title: The impact of punctal occlusion on soft contact lens wearing comfort and the tear film.
abstract: OBJECTIVE
  The purpose of this report is to describe the impact of punctal occlusion in symptomatic dry eye contact lens wearers and the relation between subjective and objective outcomes.
  
  
  METHODS
  This study was a randomized, controlled, double-masked, single center clinical trial. A previously described dry-eye questionnaire was used to determine subject eligibility. Tear interferometry was performed to evaluate prelens tear film thickness, contact lens center thickness, and postlens tear film thickness. Each subject was randomly assigned to receive the punctal plugs or a sham procedure. At the outcome examination, the subject completed the dry-eye questionnaire and answered one question rating the efficacy of the punctal plug treatment in addition to undergoing tear interferometry using an identical protocol as the first visit.
  
  
  RESULTS
  Nineteen subjects completed both visits of this study. There was a significant improvement in the dry-eye questionnaire scores from baseline to the outcome visit for both the plug (Z = -2.52, P=0.01) and sham groups (Z = -2.93, P=0.003). A significant increase in prelens tear film thickness occurred within the sham group from baseline to the outcome visit (Z = -1.96, P=0.05), but not for the punctal plug group. No other layers measured by interferometry were shown to change significantly for either group.
  
  
  CONCLUSIONS
  Results comparing the sham and plug groups were not significantly different from each other with regards to the questionnaire score and treatment benefit assessment, indicating either the treatment effect was not detected, although present, or punctal occlusion had no treatment effect at all.
authors.affiliation: Ohio State University, College of Optometry, Columbus, OH 43210, USA.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Geldis
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Nichols
mesh_terms: D003263:Contact Lenses, Hydrophilic / Q000706:statistics & numerical data*; D004311:Double-Blind Method; D015352:Dry Eye Syndromes / Q000601:surgery*; D004867:Equipment Design; D005500:Follow-Up Studies; D006801:Humans; D007765:Lacrimal Apparatus / Q000601:surgery*; D017060:Patient Satisfaction; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012030:Refractive Errors / Q000628:therapy*; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry*; D016896:Treatment Outcome