Standard radial keratotomy was performed in both eyes of 18 rabbits. Intraocular pressure (IOP) was raised by injection of saline solution into the vitreous cavity at different times after surgery: 8 eyes at one, two, and six weeks and 12 eyes at four months. Keratometric readings at 10, 20, 40, 60, and 80 mmHg were recorded by three independent observers in a masked fashion. The same procedure was performed in eight eyes that had no surgery, as controls. Increments in IOP correlated with significant reductions in corneal power at all times after surgery and for all IOP values in the operated eyes. No changes were observed in the control eyes. The results indicate that variations in IOP, even within physiological limits, may cause changes in corneal curvature after radial keratotomy, and that patients with wide fluctuations in IOP could present a higher risk for postoperative fluctuation in visual acuity after this refractive procedure.