Mineralized corneal sequestrum in a cat

An 8-month-old 3-kg (6.6-lb) sexually intact male cat was evaluated for chr onic refractory keratitis and a corneal plaque that developed after treatme nt with a corticosteroid-containing ophthalmic preparation. Pertinent ophth almic findings included blepharospasm, conjunctivitis, corneal vascularizat ion, and a tan raised corneal plaque with a dense and gritty composition. L amellar keratectomy was performed tc excise the plaque. The cornea healed w ith mild scarring. Histologic examination revealed extensive coagulation ne crosis and mineralization of the corneal stroma with increased inflammatory cells, blood vessels, and fibrosis, which is compatible with a diagnosis o f mineralized corneal sequestrum. The history suggested chronic feline herp esvirus-1 (FHV-1)-induced keratoconjunctivitis as the underlying cause. Top ical corticosteroid administration may have potentiated the preexisting cor neal necrosis and initiated mineralization. To our knowledge, mineralizatio n of a corneal sequestrum in a cat has not been reported in a clinical case but has been reported in cats experimentally infected with FHV-1.