Case Report: Management of Refractory Filamentary Keratitis with N-acetylcysteine.

Abstract

Filamentary keratitis is frequently a recurrent corneal condition characterized by the presence of filaments attached to the cornea. This condition can be challenging to manage because the clinician must treat the underlying cause and filament formation. N-acetylcysteine, a mucolytic agent, should be considered as adjunctive therapy to manage refractory cases. This case demonstrates the utility of a mucolytic agent, N-acetylcysteine, to treat and manage filamentary keratitis when conventional therapies failed to provide long-term symptomatic relief and reduction of further filament formation. A 70-year-old man with recurrent filamentary keratitis (first occurrence 8 years prior) presented to the clinic with worsening red and painful eyes for 2 days. Prior treatment and management included artificial tears and ointments, punctal plugs, topical corticosteroids, contact lenses, and eyelid hygiene. Slit-lamp examination revealed multiple corneal filaments that were removed with forceps. He was diagnosed with recurrent filamentary keratitis secondary to dry eye disease and treated with preservative-free ophthalmic ointment, oral doxycycline, and 10% N-acetylcysteine ophthalmic solution. The patient had complete resolution of corneal filaments with significant relief of symptoms at 3-week, 5-month, and 10-month follow-up examinations. N-acetylcysteine is not commercially available in an ophthalmic solution and must be compounded by a local pharmacist for patient use. Because filamentary keratitis can be challenging to manage because of frequent recurrences, addition of N-acetylcysteine to the treatment regimen should be considered a viable option in refractory cases when other therapies have failed to provide sustained symptomatic relief and resolution of filaments.