Laser refractive surgery: technological advance and tissue response.

Photorefractive keratectomy (PRK) and laser assisted in situ keratomileusis (LASIK), using an excimer laser, are the currently popular techniques of correcting refractive errors. Since these techniques work by selective ablation of corneal stroma, the tissue healing response plays a great role in the ultimate outcome of surgery. Also, various methods of wound healing modulation can be used to achieve better results. While these procedures do lead to a decrease in dioptric power and increase in unaided visual acuity, higher visual functions like contrast sensitivity can sometimes be compromised after the surgery.