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This manual is to be considered a guideline for removal of non-penetrating ocular foreign bodies. It is important that optometrists, who are considering adding this skill to their mode of practice, participate in a TPA program that includes workshops utilizing impregnated animal eyes. These workshops will introduce you to the instruments and techniques needed for foreign body removal in a nonthreatening situation. As with any evolving technique or procedure it is essential that practitioners keep current with the professional literature.
Proper foreign body removal begins before the patient enters your office. Office personnel must be trained to phone triage the more serious, potentially penetrating foreign bodies to a hospital based eye care facility. Your office should be equipped with an emergency tray, stocked with implements necessary for assessment and removal of foreign bodies. This avoids time lost to gathering equipment with the patient in the examining chair.
Foreign Body Emergency Tray
A history is needed to help determine the nature and potential seriousness of the foreign body. Information regarding the nature and size of the material, speed of entry, length of time in the eye, and any attempts by the patient or others to remove the foreign body will provide useful information for you. The patient's assessment of VA loss, photophobia, degree and nature and localization of pain will also be helpful information.
Visual acuity, as in all patient encounters, should be taken first. It may be necessary to instill a topical anesthetic (e.g. proparacaine) in both eyes to reduce the patient's pain and lid spasm. Unaided acuity and pinhole will suffice if spectacles are not available. Pupil evaluation will show possible secondary iritis (sluggish) or perforation (torn or prolapsed iris). Slit lamp evaluation will allow you to determine the size, location, nature and
depth of the foreign body. The presence and grade of cells or flare should be noted for comparison on follow-up visits. Fluorescein evaluation will help you in a
number of ways:
- Tear fluid pooling with a bright green glow around the foreign body
- Show vertical tracking on the cornea indicating presence of the foreign body under the upper lid with the densest pattern “pointing” to the particle. Lid eversion, and rarely double eversion, are necessary techniques in all foreign body evaluations. Never assume that only one foreign body is present until exhaustive search has found no others.
- Seidel's sign or rapid dilution of fluorescein glow may be indicative of possible perforation. This differs from negative staining where there is little or no tear fluid on the eye.
The main philosophy is to remove the foreign body with the least invasive instrument necessary and to "do the patient no harm". The checklist provided lists the instruments in increasing potential to do surface injury to the eye. For example, it makes sense not to use a needle to remove a foreign body that can be irrigated from the eye. Foreign bodies that are or near penetrating or are on the visual axis should be referred for ophthalmological care.
Most foreign bodies will flush from the eye with irrigation by a sterile spray or squeeze bottled saline. Three 10-15 second attempts should suffice. Irrigation is the only technique that can (and should) be done from any angle. This is done out of the slit lamp and usually with the patient's head tilted to one side to facilitate irrigation. All other instruments should be introduced and used tangentially to the eye to help avoid accidental injury.
The use of the next set of instruments, the magnet and the nylon loop, used properly, are safe and in the realm of first aide. If your history suggests a magnetic substance on the surface, the magnet may be useful. The nylon loop on the opposite end of the magnet can dislodge and move a flat foreign body, much the same as a saline impregnated cotton swab, but is safer to use as it has significantly less potential to "scuff" the cornea. As the foreign body appears deeper or has been in the eye longer, the use of spuds (golf club) or needles (Dix needle and spud) becomes necessary. The type and size of the spud or needle necessary will be determined by the depth, size and appearance of the foreign body. Patient cooperation and a steady hand are essential when using these instruments. Use the edges of the instrument to position between the cornea and the foreign body, then lift the foreign body out. Always work tangentially to the corneal plane and reassess the position, depth, etc. and your ability to handle a deep foreign body. Rust rings represent dissolved iron oxide. They are not composed of the actual rusted foreign body, which should be removed with the appropriate spud as described in the previous paragraph. Rust rings are removed using the Algerbrush. They are easier to remove 24 hours post foreign body removal, but patient circumstances, work requirements, and personalities may keep a patient from returning for a next day visit. If necessary, you should attempt to remove as much of the rust ring as possible without causing further damage to the eye. Do not attempt to remove rust rings from prior foreign bodies unless they are causing recurrent erosion(s) and/or patient discomfort.
Anything more than the most superficial corneal abrasion should be pressure patched to allow healing without lid irritation. Instillation of a cycloplegic agent will reduce photophobia and the use of a broad-spectrum antibiotic will help prevent infection. Do not patch an eye that appeared to have an infection at the time of injury as patching presents a warm, dark, moist environment. You should then consider an "ointment patch"; the instillation of antibiotic ointment every two hours until the patient is reassessed the next day. While a little less comfortable for the patient, this procedure will reduce the risk of increased infection of the eye.
Reassessment the next day includes history, VA, and slit lamp evaluation of the abrasion. Remove any remaining rust ring, if present, and repatch if necessary. The patient should continue with antibiotic ointment four times a day for four to five days and then lubricating (or the rest of the antibiotic) ointment at bedtime for at least one month to avoid recurrent corneal erosions. These can occur as long as three months post injury and often present at the change of seasons, as heated and air-conditioned environments tend to dry the eyes while sleeping.
MATERIAL: Metallic, chemical, vegetative, inert.
WHEN: The more recent, in general, the easier to remove completely.
ENVIRONMENT: Wind, working conditions, machinery, safety specs.
ACTIONS: Irrigation or attempts to remove by patient or others.
EYE REACTIONS: Decreased VA, injection, pain, photophobia, tearing.
VA: Aided or unaided acuities with pinhole.
ANESTHETIC: Instill before VA if necessary.
PUPILS: Look for sluggish or distorted.
SLIT LAMP: Determine location, depth and size of foreign body.
FLUORESCEIN: Pooling, tracks, perforation?
LID EVERSION: Upper lid, double evert if needed.
ANTERIOR CHAMBER: Cells or flare, penetration (of F.B. or NaFl).
ORDER OF TECHNIQUES: Always work tangentially to cornea in case patient moves.
- IRRIGATION: Squeeze or spray saline in a strong, steady stream.
- NYLON LOOP: Lubricate with CL wetting or lubricant solution.
- MAGNET: If history indicates magnetic particles.
- SPUDS: Blunt for flicking out; Sharp for carving.
- NEEDLES: Dix needle
- ALGERBRUSH, OPHTHO BURR: Remove rust ring at follow-up visit, if possible. Excess pressure will stop burr from penetrating cornea.
- IRRIGATE AND REASSESS
1. INSTILL CYCLOPLEGIC: Cyclopentolate, Homatropine, Scopolomine.
2. INSTILL BROAD SPECTRUM ANTIBIOTIC: Polysporin, Garamycin, Erythromycin.
3. PATCH: Pressure patch. DO NOT PATCH FOR MORE THAN 24 HOURS!!!
4. PATIENT EDUCATION: Significant pain, photophobia, etc.
5. FOLLOW-UP IN 12-24 HOURS: Reassess and consider one or more of the following as needed:
- Remove any residual rust ring
- Repatch x 24 hours
- Ointment patch with antibiotic
- D/C therapy return P.R.N.
- Refer if necessary
6. LONG TERM ISSUES
- Recurrent corneal erosions (RCE) - Lubricant drops day, Ointment H.S., hypertonic NaCl, night patching or referral for other therapy.
- Glare - Scar on visual axis - Sunglasses, education.
Your professional judgment is your most valuable tool. Make full use of your skills, experience and training, availability of support services and common sense to decide on the most appropriate actions on a case-by-case basis.
1. Potaznick WL, Scott C, Augeri P. Ocular Foreign Body Removal Workshops. Journal of Optometric Education 1991, 16(3)77-81
Walter Potaznick, O.D., FAAO is an Associate Professor of Optometry at the New England College of Optometry and is the Director of Eye Care at the South Boston Community Health Center, S. Boston, MA. He has presented lectures and workshops on foreign body removal at state, regional, and national therapeutics conferences.
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