Abstract
Purpose: :
The purpose of this study is to determine the effect of lens transmissibility and design of the SynergEyes hybrid contact lens on corneal oxygen supply under both static (non-blinking) and dynamic (blinking once every 5 seconds) conditions.
Methods: :
Corneal oxygen uptake rates were measured on the right eye of 15 human subjects at two locations (central cornea and 5.0 mm temporal to the central cornea) for the normal open eye and following 5 minutes of both static and dynamic wear of each of three contact lens base curves ("on K", 0.1 mm flatter-thank-K, and 0.1 mm steeper-than-K) with each of two contact lens skirt radii (1.0 mm and 1.3 mm flatter than the base curve). Repeated measures analysis of variance was used to examine the effects of contact lens transmissibility and corneal location on corneal oxygen uptake.
Results: :
Corneal oxygen uptake rates for both central and peripheral locations were significantly lower under dynamic than under static conditions (p=0.004). Corneal oxygen uptake rates obtained at the peripheral location were significantly higher than those obtained under central locations (p<0.0001) for both designs. At the peripheral cornea, higher oxygen uptake rates are found with the 1.3 mm skirt radius than with the 1.0 mm skirt radius; however, skirt radius does not affect oxygen uptake rates of the central cornea.
Conclusions: :
Tear exchange with the blink, lens transmissibility, and lens design influence corneal oxygen uptake rates associated with the wear of hybrid contact lenses.
Keywords: contact lens • cornea: basic science • oxygen