Corneal Foreign Body

Excerpt

Corneal foreign bodies (CFBs) are the second most common cause of ocular trauma, following corneal abrasions. While major morbidity, such as loss of visual acuity, is rare, many CFBs are superficial and benign, though they can be uncomfortable. CFBs are a common ophthalmic emergency, defined as any external object embedded on or within the corneal surface. These can include metallic, vegetative, and inorganic particles, as well as contact lens fragments. The issue of CFBs is significant due to their potential to cause pain, photophobia, tearing, blurred vision, and complications such as infections and corneal scarring, which, if inadequately managed, may result in permanent vision impairment. CFBs are particularly prevalent among industrial workers, welders, agricultural laborers, and individuals exposed to high-risk environments without appropriate eye protection (see Image. Corneal Foreign Body).

Reports indicate that CFBs contribute significantly to ocular injuries, accounting for 30% to 40% of cases in emergency ophthalmology settings. Incidence rates are higher in low-resource areas where occupational safety measures are inadequate. Patients typically present with acute ocular discomfort, foreign body sensation, redness, excessive tearing, and difficulty keeping the eye open. Clinical examination typically reveals hallmark findings such as corneal epithelial defects, embedded foreign material, corneal edema, rust rings (in metallic foreign bodies), anterior stromal infiltrates, or corneal melt. Although less common, posterior segment complications may include traumatic uveitis, vitreous hemorrhage, or endophthalmitis if the foreign body penetrates deeper ocular layers. Diagnosis starts with a thorough history of the injury, including its nature, mechanism, and duration, followed by slit-lamp biomicroscopy to localize and assess the foreign body’s depth.

Fluorescein staining is useful for highlighting corneal abrasions, whereas imaging techniques such as anterior segment optical coherence tomography (AS-OCT), x-rays, or orbital computed tomography (CT) scans may be necessary for evaluating deeper or radiopaque foreign bodies. Management focuses on the safe and timely removal of the foreign body using sterile instruments such as needles or burrs, typically performed under topical anesthesia. Rust rings from metallic foreign bodies require careful debridement to prevent persistent inflammation. Post-removal care includes prophylactic antibiotics, lubricants, and cycloplegics to prevent infection, reduce pain, and promote healing, with close follow-up to ensure epithelial recovery and prevent secondary complications.

A literature review emphasizes the importance of early intervention and appropriate techniques to minimize complications, highlighting the need for improved eye safety protocols, particularly in occupational settings. Foreign bodies can be classified into metallic, organic (vegetative), and inorganic materials, with organic bodies presenting a higher risk of infection.