Which statement is true about Filamentary Keratopathy?

• A. Filaments stain with fluorescein
• B. It never causes irritation
• C. It is exclusively a posterior corneal disease
• D. It is unrelated to neurotrophic keratopathy

Answer: (A)

Filamentary keratopathy consists of strands of degenerated epithelial cells bound together by mucus that cling to the corneal surface, often seen with dry eye or neurotrophic conditions. Fluorescein staining makes these filaments visible because the filaments contain devitalized epithelial cells and mucus that take up the dye, so the strands appear as linear staining under cobalt blue light. This staining helps highlight the filaments and differentiate them from simple surface irregularities. The condition can cause irritation and is not confined to the posterior cornea; it is indeed related to neurotrophic keratopathy.