title: Conjunctival epithelial flaps with 18 months of silicone hydrogel contact lens wear.
abstract: OBJECTIVE
  To report differences in the incidence of conjunctival epithelial flaps (CEFs) found in a group of neophyte contact wearers using two different silicone hydrogel contact lenses on a daily- and continuous-wear basis during an 18-month period.
  
  
  METHODS
  Sixty-one subjects were initially examined, and 53 were eligible to participate in the study. Eligible subjects were randomly assigned to wear one of two silicone hydrogel materials, lotrafilcon A or balafilcon A, on a daily- or continuous-wear basis. After an initial screening, subjects were monitored weekly for the first month and then after 3, 6, 12, and 18 months. The incidence of CEFs in each of the four contact lens groups was recorded.
  
  
  RESULTS
  Five of the 53 subjects enrolled in the study showed bilateral CEFs. A higher incidence of CEFs was found in subjects wearing lotrafilcon A lenses (n=4) compared to balafilcon A lenses (n=1) (chi = 4.37, P=0.04). Differences in the incidence of CEFs between subjects wearing lenses on a daily-wear basis (n=1) versus a continuous-wear basis (n=4) showed a weak statistical significance (chi=3.03, P=0.08).
  
  
  CONCLUSIONS
  Lotrafilcon A lenses were associated with a higher incidence of CEFs than balafilcon A lenses were, and this difference may be attributed to differences in the edge design, material, or modulus of rigidity between the two lens types. Subjects wearing lenses on a daily-wear basis showed fewer adverse events than did subjects wearing lenses on a continuous-wear basis. The longer wearing times of subjects wearing lenses on a continuous-wear basis are likely to exacerbate the incidence of CEFs.
authors.affiliation: Aston University, Birmingham, United Kingdom. j.santodomingo@menicon.com
authors.forename: Jacinto
authors.initials: J
authors.lastname: Santodomingo-Rubido
authors.forename: James
authors.initials: J
authors.lastname: Wolffsohn
authors.forename: Bernard
authors.initials: B
authors.lastname: Gilmartin
mesh_terms: D000293:Adolescent; D000328:Adult; D003229:Conjunctival Diseases / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D003262:Contact Lenses, Extended-Wear / Q000009:adverse effects*; D018450:Disease Progression; D004848:Epithelium / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020100:Hydrogels / Q000009:adverse effects*; D015994:Incidence; D008297:Male; D012189:Retrospective Studies; D012828:Silicones / Q000009:adverse effects*; D013997:Time Factors; D005466:Fluorocarbons
chemical_list: D020100:Hydrogels; D012828:Silicones; C523195:balafilcon A; C481129:lotrafilcon A; D005466:Fluorocarbons