title: Antioxidant and inflammatory cytokine in tears of patients with dry eye syndrome treated with preservative-free versus preserved eye drops.
abstract: OBJECTIVE
  To compare the antioxidant and inflammatory cytokine activities in tears of patients with dry eye syndrome treated with preservative-free versus preserved eye drops.
  
  
  METHODS
  A total of 100 patients with moderate to severe dry eye syndrome were randomly divided into two groups. Fifty patients (group 1) were treated four times with preservative-free 0.1% sodium hyaluronate and 0.1% fluorometholone eye drops in the first month and with preservative-free 0.1% sodium hyaluronate and 0.05% cyclosporine eye drops in the second and third months. Another 50 patients (group 2) were treated with preserved eye drops on the same schedule. Ocular Surface Disease Index, corneal fluorescein staining, Schirmer I test, tear film breakup time, impression cytology, and antioxidant and inflammatory cytokine activities in tears were evaluated.
  
  
  RESULTS
  Treatment with preservative-free eye drops led to significant improvements in symptoms, tear film breakup time, Schirmer I score, and impression cytologic findings compared to treatment with preserved eye drops (P < 0.05) in patients with dry eye syndrome. There was a statistically significant decrease in the IL-1β, IL-6, IL-12, and TNF-α concentrations and a statistically significant increase in the catalase, peroxiredoxin 2, superoxide dismutase 2 (SOD 2), and thioredoxin mean fluorescence intensity (MFI) of tears in the preservative-free group at 1, 2, and 3 months compared to initial values, respectively (P < 0.05).
  
  
  CONCLUSIONS
  Treatment with preservative-free eye drops is effective against the dry eye syndrome. Preservative-free eye drops seem to be more effective than preserved eye drops in decreasing ocular inflammation and in increasing antioxidant contents in tears of patients with dry eye syndrome.
authors.affiliation: Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Donghyun
authors.initials: D
authors.lastname: Jee
authors.affiliation: Institute of Clinical Medicine Research, Bucheon St. Mary's Hospital, Bucheon, Korea.
authors.forename: Sang Hee
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Man Soo
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Eun Chul
authors.initials: EC
authors.lastname: Kim
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D015352:Dry Eye Syndromes / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions / Q000008:administration & dosage*; D011310:Preservatives, Pharmaceutical / Q000008:administration & dosage*; D012189:Retrospective Studies; D013666:Tears / Q000737:chemistry*; D016896:Treatment Outcome
chemical_list: D000975:Antioxidants; D016207:Cytokines; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical
keywords: antioxidants; dry eye syndrome; inflammatory cytokines; preservative-free eye drops