title: Astigmatism outcomes of horizontal temporal versus nasal clear corneal incision cataract surgery.
abstract: OBJECTIVE
  To compare the short- and long-term astigmatism outcomes after cataract surgery using temporal clear horizontal corneal incisions and nasal horizontal clear corneal incisions.
  
  
  METHODS
  Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, USA.
  
  
  METHODS
  This retrospective study included a consecutive series of eyes having phacoemulsification with implantation of a 6.0 mm foldable acrylic intraocular lens through a 3.5 mm horizontal clear corneal incision at 180 degrees (temporal incision in right eyes, nasal incision in left eyes). Astigmatism was measured by keratometry readings before surgery and 6 weeks and 12 months postoperatively.
  
  
  RESULTS
  The mean preoperative astigmatism in the 178 eyes (94 right, 84 left) of 161 patients was 0.78 diopter (D); 54.5% of eyes had against-the-rule (ATR) astigmatism, 22.5% had with-the-rule (WTR) astigmatism, and 14.0% were astigmatically neutral. A significant shift toward WTR astigmatism occurred postoperatively. At 6 weeks, 48.3% of eyes had WTR astigmatism and 23.0% had ATR astigmatism. At 12 months, 43.8% had WTR astigmatism and 25.8% had ATR astigmatism. Vector analysis revealed a mean surgically induced astigmatism (SIA) of 1.17 D at 6 weeks and 1.04 D at 12 months. The side of the incision significantly affected SIA. At 6 weeks, temporal incisions yielded a mean SIA of 0.74 D and the nasal incisions, of 1.65 D. This trend in SIA persisted at 12 months: 0.71 D for temporal incisions and 1.41 D for nasal incisions.
  
  
  CONCLUSIONS
  Cataract surgery using a horizontal clear corneal incision induced WTR astigmatism 6 weeks and 12 months postoperatively. Temporal incisions induced significantly less astigmatism than nasal incisions.
authors.affiliation: Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA. wstark@jhmi.edu
authors.forename: Irina S
authors.initials: IS
authors.lastname: Barequet
authors.forename: Edward
authors.initials: E
authors.lastname: Yu
authors.forename: Susan
authors.initials: S
authors.lastname: Vitale
authors.forename: Sandi
authors.initials: S
authors.lastname: Cassard
authors.forename: Dimitri T
authors.initials: DT
authors.lastname: Azar
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Stark
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000503:physiopathology / Q000517:prevention & control*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D018918:Phacoemulsification / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control; D012029:Refraction, Ocular; D012189:Retrospective Studies; D014792:Visual Acuity