The Effect Of The Base Curve To Cornea Fitting Relationship On Lens Flexure And Residual Astigmatism Of The Allergan Advent Contact Lens.

Studies have shown that fluoropolymer contact lenses have the advantages of high oxygen transmissibility, high oxygen permeability, good wettability, and protein resistance, along with the disadvantage of poor stability. This disadvantage can lead to increased residual astigmatism and visual distortion for patients. This study was designed to evaluate the effects the base curve to cornea fitting relationship has on the flexure and residual astigmatism of the Allergan Advent contact lens. Eighteen subjects, (34 eyes) all having less than two diopters of corneal toricity were fit with three 10.1mm diameter Allergan Advent contact lenses. The lenses were fit 0.50 D steeper than K, on K, and 0.50 D flatter than K. Flexure and residual astigmatism were measured for each fitting relationship in a masked fashion. The results indicate there is very little predictability of flexure and residual astigmatism when fitting the Allergan Advent contact lens. The results give a slight indication that fitting the lens on K, rather than flatter than K, will decrease the amount of flexure and residual astigmatism.