title: Effect of wavefront optimized LASIK on higher order aberrations in myopic patients.
abstract: 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 (4(th) order aberration) and preoperative spherical equivalent.
  
  
  CONCLUSIONS
  In spite of excellent improvement in refractive error, significant amount of higher order aberrations were induced after WFO LASIK.
authors.affiliation: Dr. Muhammad Saim Khan, MBBS. Armed Forces Institute of Ophthalmology, Mall Road, Rawalpindi, Pakistan.
authors.forename: Muhammad Saim
authors.initials: MS
authors.lastname: Khan
authors.affiliation: Dr. Sadia Humayun, MBBS, MCPS, FCPS, FRCS. Armed Forces Institute of Ophthalmology, Mall Road, Rawalpindi, Pakistan.
authors.forename: Sadia
authors.initials: S
authors.lastname: Humayun
authors.affiliation: Dr. Aisha Fawad, MBBS, FCPS. Armed Forces Institute of Ophthalmology, Mall Road, Rawalpindi, Pakistan.
authors.forename: Aisha
authors.initials: A
authors.lastname: Fawad
authors.affiliation: Prof. Dr. Mazhar Ishaq, FRC Opth, FRCS, FCPS. Armed Forces Institute of Ophthalmology, Mall Road, Rawalpindi, Pakistan.
authors.forename: Mazhar
authors.initials: M
authors.lastname: Ishaq
authors.affiliation: Sabahat Arzoo, BSc (Hons) in Optometry and Orthoptics. Armed Forces Institute of Ophthalmology, Mall Road, Rawalpindi, Pakistan.
authors.forename: Sabahat
authors.initials: S
authors.lastname: Arzoo
authors.affiliation: Dr. Fawad Mashhadi, MBBS, MPH, MCPS, MPhil. Armed Forces Institute of Ophthalmology, Mall Road, Rawalpindi, Pakistan.
authors.forename: Fawad
authors.initials: F
authors.lastname: Mashhadi
keywords: Coma; Higher order aberrations; LASIK; Spherical Aberration