Dot matrix stabilization with the piggyback lens system.
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.