Posterior corneal elevation values showed stability 1 year after LASIK

Evaluation of the posterior corneal elevation 1 year after LASIK showed no trend toward increased elevation that is suggestive of ectatic changes. The changes were within measurement variation and did not exceed 6 µm, according to Joseph Ciolino, MD, of Albany Medical College, Albany, NY.

Dr. Ciolino and colleagues used Scheimpflug photographs (Pentacam, Oculus) to measure any posterior corneal elevation in 102 eyes 1 year after LASIK compared with photographs taken preoperatively.

He reported that the patients ranged in age from 22 to 56 years (average, 38 years) and the average refractive error was –4.3 D (range, –0.75 to –10 D). Average follow-up was 13.6 months, which is the average time when ectasia develops after LASIK. Average displacement was –0.47 µm, with the upper end of the range –10 µm.

"One year after LASIK, there was no significant difference in the posterior corneal elevation," Dr. Ciolino said.

The central cornea thickness, residual bed thickness, preoperative refraction, and ablation depth did not play a role in the development of ectasia, he added.

"I am not trying to suggest that post-LASIK ectasia does not exist," Dr. Ciolino said. "Contrary to previous reports that used earlier slit-scanning technology, long-term (average, 14 months) changes to the posterior corneal surface do not routinely occur in patients otherwise meeting our standard preoperative criteria."