title: Vector analysis of astigmatic changes after cataract surgery with implantation of a new toric multifocal intraocular lens.
abstract: OBJECTIVE
  To analyze the astigmatic changes after cataract surgery with the implantation of a new toric multifocal intraocular lens (IOL) using the Alpins vector method.
  
  
  METHODS
  Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain.
  
  
  METHODS
  Prospective case series.
  
  
  METHODS
  After cataract surgery with implantation of an AT Lisa 909M toric multifocal IOL, the visual, refractive, corneal topographic, internal astigmatism, defocus curves, and contrast sensitivity outcomes were evaluated over 6 months. Refractive astigmatic changes (target astigmatism [TIA]; surgically induced astigmatism [SIA]; difference vector; magnitude of error; flattening effect; torque) were analyzed using the Alpins vectorial method.
  
  
  RESULTS
  The study enrolled 23 eyes (12 patients). Postoperatively, there was a significant reduction in refractive cylinder (P < .01) with an associated visual improvement for near (P = .03) and distance (P=.01). The magnitude of SIA vector was significantly larger than the TIA 3 months postoperatively (P = .03). The mean magnitude of the difference vector was 0.67 diopter (D) ± 0.51 (SD) at 6 months. The mean magnitude of error remained positive and close to zero over the entire follow-up (P ≥ .19). The mean magnitude of torque vector was 0.49 ± 0.54 D at 6 months. Significant positive correlation was found between the magnitude of torque and the difference vector (r ≥ 0.70, P<.01).
  
  
  CONCLUSIONS
  The new toric IOL restored distance and near visual function with excellent predictability in eyes with moderate to high corneal astigmatism having cataract surgery.
authors.affiliation: Instituto Oftalmológico de Alicante, Vissum-Instituto de Oftalmológico de Alicante, the Division of Ophthalmology, Universidad Miguel Hernández, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain. jlalio@vissum.com
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Alió
authors.forename: David P
authors.initials: DP
authors.lastname: Piñero
authors.forename: Javier
authors.initials: J
authors.lastname: Tomás
authors.forename: Ana B
authors.initials: AB
authors.lastname: Plaza
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology*; D058452:Axial Length, Eye; D001699:Biometry; D002452:Cell Count; D019781:Corneal Topography; D003867:Depth Perception / Q000502:physiology; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D011183:Postoperative Complications; D011446:Prospective Studies; D011474:Prosthesis Design; D019591:Pseudophakia / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology