title: Dot matrix stabilization with the piggyback lens system.
abstract: BACKGROUND
  The piggyback system of contact lens correction is used in specialized cases to provide corneal protection with the soft lens and optical correction with a rigid gas-permeable lens. Controlling the position and amount of movement of the RGP lens over the soft lens is a critical factor in fitting the piggyback system.
  
  
  METHODS
  The movement of rigid gas-permeable lenses as part of a piggyback system was investigated under two different conditions. The RGP lens was placed on a smooth-surface soft lens and compared to a RGP lens placed on a dot matrix designed front-surface soft lens.
  
  
  RESULTS
  When placed over a dot matrix front-surface soft lens, the RGP lens moved significantly less than when placed on the front surface of a smooth-surface soft lens.
  
  
  CONCLUSIONS
  This controlled movement can increase patient comfort and reduce RGP slippage and lens dislocation when the piggyback lens system is prescribed.
authors.affiliation: Illinois College of Optometry, Chicago, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Jurkus
authors.forename: D S
authors.initials: DS
authors.lastname: Rabbitt
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic; D003315:Cornea / Q000033:anatomy & histology*; D005548:Foreign-Body Migration; D006801:Humans; D012016:Reference Values; D013499:Surface Properties