A 35-year-old Caucasian male with no significant past medical history presents to the emergency department complaining of severe pain in his left eye. Earlier that afternoon he was working on his boat when he dropped a heavy metal crate onto the boat's wooden deck. Immediately after he dropped the crate, he felt one or more small foreign objects enter his left eye. The eye began to water profusely and he was unable to open it sufficiently to examine the cornea. He states that he does not wear contact lenses. Physical examination of the left eye reveals edema of the upper eyelid, conjunctival hyperemia, diffuse corneal inflammation, and corneal abrasion. After a topical anesthetic was applied to the injured eye, irrigation with saline was successful in removing all debris. What organism is most commonly cultured from corneal foreign bodies?

Question

A 35-year-old Caucasian male with no significant past medical history presents to the emergency department complaining of severe pain in his left eye.  Earlier that afternoon he was working on his boat when he dropped a heavy metal crate onto the boat's wooden deck.  Immediately after he dropped the crate, he felt one or more small foreign objects enter his left eye.  The eye began to water profusely and he was unable to open it sufficiently to examine the cornea.  He states that he does not wear contact lenses.  Physical examination of the left eye reveals edema of the upper eyelid, conjunctival hyperemia, diffuse corneal inflammation, and corneal abrasion.  After a topical anesthetic was applied to the injured eye, irrigation with saline was successful in removing all debris.  What organism is most commonly cultured from corneal foreign bodies?

Quizplus · Accepted Answer

Explanation: Although rarely sent for culture in practice, corneal foreign bodies are known to frequently test positive for pathogens. Studies have shown that the most common pathogen isolated from these cultures is coagulase negative Staphylococcus (Choice B). Other common pathogens include Streptococcus, Haemophilus, and Pseudomonas. Therefore, the treatment for all foreign-body associated corneal abrasions should include empiric broad-spectrum antibiotic eye drops or ointments (e.g., erythromycin, sulfacetamide, ciprofloxacin, ofloxacin). Staphylococcus Streptococcus Haemophilus Pseudomonas Pseudomonas (Choice A) is a common cause of bacterial infection in contact lens wearers. Pseudomonas Neisseria gonorrhoeae (Choice C) can penetrate intact corneal epithelium and cause bacterial keratitis. This is one of many possible manifestations of gonorrheal infection resulting from sexual transmission or passage through the birth canal. Neisseria gonorrhoeae Sporotrichosis (Choice D) is a fungal infection most often found in persons handling thorny plants, sphagnum moss, or baled hay. It typically manifests as nodules on the skin that ulcerate and are slow to heal. Candidal (Choice E) infection of the eye is most often found in immunosuppressed patients or those with chronic diseases of the ocular surface. Educational Objective: The most common pathogen isolated from cultures of corneal foreign bodies is coagulase negative Staphylococcus. Other common pathogens include Streptococcus, Haemophilus, and Pseudomonas. Staphylococcus Streptococcus Haemophilus Pseudomonas

A 35-Year-Old Caucasian Male with No Significant Past Medical History