This article is more than 5 years old. Information may no longer be current.
Astigmatic overcorrection possible after LASIK in eyes with low cylinder
LASIK in myopic eyes with a preoperative cylinder of 0.5 D or less may result in astigmatic overcorrection, according to a study.
The retrospective cross-sectional study comprised 448 myopic eyes of 448 patients with a preoperative refractive cylinder of 0.75 D or less and a preoperative subjective sphere between –2.75 D and –11.5 D.
Patients were categorized into three groups based on preoperative refractive cylinder— 0.25 D, 0.5 D and 0.75 D.
All eyes underwent LASIK using the Allegretto excimer laser platform (Alcon). Astigmatic changes were analyzed using the Alpins vector method.
Mean patient age was 37.8 years.
Mean uncorrected distance visual acuity was 0.10 ± 0.13 logMAR and the mean manifest refraction spherical equivalent was –0.05 ± 0.68 D at 4 months after surgery, which were appropriate results, the study authors said.
There was a statistically significant difference in surgically induced astigmatism between the groups (P < .001). The correction index, magnitude of error, index of success and flattening index all showed astigmatic overcorrection for eyes with a preoperative cylinder of 0.25 D and 0.5 D.