Thursday, December 30, 2010

EXTRAOCULAR FOREIGN BODIES: types, removal, prophylaxis

Extraocular foreign bodies are quite common in
industrial and agricultural workers. Even in day-today
life, these are not uncommon.
Common sites. A foreign body may be impacted in
the conjunctiva or cornea (Fig. 17.1).
On the conjunctiva, it may be lodged in the
sulcus subtarsalis, fornices or bulbar conjunctiva.
In the cornea, it is usually embedded in the
epithelium, or superficial stroma and rarely into
the deep stroma.

Common types. The usual foreign bodies:
In industrial workers are particles of iron
(especially in lathe and hammer-chisel workers),
emery and coal.
In agriculture workers, these are husk of paddy
and wings of insects.
Other common foreign bodies are particles of
dust, sand, steel, glass, wood and small insects
Symptoms. A foreign body produces immediate:
Discomfort, profuse watering and redness in the
Pain and photophobia are more marked in corneal
foreign body than the conjunctival.
Defective vision occurs when it is lodged in the
centre of cornea.
Signs. Examination reveals marked blepharospasm
and conjunctival congestion. A foreign body can be
localized on the conjunctiva or cornea by oblique
illumination. Slit-lamp examination after fluorescein
staining is the best method to discover corneal foreign
body. Double eversion of the upper lid is required to
discover a foreign body in the superior fornix.
Complications. Acute bacterial conjunctivitis may
occur from infected foreign bodies or due to rubbing
with infected hands. A corneal foreign body may be
complicated by ulceration. Pigmentation and/or
opacity may be left behind by an iron or emery
particles embedded in the cornea.
Treatment. Extraocular foreign bodies should be
removed as early as possible.
1. Removal of conjunctival foreign body. A foreign
body lying loose in the lower fornix, sulcus
subtarsalis or in the canthi may be removed with
a swab stick or clean handkerchief even without
anaesthesia. Foreign bodies impacted in the
bulbar conjunctiva need to be removed with the
help of a hypodermic needle after topical
2. Removal of corneal foreign body. Eye is
anaesthetised with topical instillation of 2 to 4
percent xylocaine and the patient is made to lie
supine on an examination table. Lids are separated
with universal eye speculum, the patient is asked
to look straight upward and light is focused on
the cornea. First of all, an attempt is made to
remove the foreign body with the help of a wet
cotton swab stick. If it fails then foreign body
spud or hypodermic needle is used. Extra care is
taken while removing a deep corneal foreign
body, as it may enter the anterior chamber during
manoeuvring. If such a foreign body happens to
be magnetic, it is removed with a hand-held
magnet. After removal of foreign body, pad and
bandage with antibiotic eye ointment is applied
for 24 to 48 hours. Antibiotic eyedrops are
instilled 3-4 times a day for about a week.
Prophylaxis. Industrial and agricultural workers
should be advised to use special protective glasses.
Cyclists and scooterists should be advised to use
protective plain glasses or tinted goggles. Special
guards should be put on grinding machines and use
of tools with overhanging margins should be banned.
Eye health care education should be imparted,
especially to the industrial and agricultural workers.

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