title: Early induced astigmatism following phacoemulsification and flexible lens implantation through an oblique corneal tunnel.
abstract: OBJECTIVE
  To analyse the early surgically induced corneal astigmatism (SICA) with a 3.5 mm oblique clear corneal incision (CCI) for phacoemulsification and flexible silicone implant.
  
  
  METHODS
  Sixty-four consecutive patients were included in this study. The keratometry readings were recorded on the day prior to surgery, the first day post-operatively and at 6 weeks. The SICA was evaluated according to four different methods: (i) simple subtraction, (ii) vector analysis, (iii) vector decomposition and (iv) Naeser polar values.
  
  
  RESULTS
  At 6 weeks post-operatively the SICA was equally divided between with-the-rule (WTR) and against-the-rule (ATR) astigmatism, according to the vector analysis in combination with vector decomposition. Both the simple subtraction method and Naeser polar values were misleading.
  
  
  CONCLUSIONS
  The oblique clear corneal section for phacoemulsification is a comfortable and safe incision with a predictable and acceptable degree of SICA that may be better tolerated than that induced by superior incision.
authors.affiliation: Eye Department, Royal United Hospital, Bath, UK.
authors.forename: F
authors.initials: F
authors.lastname: Mercieca
authors.forename: J
authors.initials: J
authors.lastname: Luck
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification / Q000009:adverse effects* / Q000379:methods; D011184:Postoperative Period; D011446:Prospective Studies