title: Role of cysteine in corneal wound healing after photorefractive keratectomy.
abstract: OBJECTIVE
  To evaluate the efficacy of cysteine oral supplements in corneal wound healing after photorefractive keratectomy (PRK).
  
  
  METHODS
  A total of 200 eyes (100 patients) underwent PRK. We divided patients into 2 groups; each group was composed of 50 patients (100 eyes). Group 1 patients were assigned to use oral L-cysteine, with a daily dose of 200 mg (100-mg pills to be taken twice a day) for a duration of 14 days, starting from the week preceding the operation; the patients in group 2 were used as a control, and received the oral supplementation of 40-mg placebo pills to be taken twice a day for a duration of 14 days, starting from the week preceding the operation.
  
  
  RESULTS
  All the eyes of patients treated with cysteine oral supplements showed shorter times to re-epithelization than the eyes of the control group. The mean time of corneal wound healing observed in group 1 was 102 +/- 15 h, compared to an average of 159 +/- 9 h in group 2.
  
  
  CONCLUSIONS
  Our research showed that oral cysteine supplementation, in a daily dose of 200 mg, reduces mean corneal wound healing time in patients after PRK.
authors.affiliation: Department of Surgical Specialities, Ophthalmology Clinic, University of Messina, Messina, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Meduri
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Grenga
authors.forename: Lucia
authors.initials: L
authors.lastname: Scorolli
authors.forename: Piero
authors.initials: P
authors.lastname: Ceruti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ferreri
mesh_terms: D000284:Administration, Oral; D000328:Adult; D003545:Cysteine / Q000008:administration & dosage*; D019573:Epithelium, Corneal / Q000187:drug effects*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000601:surgery; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000601:surgery; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D016037:Single-Blind Method; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D003545:Cysteine