title: Vector Analysis of Corneal Astigmatism After Combined Femtosecond-Assisted Phacoemulsification and Arcuate Keratotomy.
abstract: OBJECTIVE
  To evaluate the outcomes of femtosecond-assisted arcuate keratotomy combined with cataract surgery in eyes with low to moderate corneal astigmatism.
  
  
  METHODS
  Retrospective, interventional case series.
  
  
  METHODS
  This study included patients who underwent combined femtosecond-assisted phacoemulsification and arcuate keratotomy between March 2013 and August 2013. Keratometric astigmatism was evaluated before and 2 months after the surgery. Vector analysis of the astigmatic changes was performed using the Alpins method.
  
  
  RESULTS
  Overall, 54 eyes of 54 patients (18 male and 36 female; mean age, 68.8 ± 11.4 years) were included. The mean preoperative (target-induced astigmatism) and postoperative astigmatism was 1.33 ± 0.57 diopters (D) and 0.87 ± 0.56 D, respectively (P < .001). The magnitude of error (difference between surgically induced and target-induced astigmatism) (-0.13 ± 0.68 D), as well as the correction index (ratio of surgically induced and target-induced astigmatism) (0.86 ± 0.52), demonstrated slight undercorrection. The angle of error was very close to 0, indicating no significant systematic error of misaligned treatment. However, the absolute angle of error showed a less favorable range (17.5 ± 19.2 degrees), suggesting variable factors such as healing or alignment at an individual level. There were no intraoperative or postoperative complications.
  
  
  CONCLUSIONS
  Combined phacoemulsification with arcuate keratotomy using femtosecond laser appears to be a relatively easy and safe means for management of low to moderate corneal astigmatism in cataract surgery candidates. Misalignment at an individual level can reduce its effectiveness. This issue remains to be elucidated in future studies.
authors.affiliation: Hong Kong Eye Hospital, Kowloon, Hong Kong; Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Tommy C Y
authors.initials: TC
authors.lastname: Chan
authors.affiliation: Hong Kong Laser Eye Center, Hong Kong.
authors.forename: George P M
authors.initials: GP
authors.lastname: Cheng
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Hong Kong Eye Hospital, Kowloon, Hong Kong; Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Clement C Y
authors.initials: CC
authors.lastname: Tham
authors.affiliation: Hong Kong Laser Eye Center, Hong Kong.
authors.forename: Victor C P
authors.initials: VC
authors.lastname: Woo
authors.affiliation: Hong Kong Eye Hospital, Kowloon, Hong Kong; Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong. Electronic address: vishaljhanji@gmail.com.
authors.forename: Vishal
authors.initials: V
authors.lastname: Jhanji
mesh_terms: D000368:Aged; D001251:Astigmatism / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D002386:Cataract / Q000150:complications*; D003316:Corneal Diseases / Q000150:complications / Q000601:surgery*; D005260:Female; D006801:Humans; D015948:Keratoplasty, Penetrating; D008297:Male; D018918:Phacoemulsification; D011184:Postoperative Period; D011446:Prospective Studies; D012029:Refraction, Ocular; D014792:Visual Acuity