use of a shackhartmann aberrometer to assess the optical outcome of corneal transplantation in a keratoconic eye we report the optical outcome of corneal transplantation treatment on a keratoconic eye as measured with a shackhartmann aberrometer and we compare the results with the recovery of visual acuity after surgery before surgery the naked keratoconic eye exhibited extremely large aberrations that could not be measured unless the patient wore a rigid gaspermeable contact lens with the lens the computed pointspread function of the eye was large and multimodal and simulated retinal images confirmed the patients subjective report of multiple overlapping images after full recovery from surgery aberrations of the corrected eye were much smaller compared with the presurgical eye which implied a more compact pointspread function and clearer retinal images these optical changes were mirrored by an improvement in uncorrected visual acuity from 13 logarithm of the minimum angle of resolution logmar before surgery to 0 logmar with spectacle correction after full recovery we conclude that the shackhartmann aberrometer provides an objective quantitative assessment of the optical outcome of penetrating keratoplasty that allows the clinician to measure retinal image quality objectively and to accurately simulate the complex visual distortions associated with keratoconus