title: Corneal astigmatism change and wavefront aberration evaluation after cataract surgery: "Single" versus "paired opposite" clear corneal incisions.
abstract: BACKGROUND
  Correcting the pre-existing astigmatism is an optimal goal in cataract surgery. The aim of this study is to compare the astigmatic correcting effect of a single regular 3.2 mm clear corneal incision (CCI) with paired opposite CCI in cataract patients and effect of these incisions on optical aberrations using the wavefront quantitative analysis.
  
  
  METHODS
  This was a randomized controlled trial study undertaken in an ophthalmology referral center on 50 patients planned for cataract surgery who were randomized to either single 3.2 mm CCI or paired opposite CCI group. Post-operative evaluation was performed at 12 weeks and included refraction, keratometery, corneal topography and wavefront analysis. Corneal astigmatism and post-operative values were compared in two groups.
  
  
  RESULTS
  The mean pre-operative corneal astigmatism was 2.58 ± 1.03 D in the single incision group and 2.70 ± 0.94 D in the paired opposite incisions group. After 12 weeks of surgery, the corneal astigmatism was reached to 2.15 ± 0.82 D in single incision group and 1.63 ± 1.21 in the paired opposite incisions group. There was a statistically significant difference in two arms of treatment regarding to surgically induced astigmatism after 3 months. The mean post-operative total and higher order aberrations and values were not significantly different in two groups.
  
  
  CONCLUSIONS
  The results of our study showed that paired opposite incisions is an effective procedure for reducing pre-existing corneal astigmatism in cataract surgery. Paired incisions did not show any beneficial effect regarding wavefront aberrations compared with conventional single incision method.
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hasan
authors.initials: H
authors.lastname: Razmjoo
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Nima
authors.initials: N
authors.lastname: Koosha
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Hadi
authors.initials: MH
authors.lastname: Vaezi
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Behrooz
authors.initials: B
authors.lastname: Rahimi
authors.affiliation: Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Peyman
keywords: Astigmatism; cataract; opposite clear corneal incision; optical aberrations; single clear corneal incision