Ocular foreign body injuries

Issue: BCMJ, Vol. 59, No. 3, April 2017, page(s) 188 WorkSafeBC
Kevin Parkinson, MD, FRCSC

An ocular foreign body injury is one of the most common workplace injuries—yet it is one of the most easily prevented, provided workers and employers fully embrace the importance of properly fitting eye protection that does not compromise vision. These injuries may be physical, chemical, environmental, or infective. Appropriate eyewear is readily available and should not hamper work performance in any way. To prevent injury, proper eyewear should be worn whenever ocular trauma is a risk.

The typical presentation is eye pain, which can be severe, accompanied by redness and watering. The patient may be unable to keep the eye open. The first priority is to rule out or diagnose a full thickness penetration of the globe. A detailed history is important to determine the following:
•    The worker’s exposure to a high-velocity projectile or blunt-force trauma.
•    Whether eye protection was worn and, if so, if it contained protection from tangential projectiles—absence of eye protection raises the suspicion of a ruptured globe.
•    The mechanism of insult to the eye.
•    Treatment already administered.
•    Previous visual status/acuity.

On examination, if a penetrating eye injury is suspected, do not proceed with the exam or put any pressure on the globe. Findings may include significant loss of vision; obvious conjunctival or sclera laceration, possibly with a positive Seidel test; large subconjunctival hemorrhage; hyphema; diminished red reflex; soft-feeling eye; or irregular pupil. Immediately refer these patients to an ophthalmologist.

If you feel the injury involves only the superficial aspects of the eye, then the exam should proceed from front to back, utilizing available equipment. Applying a topical anesthetic prior to examination may help the patient cooperate more fully. Document visual acuity for both eyes with the patient’s glasses on, if glasses are worn. Inspect lids, cornea, and conjuctiva for lacerations, abrasions, or other signs of trauma. Consider everting the upper lid to look for debris, even if you see a foreign body on the conjunctiva or cornea, as there may be more than one object. Use fluorescein dye, if available, to view the eye under cobalt-blue light, to help visualize defects and abnormalities. If you are confident the injury is superficial, further investigations are not required.

CT scan is the best choice for detecting intraocular foreign bodies. Plain X-rays are less useful, although they could be used to detect periocular foreign bodies when there is a mechanism consistent with a high-velocity projectile and only an apparent superficial wound is found. MRIs are contraindicated if you suspect metallic foreign bodies in or around the eye.

Examination findings should dictate treatment. Small corneal abrasions can be treated with ocular lubrication and topical antibiotics. Patching is not advised, as this can delay healing and usually does not decrease pain. In cases of larger abrasions, referral to an optometrist/ophthalmologist for consideration of a bandage soft contact lens is often indicated.

An ophthalmologist is recommended to remove deep or central corneal objects. If possible, and if you are confident with the procedure, you can remove superficial foreign bodies, using topical anesthetic. Use forceps for particles lodged under the upper lid, after everting the lid over a cotton applicator. Leave the eye unpatched, treat with a topical antibiotic (e.g., fourth-generation fluoroquinolone), and review in 24 hours. Rust rings in the cornea that may occur hours after removing a corneal foreign body containing iron are best removed at a slit lamp, using a rotating sterile burr.

In all but the most minor cases, an appropriate eye-care professional should follow up with the patient.

For more information
For questions or assistance with a worker patient with an ocular foreign body injury, please contact a medical advisor in your nearest WorkSafeBC office.
—Kevin Parkinson, MD, FRCSC
WorkSafeBC Ophthalmology Consultant

This article is the opinion of WorkSafeBC and has not been peer reviewed by the BCMJ Editorial Board.