Which description describes foreign body tracking?

Which description describes foreign body tracking?

• A. Subconjunctival hemorrhage that tracks with blink
• B. Linear superficial corneal epithelial staining; tracking due to lens movement with blink
• C. Central corneal ulcer
• D. Epithelial edema

Answer: (B)

Foreign body tracking shows up as a linear streak of superficial corneal epithelial staining that follows the path created by blinking. This pattern happens because a tiny foreign body or the edge of a contact lens drags across the cornea with each blink, scraping the epithelium and leaving a straight line that fluorescein highlights. It’s a distinctive, elongated track rather than a single focal defect, and it remains tied to the movement of the lid and lens. In contrast, a subconjunctival hemorrhage would present as a red hemorrhagic area on the sclera without corneal staining or a linear epithelial track. A central corneal ulcer presents as a focal, often larger epithelial defect with possible stromal infiltration and inflammation, not a linear track. Epithelial edema would cause diffuse haziness and swelling of the cornea rather than a defined linear staining pattern.

Foreign body tracking shows up as a linear streak of superficial corneal epithelial staining that follows the path created by blinking. This pattern happens because a tiny foreign body or the edge of a contact lens drags across the cornea with each blink, scraping the epithelium and leaving a straight line that fluorescein highlights. It’s a distinctive, elongated track rather than a single focal defect, and it remains tied to the movement of the lid and lens.

In contrast, a subconjunctival hemorrhage would present as a red hemorrhagic area on the sclera without corneal staining or a linear epithelial track. A central corneal ulcer presents as a focal, often larger epithelial defect with possible stromal infiltration and inflammation, not a linear track. Epithelial edema would cause diffuse haziness and swelling of the cornea rather than a defined linear staining pattern.