Photorefractive Keratectomy (PRK) is a surgical procedure widely performed to correct myopia. In this work, the effect of the intraocular pressure (IOP) on the refractive correction achieved by the PRK surgery was analyzed using a numerical model. Simulations of PRK surgery at 10, 15 and 21 mmHg of IOP were performed and the post-surgical diopters were estimated. For low and medium values of IOP (10 and 15 mmHg), the computed results were close to those used by clinicians based on experience and defined without considering the IOP, while an undercorrection was predicted for the highest value of IOP (21 mmHg). From these results, we suggest that IOP should be considered in the determination of the depth of ablation, in addition to other factors such as the level of myopia or the corneal central thickness.