Risk factors for corneal ectasia after LASIK identified

Surgeons are better able to identify patients at high risk for developing corneal ectasia after LASIK with the help of a stratified risk factor scale, according to J. Bradley Randleman, MD.

Dr. Randleman and his co-authors Maria Woodward, MD, and R. Doyle Stulting, MD, from Emory University, Atlanta, undertook a retrospective review of 27 ectasia cases that occurred after LASIK from 1997 to 2005 and compared them with 50 consecutive controls who did not develop ectasia after LASIK. They examined patient age, gender, spherical equivalent refraction, pachymetry, predicted residual stromal bed, and topographic patterns.

They found in the ectasia cases abnormal topography patterns preoperatively, significantly lower preoperative corneal thickness and residual stromal bed (

Topographic patterns were assessed and corneas were characterized as normal (symmetrical), suspicious (presenting as asymmetric bowtie or inferior steepening or skewed radial axis), or abnormal (keratoconus).

A risk score model was developed with five risk factors: topographic abnormalities, extreme myopia, low residual stromal bed, patient age, and preoperative corneal thickness. If patients scored 4 or more on the risk score model, then the surgeon should not perform LASIK, Dr. Randleman said.

Dr. Randleman was honored with the award for best paper for the session on keratorefractive ectasia and corneal instability during the American Society of Cataract and Refractive Surgery annual meeting.