Irregular corneas may increase HOAs after laser surgery

Higher-order aberrations seem to correlate with a patient’s corneal topography and are generally greater in patients with highly irregular corneas, according to a study. The authors note patients with irregular corneas may have higher-order aberrations that are 2.3 to 3.5 times greater than asymptomatic postoperative LASIK or normal preoperative eyes.

Gregory J. McCormick, MD, and colleagues at the University of Rochester in New York analyzed data from 33 symptomatic postoperative LASIK or PRK eyes with subjective visual complaints not corrected by spectacles more than 6 months after surgery. Shack-Hartmann wavefront measurements were then compared against 46 normal preop and 46 asymptomatic successful postop conventional LASIK eyes.

Symptomatic patients had higher-order wavefront errors 3.46 times greater than the average magnitutde of the normal preop eyes, and 2.3 times greater than the asymptomatic postop conventional eyes. In addition, larger pupils were associated with an increased wavefront error.

Eyes with central islands had the most vertical coma. Central islands coupled with decentered ablations had elevated amounts of spherical aberration. And eyes with a topographic baby bowtie demonstrated the most secondary astigmatism, the authors said.

The study is published in Ophthalmology.