title: Corneal abrasion associated with contact lens correction of keratoconus--a retrospective study.
abstract: BACKGROUND
  Corneal abrasion is a frequently encountered complication of contact lens wear, but we are not aware of any previous study of relative frequency comparing keratoconic to nonkeratoconic patients.
  
  
  METHODS
  We retrospectively studied the incidence of corneal abrasion during 2 months of contact lens practice.
  
  
  RESULTS
  784 contact lens-related patient visits (494 total patients); patients were assessed by 3 optometrists and 13 abrasions (11 patients) were diagnosed. Only the total number of individual patients and the first abrasion for each patient were statistically considered; the overall frequency of abrasion was therefore 11/494 (2.3%)/2 months. The frequency of abrasion was 5/68 (7.4%)/2 months for keratoconic patients and 6/426 (1.4%)/2 months for nonkeratoconic patients and this difference was significant (chi 2 test: p < 0.01). Among nonkeratoconic patients, the frequency of abrasion was 2/246 (0.8%)/2 months with hydrogel contact lens wear and 4/178 (2.2%)/2 months with rigid gas permeable (RGP) contact lens wear, but this difference did not achieve significance (chi 2 test: p = 0.10). IDENTIFIED RISK FACTORS INCLUDED: Contact lens wear; a torn lens and chemical keratitis for hydrogel lens wearers; an adherent "bound" lens and keratoconus for rigid lens wearers.
  
  
  CONCLUSIONS
  Keratoconus appears to be a statistically significant risk factor for corneal abrasion among contact lens wearers.
authors.affiliation: Jules Stein Eye Institute, Department of Ophthalmology, UCLA School of Medicine.
authors.forename: B
authors.initials: B
authors.lastname: Weissman
authors.forename: M W
authors.initials: MW
authors.lastname: Chun
authors.forename: L A
authors.initials: LA
authors.lastname: Barnhart
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003261:Contact Lenses / Q000009:adverse effects*; D003315:Cornea / Q000473:pathology; D065306:Corneal Injuries; D005260:Female; D006801:Humans; D015994:Incidence; D007640:Keratoconus / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors