title: Regular and irregular astigmatism after superior versus temporal scleral incision cataract surgery.
abstract: OBJECTIVE
  To evaluate the effect of superior and temporal scleral incisions on regular and irregular astigmatism in small incision cataract surgery.
  
  
  METHODS
  Prospective, randomized, comparative clinical trial.
  
  
  METHODS
  One hundred seventy-four eyes of 87 patients with bilateral cataracts scheduled to undergo routine cataract surgery.
  
  
  METHODS
  One eye of each patient was randomly assigned to the superior incision group, and the contralateral eye was allocated to the temporal incision group. Phacoemulsification and intraocular lens implantation were performed through an unsutured 4.1-mm scleral incision. Patients were examined 1 day and 1, 3, and 6 months after surgery.
  
  
  METHODS
  Surgically-induced regular astigmatism calculated with vector analysis method, irregular astigmatism obtained by Fourier analysis of videokeratography data, and uncorrected and corrected visual acuity.
  
  
  RESULTS
  Postoperatively, the superior incision group showed slight against-the-rule astigmatic changes, whereas slight with-the-rule astigmatism was seen in the temporal incision group. The amount of against-the-wound astigmatism and absolute value of length of the induced vector did not differ significantly between groups (P > 0.05, paired t test). In both groups, irregular astigmatism 1 day after surgery was significantly greater than the preoperative levels (P < 0.001), but not thereafter. No significant intergroup difference was observed in the amount of irregular astigmatism at any postoperative visits (P > 0.05). There was no significant difference in uncorrected and corrected visual acuity between groups postoperatively (P > 0.05, chi-square test).
  
  
  CONCLUSIONS
  In small scleral incision cataract surgery, superior and temporal approaches are comparable in terms of visual rehabilitation and induction of regular and irregular astigmatism.
authors.affiliation: Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Oshika
authors.forename: G
authors.initials: G
authors.lastname: Sugita
authors.forename: T
authors.initials: T
authors.lastname: Tanabe
authors.forename: A
authors.initials: A
authors.lastname: Tomidokoro
authors.forename: S
authors.initials: S
authors.lastname: Amano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000175:diagnosis / Q000209:etiology*; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D005583:Fourier Analysis; D006801:Humans; D007429:Intraocular Pressure; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D018918:Phacoemulsification / Q000009:adverse effects* / Q000379:methods; D011446:Prospective Studies; D012590:Sclera / Q000601:surgery*; D014792:Visual Acuity; D014945:Wound Healing