Lacrimal lens effects in Bausch and Lomb Soflens contact lens wear

The correlation between lacrimal lens power changes and changing posterior apical radii was examined for a sample of 20 eyes wearing Bausch and Lomb Soflens contact lenses. Power changes caused by in situ lens flexure were calculated for principal meridians and both calculated in situ contact lens powers and over-refraction corrections were subtracted from the patient's spectacle corrections to determine lacrimal lens powers in each meridian. A significant correlation (p less than 0.01) was found in the flatter meridians for B, F, J, and N series lenses. To support the validity of the study a correlation was done between K's calculated from refractions done over the Bausch and Lomb Soflens contact lenses and both the K's calculated from refractions done over PMMA diagnostic lenses and the K's as measured with the keratometer. There was a significant (p less than 0.01) correlation in both series, indicating that calculated K's can validate the presence and power of a lacrimal lens in soft (hydrogel) contact lens wear as well as in conventional contact lens wear. (A correlation between the K's as measured with the keratometer and the K's calculated from refractions done over PMMA diagnostic lenses were also significant (p less than 0.01).