Overview of laser refractive surgery.

Since approval of the use of the excimer laser in 1995 to reshape the cornea, significant developments in the correction of refractive errors such as myopia, hyperopia, and astigmatism have been achieved. Combined with other advanced ophthalmological instruments (e.g. anterior segment imaging systems, the femtosecond laser, wavefront-guided customized ablation) and the knowledge accumulated concerning the basic science of refractive errors (e.g. biomechanics and wound healing of the cornea, higher-order aberrations), laser refractive surgery has promisingly outshone other conventional techniques (e.g. radial keratotomy [RK], automated lamellar keratectomy [ALK]) in terms of both safety and efficacy. Photorefractive keratectomy (PRK) produces stable and predictable results with a safe profile. Similarly, laser in situ keratomileusis (LASIK) is also safe and efficacious with the additional advantages of rapid visual recovery and minimal postoperative pain. The choice between the two methods is made only after thoughtful discussion between the surgeon and the patient. Despite these advances, certain limitations and complications do exist. There are also specific and controversial circumstances for which studies should be conducted to make further breakthroughs and avoid annoying complications. In this review, the basic knowledge, surgical issues, and clinical outcomes, of laser refractive surgery, as well as complex cases, will be presented.