title: Time to resolution of contact lens-induced corneal warpage prior to refractive surgery.
abstract: OBJECTIVE
  To evaluate the resolution of contact lens-induced corneal warpage before keratorefractive surgery.
  
  
  METHODS
  We prospectively studied the eyes of 165 consecutive contact lens-wearing patients evaluated for keratorefractive surgery. Significant contact lens-induced corneal warpage was detected by comeal topography in 20 eyes of 11 patients. Manifested refraction, keratometry, and cornea topography were subsequently recorded during weekly or biweekly reevaluations and were compared with previous measurements for stability. Effects of age, sex, type, and duration of contact-lens wear and the recovery time period to stabilization were analyzed.
  
  
  RESULTS
  Overall, a 12% incidence of significant contact lens-induced corneal warpage was found. In patients demonstrating lens-associated warpage, the mean duration of prior contact lens wear was 21.2 years (range 10 to 30 years); lens use included daily wear soft (n=2), extended-wear soft (n=6), toric (n=4), and rigid gas-permeable contact lenses (n=8). Up to 3.0 diopter (D) refractive and 2.5D keratometric shifts accompanied by significant topography pattern differences were observed. The average recovery time for stabilization of refraction, keratometry (change within +/- 0.5D), and topography pattern was 7.8+/-6.7 weeks (range 1 to 20 weeks). Recovery rates differed between the lens types: soft extended-wear 11.6+/-8.5 weeks, soft toric lens 5.5+/-4.9 weeks, soft daily wear 2.5+/-2.1 weeks, and rigid gas-permeable 8.8+/-6.8 weeks.
  
  
  CONCLUSIONS
  We observed a 12% incidence of significant contact lens-induced corneal warpage in patients undergoing evaluation for keratorefractive surgery. Warpage occurred with all types of contact lens wear but resolved at different rates. To optimize the quality and predictability of keratorefractive procedures, an appropriate waiting period is necessary for contact lens-induced corneal warpage to stabilize. We suggest that resolution of corneal warpage be documented by stable serial manifested refractions, keratometry, and corneal topographic patterns before scheduling patients for keratorefractive surgery.
authors.affiliation: Department of Ophthalmology, The University of Texas Southwestern Medical Center at Dallas, 75390-9057, USA.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.forename: James P
authors.initials: JP
authors.lastname: McCulley
authors.forename: R Wayne
authors.initials: RW
authors.lastname: Bowman
authors.forename: H Dwight
authors.initials: HD
authors.lastname: Cavanagh
mesh_terms: D000328:Adult; D003261:Contact Lenses / Q000009:adverse effects*; D003262:Contact Lenses, Extended-Wear / Q000009:adverse effects; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects; D003315:Cornea / Q000601:surgery; D003316:Corneal Diseases / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D011446:Prospective Studies; D054140:Refractive Surgical Procedures; D013997:Time Factors