title: The effect of degree of refractive error on hydrogel contact lens-induced complications and patient self-management behaviors.
abstract: BACKGROUND
  Although many aspects of hydrogel lens wear have been explored over the last 20 years, little attention has been paid to the role of refractive error magnitude in determining patients' ocular responses or associated contact lens behaviors.
  
  
  METHODS
  A cross-sectional study was conducted in 32 optometric and ophthalmologic practices. We enrolled 2161 spherical soft contact lens-wearing patients. High ametropes were defined as those with at least +/- 5.00 D spherical equivalent refractive error in the right eye. Data on current contact lenses, prescribed care regimens, and slit lamp biomicroscopic signs were provided by the eye care practitioners, and information on actual lens care behaviors and attitudes toward contact lens wear were gathered by survey directly from the patients. All differences between high and low ametropes were compared using the chi-square test.
  
  
  RESULTS
  Compared with low ametropes, high ametropes were more satisfied with their vision with contact lenses (p < 0.001). More high ametropes wore their lenses on an extended-wear schedule (p = 0.015). Both groups of patients reported a similar degree of lens awareness and lens-associated pain, but fewer high ametropes reported foreign body sensation (p = 0.002). In managing contact lens discomfort, high ametropes were more likely to use an old spare lens (p = 0.01) and more likely to continue wearing their lenses (p = 0.016)--indicators of a propensity for self-management. In response to a damaged lens, high ametropes were less likely to remove both of their lenses (p = 0.002). High ametropes showed more conjunctival staining (p = 0.001) and more corneal scars (p = 0.033). High ametropes also presented with more corneal fluorescein staining (p = 0.001) and more corneal vascularization (p < 0.001). These relations between the degree of ametropia and slit lamp signs of contact lens wear were not significantly affected by daily- vs. extended-wear status.
  
  
  CONCLUSIONS
  In summary, practitioners should consider the implications of the patient's degree of ametropia when prescribing contact lenses. These results indicate the need for closer observation and specific advice concerning management of contact lens-related problems when caring for patients with high refractive errors.
authors.affiliation: The Ohio State University College of Optometry, Columbus 43210-1240, USA. zadnik.4@osu.edu
authors.forename: K
authors.initials: K
authors.lastname: Zadnik
authors.forename: D O
authors.initials: DO
authors.lastname: Mutti
authors.forename: G R
authors.initials: GR
authors.lastname: Cutter
authors.forename: R L
authors.initials: RL
authors.lastname: Chalmers
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects* / Q000706:statistics & numerical data; D003316:Corneal Diseases / Q000209:etiology / Q000628:therapy*; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D012030:Refractive Errors / Q000150:complications*; D012307:Risk Factors; D012648:Self Care / Q000523:psychology*; D012650:Self Disclosure
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate