title: Evaluation of factors influencing the remaining astigmatism after toric intraocular lens implantation.
abstract: OBJECTIVE
  To evaluate the influencing factors on remaining astigmatism after implanting a toric intraocular lens during cataract surgery.
  
  
  METHODS
  In this observational study, consecutive patients with cataract from three different centers who received toric intraocular lenses were included. Keratometry was performed with an optical biometry device preoperatively. The IOLMaster 500 (Carl Zeiss Meditec AG, Jena, Germany) was used in Vienna, Lenstar (Haag-Streit, Köniz, Switzerland) in Castrop-Rauxel, and IOLMaster (Carl Zeiss Meditec AG) in London. Partial least squares regression was used to detect the influence of different parameters on remaining astigmatism.
  
  
  RESULTS
  In total, 235 eyes of 200 patients were included. Mean corneal astigmatism measured preoperatively with the optical biometry device was -2.24 ± 0.87 diopters (D) (range: -5.75 to -1.00 D). Mean absolute and vector difference between the aimed for and the postoperatively measured astigmatism were 0.48 ± 0.37 D (range: 0.00 to 2.05 D) and 0.73 ± 0.46 D (range: 0.031 to -2.20 D), respectively (P = .576). Partial least squares regression showed a significant effect of preoperatively measured corneal astigmatism and deviation between preoperative measurements of the cornea on the postoperative (unintended) remaining astigmatism.
  
  
  CONCLUSIONS
  The main source of error when using toric intraocular lenses is the preoperative measurement of corneal astigmatism, especially in eyes with low astigmatism. The influence of the postoperative anterior chamber depth on the cylindrical power of toric intraocular lenses and the effect of misalignment on the reduction of the astigmatism-reducing effect can be easily calculated.
authors.forename: Nino
authors.initials: N
authors.lastname: Hirnschall
authors.forename: Peter C
authors.initials: PC
authors.lastname: Hoffmann
authors.forename: Petra
authors.initials: P
authors.lastname: Draschl
authors.forename: Sophie
authors.initials: S
authors.lastname: Maedel
authors.forename: Oliver
authors.initials: O
authors.lastname: Findl
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000175:diagnosis* / Q000503:physiopathology; D001699:Biometry; D003315:Cornea / Q000503:physiopathology; D063171:Corneal Pachymetry; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D012029:Refraction, Ocular / Q000502:physiology; D012307:Risk Factors; D014792:Visual Acuity / Q000502:physiology