Post PRK-patients require a wider range of IOL asphericity for optimal optical quality

Researchers simulated aspheric IOL implantation in 77 patients with previous wavefront-guided myopic photorefractive keratectomy to produce residual spherical aberration ranging from -0.50 mm to +0.50 mm with 0.01 mm intervals. The IOL spherical aberration required to produce the optimum image quality varied widely (from -1.00 to +0.10 mm) with 6.0 mm and 4.0 mm pupils with zero defocus. They also provide a formula to calculate optimum IOL asphericity based on anterior corneal 4th-order and 6th-order spherical aberration.