechanism can cause intraocular foreign bodies by causing small particles to fly in a person’s face. For example, using high-speed machines (such as drills and saws) or hammering a nail or other metal object with a hammer can produce white-hot particles of metal that resemble sparks. Any of these white-hot particles can enter the unprotected eye and become embedded deep within it.
Foreign bodies that penetrate the inside of the eye can damage the structures within the eyeball and lead to an infection inside of the eye (endophthalmitis).
During the first hours after injury, symptoms of intraocular foreign bodies may be similar to those of corneal abrasions and foreign bodies. However, people with intraocular foreign bodies may also have a noticeable loss of vision. Fluid may leak from the eye, but if the foreign body is small, the leak may be so small that the person is not aware of it. Also, pain and vomiting may increase after the first several hours, usually because pressure increases inside the eye.
When a foreign object has penetrated the eye, an ophthalmologist (a medical doctor who specializes in the evaluation and treatment—surgical and nonsurgical—of eye disorders) should examine the person as soon as possible. The eye is examined as for corneal abrasions and foreign bodies by using eye drops that contain a dye that glows under special lighting (fluorescein) and a slit lamp. The dye and slit lamp make visible any small leaks of fluid from the eye and puncture marks.
Any foreign bodies outside of the eyeball are removed. If an intraocular foreign body is suspected after the examination, a CT is done.
Antibiotics such as ceftazidime and vancomycin are given by vein. An antibiotic eye drop is also used. A tetanus vaccine is given as soon as possible.
If necessary, pain and vomiting can be controlled with drugs.
As soon as possible, a protective shield (such as a commercially prepared shield or the bottom part of a paper cup) is taped over the eye to avoid unintentional pressure that could further damage the eye.
An ophthalmologist should remove the foreign body as soon as possible. Prompt removal reduces the risk of infection. Usually a surgical procedure is needed to remove the foreign body.