1 Clinical evaluation of corneal foreign bodies includes lid eversion and fluorescein staining Ocular trauma accounts for 8% of emergency department visits; of these, 31% involve corneal foreign bodies. A focused history includes presenting symptoms, type of foreign body, penetrability, entry velocity, duration since injury, concurrent contact lens usage and ocular history.1 Evaluation includes assessment of visual acuity, pupillary response and extraocular movements, and fluorescein staining. Vertical scratch marks that stain with fluorescein suggest a foreign body under the upper lid. In this case, the upper lid should be fully everted during examination. A Wood lamp has low sensitivity (52%) for fluorescein uptake compared with a slit lamp. Patients who continue to be symptomatic 24 hours after a negative Wood lamp examination should be re-examined in the emergency department or clinic. 2 Clinicians should screen for penetrating injuries of the globe It is important to rule out open-globe injuries, as these complicate some presentations of corneal foreign bodies. A penetrated globe can be iden-tified if a green streak flows out from a fluorescein-soaked foreign body; however, the streak may be absent when penetrating injuries are selfsealing. If an intraocular foreign body is suspected, orbital computed tomography should be performed. Penetrating injuries require urgent referral to an ophthalmologist without displacing the foreign body.
NSTL
Cma-Canadian Medical Assoc
