Conjunctival foreign bodies of the eye are common and can be removed with proper technique. A conjunctival foreign body should be suspected if a patient presents with a sensation of something in the eye. Patients with a conjunctival foreign body often state that their eye feels as if an irritating object—like grit, “junk,” sand, or glass—is in it but that they cannot localize exactly where the sensation is. The foreign body sensation is often worse upon blinking when the foreign body is located on the conjunctival (inner) surface of the upper lid.
Before embarking on removal of the foreign body, ensure that a conjunctival foreign body is the cause of the presenting complaint, and perform an appropriate preprocedural assessment.
Before any manipulation of the eyelid or eye, measure the visual acuity in both the affected eye and the fellow eye. A conjunctival foreign body should not cause a significant decrease in visual acuity.
Before pressing on the eyelid or eye, make certain that no penetrating injury of the eye has occurred. Such an injury should always be considered when there is a history of power tool use or of hammering metal with metal (see the image below). If something on the bulbar conjunctiva is not easily removable with a cotton swab, it could be a penetrating foreign body or a conjunctival pigmented lesion.
Penetrating metallic foreign body—not simple conjunctival foreign body.
To minimize the chance of complications, take a careful history, and always perform a visual acuity determination and a corneal and anterior chamber examination. In addition, use an ophthalmoscope to look for the presence of a red reflex. An isolated conjunctival foreign body has few complications but may be associated with more significant ocular trauma.
Corneal abrasions related to conjunctival foreign bodies must be recognized and treated appropriately to prevent corneal infection or scarring.