Atlas of Primary Care Procedures, 1st Edition

Ear, Nose, and Throat Procedures

53

Conjunctival and Corneal Foreign Body Removal

Conjunctival and corneal foreign objects are commonly seen problems in the primary care office and in the emergency department. Usually, removal of the foreign object is easily accomplished and can be performed in the outpatient setting. When a patient presents, document a thorough history, including mechanism of injury, job status, probable type of foreign body (especially if it may be iron based), whether first aid was rendered, and the condition of the eye before injury. Always test and document the patient's vision before and after treatment. Use a Snellen chart or an equivalent visual acuity chart if possible.

The corneal and conjunctival epithelia are some of the fastest-healing areas of the body. If considerable progress toward healing has not been made within 24 hours of foreign body extraction, reexamine for additional foreign bodies or signs of infection. Local anesthetic drops are often used during mechanical removal of foreign objects but should not be prescribed for outpatient use because they may retard corneal healing and because pain may be an important indicator of developing corneal ulceration or that additional foreign bodies are present. Topical steroids also should be avoided.

There are some guidelines for when to refer patients to decrease the risk of impaired vision or blindness. The intraocular presence of an object requires prompt referral to an ophthalmologist. Injury from chemicals may be mild to severe. If pain or functional impairment persists after irrigation, the patient should be referred to an ophthalmologist. Possible acid or alkali contamination of the eye is a true ophthalmologic emergency.

Clinicians must use extreme caution when attempting to remove foreign objects by mechanical means such as cotton-tipped applicators or needles. Any downward pressure on the object may result in more damage to the epithelium or deeper layers. If clinicians are unsure of their ability to remove an object without exerting downward pressure on it, the patient should be referred to an ophthalmologist for removal. Object removal is most successful in cases of recent, superficial foreign bodies.

Traditionally, eye patches were applied in accordance with the theory that they decreased photophobia, tearing, foreign body sensation, pain, and healing times. However, later studies indicate that patching does not improve pain scores,

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healing times, or treatment outcomes and may slow healing and decrease compliance with treatment plans.

Because of the risk of complications, obtaining informed consent makes practical sense. Possible complications of foreign body removal include infection, perforation of the cornea, and incomplete removal of a foreign body. Special care must be taken with iron-based foreign objects, because rust is toxic to the cornea and may prevent it from healing. There is a risk of scarring, and when the injury is in the cornea, there is an additional risk of permanent visual impairment.

If the patient has significant pain, consider using a cycloplegic agent to decrease spasm of the iris. Apply antibiotic drops or ointment for antibiotic prophylaxis. Prescribe oral pain medication as indicated. Instruct the patient not to rub the eye, because it may disrupt the new epithelial layers on the cornea. Reepithelialization is complete in 3 to 4 days for more than 90% of patients, but it can take weeks. Reexamine every 24 hours until the eye is healed. Perform and document a visual acuity test on the last visit. Continue antibiotic drops for an additional 3 days after the eye is symptom free. The patient may be unusually receptive at this time to education about eye safety measures such as protective eyewear. If at any time during the follow-up the pain increases or signs of conjunctival or orbital infection are seen, immediately refer the patient to an ophthalmologist.

INDICATIONS

• Small, conjunctival or corneal foreign bodies embedded less than 24 hours

CONTRAINDICATIONS

• Foreign bodies embedded in the cornea for more than 24 hours (i.e., risk of infection)
• Iron-based foreign bodies, which may cause a rust ring (relative contraindication)
• Uncooperative patient
• Deeply or centrally embedded foreign bodies (i.e., ophthalmologic referral)
• Possible acid or alkali contamination of the eye (i.e., ophthalmologic emergency)
• Ruptured globe (i.e., ophthalmologic emergency)
• Hyphema, lens opacification, abnormal anterior chamber examination, or irregularity of the pupil (i.e., possible ruptured globe, which is an ophthalmologic emergency)
• Signs or symptoms of infection (i.e., ophthalmologic referral)

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PROCEDURE

Check and record the patient's visual acuity using a Snellen chart. Then position the patient in the supine position (Figure 1A). For corneal foreign bodies, position the patient's head so that the foreign body and the eye are in the most elevated position (Figure 1B). For conjunctival foreign bodies, position the head to give the examiner maximal access to the affected area.

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Hold the patient's eyelids apart with your thumb and index finger of the nondominant hand. A wire eye speculum may be used but usually is not available in primary care offices. Ask the patient to fix and maintain his or her gaze on a distant object and to hold the head as motionless as possible throughout the procedure.

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If the object is not readily visible, put 2 drops of topical anesthetic into the retracted lower eyelid while the patient gazes in an upward direction. Wet a fluorescein strip with the same solution, and apply it to the underside of the lower eyelid. Inspect the cornea for dye pooling near objects or abrasions that may help identify the location of a foreign body.

PITFALL: Putting drops directly on a scratched cornea can be very painful.

PITFALL: Vertical scratches on the cornea may indicate a foreign body imbedded in the upper lid, necessitating eyelid eversion and examination with a cotton-tipped applicator.

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Attempt to wash out the object using sterile normal saline or an ophthalmic irrigant. This may be done by pouring a small, continuous volume of fluid into the affected eye. An alternative method is to place an intravenous bag of normal saline with tubing on a pole, cut off the end of the tubing, and use the gentle stream coming from the end of the tubing to irrigate the eye.

If this is unsuccessful, attempt to dislodge the object using a cotton-tipped applicator or corner of a soft cotton gauze. Moisten the cotton with local anesthetic, and gently lift the object by lightly touching it.

PITFALL: Never use force or rub the cornea because this can produce pain, damage the epithelium, and cause deeper corneal injuries.

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If the object is still lodged, a sterile needle may be used to remove the object. Place a 26-gauge needle on a tuberculin syringe and hold it in with a pencil grip. Stabilize your operating hand on the patient's brow or zygomatic arch. Approach the object with the needle bevel upward from a tangential direction, and use the needle tip to gently lift the object.

PITFALL: If the object cannot be readily removed, refer the patient for removal under slit lamp by an ophthalmologist.

PITFALL: If any residual corneal rust is found, immediately refer the patient to an ophthalmologist because rust is toxic to corneal epithelium.

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Turn the patient's head laterally, and copiously irrigate the eye. Retest and record the patient's visual acuity.

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CODING INFORMATION

INSTRUMENT AND MATERIALS ORDERING

A Snellen chart or equivalent visual acuity chart can be obtained from Premier Medical, P.O. Box 4132, Kent, WA 98032 (phone: 800-955-2774; http://www.premieremedical.safeshopper.com/).

Magnification devices, loupes, and Wood's lights may be ordered from medical supply companies. Topical ophthalmic anesthetic, cycloplegic drops, and fluorescein strips may be ordered from pharmacies.

BIBLIOGRAPHY

Appen RE, Hutson CF. Traumatic injuries: office treatment of eye injury. 1. Injury due to foreign materials. Postgrad Med 1976;60:223–225, 237.

Holt GR, Holt JE. Management of orbital trauma and foreign bodies. Otolaryngol Clin North Am 1988;21:35–52.

Kaiser PK. A comparison of pressure patching versus no patching for corneal abrasions due to trauma or foreign body removal. Corneal Abrasion Patching Study Group. Ophthalmology 1995;102:1936–1942.

Le Sage N, Verreault R, Rochette L. Efficacy of eye patching for traumatic corneal abrasions: a controlled clinical trial. Ann Emerg Med2001;38:129–134.

Nayeen N. Stansfield D. Management of corneal foreign bodies in A&E departments. Arch Emerg Med 1992;9:257.

Newell SW. Management of corneal foreign bodies. Am Fam Physician 1985;31:149–156.

Owens JK, Scibilia J, Hezoucky N. Corneal foreign bodies—first aid, treatment, and outcomes. Skills review for an occupational health setting. AAOHN J 2001;49:226–230.

Reich JA. Removal of corneal foreign bodies. Aust Fam Physician 1990;19:719–721.