An STFB or Subtarsal foreign body – Urgent eye problems
A particle can blow into or fall into your eye while walking, working under the car, or doing do-it-yourself in the house. Frequently, a little fleck of foreign body can blow in from an unknown source if it is a windy day or if you are walking past a building site. If the little foreign body lodges underneath the eyelid, it can stick to the velvety membrane lining the upper lid. It can rub against the front surface of the eye with each blink causing a foreign body sensation, acute pain, a watering eye and red eye.
Diagnosing a Subtarsal foreign body (STFB)
Subtarsal foreign body (STFB) is a very common urgent eye problem, which can be dealt with in an eye clinic or eye casualty. At Clinica London, we have an urgent eye care clinic, where patients can be seen between 8:30 and 19:00 by a prior arrangement phone call or e-mailing in to arrange the appointment. An ophthalmic specialist is available most days of the week to treat subtarsal foreign body (STFB).
A subtarsal foreign body is easily diagnosed and visualised by the ophthalmologist because of the vertical foreign body tracks that are seen on the cornea, which is the shiny bit of the eye in front of the iris when fluorescein drops are put in. The fluorescein stains the foreign body tracks or scratches and then on looking underneath the eyelid there will be redness and an embedded foreign body will be found on the tarsal conjunctival surface.
The STFB on the inner surface of the upper eyelid is a common reason for getting urgent eye care. There usually is a history of trauma or having something blown into the eye and typically the symptoms are foreign body sensation, watering, pain and red eye. There may be an easily visible subtarsal foreign body with a corneal abrasion line seen on the cornea.
Treating a subtarsal foreign body (STFB)
The ophthalmologist will examine the eye after measuring the vision. They will first of all put in a drop of local anaesthetic and then a drop of fluorescein dye which will show the scratches. They will use a blue light on the machine called a slit lamp to look at the surface of the eye. Then they will evert the upper eyelid to confirm the presence of the subtarsal foreign body. The ophthalmologist will use a moistened cotton bud to gently remove the foreign body sweeping it away from the undersurface of the eyelid. The eye is then treated with Chloramphenicol ointment or drops four times a day for up to five days.
If you think that you may have a subtarsal foreign body, you can make an appointment with us to discuss and arrange to be seen by an ophthalmic specialist. Usually, after the subtarsal foreign body has been removed, the eye does not have to be padded, and there is only eye drops or ointment to put in for a few days. It should not stop you from going back to work the day afterwards. It is a quick walk-in and walk-out appointment lasting up to half an hour and follow-up is not essential as the corneal scratches will rapidly settle within 24 hours.