Learn how you can treat a corneal foreign body
It can be very dangerous to self-treat a corneal foreign body. This is because a corneal foreign body most often becomes embedded on the corneal surface or underneath the eyelid. A corneal foreign body (CFB) is a foreign material and potentially a serious problem that needs assessment and treatment by an ophthalmologist to prevent the eye from developing an infection that could possibly threaten your vision.
What should you do in case of a foreign body?
This is a first-aid emergency, and all you can really do if you think that you have a foreign body is to irrigate the eye with tap water or saline solution. The tap water should be warm and clean, and you should aim to flush out what is likely to be an embedded corneal foreign body. The sooner a corneal foreign body is washed out after it has blown into the eye, the easier it is to remove. Once it is embedded, it has to be removed under the microscope by a skilled ophthalmic specialist.
Typically a corneal foreign body is unilateral, has been blown into your eye by the wind, or it has occurred as a high-velocity injury as a result of hammering metal, for example, or working underneath a car. Or such an injury may be related to occupations such as building or gardening. Of course, you can reduce the risk of a corneal foreign body getting into your eye by wearing eye protection. Once you are affected, however, you will be aware of the sensation of a foreign body in your eye. A corneal foreign body is also likely to cause pain, irritation, a watering eye, sometimes a red eye and even blurred vision.
The ophthalmologist will see the corneal foreign body stuck on the surface of the cornea and, if it is a conjunctival sub-tarsal foreign body, they will be able to see linear corneal scratches by using a fluorescein stain. Just occasionally the foreign body has in fact washed out, but if it was metal, it might leave a corneal rust ring. This rust ring is the staining of the epithelium and superficial stroma with the ferrous content from the metal.
If you leave a corneal foreign body, you could suffer from swelling and even infection, with a corneal ulcer (keratitis) posing a risk to your vision.
When your ophthalmologist prepares your history, you need to explain to them exactly what has happened. You need to tell them when the corneal foreign body went into your eye, whether it was a high-speed particle, whether it could have been metal, possibly leaving a rust ring, which is called haemosiderosis. You also need to let them know if it could be matter from the garden, as vegetable matter raises the risk of secondary fungal infection. The ophthalmologist will then examine your eye and remove the corneal foreign body.