The ideal refractive surgical procedure is simple to perform, inexpensive, and applicable to a wide range of ametropias. Astigmatic keratotomy (AK) is one such procedure. Astigmatic keratotomy is used to treat numerous refractive disorders, including congenital astigmatism, residual corneal astigmatism at the time of or following cataract surgery, post-traumatic astigmatism, and astigmatism after corneal transplantation.
Even with the extensive use of excimer laser vision correction platforms to treat refractive error (eg, photorefractive keratoplasty [PRK], LASIK), astigmatic keratotomy continues to be a valuable and versatile tool for the treatment of many eyes.
Early investigative surgeons of astigmatic keratotomy, Thornton, Buzard, Price, Grene, Nordan, and Lindstrom, demonstrated the efficacy, safety and reproducibility of refractive outcomes, and led, albeit over more than a decade, to the adoption of the procedure by the broader ophthalmological community.
Within the past few years, much consideration has been given to an evolutionary variant of the procedure, the limbal relaxing incision (LRI). By moving the incision farther to the periphery, cataract surgeons can safely and predictably remediate mild to moderate amounts of regular astigmatism at the time of cataract surgery by performing this incisional technique, either by hand or by application of femtosecond laser technology.
Femtosecond laser offers several potential advantages over manual incision, including fully customizable and reproducible incision parameters, as well as increased safety and titration of effect via intrastromal ablations.