Abstract
Abstract: :
Purpose:Following refractive surgery some patients suffer from dramatic elevation of spherical aberration that causes night vision problems such as glare and haloes. Customized contact lenses that both fit the shape of the post-surgical cornea and correct for spherical aberration may be useful for alleviating these problems. Methods:Orbscan corneal topographic data was combined with Shack-Hartmann wavefront data to design customized contact lenses. The posterior surface of the contact was designed to be similar to the contour of the flat axis of the cornea, except with sufficient edge lift to promote tear exchange. The anterior surface of the lens was designed to eliminate the total spherical aberration of the eye/lens combination. The lens edges were designed with a spline technique. Results:Following refractive surgery, the left eye of our subject exhibited 1.218 microns for a 7.36 mm pupil and the right eye exhibited 0.829 microns for 6.95 mm pupil. Custom lenses were designed to give a maximum of 30 microns edge lift on the lens, while simultaneously reducing spherical aberration. The lenses reduced spherical aberration to –0.028 microns for the left eye and 0.108 microns for the right eye. Conclusion:The techniques developed in this work demonstrate a straightforward means for designing custom contact lenses that both fit the contour of the post surgical cornea and reduce spherical aberration. These custom lenses are rotationally symmetric and can be cut using traditional lathe techniques. Further research will determine if this reduction in aberration correlates to a clinically significant increase in visual performance and reduction in glare and haloes.
Keywords: 500 optical properties • 367 contact lens • 547 refractive surgery: corneal topography