title: [Topographic and pachymetric changes caused by prolonged use contact lenses].
abstract: OBJECTIVE
  To evaluate the topographic and pachymetric alterations caused by soft contact lenses for prolonged use and DK/t >100 after wearing them continuously for 3 weeks.
  
  
  METHODS
  Our study included 24 eyes of 12 patients aged between 19 and 32 years who were given the new Night & Day contact lens to wear. Various topographic parameters -central corneal power, corneal radii at 3, 5 and 7 mm and simulated keratometry- were analyzed together with pachymetry before the lenses were put in and the 1st and 21st day after insertion. Wilcoxon's test for matched-pairs is used for the comparison, and vectorial analysis to evaluate the sphere, cylinder and axis of the astigmatism caused by the lens.
  
  
  RESULTS
  The mean refraction of the patient was of -3.28 D. The initial mean central corneal power was 42.5 D. There were no significant differences in central corneal power and radii after 21 days of use of the lens. The initial mean pachymetry was of 541.46 micrometer and 557.64 micrometer after 24 h of use. There were significant differences in the pachymetry after the use of the lens.
  
  
  CONCLUSIONS
  No significant topographic alterations were produced following prolonged use of the contact lenses (21 days). The corneal thickness after wearing the lens was <5% in all cases.
authors.affiliation: Hospital General Universitario, Elche, Alicante, España.
authors.lastname: Romero Caballero MD
authors.lastname: Soler Ferrández FL
authors.lastname: Juan Campos L
mesh_terms: D000328:Adult; D003262:Contact Lenses, Extended-Wear / Q000009:adverse effects*; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D008297:Male; D013997:Time Factors