CLPUs are associated with which factor?

CLPUs are associated with which factor?

• A. Bacterial keratitis due to Pseudomonas
• B. Viral keratitis secondary to adenovirus
• C. Hypersensitivity to gram-positive Staphylococcus aureus exotoxins, acute inflammatory event associated with overnight wear
• D. Fungal infection from poor storage

Answer: (C)

CLPU reflects a sterile inflammatory reaction driven by a hypersensitivity to exotoxins produced by Staphylococcus aureus that colonize the lid margins and lens surfaces, especially with overnight wear. This toxins-induced immune response around the cornea creates an acute inflammatory infiltrate without an active infectious organism invading the cornea itself. Overnight lens wear and suboptimal hygiene increase exposure to these exotoxins and trigger the reaction. In contrast, bacterial keratitis from Pseudomonas is an infectious infection of the cornea, viral keratitis from adenovirus is a viral disease with distinct epithelial signs, and fungal keratitis from poor storage is a fungal infection—each has a different infectious etiology rather than the sterile inflammatory mechanism seen in CLPU.

CLPU reflects a sterile inflammatory reaction driven by a hypersensitivity to exotoxins produced by Staphylococcus aureus that colonize the lid margins and lens surfaces, especially with overnight wear. This toxins-induced immune response around the cornea creates an acute inflammatory infiltrate without an active infectious organism invading the cornea itself. Overnight lens wear and suboptimal hygiene increase exposure to these exotoxins and trigger the reaction. In contrast, bacterial keratitis from Pseudomonas is an infectious infection of the cornea, viral keratitis from adenovirus is a viral disease with distinct epithelial signs, and fungal keratitis from poor storage is a fungal infection—each has a different infectious etiology rather than the sterile inflammatory mechanism seen in CLPU.