Influence of Lens Design on the Tear Pump Efficiency Associated with Plus-Power Rigid Contact Lenses: A Comparison of Single Cut, Lenticular, and Minus-Carrier Designs

摘要

In order to determine the tear pump efficiencies associated with three plus-power rigid contact lens designs (single cut, lenticular, and minus-carrier), we measured corneal oxygen uptake rates on the right eyes of six human subjects under three conditions: (1) normal open eye, (2) after 5 min of static (without blinking) wear of the contact lens, and (3) after 5 min of dynamic (with blinking once every 5 s) wear of the same lens. The differences among the corneal oxygen uptake rates measured under static and dynamic conditions, relative to those measured for the normal open eye, served as an index of tear pump efficiency. Under both static and dynamic conditions, no significant differences were found among the corneal oxygen uptake rates associated with the three plus-power lens designs. In addition, no significant differences were found in the differences among the static and dynamic condition data, an indication of tear pump efficiency, associated with the three plus-power lens designs. This was true for both the population data and for the data from each subject. Nevertheless, there were significant differences among subjects in the static condition, dynamic condition, and difference data.