To evaluate the efficacy, predictability, and safety of Visx CustomVue wavefront-guided enhancement after previous keratorefractive surgery. Stanford University Eye Laser Center, Stanford, California, USA. A retrospective analysis was used to evaluate wavefront-guided enhancement in a preliminary set of 120 eyes of 102 patients. All eyes had previous keratorefractive surgery (photorefractive keratoplasty [PRK] in 1 eye, laser in situ keratomileusis [LASIK] in 119 eyes); the prekeratorefractive surgery spherical equivalent (SE) refraction ranged from -1.25 diopters (D) to -7.00 D. Primary outcome variables including uncorrected visual acuity (UCVA), manifest refraction, and complications were evaluated at 1 and 3 months. At 1 month, the mean pre-enhancement SE was reduced from -0.91 D +/- 0.40 (SD) (range -2.375 to -0.125 D) to -0.13 +/- 0.33 D (range -1.25 to 0.75 D) with 91% of eyes within +/-0.5 D of emmetropia and 100% within +/-1.0 D. All eyes showed equal or improved UCVA (range 20/15 to 20/30) with 20/20 or better in 84 of 91 eyes. At 3 months, the mean was -0.20 +/- 0.32 D (range -0.75 to 0.75 D) with 100% of eyes within +/-0.75 D of emmetropia. All eyes showed equal or improved UCVA (range 20/15 to 20/30) with 20/20 or better in 74 of 84 eyes. Higher-order wavefront aberration analysis showed that the mean root-mean-square error was reduced from 0.39 +/- 0.14 microm (range 0.16 to 0.86 microm) to 0.34 +/- 0.12 microm (range 0.12 to 0.78 microm). Coma was reduced from 0.22 +/- 0.13 microm (range 0.02 to 0.71 microm) to 0.16 +/- 0.11 microm (range 0.01 to 0.62 microm), and trefoil was reduced from 0.16 +/- 0.09 microm (range 0.01 to 0.62 microm) to 0.11 +/- 0.07 microm (range 0.01 to 0.27 microm). Spherical aberration was unchanged from 0.14 +/- 0.14 microm (range -0.18 to 0.59 microm) to 0.14 +/- 0.14 microm (range -0.16 to 0.5 microm). Preliminary data show that Visx CustomVue wavefront-guided enhancement after keratorefractive surgery is an effective, predictable, and safe procedure.