title: Variables affecting rigid contact lens comfort in the collaborative longitudinal evaluation of keratoconus (CLEK) study.
abstract: OBJECTIVE
  To identify factors associated with rigid contact lens comfort in keratoconus.
  
  
  METHODS
  Baseline data from the 16 Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study clinical sites were analyzed for all patients wearing a rigid contact lens in their more severely keratoconic eye (as determined by steep keratometry). Corneal transplant patients, patients who did not wear a rigid contact lens in either eye, patients who did not wear a rigid lens in their worse eye, and patients with missing contact lens comfort data were excluded from the sample. A total of 751 eyes were included. Variables assessed included measures of disease severity, visual acuity through the patients' habitual rigid contact lenses, contact lens wearing time, the apical fitting relationship of the contact lens, the degree of peripheral clearance, and the presence of corneal scarring and staining. Comfort was measured by asking the patients "In general, how comfortable are your contact lenses?" (1 = very comfortable through 5 = very irritating).
  
  
  RESULTS
  Measures of disease severity (steep keratometry and the first definite apical clearance lens) were not associated with lens comfort. There was no difference in self-reported contact lens comfort between patients fitted with apical touch vs. apical clearance. Patients with a peripheral clearance rating of "minimal unacceptable" (more common among patients with milder keratoconus) were approximately half as likely to report good contact lens comfort compared with patients with "average" peripheral clearance (unadjusted odds ratio, 0.39; 95% confidence interval, 0.19 to 0.79). There was no association between contact lens comfort and the other peripheral clearance ratings compared with ratings of average.
  
  
  CONCLUSIONS
  There does not appear to be an association between decreasing patient-reported rigid lens comfort and increasing disease severity as measured by steep keratometry or first definite apical clearance lens in this sample. The apical fitting relationship (flat vs. steep) does not appear to be associated with patient-reported comfort. Minimal peripheral clearance may contribute to decreased rigid contact lens comfort in keratoconus.
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Edrington
authors.forename: Ralph E
authors.initials: RE
authors.lastname: Gundel
authors.forename: David P
authors.initials: DP
authors.lastname: Libassi
authors.forename: Heidi
authors.initials: H
authors.lastname: Wagner
authors.forename: Gilbert E
authors.initials: GE
authors.lastname: Pierce
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Walline
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Barr
authors.forename: Harald E
authors.initials: HE
authors.lastname: Olafsson
authors.forename: Karen
authors.initials: K
authors.lastname: Steger-May
authors.forename: Joel
authors.initials: J
authors.lastname: Achtenberg
authors.forename: Brad S
authors.initials: BS
authors.lastname: Wilson
authors.forename: Mae O
authors.initials: MO
authors.lastname: Gordon
authors.forename: Karla
authors.initials: K
authors.lastname: Zadnik
mesh_terms: D000328:Adult; D003261:Contact Lenses; D003315:Cornea / Q000502:physiology*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000628:therapy*; D008137:Longitudinal Studies; D008297:Male; D017060:Patient Satisfaction; D011446:Prospective Studies; D017755:Prosthesis Fitting; D011788:Quality of Life; D014785:Vision, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology