Oral guaifenesin for treatment of filamentary keratitis: A pilot study

Pilot study to evaluate the safety and efficacy of oral guaifenesin in reducing the signs and symptoms of filamentary keratitis.

Prospective, uncontrolled open-label pilot study. Twelve patients with non-Sjögren dry eye disease (DED) and secondary filamentary keratitis received treatment with oral guaifenesin 600 mg twice a day (total dose of 1.2 g/day) for 4 weeks. Adverse events, change in the number of corneal filaments, corneal fluorescein staining (CFS; NEI grading system), and symptoms (Ocular Surface Disease Index) were assessed.

Before starting oral guaifenesin, all patients were on topical medical therapy for their condition. At baseline, the mean number of filaments was 5.8 ± 2.9, CFS score 7.3 ± 3.2, and OSDI score 55.6 ± 25. After 4 weeks of treatment, the number of filaments was 2.1 ± 2.2 (p = 0.04 vs. baseline), CFS score 6.5 ± 3.1 (p = 0.5), and OSDI score 46.1 ± 30.9 (p = 0.2). One patient discontinued the medication due to gastrointestinal side effects.

Oral guaifenesin was safe and generally well tolerated, and demonstrated modest efficacy in reducing the severity of filamentary keratitis. These results should be considered preliminary; however, placebo-controlled investigations would be justified to evaluate the therapeutic efficacy of oral guaifenesin as a mucolytic in treatment of filamentary keratitis.