title: Effect of steepest-meridian clear corneal incision for reducing preexisting corneal astigmatism using a meridian-marking method or surgeon's intuition.
abstract: OBJECTIVE
  To compare the effect of steepest-meridian clear corneal incisions (CCIs) for reducing preexisting corneal astigmatism between a meridian-marking method and a surgeon's-intuition method.
  
  
  METHODS
  Hayashi Eye Hospital, Fukuoka, Japan.
  
  
  METHODS
  Randomized controlled trials.
  
  
  METHODS
  Eyes scheduled for phacoemulsification were randomized to 1 of 2 groups: a 2.65 mm steepest-meridian CCI using the meridian-marking method or a 2.65 mm steepest-meridian CCI using the surgeon's intuition. Regular and irregular corneal astigmatism, surgically induced astigmatism (SIA) vector, refractive status, higher-order aberrations (HOAs), uncorrected (UDVA) and corrected (CDVA) distance visual acuities, and physical meridian misalignment of the steepest-meridian CCI measured using anterior segment optical coherence tomography were evaluated preoperatively and 1 month and 3 months postoperatively.
  
  
  RESULTS
  The mean meridian misalignment of the steepest-meridian CCIs was significantly smaller in the meridian-marking group (4.4 degrees ± 2.8 [SD]) than in the surgeon's-intuition group (8.6 ± 4.4 degrees) (P ≤.0001). Regular and irregular corneal astigmatism and corneal HOAs did not change significantly postoperatively in either group. No significant difference was found in regular or irregular corneal astigmatism, refractive cylinder, manifest spherical equivalent value, SIA, HOAs, UDVA, or CDVA between the meridian-marking group and the surgeon's-intuition group throughout the follow-up.
  
  
  CONCLUSIONS
  The physical meridian misalignment of steepest-meridian CCI was significantly smaller with the meridian-marking method than with the surgeon's-intuition method; however, the effect of the difference was not large enough to decrease remaining astigmatism and HOAs or to improve the UDVA.
authors.affiliation: From Hayashi Eye Hospital, Fukuoka, Japan. Electronic address: hayashi-ken@hayashi.or.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: From Hayashi Eye Hospital, Fukuoka, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: From Hayashi Eye Hospital, Fukuoka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoshimura
mesh_terms: D000368:Aged; D001251:Astigmatism / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000473:pathology* / Q000601:surgery*; D063171:Corneal Pachymetry; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000175:diagnosis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D019545:Intuition; D019654:Lens Implantation, Intraocular; D008297:Male; D018918:Phacoemulsification / Q000379:methods*; D019591:Pseudophakia / Q000503:physiopathology; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology