Therapeutic Uses of the Excimer Laser Photorefractive Keratectomy

Phototherapeutic keratectomy (PTK) has been used to improve vision and reduce ocular symptoms in a variety of disorders. These include corneal dystrophies, scars, nodules, recurrent erosions, surgically induced astigmatism, and active infections. Using the criteria of two lines of improvement in best-corrected visual acuity, successful outcomes in large series range from approximately 60% to 80% of patients. PTK can obviate the need for penetrating or lamellar keratoplasty in over 70% of patients. Complications include a hyperopic shift in refractive error, corneal scarring, irregular astigmatism, corneal infection/ulceration, induced astigmatism, glare, and reactivation of herpes simplex. PTK has become a useful surgical tool for the treatment of corneal disorders. It can delay or eliminate the need for more invasive procedures, such as penetrating keratoplasty.