2.04 Conjunctival Foreign Body
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agk's Library of Common Simple Emergencies

Presentation
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Low-velocity projectiles, like wind blown dust 
particles, can be loose in the tear film or 
lodged in a conjunctival sac. The patient may 
not be very accurate in locating the foreign 
body by sensation alone. On exam, normally 
occurring white papules inside lids can be 
mistaken for foreign bodies, and transparent 
foreign bodies can be invisible in the tear 
film (until outlined by fluorescein dye).

What to do:
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- Instill topical anesthetic drops.
- Perform visual acuity and funduscopy, examine 
   the anterior chamber and tear film with a 
   bright light (best done with a slit lamp) 
   and examine the conjunctival sacs.
- To examine the lower sac, pull the lower lid 
   down with your finger while the patient 
   looks up.
- To examine the upper sac, hold the proximal 
   portion of the upper lid down with a 
   cotton-tipped swab while pulling the lid out 
   and up by its lashes, everting most of the 
   lid, as the patient looks down. Push the 
   cotton swab downward to help turn the upper 
   conjunctival sac "inside out." The stiff 
   tarsal plate usually keeps the upper lid 
   everted after the swab is removed, and as 
   long as the patient continues looking down. 
   Looking up reduces the lid to its usual 
   position.
- A loose foreign body usually adheres to a 
   swab lightly touched to the surface of the 
   conjunctiva, or will be washed out by 
   copious irrigation with saline.
- Perform a fluorescein exam to disclose any 
   corneal abrasion caused by the foreign body. 
   These vertical scratches occur when the lid 
   blinks over a coarse object and should be 
   treated as described under "[Corneal 
   Abrasion]."
- Follow with saline irrigation for possible 
   fragments.

What not to do:
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- Do not overlook a foreign body in the deep 
   recesses of the upper conjunctival sac.
- Do not overlook an eyelash that has turned in 
   and is rubbing on the surface of the eye. 
   Sometimes you may see a lash sticking out of 
   the inferior lacrimal punctum. Extract any 
   such lashes.
- Do not overlook an embedded or penetrating 
   foreign body.
- Do not overlook a corneal abrasion.

Discussion
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Good first aid (copious irrigation and not 
rubbing eyes) will take care of most ocular 
foreign bodies. The history of injury with a 
high velocity fragment such as a metal shard 
chipped off a hammer or chisel should raise 
the question of a penetrating foreign body, and 
x-rays should be obtained. Techniques for 
conjunctival foreign body removal can also be 
applied to locating a [displaced contact lens], 
(see) but be aware that fluorescein dye 
absorbed by soft contact lenses fades slowly.

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