"Steel wool keratopathy": A clinical sign of chronic inflammation

PURPOSE: To introduce into the clinical nomenclature a sign frequently observed in our patients with persistent corneal inflammation associated with herpetic stromal keratitis. METHODS: Case reports and review of the literature. RESULTS: Four representative patients with herpesvirus stromal keratitis are presented. Herpes simplex virus-1 (HSV-1) was confirmed by culture in 1 case and by polymerase chain reaction in a second case. In the remaining 2 cases, the diagnosis was made based on characteristic clinical findings for herpes simplex virus and varicella zoster virus (VZV). On clinical examination, all 4 representative cases of stromal keratitis revealed a well-defined, localized region of intertwined, metallic-like, polychromatic material in the corneal stroma, a sign we have termed steel wool keratopathy. We have only rarely observed this finding in patients with stromal keratitis not caused by a herpesvirus. CONCLUSION: Steel wool keratopathy seems to represent a focal region of stromal degeneration or deposition associated with chronic inflammation. Although we most often observe this finding in patients with stromal keratitis secondary to HSV or VZV, we cannot exclude the possibility that this sign represents the sequelae of chronic/recurrent inflammation rather than a specific pathologic response to herpetic antigens.