Effect of wavefront optimized LASIK on higher order aberrations in myopic patients

Objective: To determine mean change induced in root mean square value of higher order aberrations in myopic patients undergoing wavefront optimized laser assisted in situ keratomileusis. Methods: This quasi experimental study was conducted at Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan from Jan 2014 to Dec 2014. Sixty eyes of 35 myopic patients were included in the study. All patients underwent wavefront optimized (WFO) laser assisted in situ keratomileusis (LASIK) using femtosecond laser (FM 200Wavelight technologies) and excimer laser (Ew 500Wavelight technologies). Higher order aberrations (HOAs) were measured with aberrometer (Wavelight allegro analyzer version 1073) during preoperative assessment and one month after surgery. Results: All 35 patients ranged from 20 to 32 years with a mean age of 24 ± 3.41 years. Refractive error ranged from -1.00 to -9.50 DS with a mean spherical equivalent (SE) of -3.73 ± 1.95 before surgery and - 0.36 ± 1.50DS one month after LASIK. Uncorrected visual acuity (UCVA) was improved to 0.00 or better in all 60 eyes. An increase of 1.56 fold was observed in RMS of total HOAs. Among the HOAs, a statistically significant positive correlation was observed between spherical aberrations (4th order aberration) and preoperative spherical equivalent. Conclusion: In spite of excellent improvement in refractive error, significant amount of higher order aberrations were induced after WFO LASIK.